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Sample records for subgenus melanocrommyum electronic

  1. Allium discoloration: the precursor and formation of the red pigment in giant onion (Allium giganteum Regel) and some other subgenus Melanocrommyum species.

    Science.gov (United States)

    Kucerová, Petra; Kubec, Roman; Simek, Petr; Václavík, Lukás; Schraml, Jan

    2011-03-09

    The precursor of the orange-red pigment formed upon wounding the bulbs of Allium giganteum (Allium subg. Melanocrommyum) was isolated and shown to be S-(2-pyrrolyl)cysteine S-oxide. In addition, two other pyrrolylsulfinyl derivatives were found in an extract from the bulbs, namely, 3-(2-pyrrolylsulfinyl)lactic acid and S-(3-pyrrolyl)cysteine S-oxide. Contrary to a previous report, the latter compound was shown not to serve as the precursor of the pigment, being in fact only an artifact formed during isolation. The formation of pyrrolyl-containing compounds following disruption of A. giganteum bulbs was studied by a combination of LC-MS, LC-NMR and DART-MS. It was found that S-(2-pyrrolyl)cysteine S-oxide is cleaved by a C-S lyase (alliinase) to yield 2-pyrrolesulfenic acid. Two molecules of the latter compound give rise to highly reactive S-(2-pyrrolyl) 2-pyrrolethiosulfinate which in turn converts into red 2,2'-epidithio-3,3'-dipyrrole (dipyrrolo[2,3-d:2',3'-e]-1,2-dithiin). Several other pyrrolyl-containing compounds were detected in A. giganteum for the first time, including S-methyl 2-pyrrolethiosulfinate, S-(2-pyrrolyl) methanethiosulfinate, di(2-pyrrolyl) disulfide, and S-(2-pyrrolyl) 2-pyrrolethiosulfonate. It can be concluded that the formation of the orange-red pigment in Allium subg. Melanocrommyum species, despite sharing several analogous features, is of a different nature than the pink discoloration of onion (A. cepa).

  2. A new subgenus of Heterotrigona from New Guinea (Hymenoptera: Apidae)

    DEFF Research Database (Denmark)

    Engel, Michael S.; Rasmussen, Claus

    2017-01-01

    A new subgenus is established within the Indomalayan stingless bee genus Heterotrigona Schwarz (Meliponini). Sahulotrigona Engel & Rasmussen, new subgenus, is distinguished from amongst other Heterotrigona, particularly the subgenus Platytrigona Moure, within which one of the two included species...

  3. Aspergillus subgenus Polypaecilum from the built environment

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    J.B. Tanney

    2017-09-01

    Full Text Available Xerophilic fungi, especially Aspergillus species, are prevalent in the built environment. In this study, we employed a combined culture-independent (454-pyrosequencing and culture-dependent (dilution-to-extinction approach to investigate the mycobiota of indoor dust collected from 93 buildings in 12 countries worldwide. High and low water activity (aw media were used to capture mesophile and xerophile biodiversity, resulting in the isolation of approximately 9 000 strains. Among these, 340 strains representing seven putative species in Aspergillus subgenus Polypaecilum were isolated, mostly from lowered aw media, and tentatively identified based on colony morphology and internal transcribed spacer rDNA region (ITS barcodes. Further morphological study and phylogenetic analyses using sequences of ITS, β-tubulin (BenA, calmodulin (CaM, RNA polymerase II second largest subunit (RPB2, DNA topoisomerase 1 (TOP1, and a pre-mRNA processing protein homolog (TSR1 confirmed the isolation of seven species of subgenus Polypaecilum, including five novel species: A. baarnensis, A. keratitidis, A. kalimae sp. nov., A. noonimiae sp. nov., A. thailandensis sp. nov., A. waynelawii sp. nov., and A. whitfieldii sp. nov. Pyrosequencing detected six of the seven species isolated from house dust, as well as one additional species absent from the cultures isolated, and three clades representing potentially undescribed species. Species were typically found in house dust from subtropical and tropical climates, often in close proximity to the ocean or sea. The presence of subgenus Polypaecilum, a recently described clade of xerophilic/xerotolerant, halotolerant/halophilic, and potentially zoopathogenic species, within the built environment is noteworthy.

  4. Genome Duplication in Soybean (Glycine Subgenus Soja)

    Science.gov (United States)

    Shoemaker, R. C.; Polzin, K.; Labate, J.; Specht, J.; Brummer, E. C.; Olson, T.; Young, N.; Concibido, V.; Wilcox, J.; Tamulonis, J. P.; Kochert, G.; Boerma, H. R.

    1996-01-01

    Restriction fragment length polymorphism mapping data from nine populations (Glycine max X G. soja and G. max X G. max) of the Glycine subgenus soja genome led to the identification of many duplicated segments of the genome. Linkage groups contained up to 33 markers that were duplicated on other linkage groups. The size of homoeologous regions ranged from 1.5 to 106.4 cM, with an average size of 45.3 cM. We observed segments in the soybean genome that were present in as many as six copies with an average of 2.55 duplications per segment. The presence of nested duplications suggests that at least one of the original genomes may have undergone an additional round of tetraploidization. Tetraploidization, along with large internal duplications, accounts for the highly duplicated nature of the genome of the subgenus. Quantitative trait loci for seed protein and oil showed correspondence across homoeologous regions, suggesting that the genes or gene families contributing to seed composition have retained similar functions throughout the evolution of the chromosomes. PMID:8878696

  5. A new subgenus and species of Neotropical Trichomyia (Diptera: Psychodidae

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    Maíra Xavier Araújo

    2013-08-01

    Full Text Available A singular group of 19 species of Neotropical Trichomyia Haliday in Curtis, 1839 presents four segments in the palpus, the first two partially fused; five of these species were included in the subgenus Opisthotrichomyia Bravo, 2001 and seven in the subgenus BrachiotrichomyiaBravo & Araújo, 2013. A new species from Brazil is described and a new subgenus proposed for four Neotropical species of this morphological group: T. biloba Quate, 1999 from Panama, and T. onorei Bravo, 2002, T. queirozi Bravo, 2002 and T. horrida sp. nov. from Brazil. Syntrichomyia subgen. nov. can be recognized by its fused gonocoxites and gonostyli, and by its bilobed hypoproct. A key to the known species (males of this new subgenus is presented.

  6. Hygrophoraceae of the Greater Antilles : Hygrocybe subgenus Hygrocybe

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    Sharon A. Cantrell; D. Jean Lodge

    2000-01-01

    A key to six taxa of Hygrocybe, subgenus Hygrocybe, sections Chlorophanae and Hygrocybe is provided. One species is new and four species are reported for the first time from the Greater Antilles. The new species is H. chimaeroderma (section Chlarophanae). Hygrocybe acutoconica, H. calyptriformis and H. incolor (section Hygrocybe) are reported for the first time, and...

  7. Korean Species of the Subgenus Ophina (Diptera: Tachinidae

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    Jong-Su Lim

    2013-07-01

    Full Text Available We recognized Linnaemya microchaetopsis Shima, L. picta (Meigen and L. zachvatkini Zimin in Korean Linnaemya subgenus Ophina Robineau-Desvoidy and the latter two are reported for the first time in Korea. The subgenus Ophina shares the following morphological characteristics (sensu Shima: 1 the male tergite 6 is fused mid-dorsally with sternite 7+8; 2 the female tergite 6 and tergite 7 are almost always divided longitudinally into two hemitergites; 3 the female tergite 6 is always longer than the tergite 7; 4 circus parallelsided in caudal view; 5 epiphallus present; and 6 pteropleural seta long, reaching posterior margin of lower calypter. We provide a key to the included Korean species, as well as descriptions and illustrations with their diagnostic characters indicated.

  8. Penicillium subgenus Penicillium - A guide to identification of food and air-borne terverticillate Penicillia and their mycotoxins

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R.A.

    2004-01-01

    Species in Penicillium subgenus Penicillium have terverticillate penicilli and are related to the ascomycete genus Eupenicillium series Crustacea, Many of its species are very common, being associated with stored foods of human beings and other animals, but also with animal dung and building...... illustrations of the colonies and micromorphology of the 58 accepted species are given. Keys to the taxa in the various series are given, but for a more detailed electronic database including partial beta tubulin sequences reference is made to http: //www.cbs.knaw.nl/ penicillium.htm...

  9. Holothuria (Selenkothuria) parvispinea n. sp. (Echinodermata, Hololthuroidea, Holothuriidae) with key to the sub-genus Selenkothuria.

    Science.gov (United States)

    Massin, Claude

    2013-01-30

    Description of a new species from Australia, belonging to the subgenus Selenkothuria (Holothuria, Aspidochirotida). A dichotomous key of the thirteen valid species included in the subgenus is also given. The species H. perrieri Thandar, 1977 and H. spinea Cherbonnier, 1988 are considered as non valid.

  10. A New Subgenus of CULEX in the Neotropical Region (Diptera: Culicidae)

    Science.gov (United States)

    1992-11-01

    subgenus in the the Greek nouns phtwna.v (m, deceiver, cheat. New World, and the results of the present impostor: combining form /phnaco’-) and study...mistaken for members of the characters oftthe lar\\al stage, subgenus (’tlehv. The name is feminine in The affinities of tth’nao,,. via arc un- gender. The

  11. Cortinarius subgenus Callistei in North America and Europe-type studies, diversity, and distribution of species.

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    Niskanen, Tuula; Liimatainen, Kare; Kytövuori, Ilkka; Lindström, Håkan; Dentinger, Bryn T M; Ammirati, Joseph F

    2016-09-01

    Five species of Cortinarius subgenus Callistei, are recognized in Europe and North America. Cortinarius callisteus, C. infucatus, and C. neocallisteus sp. nov. have a broad distribution, extending from western North America to Europe. Cortinarius tofaceus is known from eastern North America and Europe, while C. callistei sp. is known only from one locality in Sweden. All five species are primarily associated with coniferous trees. Previously the species were included either in subgenus Leprocybe or subgenus Cortinarius, but recently they have been separated into subgenus Callistei based on molecular data. Type specimens of the names associated with this subgenus were studied and a neotype proposed for C. tofaceus and an epitype for C. infucatus Barcodes for the species are deposited in RefSeq and UNITE. © 2016 by The Mycological Society of America.

  12. Dehydrogenase isoenzyme polymorphism in genus Prunus, subgenus Cerasus

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    Čolić Slavica

    2012-01-01

    Full Text Available Dehydrogenase polymorphism was studied in 36 sour cherry (Prunus cerasus L., sweet cherry (Prunus avuim L., mahaleb (Prunus mahaleb L., ground cherry (Prunus fruticosa Pall., duke cherry (Prunus gondounii Redh., Japanese flowering cherry (Prunus serrulata Lindl. and four iterspecific hybrids (standard cherry rootstocks ‘Gisela 5’, ‘Gisela 6’, ‘Max Ma’ and ‘Colt’. Inner bark of one-year-old shoots, in dormant stage, was used for enzyme extraction. Vertical PAGE was used for isoenzyme analysis: alcohol dehydrogenase (ADH, formate dehydrogenase (FDH, glutamate dehydrogenase (GDH, isocitrate dehydrogenaze (IDH, malate dehydrogenase (MDH, phosphogluconate dehydrogenase (PGD, and shikimate dehydrogenase (SDH. All studied systems were polymorphic at 10 loci: Adh -1 (3 genotypes and Adh-2 (5 genotypes, Fdh-1 (2 genotypes, Gdh-1 (3 genotypes, Idh-1 (4 genotypes i Idh -2 (5 genotypes, Mdh-1 (3 genotypes, Pgd-1 (4 genotypes, Sdh-1 (1 genotype i Sdh-2 (3 genotypes. Cluster analysis was used to construct dendrogram on which four groups of similar genotypes were separated. Obtained results indicate that studied enzyme systems can be used for determination of genus Prunus, subgenus Cerasus. Among studied enzyme systems ADH, IDH and SDH were the most polymorphic and most useful to identify genetic variability. Polymorphism of FDH and GDH in genus Prunus, subgenus Cerasus was described first time in this work. First results for dehydrogenase variability of Oblačinska indicate that polymorphism of loci Idh-2 and Sdh-2 can be useful for discrimination of different clones.

  13. Evolution of a soldier caste specialized to lay unfertilized eggs in the ant genus Crematogaster (subgenus Orthocrema).

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    Peeters, Christian; Lin, Chung-Chi; Quinet, Yves; Martins Segundo, Glauco; Billen, Johan

    2013-05-01

    Among social Hymenoptera, only some ant genera have more than one morphological kind of non-reproductive adults. Individuals that are bigger than ordinary workers can function for defence and/or food storage. In Crematogaster (Orthocrema) smithi from Arizona, a third caste exists in addition to winged queens and workers; it is intermediate in size, weight and morphology, and individuals lay many unfertilized eggs that are mostly eaten by larvae (Heinze et al., 1995, 1999). We studied another three species belonging to the subgenus Orthocrema: Crematogaster pygmaea from Brazil, Crematogaster biroi and Crematogaster schimmeri from Taiwan. Using scanning electron microscopy and ovarian dissections, we show that 'intermediates' are a patchwork of queen-like and worker-like traits, just as in C. smithi; importantly the combinations differ across species. 'Intermediates' are numerically few in the colonies, and in C. pygmaea they are produced seasonally. Using histology we confirmed the lack of a spermatheca, thus they are not ergatoid queens. Based on the similarity of their mosaic phenotypes with those in other ant lineages, we suggest that Orthocrema 'intermediates' are a soldier caste with a specialized trophic function. This soldier caste has been reported in other Orthocrema species from Madagascar, Guinea and Costa Rica, suggesting that it is widespread in this subgenus. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Developmental and ultrastructural characters of the pollen grains and tapetum in species of Nymphaea subgenus Hydrocallis.

    Science.gov (United States)

    Zini, Lucía Melisa; Galati, Beatriz Gloria; Zarlavsky, Gabriela; Ferrucci, María Silvia

    2017-07-01

    Variations in pollen characters and tapetum behavior were recently acknowledged in the early-divergent family Nymphaeaceae and even within the genus Nymphaea, which probably is not monophyletic; some traits such as infratectum and tapetum type are also a matter of different interpretations. In this study, developmental characters of the pollen grains and tapetum in Nymphaea subgenus Hydrocallis are provided for the first time. Observations were made in N. amazonum, N. gardneriana, and N. prolifera using light, scanning, and transmission electron microscopy. Tapetum is of the secretory type and produces orbicules. At microspore and pollen grain stages, the distal and proximal walls differ considerably. This result supports the operculate condition of the aperture in Hydrocallis, and such aperture might be plesiomorphic for Nymphaeoideae. The infratectum is intermediate, composed of inter-columellae granular elements, robust columellae consisting of agglomerated granules, complete columellae, and fused columellae. Narrow microchannels are present and persist until the mature pollen grain stage. The membranous granular layer is often present in the pollen grains of Nymphaeaceae. In N. gardneriana, this layer is most probably a component of the intine because it is lost after acetolysis. Orbicules in the Nymphaeaceae are characterized as spherical or subspherical, with a smooth sporopolleninic wall that surrounds an electron-lucent core and with individual orbicules that usually merge to give irregular aggregations. The aperture, pollen wall ultrastructure, and the tapetum of the studied species are discussed in an evolutionary and systematic context, and these characters are also compared with those of other angiosperm lineages.

  15. Neopetromyces gen. nov and an overview of teleomorphs of Aspergillus subgenus Circumdati

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Samson, R. A.

    2000-01-01

    Species in the anamorph genus Aspergillus are associated with several teleomorphic genera in the Eurotiales and the most important mycotoxin producers are concentrated in Aspergillus subgenus Circumdati. A new genus, Neopetromyces, is proposed for the recently described Petromyces muricatus, beca...

  16. [Polymorphism of KPI-A genes from plants of the subgenus Potatoe (sect. Petota, Estolonifera and Lycopersicum) and subgenus Solanum].

    Science.gov (United States)

    Krinitsyna, A A; Mel'nikova, N V; Belenikin, M S; Poltronieri, P; Santino, A; Kudriavtseva, A V; Savilova, A M; Speranskaia, A S

    2013-01-01

    Kunitz-type proteinase inhibitor proteins of group A (KPI-A) are involved in the protection of potato plants from pathogens and pests. Although sequences of large number of the KPI-A genes from different species of cultivated potato (Solanum tuberosum subsp. tuberosum) and a few genes from tomato (Solanum lycopersicum) are known to date, information about the allelic diversity of these genes in other species of the genus Solanum is lacking. In our work, the consensus sequences of the KPI-A genes were established in two species of subgenus Potatoe sect. Petota (Solanum tuberosum subsp. andigenum--5 genes and Solanum stoloniferum--2 genes) and in the subgenus Solanum (Solanum nigrum--5 genes) by amplification, cloning, sequencing and subsequent analysis. The determined sequences of KPI-A genes were 97-100% identical to known sequences of the cultivated potato of sect. Petota (cultivated potato Solanum tuberosum subsp. tuberosum) and sect. Etuberosum (S. palustre). The interspecific variability of these genes did not exceed the intraspecific variability for all studied species except Solanum lycopersicum. The distribution of highly variable and conserved sequences in the mature protein-encoding regions was uniform for all investigated KPI-A genes. However, our attempts to amplify the homologous genes using the same primers and the genomes of Solanum dulcamarum, Solanum lycopersicum and Mandragora officinarum resulted in no product formation. Phylogenetic analysis of KPI-A diversity showed that the sequences of the S. lycopersicum form independent cluster, whereas KPI-A of S. nigrum and species of sect. Etuberosum and sect. Petota are closely related and do not form species-specific subclasters. Although Solanum nigrum is resistant to all known races of economically one of the most important diseases of solanaceous plants oomycete Phytophthora infestans aminoacid sequences encoding by KPI-A genes from its genome have nearly or absolutely no differences to the same from

  17. A new subgenus and species of Topomyia (Diptera: Culicidae: Sabethini) based on a remarkable male mosquito from Sabah, Malaysia.

    Science.gov (United States)

    Harbach, Ralph E; Culverwell, C Lorna

    2014-05-08

    Miyagiella Harbach, subgen. nov., is introduced as a new subgenus of Topomyia Leicester for a remarkable male mosquito, Topomyia discors Harbach, sp. nov., from Sabah, Malaysia. A diagnosis of the subgenus is provided that features unique anatomical characters of the genitalia of the holotype male. Miyagiella is very distinct from the two previously recognised subgenera of Topomyia, but is perhaps more closely related to the nominotypical subgenus than to subgenus Suaymyia Thurman. Salient differences that distinguish the three subgenera are contrasted; the holotype male of To. discors is described and its unique genitalia are illustrated.

  18. Anatomical study of Rubus subgenus Rubus in Iran

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    Razieh Kasalkheh

    2016-06-01

    Full Text Available Rubus L. genus from Rosaceae has about 750 species, from which 8 species and 5 hybrids from Iran. In this study stem, leaflet, petiole, stipule and pedicle anatomy of 7 species of the genus Rubus subgenus. Rubus is invesgitated. These species include R. sanctus, R. persicus, R. hyrcanus, R. hirtus, R. dilichocarpus, R. discolor and R. caesius. Plant samples were collected and then fixed and handmade cross-section of leave were prepared and stained with methyl green and carmine. Several slides were studies and photographed with light microscope (LM. Among studied character, five quantitative features such as shape of transvers cross section, type of glandular and non-glandular trichome, presence or absence of stalk glandular trichome, distribution of calcium oxalate crystal and thickness of cuticle were studied in separation of species. Also, five quantitative features such as number of vascular bundles, number of collenchyma layer (in stem and petiole, number of palisade and spongy paranchymatous layer (in leaflet and presence or absence palisade paranchymatous in stipule are valuable and can be used in distinguishing species.

  19. Morphological and Genotypic Variations among the Species of the Subgenus Adlerius (Diptera: Psychodidae, Phlebotomus in Iran

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    Alireza Zahraei-Ramazani

    2015-10-01

    Full Text Available Background: Female sand flies of subgenus Adlerius are considered as probable vectors of visceral leishmaniasis in Iran. The objective of this study was to determine the morphological and genotypic variations in the populations of this subgenus in the country.Methods: Sand flies collected using sticky traps from 17 provinces during 2008–2010. The morphometric measurements were conducted with an Ocular Micrometer. Data was analyzed by SPSS. The Cytb gene was used to estimate population genetic diversity and identify the female specimens. UPGMA phenetic tree was used for DNA haplotypes of Cytb gene.Results: Six species of subgenus Adlerius identified from which one species, P. (Adlerius kabulensis, is new record. The identification key is provided for males. Results revealed the molecular systematic in the species of subgenus Adlerius and determine the relationship of three females of P. comatus, P. balcanicus and P. halepensis.Conclusion: The positions of three females and the males in the UPGMA tree are correct and the similarities among them confirm our results. The branches of each species are not genetically distinct which justify the overlapping morphological characters among them. Molecular sequencing of Cytb-mtDNA haplotypes can be used for female identification for different species of subgenus Adlerius in Iran.

  20. Phylogeny and nomenclature of the genus Talaromyces and taxa accommodated in Penicillium subgenus Biverticillium

    DEFF Research Database (Denmark)

    Samson, R.A.; Yilmaz, N.; Houbraken, J.

    2011-01-01

    . Talaromyces species and most species of Penicillium subgenus Biverticillium sensu Pitt reside in a monophyletic clade distant from species of other subgenera of Penicillium. For detailed phylogenetic analysis of species relationships, the ITS region (incl. 5.8S nrDNA) was sequenced for the available type...... in Penicillium and should be taxonomically unified with the Talaromyces species that reside in the same clade. Following the concepts of nomenclatural priority and single name nomenclature, we transfer all accepted species of Penicillium subgenus Biverticillium to Talaromyces. A holomorphic generic diagnosis......The taxonomic history of anamorphic species attributed to Penicillium subgenus Biverticillium is reviewed, along with evidence supporting their relationship with teleomorphic species classified in Talaromyces. To supplement previous conclusions based on ITS, SSU and/or LSU sequencing...

  1. Taxonomic study of Festuca L. subgenus Schedonorus (P. Beauv. Peterm. in Iran

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    Sayed Zabihollah Hosseini

    2013-11-01

    Full Text Available This study was based upon a taxonomic review of the subgenus Schedonorus in Iran. A collection of 30 specimens belonging to the herbaria: W, B and HUI (herbarium of the University of Isfahan were studied. Based on the results of this study, this subgenus included three species: Festuca arundinacea, F. gigantea and F. pratensis in Iran. Furthermore, this study showed that F. arundinacea, occured in this country with two subspecies: orientalis (Hack. Tzvelev and fenas (Lag. Arcang. with the greatest area of distribution compared to the other two species. Our examination of the type specimen of F. elatior subsp. pratensis var. elbursiana confirmed its synonymy with F. arundinacea.

  2. Phylogeography of three snubnose darters (Percidae: subgenus Ulocentra) endemic to the southeastern U.S

    Science.gov (United States)

    Steven L. Powers; Melvin L Warren

    2009-01-01

    The Yazoo Darter, Etheostoma raneyi (Percidae: subgenus Ulocentra), is a narrowly restricted endemic occurring in small tributaries in the Loessial Hills of the upper Yazoo River basin in northern Mississippi. The range of the species is shared between the Little Tallahatchie and adjacent upper Yocona rivers, but populations in the two...

  3. On the West-African species of the subgenus Eupalaemon Ortm

    NARCIS (Netherlands)

    Man, de J.G.

    1911-01-01

    In addition to my description of Palaemon (Eupalaemon) Lenzii de Man (see p. 225 of this volume) I give here a key to the species of the subgenus Eupalaemon Ortm. as yet known to occur in the rivers of West-Africa. Six species are at present known from there, viz.: 1. Pal. (Eupalaemon) macrobrachion

  4. Hygrophoraceae (Agaricales) of the Greater Antilles : Hygrocybe subgenus Pseudohygrocybe sections Coccineae and Neohygrocybe

    Science.gov (United States)

    Sharon A. Cantrell; D. Jean Lodge

    2004-01-01

    A key to 17 species in the genus Hygrocybe, subgenus Pseudohygrocybe, sections Coccineae and Neohygrocybe sensu Boertmann is provided for the Greater Antilles. Five new species and five taxa that are new reports for the region are described. The new species in section Coccineae are H. pseudoadonis, H. viridiphylla, and H. zonata. The new species in section Neohygrocybe...

  5. Typification of the Linnaean names Plantago serraria and P. subulata (Plantago subgenus Coronopus, Plantaginaceae)

    DEFF Research Database (Denmark)

    Hassemer, Gustavo; Iamonico, Duilio; Rønsted, Nina

    2017-01-01

    Plantago subg. Coronopus is a mainly Mediterranean group of plantains whose taxonomy is very complex. Two Linnaean names within this subgenus still remain untypified: P. serraria and P. subulata. We here discuss the possible types for these names, and designate lectotypes for both....... For nomenclatural purposes, the names P. triquetra and P. pungens are also included in the treatment of P. subulata....

  6. On the Iberian distribution of the species of Tipula, subgenus Tipula (Diptera, Tipulidae)

    NARCIS (Netherlands)

    Oosterbroek, Pjotr

    1994-01-01

    A list is provided for the species of Tipula, subgenus Tipula, indicating from which Spanish and Portuguese provinces they are known. T. (T.) oleracea is apparently distributed throughout the peninsula, the other three species and kleinschmidti) seem to possess a more limited distribution. The four

  7. On the Iberian distribution of the species of Tipula, subgenus Tipula (Diptera, Tipulidae)

    OpenAIRE

    Oosterbroek, Pjotr

    1994-01-01

    A list is provided for the species of Tipula, subgenus Tipula, indicating from which Spanish and Portuguese provinces they are known. T. (T.) oleracea is apparently distributed throughout the peninsula, the other three species and kleinschmidti) seem to possess a more limited distribution. The four species are recorded here for the first time from Portugal. (paludosa, mediterranean

  8. Phylogeny of osmophillic aspergilli (subgenus Aspergillus) and taxonomic revision of section Restricti

    Science.gov (United States)

    Aspergillus section Restricti together with sister sect. Aspergillus (formerly Eurotium) comprises osmophilic species, that are able to grow on substrates with low water activity and in extreme environments. We addressed the monophyly of both sections within subgenus Aspergillus and applied multidis...

  9. Studies of Lactarius from Mexico: a new species in subgenus Piperites

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    Montoya, L.; Bandala, V.M.; Moreno, G.

    1998-01-01

    Lactarius lacteolutescens is described as a new member in subgenus Piperites subsect. Croceini. It was found growing in a mixed forest of Pinus spp. and Abies hickellii, at Mt. Cofre de Perote, Central Region of the State of Veracruz (Gulf Area, Mexico).

  10. Contribution to the knowledge of the subgenus Scymnus (Parapullus Yang, 1978 (Coleoptera, Coccinellidae, with description of eight new species

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    Xiaosheng Chen

    2015-08-01

    Full Text Available Eight new species of the subgenus Scymnus (Parapullus Yang, 1978 from China are described and illustrated: S. (P. hastatus sp. n., S. (P. baxianshanensis sp. n., S. (P. laojielingensis sp. n., S. (P. annuliformis sp. n., S. (P. papillatus sp. n., S. (P. dichotomus sp. n., S. (P. shenmuensis sp. n. and S. (P. yanzigouensis sp. n. Diagnoses and distributions are provided for each species. An updated key to the Chinese species of the subgenus Parapullus is given. A catalogue to all known species of this subgenus is also presented.

  11. Euglossa obrima, a new species of orchid bee from Mesoamerica, with notes on the subgenus Dasystilbe Dressler (Hymenoptera, Apidae).

    Science.gov (United States)

    Hinojosa-Díaz, Ismael A; Melo, Gabriel A R; Engel, Michael S

    2011-05-11

    A new species of the orchid bee subgenus Dasystilbe Dressler (Euglossini: Euglossa Latreille) is described and figured from a series of males and females collected broadly in Mesoamerica. Euglossa (Dasystilbe) obrima, sp. n., is differentiated from the one known species of Dasystilbe, Euglossa (Dasystilbe) villosa Moure, which occurs only in Panamá and perhaps Costa Rica. The subgenus and its constituent species are diagnosed, and comments provided on Dasystilbe.

  12. Phylogeny of xerophilic aspergilli (subgenus Aspergillus) and taxonomic revision of section Restricti.

    Science.gov (United States)

    Sklenář, F; Jurjević, Ž; Zalar, P; Frisvad, J C; Visagie, C M; Kolařík, M; Houbraken, J; Chen, A J; Yilmaz, N; Seifert, K A; Coton, M; Déniel, F; Gunde-Cimerman, N; Samson, R A; Peterson, S W; Hubka, V

    2017-09-01

    Aspergillus section Restricti together with sister section Aspergillus (formerly Eurotium) comprises xerophilic species, that are able to grow on substrates with low water activity and in extreme environments. We adressed the monophyly of both sections within subgenus Aspergillus and applied a multidisciplinary approach for definition of species boundaries in sect. Restricti. The monophyly of sections Aspergillus and Restricti was tested on a set of 102 isolates comprising all currently accepted species and was strongly supported by Maximum likelihood (ML) and Bayesian inferrence (BI) analysis based on β-tubulin (benA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) loci. More than 300 strains belonging to sect. Restricti from various isolation sources and four continents were characterized by DNA sequencing, and 193 isolates were selected for phylogenetic analyses and phenotypic studies. Species delimitation methods based on multispecies coalescent model were employed on DNA sequences from four loci, i.e., ID region of rDNA (ITS + 28S), CaM, benA and RPB2, and supported recognition of 21 species, including 14 new. All these species were also strongly supported in ML and BI analyses. All recognised species can be reliably identified by all four examined genetic loci. Phenotype analysis was performed to support the delimitation of new species and includes colony characteristics on seven cultivation media incubated at several temperatures, growth on an osmotic gradient (six media with NaCl concentration from 0 to 25 %) and analysis of morphology including scanning electron microscopy. The micromorphology of conidial heads, vesicle dimensions, temperature profiles and growth parameters in osmotic gradient were useful criteria for species identification. The vast majority of species in sect. Restricti produce asperglaucide, asperphenamate or both in contrast to species in sect. Aspergillus. Mycophenolic acid was detected for the first time in

  13. Sphincterochilidae from Tunisia, with a note on the subgenus Rima Pallary, 1910 (Gastropoda, Pulmonata).

    Science.gov (United States)

    Abbes, Intidhar; Nouira, Said; Neubert, Eike

    2011-01-01

    In order to establish an updated checklist of terrestrial gastropod from Tunisia, a revision of the species of Sphincterochilidae is presented, using bibliographic and museum records and the results of our own field work. As a result, only two species, Sphincterochila candidissima and Sphincterochila tunetana, are accepted to occur in Tunisia, and their type specimens are illustrated. The study of the morphological characters of the genital organs of both species clarified their subgeneric affiliation. Comparison of Sphincterochila tunetana with Sphincterochila cariosa from Lebanonshowed that the first has to be classified within the subgenus Albea, and the latter within Sphincterochila s. str.; the subgenus Rima Pallary, 1910 remains in the synonymy of Sphincterochila s. str. Bibliographic records of Sphincterochila baetica and Sphincterochila otthiana from Tunisia could not be confirmed, the latter probably lives close to the border with Algeria.

  14. Sphincterochilidae from Tunisia, with a note on the subgenus Rima Pallary, 1910 (Gastropoda, Pulmonata

    Directory of Open Access Journals (Sweden)

    Intidhar Abbes

    2011-12-01

    Full Text Available In order to establish an updated checklist of terrestrial gastropod from Tunisia, a revision of the species of Sphincterochilidae is presented, using bibliographic and museum records and the results of our own field work. As a result, only two species, Sphincterochila candidissima and S. tunetana, are accepted to occur in Tunisia, and their type specimens are illustrated. The study of the morphological characters of the genital organs of both species clarified their subgeneric affiliation. Comparison of S. tunetana with S. cariosa from Lebanon showed that the first has to be classified within the subgenus Albea, and the latter within Sphincterochila s. str.; the subgenus Rima Pallary, 1910 remains in the synonymy of Sphincterochila s. str. Bibliographic records of S. baetica and S. otthiana from Tunisia could not be confirmed, the latter probably lives close to the border with Algeria.

  15. Sesquiterpene lactones. XXXIII. Guaianolides in the subgenus Psephellus (Cass. Schmalh., genus Centaurea L.

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    Gerard Nowak

    2014-01-01

    Full Text Available Sesquiterpene lactones were found to occur in all of the studied species of the subgenus Psephellus (Cass. Schmalh. Differing compositions were found in the representatives of three sections. In Centaurea declinata MB. from the section Leucophylle (Sosn. Sosn.. 15-deoxyrepin, linichlorin B and cynaropicrin were found. Linichlorin B dominated in Centaurea hypoleucu DC. from section Hypoleucae (Sosn. Sosn., while in the species classified in section Psephellus Sosn., repin, acroptilin, jenerin, centaurepensin and, in some, also cynaropicrin. dominated.

  16. Contributions to the Mosquito Fauna of Southeast Asia. XV. Genus Aedes Meigen, Subgenus Ayurakitia Thurman

    Science.gov (United States)

    1972-01-01

    small hair- like spicules; proctiger long, paraproct pigmented and bluntly pointed at apex, cereal setae absent; phallosome with aedeagus divided into...Thailand. The range of the subgenus may well extend into the mountain ranges of eastern Burma and northern Malaysia since similar habitats and climates...large flattened, curved bristle at apex, proctiger with cereal setae, and gonostylus long, narrow with an apical gonostylar claw; pupae with abdominal

  17. The genus Solanum (Solanaceae in southern Africa: subgenus Leptostemonum, section Giganteiformia

    Directory of Open Access Journals (Sweden)

    W. G. Welman

    2008-12-01

    Full Text Available In the genus Solanum L. (Solanaceae, subgenus Leptostemonum (Dunal Bitter, section Giganteiformia (Bitter Child has four representatives in the Flora of southern Africa region (South Africa, Namibia. Botswana. Swaziland. Lesotho, namely S. giganteum Jacq.. S. goetzei Dammer, S. tettense Klotzsch var.  renschii (Vatke A.E.Gonsalves and S. tettense Klotsch var.tettense. Descriptions, discussions, distribution maps and keys are presented, as well as an illustration of  S. goetzei.

  18. The taxonomic significance of seed morphology in the Passiflora subgenus Astrophea (Passifloraceae

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    Ana Carolina Mezzonato-Pires

    Full Text Available ABSTRACT The center of diversity for Passiflora subg. Astrophea is in low altitude areas of northern South America. The majority of species of this group are difficult to find in nature. Seed morphology was described in detail for 25 species of Passiflora subgenus Astrophea, a subgenus that until now did not exist. For morphological analysis, 20 seeds per species were measured for length, width and thickness, and the arithmetic means calculated. The seeds varied in length, width and thickness. Eight types of ornamentation were found. The margins varied among crestate, dentate, parted, entire and parted-crestate. The seed apex can be distinguished by the shape and position of the apical appendage. Seed shape varied among obovate, lanceolate, cordiform, and oblong to elliptical. An identification key was developed and a PCA was performed both using the principal morphological characters. Morphological characters of seeds are a new source of data for delimiting taxa with quite conflicting morphological boundaries, such as seen here with the Passiflora subgenus Astrophea. Furthermore, seed morphology is especially useful for the identification of specimens with only fruits and, consequently, seeds available.

  19. Bathyraja panthera, a new species of skate (Rajidae: Arhynchobatinae) from the western Aleutian Islands, and resurrection of the subgenus Arctoraja Ishiyama

    OpenAIRE

    Orr, James W.; Stevenson , Duane E.; Hoff, Gerald R.; Spies, Ingrid; McEachran, John D.

    2011-01-01

    We provide morphological and molecular evidence to recognize a new species of skate from the North Pacific, Bathyraja panthera. We also resurrect the skate subgenus Arctoraja Ishiyama, confirming its monophyly and the validity of the subgenus. Arctoraja was previously recognized as a distinct subgenus of Breviraja and later synonymized with Bathyraja (family Rajidae). Although the nominal species of Arctoraja have all been considered synonyms of Bathyraja parmifera by various authors, on t...

  20. Pollen morphology of some Geranium subgenus Robertium species of Iran

    Directory of Open Access Journals (Sweden)

    M. Keshavarzi

    2016-06-01

    Full Text Available Geranium (Geraniaceae comprises more than 23 annual or perennial species in Iran. There is no study in Iran with pollen morphology emphasize. The main aim of this study is to find diagnostic pollen characters in studied species. Totally 40 accessions of five species (G. albanum, G. molle, G. purpureum, G. mascatense and G. pusillum were collected. Pollen grains were studied by use of light and Scanning electron microscopy. To reveal the species relationships different multivariate statistical methods were used. The pollen grains were monad, isopolar, radially symmetric and of spheroid, prolate-spheroid or oblate-spheroid classes. The main ornamentation type was clavate, however reticulate but striate was also observed. All sections are clearly separated by their pollen features except of Batrachioidea which show confusion with Ruberta. Species relationship is discussed.

  1. Mitochondrial COI gene as a tool in the taxonomy of mosquitoes Culex subgenus Melanoconion.

    Science.gov (United States)

    Torres-Gutierrez, Carolina; Bergo, Eduardo Sterlino; Emerson, Kevin J; de Oliveira, Tatiane M P; Greni, Susan; Sallum, Maria Anice Mureb

    2016-12-01

    The subgenus Melanoconion is the second largest subgenus within the genus Culex, with 160 described species. Several of the species are proven vectors of arboviruses, including West Nile virus, Venezuelan equine encephalitis virus complex and Eastern equine encephalomyelitis virus. Species of Melanoconion are well distributed from southern North America to most countries of South America and display the highest species diversity in tropical regions. Taxonomical identification within this group has been primarily based on morphological characters, with the male genitalia as the source of the most solid diagnostic features. The difficulty in reaching accurate species determinations when studying specimens of Culex (Melanoconion) has been extensively documented as a real limitation to expand knowledge of these insects. We tested the utility of the mitochondrial gene COI as a complementary tool in the taxonomy of Melanoconion. Using a data set of 120 COI sequences from Culex specimen captured in several localities in Brazil, the utility of COI barcodes for species delimitation is discussed through the evaluation of genetic divergences among specimens and the clustering patterns of species in three topologies obtained with Neighbor Joining, Maximum Likelihood and Bayesian phylogenetic inference. For all specimens included in this study a previous morphological examination was performed, and most of the taxonomical determinations were corroborated using the COI barcode. We generated COI sequences that belong to 48 species of Melanoconion, with a mean intraspecific K2P genetic divergence of 3%; and all interspecific divergence values higher than the intraspecific divergence values. This is the first comprehensive study of subgenus Melanoconion, with evidence of COI as a useful and accessible DNA barcode. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. The oribatid mite subgenus Galumna (Galumna (Acari, Oribatida, Galumnidae in the Philippines

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    Sergey Ermilov

    2014-11-01

    Full Text Available Five species of the subgenus Galumna (Galumna (Acari, Oribatida, Galumnidae are registered in the Philippine oribatid mite fauna. A new species, G. (G. makilingensis sp. n., is described; it is most similar morphologically to G. (G. tokyoensis Aoki, 1966, but differs from the latter by the morphology of porose areas Aa and Ap, rostral setae, and length of interlamellar setae. Three species, G. (G. crenata Deb & Raychaudhuri, 1975, G. (G. cf. exigua Sellnick, 1925 and G. (G. khoii Mahunka, 1989, are recorded in the Philippines for the first time. The species G. (G. crenata is redescribed. An identification key to the Philippine species of Galumna (Galumna is given.

  3. A new species of Cladotanytarsus (Lenziella) from Oregon supports the systematic concept of the subgenus (Diptera: Chironomidae).

    Science.gov (United States)

    Puchalski, Mateusz; Giłka, Wojciech

    2017-05-18

    A new species of the genus Cladotanytarsus Kieffer, 1921 and the small subgenus Lenziella Kieffer, 1922 is described from Southern Oregon, USA. The adult male of C. (L.) glaber Giłka et Puchalski, sp. nov., featuring tibial lobes armed with dense setae and a large globular swelling of the hypopygial inferior volsella, supports the recently defined systematic concept for Lenziella. This subgenus is known from seven species distributed in the Northern Hemisphere (1 European, 1 Palaearctic and 5 Nearctic), the males of which are included in an updated identification key.

  4. Phenotypic differentiation and phylogenetic signal of wing shape in western European biting midges, Culicoides spp., of the subgenus Avaritia

    DEFF Research Database (Denmark)

    Muñoz-Muñoz, F.; Talavera, S.; Carpenter, S.

    2014-01-01

    of cytochrome oxidase subunit I barcode sequencing and geometric morphometric analyses to investigate wing shape as a means to infer species identification within this subgenus. In addition the congruence of morphological data with different phylogenetic hypotheses is tested. Five different species...... of the subgenus Avaritia were considered in the study (C. obsoletus (Meigen); C. scoticus Kettle and Lawson; C. chiopterus (Meigen); C. dewulfi Goetghebuer and C. imicola (Kieffer)). The study demonstrated that over 90% of individuals could be separated correctly into species by their wing shape and that patterns...

  5. Molecular phylogeny of Crematogaster subgenus Decacrema ants (Hymenoptera: Formicidae) and the colonization of Macaranga (Euphorbiaceae) trees.

    Science.gov (United States)

    Feldhaar, Heike; Fiala, Brigitte; Gadau, Jürgen; Mohamed, Maryati; Maschwitz, Ulrich

    2003-06-01

    To elucidate the evolution of one of the most species-rich ant-plant symbiotic systems, the association between Crematogaster (Myrmicinae) and Macaranga (Euphorbiaceae) in South-East Asia, we conducted a phylogenetic analysis of the ant partners. For the phylogenetic analysis partial mitochondrial cytochrome oxidase I and II were sequenced and Maximum Parsimony analysis was performed. The analyzed Crematogaster of the subgenus Decacrema fell into three distinct clades which are also characterized by specific morphological and ecological traits (queen morphology, host-plants, and colony structure). Our results supported the validity of our currently used morphospecies concept for Peninsula Malaysia. However, on a wider geographic range (including North and North-East Borneo) some morphospecies turned out to be species complexes with genetically quite distinct taxa. Our phylogenetic analysis and host association studies do not indicate strict cocladogenesis between the subgenus Decacrema and their Macaranga host-plants because multiple ant taxa occur on quite distinct host-plants belonging to different clades within in the genus Macaranga. These results support the view that host-shifting or host-expansion is common in the ants colonizing Macaranga. Additionally, the considerable geographic substructuring found in the phylogenetic trees of the ants suggests that allopatric speciation has also played a role in the diversification and the current distribution of the Decacrema ants.

  6. Unusual sub-genus associations of faecal Prevotella and Bacteroides with specific dietary patterns.

    Science.gov (United States)

    De Filippis, Francesca; Pellegrini, Nicoletta; Laghi, Luca; Gobbetti, Marco; Ercolini, Danilo

    2016-10-21

    Diet has a recognized effect in shaping gut microbiota. Many studies link an increase in Prevotella to high-fibre diet, while Bacteroides abundance is usually associated with the consumption of animal fat and protein-rich diets. Nevertheless, closely related species and strains may harbour different genetic pools; therefore, further studies should aim to understand whether species of the same genus are consistently linked to dietary patterns or equally responsive to diet variations. Here, we used oligotyping of 16S rRNA gene sequencing data to exploit the diversity within Prevotella and Bacteroides genera in faecal samples of omnivore and non-omnivore subjects from a previously studied cohort. A great heterogeneity was found in oligotype composition. Nevertheless, different oligotypes within the same genus showed distinctive correlation patterns with dietary components and metabolome. We found that some Prevotella oligotypes are significantly associated with the plant-based diet but some are associated with animal-based nutrients, and the same applies to Bacteroides. Therefore, an indiscriminate association of Bacteroidetes genera with specific dietary patterns may lead to an oversimplified vision that does not take into account sub-genus diversity and the different possible responses to dietary components. We demonstrated that Prevotella and Bacteroides oligotypes show distinctive correlation patterns with dietary components and metabolome. These results substantiate a current oversimplification of diet-dependent microbe-host associations and highlighted that sub-genus differences must be taken into account when planning gut microbiota modulation for health benefits.

  7. Revision of the Neotropical species of the subgenus Atrichopogon (Psilokempia) (Diptera: Ceratopogonidae).

    Science.gov (United States)

    Spinelli, Gustavo R; Marino, Pablo I; Huerta, Herón

    2015-08-20

    This revision of the midges in the subgenus Psilokempia Enderlein of Atrichopogon Kieffer provides a brief description of the subgenus, diagnoses, descriptions, illustrations and a key to adult males and females of the 17 species from the Neotropical region, as well as distributional records of both new and previously described species. Six new species are described and illustrated: A. arti, A. javieri, A. longirostris, A. nahuelbutensis, A. sergioi and A. woodruffi (n. spp.). The type materials of all previously known Neotropical species except A. penicillatus Delècolle & Rieb were examined. Atrichopogon altivolans Macfie, A. aridus Spinelli & Marino, A. domizii Spinelli, A. glaber Macfie, A. gordoni Macfie, A. insigniventris Macfie, A. pectinatus Macfie and A. penicillatus are redescribed and illustrated, and notes on the types of A. echinodes Macfie, A. harrisi Macfie and A. sanctaeclarae Macfie are provided. Lectotypes are designated for A. glaber, A. insigniventris and A. pectinatus. The previously unknown males of A. altivolans, A. pectinatus and A. penicillatus are described and illustrated, and A. fimbriatus Macfie is recognized as a junior synonym of A. gordoni.

  8. Sesquiterpene lactones. XXIX. Cnicin in species of the subgenus Acrolophus (Cass. Dobrocz

    Directory of Open Access Journals (Sweden)

    Gerard Nowak

    2014-01-01

    Full Text Available Cnicin was isolated from 18 species or subspecies of the subgenus Acrolophus (Cass. Dobrocz.: Centaurea aplolepa Moretti subsp. aplolepa, C. aplolepa Moretti subsp. lunensis (Fiori Dostal, C. arenaria Bieb. ex Wild. subsp. arenaria, C. arenaria Bieb. ex Wild, subsp. odessana (Prodan Dostal, C. arenaria Bieb ex Wild. subsp. majorowii (Dumbadze Dostal, C. calvescens Pančić, C. cineraria L. subsp. cineraria, C. cineraria L. var, circae Somm., C. diffusa Lam. var. brevispina Boiss., C. grisebachi (Nyman Form. subsp. grisebachi, C. grisebachi (Nyman Form. subsp. confusa (Halácsy Dostal, C. leucophaea Jordan subsp. leucophaea, C. attica Nyman subsp. ossaea (Halácsy Dostal, C. pallidior Halácsy subsp. palidior, C. pelia DC., C. rhenana Boreau subsp. savranica (Klokow Dostal, C. tymphaea Hausskn subsp. tymphaea, C. tymphaea Hausskn subsp. brevispina Hausskn (Dostal. Chromatographic analysis has shown appearance of cnicin in 10 investigated species or subspecies of subgenus Acrolophus (Cass. Dobrocz.: Centaurea attica Nyman subsp. drakiensis (Freyn, Sint. Dostal, C. kartschiana Scop., C. aggregata Fisch. et Mey, C. cuneifolia Sibth. SM. subsp. pallida (Friv. Hayek, C. exarata Boiss. ex Cosson., C. mantoudii Georg., C. orphanidea Heldr. Sart. ex Boiss, subsp. orphanidea, C. spinosa L. subsp. spinosa, C. transiens Halácsy, C. zuccariniana DC.

  9. ARCHITECTONICS OF BOREAL SPECIES IN THE SUBGENUS SALIX AND VETRIX DUMORT.

    Directory of Open Access Journals (Sweden)

    O. I. Nedoseko

    2017-09-01

    Full Text Available Background. The basis for understanding the patterns of plant growth and development is the research of their structural and functional organization. One of the successfully developing areas of this research is the study of architectural models of woody plants. At the same time, widespread species of willow in the middle belt of European Russia from subgenus Salix and Vetrix are not fully studied in this respect. The goal is to develop a methodology for studying the structural and functional organization of dioecious tree species and on its basis to identify and describe the main structural and functional units (architectural modules of boreal species of willows of subgenus Salix and Vetrix. Materials and methods. Architectural modules are described for 15 boreal species in subgenus Salix and Vetrix. For this, a method based on the analysis of three features of the structural and functional organization of the species was developed: ramification type, the size of the vegetative shoots die-off zone and the longevity of the vegetative parts of the earrings. Results. 7 architectural modules have been identified in the examined species: one- and two-stage drop-down earrings on the basis of acro-, meso- and basitonium, and also with conditionally non-decreasing earrings based on acrotonia. It is established that the degree of death of the upper metamers of annual shoots correlates with the development of shoots from sleeping buds: in low shrubs such shoots develop 4–6 times more often than in trees and high shrubs. It is determined that the architectural modules of female individuals, unlike male individuals, are more branched and contain a greater number of annual assimilative shoots. It is shown that maximum number of architectural types is characteristic of the upper and middle branches, and the smaller of the lower branches in the crowns of female and male individuals of trees and tall shrubs. Conclusions. The offered technique allows us to

  10. Phylogeny and taxonomic revision of the subgenus Velleius Leach (Coleoptera: Staphylinidae: Staphylininae).

    Science.gov (United States)

    Zhao, Zong-Yi; Zhou, Hong-Zhang

    2015-05-15

    The subgenus Velleius Leach, 1819 of the genus Quedius Stephens, 1829 is a small and very distinctive group in the subtribe Quediina (Staphylinidae: Staphylininae) with pectinate antennal segments and larvae living in nests of Vespa species. This paper reviews the taxonomy of all Velleius species and analyzes the phylogeny of this group. Two new species, Quedius (Velleius) sagittalis sp. nov. from Shaanxi, China and Q. (V.) rectilatus sp. nov. from Guangdong, China, are described. Q. (V.) simillimus (Fairmaire,1891) syn. nov. is proposed as a new synonym of Q. (V.) pectinatus (Sharp, 1874). Phylogenetic result shows that all nine Velleius species can be divided into two clades and both have strong tree supports of Bremer/Bootstrap/Jackknife values.

  11. Growth and differentiation on a trypanosome of the subgenus Schizotrypanum from the bat Phyllostomus hastatus

    Directory of Open Access Journals (Sweden)

    Sônia I. Hamanaka

    1993-12-01

    Full Text Available The effects of temperature, pH, osmolarity and aeration on the growth and differentiation of a trypanosome ofthe subgenus Schizotrypanum isolatedfrom the bat Phyllostomus hastatus were studied. In general, the growth characteristics ofthe flagellate were similar to those of Trypanosoma (Schizotrypanum cruzi. However, the parasite did not growth at 33 or 37C. Increase in the osmolarity and aeration promoted growth at 33C. Significant metacyclogenesis was detected only in the growth condition where maximal growth occured (28C, pH 7.3, 380m0s/kg, in tissue cullure flasks, at the end ofthe exponential growth phase. The begining of the metacyclogenesis process was coincident with most glucose utilization and lowest pH. During metacyclogenesis both culture medium pH and osmolarity increased steadly.

  12. The genus Solanum (Solanaceae in southern Africa: subgenus Leptostemonum, the introduced sections Acanthophora and Torva

    Directory of Open Access Journals (Sweden)

    W. G. Welman

    2003-12-01

    Full Text Available In the genus Solanum L. (Solanaceae, subgenus Leptostemonum (Dunal Bitter, section Acanthophora Dunal has four representatives in the Flora of southern Africa region (South Africa. Lesotho, Swaziland, Namibia. Botswana, namely  S. aculeatissimum Jacq.. S. capsicoides Allioni. S. mammosum L. (cultivated only and S. viarum Dunal. Section  Ton a Nees has two representatives in southern Africa, namely S.  chnsotriclium Schltdl. (S.  hispidum auctt. non Pers. and S.  ton um Sw.; both are naturalized weeds.  Solanum capsicoides, S. viarum and S.  torvum have not been listed before for southern Africa. All are introduced species native to the New World. Descriptions, discussions, illustrations and distribution maps of the naturalized species are presented, as well as keys to the species of both sections.

  13. Systematic studies on Anopheles galvaoi Causey, Deane & Deane from the subgenus Nysssorhynchus blanchard (Diptera: Culicidae

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    Maria Anice Mureb Sallum

    2002-12-01

    Full Text Available Anopheles galvaoi, a member of the subgenus Nyssorhynchus, is redescribed based on morphological characters of the adults male and female, fourth-instar larva and pupa. Female, male genitalia, larval and pupal stages are illustrated. Data about medical importance, bionomics, and distribution are given based on literature records. Adult female of An. galvaoi can be easily misidentified as An. benarrochi Gabaldón and An. aquasalis Curry. A few characters are indicated for identifying female and immatures of An. galvaoi. Phylogenetic relationships among An. galvaoi and six other species of the Oswaldoi Subgroup are estimated using COII mtDNA and ITS2 rDNA gene sequences. Lectotype of An. galvaoi, an adult female from Rio Branco, State of Acre, is invalidated.

  14. The genus Solanum (Solanaceae in southern Africa: subgenus Leptostemonum, the introduced sections Acanthophora and Torva

    Directory of Open Access Journals (Sweden)

    W. G. Welman

    2003-09-01

    Full Text Available In the genus Solanum L. (Solanaceae, subgenus Leptostemonum (Dunal Bitter, section Acanthophora Dunal has four representatives in the Flora of southern Africa region (South Africa. Lesotho, Swaziland, Namibia. Botswana, namely  S. aculeatissimum Jacq.. S. capsicoides Allioni. S. mammosum L. (cultivated only and S. viarum Dunal. Section  Ton a Nees has two representatives in southern Africa, namely S.  chnsotriclium Schltdl. (S.  hispidum auctt. non Pers. and S.  ton um Sw.; both are naturalized weeds.  Solanum capsicoides, S. viarum and S.  torvum have not been listed before for southern Africa. All are introduced species native to the New World. Descriptions, discussions, illustrations and distribution maps of the naturalized species are presented, as well as keys to the species of both sections.

  15. Phylogenetic analysis of Penicillium subgenus Penicillium using partial P-tubulin sequences

    DEFF Research Database (Denmark)

    Samson, R.A.; Seifert, K.A.; Kuijpers, A.F.A.

    2004-01-01

    with the classification into sections and series proposed in the accompanying monograph. There was good strict consensus support for much of the gene tree, and good bootstrap support for some parts. The phylogenetic analyses suggested that sect. Viridicata, the largest section in the subgenus, is divided into three...... the paraphyletic P. nordicum. The phylogeny for sect. Roqueforti (100%) was robust, with excellent bootstrap support for all included species, i.e. P. roqueforti (100%), P. carneum (94%) and P. paneum (100%). In sect. Penicillium, Series Expansa was paraphyletic, with the monophyletic ser. Italica derived within...... it. The synnematous species in ser. Claviformia were a paraphyletic group with the species of ser. Urticicolae., including P. griseofulvum (99%), derived within. Section Digitata, ser. Digitata comprised a single well-supported species, P. digitatum (100%). The phylogenetic structure of sect...

  16. Phylogenetic Patterns of Geographical and Ecological Diversification in the Subgenus Drosophila

    Science.gov (United States)

    Morales-Hojas, Ramiro; Vieira, Jorge

    2012-01-01

    Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. Members of the subgenus Drosophila are distributed across the globe and show a large diversity of ecological niches. Furthermore, taxonomic classification of Drosophila includes the rank radiation, which refers to closely related species groups. Nevertheless, it has never been tested if these taxonomic radiations correspond to evolutionary radiations. Here we present a study of the patterns of diversification of Drosophila to test for increased diversification rates in relation to the geographic and ecological diversification processes. For this, we have estimated and dated a phylogeny of 218 species belonging to the major species groups of the subgenus. The obtained phylogenies are largely consistent with previous studies and indicate that the major groups appeared during the Oligocene/Miocene transition or early Miocene, characterized by a trend of climate warming with brief periods of glaciation. Ancestral reconstruction of geographic ranges and ecological resource use suggest at least two dispersals to the Neotropics from the ancestral Asiatic tropical disribution, and several transitions to specialized ecological resource use (mycophagous and cactophilic). Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. However, diversification analyses show no significant support for adaptive radiations as a result of geographic dispersal or ecological resource shift. Also, cactophily has not resulted in an increase in the diversification rate of the repleta and related groups. It is thus concluded that the taxonomic radiations do not correspond to adaptive radiations. PMID:23152919

  17. Phylogenetic patterns of geographical and ecological diversification in the subgenus Drosophila.

    Directory of Open Access Journals (Sweden)

    Ramiro Morales-Hojas

    Full Text Available Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. Members of the subgenus Drosophila are distributed across the globe and show a large diversity of ecological niches. Furthermore, taxonomic classification of Drosophila includes the rank radiation, which refers to closely related species groups. Nevertheless, it has never been tested if these taxonomic radiations correspond to evolutionary radiations. Here we present a study of the patterns of diversification of Drosophila to test for increased diversification rates in relation to the geographic and ecological diversification processes. For this, we have estimated and dated a phylogeny of 218 species belonging to the major species groups of the subgenus. The obtained phylogenies are largely consistent with previous studies and indicate that the major groups appeared during the Oligocene/Miocene transition or early Miocene, characterized by a trend of climate warming with brief periods of glaciation. Ancestral reconstruction of geographic ranges and ecological resource use suggest at least two dispersals to the Neotropics from the ancestral Asiatic tropical disribution, and several transitions to specialized ecological resource use (mycophagous and cactophilic. Colonisation of new geographic regions and/or of new ecological resources can result in rapid species diversification into the new ecological niches available. However, diversification analyses show no significant support for adaptive radiations as a result of geographic dispersal or ecological resource shift. Also, cactophily has not resulted in an increase in the diversification rate of the repleta and related groups. It is thus concluded that the taxonomic radiations do not correspond to adaptive radiations.

  18. Two new species of the acifer species group of Polypedilum subgenus Tripodura Townes from China (Diptera: Chironomidae).

    Science.gov (United States)

    Zhang, Ruilei; Song, Chao; Wang, Liqing; Wang, Xinhua

    2015-02-13

    Polypedilum (Tripodura) falcatum sp. n. and P. (T.) procerum sp. n. of the acifer species group of Polypedilum subgenus Tripodura Townes are described and illustrated as male imagines from China. The male adult of P. (T.) falcatum sp. n. is distinguished by the presence of two faint markings on wing; short and interrupted abdominal tergite bands; the sickle-like superior volsella bearing 0-2 outer setae and a tuft of short setae on its apex. The male adult of P. (T.) procerum sp. n. differs in having short abdominal tergite bands; a long, slender and apically curved superior volsella; a high fore leg ratio (2.30-2.33). A key to known male imagines of Polypedilum subgenus Tripodura from China is presented.

  19. Phylogeography, population structure and evolution of coral-eating butterflyfishes (Family Chaetodontidae, genus Chaetodon , subgenus Corallochaetodon )

    KAUST Repository

    Waldrop, Ellen

    2016-01-11

    Aim This study compares the phylogeography, population structure and evolution of four butterflyfish species in the Chaetodon subgenus Corallochaetodon, with two widespread species (Indian Ocean – C. trifasciatus and Pacific Ocean – C. lunulatus), and two species that are largely restricted to the Red Sea (C. austriacus) and north-western (NW) Indian Ocean (C. melapterus). Through extensive geographical coverage of these taxa, we seek to resolve patterns of genetic diversity within and between closely related butterflyfish species in order to illuminate biogeographical and evolutionary processes. Location Red Sea, Indian Ocean and Pacific Ocean. Methods A total of 632 individuals from 24 locations throughout the geographical ranges of all four members of the subgenus Corallochaetodon were sequenced using a 605 bp fragment (cytochrome b) of mtDNA. In addition, 10 microsatellite loci were used to assess population structure in the two widespread species. Results Phylogenetic reconstruction indicates that the Pacific Ocean C. lunulatus diverged from the Indian Ocean C. trifasciatus approximately 3 Ma, while C. melapterus and C. austriacus comprise a cluster of shared haplotypes derived from C. trifasciatus within the last 0.75 Myr. The Pacific C. lunulatus had significant population structure at peripheral locations on the eastern edge of its range (French Polynesia, Johnston Atoll, Hawai\\'i), and a strong break between two ecoregions of the Hawaiian Archipelago. The Indian Ocean C. trifasciatus showed significant structure only at the Chagos Archipelago in the central Indian Ocean, and the two range-restricted species showed no population structure but evidence of recent population expansion. Main conclusions Patterns of endemism and genetic diversity in Corallochaetodon butterflyfishes have been shaped by (1) Plio-Pleistocene sea level changes that facilitated evolutionary divergences at biogeographical barriers between Indian and Pacific Oceans, and the Indian

  20. Systematics and biology of Xylocopa subgenus Schonnherria (Hymenoptera, Apidae) in Argentina

    Science.gov (United States)

    Lucia, Mariano; Gonzalez, Victor H.; Abrahamovich, Alberto H.

    2015-01-01

    Abstract Biological information on the species of the large carpenter bee Xylocopa subgenus Schonnherria occurring in Argentina is revised. Based on the appraisal of museum specimens, the study of type material, and field surveys conducted across 15 provinces between 2007 and 2011, the following seven species are recognized for the country: Xylocopa bambusae Schrottky, Xylocopa chrysopoda Schrottky, Xylocopa macrops Lepeletier de Saint Fargeau, Xylocopa simillima Smith Xylocopa splendidula Lepeletier de Saint Fargeau, Xylocopa pulchra Smith, and Xylocopa viridis Smith. Previous literature records of Xylocopa dimidiata Latreille, Xylocopa subcyanea Pérez, and Xylocopa varians Smith for the province of Misiones appear to have been misidentified specimens, although the presence of these species in Argentina cannot be entirely ruled out given the proximity of this province to Brazil and Paraguay where they occur; Xylocopa boops Maidl was described from a male specimen with unusually enlarged eyes and is newly synonymized under Xylocopa macrops. Males and females of all species are diagnosed, described, and figured, including details of the male genitalia. Taxonomic comments, data on the geographical distribution and nesting substrates, and identification keys to all Argentinean species of Schonnherria are provided. The nesting biologies of Xylocopa splendidula and Xylocopa viridis are documented. PMID:26798288

  1. A review of the orientalis group of the Otostigmus subgenus Otostigmus Porat, 1876 (Chilopoda: Scolopendromorpha: Scolopendridae).

    Science.gov (United States)

    Lewis, John G E

    2014-12-02

    The Otostigmus subgenus Otostigmus, which currently comprises 58 species, was subdivided by Lewis (2010a) into nine species groups based on Attems' (1930a) monograph. The orientalis group comprising 19 species and two subspecies is the subject of this paper. In most cases, the type material is redescribed and variation discussed. The following species are valid: O. ateles Chamberlin, 1920, O. australianus Attems, 1930, O. brevidentatus Verhoeff, 1937, O. foveolatus Verhoeff, 1937, O. kashmiranus Lewis, 1992, O. metallicus Haase, 1887, O. multidens multidens Haase, 1887, O. oatesi Kraepelin, 1903, O. orientalis Porat, 1876, O. ruficeps Pocock, 1890, and O. striolatus Verhoeff, 1937. O. seychellarum Attems, 1900, is reinstated as a valid species and O. niasensis Silvestri, 1895, and O. sucki Krae-pelin, 1903 which may be O. metallicus are regarded as valid pro tem. O. greggi Chamberlin, 1944, is a junior subjective synonym of O. astenus (Kohlrausch, 1881), and O. loriae Silvestri, 1895, and O. multidens carens Attems, 1938, junior subjective synonyms of O. multidens. O. loriae nordicus Schileyko, 1995, becomes O. multidens nordicus comb. nov. O. nemorensis Silvestri, 1895, O. poonamae Khanna & Tripathi, 1986, and O. telus Chamberlin, 1939, are nomina dubia. A key to the species is provided.

  2. The rediscovery of Passiflora kwangtungensis Merr. (subgenus Decaloba supersection Disemma: a critically endangered Chinese endemic

    Directory of Open Access Journals (Sweden)

    Shawn Krosnick

    2013-06-01

    Full Text Available Passiflora kwangtungensis is a critically endangered Chinese species known from Guangxi, Guangdong, and Jiangxi Provinces. The species belongs to Passiflora subgenus Decaloba, supersection Disemma, section Octandranthus. Field observations decreased rapidly during the 1970s to 1980s, and it was suspected that this species might have been extirpated due to repeated deforestation events throughout southern China. In recent years, however, small isolated populations of this species have been rediscovered in Hunan Province, representing new locality records for P. kwangtungensis. New herbarium collections, color photographs, and silica gel collections have provided an unexpected opportunity to examine the evolutionary significance of this species. The current study presents a revised morphological description of P. kwangtungensis based on fresh material, along with an updated distribution map. Using nrITS sequence data, preliminary insights into the phylogenetic position of P. kwangtungensis are presented. Molecular data support the placement of P. kwangtungensis within supersection Disemma section Octandranthus. However, the exact placement of P. kwangtungensis within this lineage is unclear. The nrITS data suggest that P. kwangtungensis may be sister to a clade containing Passiflora from China, Nepal, India, and Southeast Asia. Morphologically, P. kwangtungensis displays the most similarity P. geminiflora (Nepal, India and P. henryi (China. Lastly, conservation status and recommendations are made for P. kwangtungensis following the IUCN Red List Criteria, where this species is classified as CR C1+C2a(i; D.

  3. Multigenomic Delineation of Plasmodium Species of the Laverania Subgenus Infecting Wild-Living Chimpanzees and Gorillas.

    Science.gov (United States)

    Liu, Weimin; Sundararaman, Sesh A; Loy, Dorothy E; Learn, Gerald H; Li, Yingying; Plenderleith, Lindsey J; Ndjango, Jean-Bosco N; Speede, Sheri; Atencia, Rebeca; Cox, Debby; Shaw, George M; Ayouba, Ahidjo; Peeters, Martine; Rayner, Julian C; Hahn, Beatrice H; Sharp, Paul M

    2016-07-02

    Plasmodium falciparum, the major cause of malaria morbidity and mortality worldwide, is only distantly related to other human malaria parasites and has thus been placed in a separate subgenus, termed Laverania Parasites morphologically similar to P. falciparum have been identified in African apes, but only one other Laverania species, Plasmodium reichenowi from chimpanzees, has been formally described. Although recent studies have pointed to the existence of additional Laverania species, their precise number and host associations remain uncertain, primarily because of limited sampling and a paucity of parasite sequences other than from mitochondrial DNA. To address this, we used limiting dilution polymerase chain reaction to amplify additional parasite sequences from a large number of chimpanzee and gorilla blood and fecal samples collected at two sanctuaries and 30 field sites across equatorial Africa. Phylogenetic analyses of more than 2,000 new sequences derived from the mitochondrial, nuclear, and apicoplast genomes revealed six divergent and well-supported clades within the Laverania parasite group. Although two of these clades exhibited deep subdivisions in phylogenies estimated from organelle gene sequences, these sublineages were geographically defined and not present in trees from four unlinked nuclear loci. This greatly expanded sequence data set thus confirms six, and not seven or more, ape Laverania species, of which P. reichenowi, Plasmodium gaboni, and Plasmodium billcollinsi only infect chimpanzees, whereas Plasmodium praefalciparum, Plasmodium adleri, and Pladmodium blacklocki only infect gorillas. The new sequence data also confirm the P. praefalciparum origin of human P. falciparum. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  4. Molecular differentiation of Culicoides biting midges (Diptera: Ceratopogonidae) from the subgenus Culicoides Latreille in Denmark

    DEFF Research Database (Denmark)

    Lassen, S. B.; Nielsen, S. Achim; Skovgård, H.

    2012-01-01

    complexes are hard to distinguish. We evaluated the use of the mitochondrial DNA cytochrome oxidase I gene (COI) barcode region in the identification of species within the subgenus Culicoides. COI barcode sequence divergence within species was ... impunctatus, and Culicoides grisescens. Additionally, this study confirms the existence of Culicoides halophilus as a valid taxon and presents the first Culicoides deltus barcode sequences. Three additional groups of specimens were identified: Culicoides dk1 with a COI barcode diverging by 14.3% to 17.2% from...... other subgenus Culicoides species and Culicoides Kalix and Culicoides dk3, which diverged by 5.9% from each other and showed 12.5% to 17.6% divergence in COI barcode to subgenus Culicoides specimens....

  5. New species and records of Chimarra (Trichoptera, Philopotamidae) from Northeastern Brazil, and an updated key to subgenus Chimarra (Chimarrita)

    Science.gov (United States)

    Vilarino, Albane; Calor, Adolfo Ricardo

    2015-01-01

    Abstract Two new species of Chimarra (Chimarrita) are described and illustrated, Chimarra (Chimarrita) mesodonta sp. n. and Chimarra (Chimarrita) anticheira sp. n. from the Chimarra (Chimarrita) rosalesi and Chimarra (Chimarrita) simpliciforma species groups, respectively. The morphological variation of Chimarra (Curgia) morio is also illustrated. Chimarra (Otarrha) odonta and Chimarra (Chimarrita) kontilos are reported to occur in the northeast region of Brazil for the first time. An updated key is provided for males and females of the all species in the subgenus Chimarrita. PMID:25878540

  6. From introduced American weed to Cape Verde Islands endemic: the case of Solanum rigidum Lam. (Solanaceae, Solanum subgenus Leptostemonum).

    Science.gov (United States)

    Knapp, Sandra; Vorontsova, Maria S

    2013-01-01

    A Solanum species long considered an American introduction to the Cape Verde Islands off the west coast of Africa is identified as Solanum rigidum, a member of the Eggplant clade of Old World spiny solanums (Solanum subgenus Leptostemonum) and is probably endemic to the Cape Verde Islands. Collections of this species from the Caribbean are likely to have been introduced from the Cape Verde Islands on slave ships. We discuss the complex nomenclatural history of this plant and provide a detailed description, illustration and distribution map. The preliminary conservation status of Solanum rigidum is Least Concern, but needs to be reassessed in light of its endemic rather than introduced status.

  7. Taxonomy of 'Euconnus complex'. Part III. Morphology of Euconnus subgenus Napochus and revision of the Australian species (Coleoptera, Staphylinidae, Scydmaeninae).

    Science.gov (United States)

    Jałoszyński, Paweł

    2015-02-26

    Morphological structures of the type species of Euconnus (Napochus) are described and illustrated, and compared with those of Euconnus s. str. Napochus is maintained as a subgenus of Euconnus, and its revised diagnosis is given. Australian species of Napochus are revised: E. palmwoodianus Franz and E. pisoniae Franz are redescribed, and E. setiphallus sp. n., E. yadhaigana sp. n., E. microlaminatus sp. n, E. feeneyi sp. n. (with a subspecies E. feeneyi parallelilaminatus ssp. n.) are described. An unusual variability in body size and proportions of body parts found in E. feeneyi is analyzed and discussed.

  8. Taxonomic study on the subgenus Uresipedilum (Diptera: Chironomidae: Polypedilum, with description of a new species from the Yaewyama Islands, Okinawa, Japan

    Directory of Open Access Journals (Sweden)

    Nao Yamamoto

    2015-07-01

    Full Text Available As a result of a multi-year survey, we recognized four species including a new species of the subgenus Uresipedilum from the Yaeyama Islands, the Ryukyus, Japan. Polypedilum (Uresipedilum paraconvictum sp. nov. is described. P. (U. classiglobum Zhang et Wang (2004 P. (U. bingoparadoxum Kawai et al. (1998 and P. (U. iriofegeum Sasa et Suzuki (2000 are re-described. The first species is newly recorded from Japan, and the second species is new to the Ryukyus. The diagnostic characters of the subgenus are discussed.

  9. A review of the genus Mirostenella Bayer, 1988 (Octocorallia: Primnoidae) with a description of a new subgenus and species

    Science.gov (United States)

    Zapata-Guardiola, Rebeca; López-González, Pablo J.; Gili, Josep-Maria

    2013-06-01

    In the present study, the genus Mirostenella Bayer (Proc Biol Soc Wash 101:251-256, 1988) is revised. We add to knowledge of the type species of the genus M. articulata Bayer (Proc Biol Soc Wash 101:251-256, 1988) from newly collected material from the Antarctic cruise Polarstern ANT XIX/5, and an illustrated description of this species is included. Cairns and Bayer (Smithson Contrib Zool 629:1-79, 2009) included Dicholaphis delicatula Thomson and Rennet (Sci Rept C Zool Bot 9(3):1-46, 1931) in the genus Mirostenella but after the examination of the type material, it is proposed to include the species in the recently described Plumarella subgenus, Faxiella (Zapata-Guardiola and López-González in Sci Mar 76:357-380, 2012). In addition, a new species of Plumarella, Plumarella castellviae sp. nov. from SubAntarctic waters is also described and illustrated. The species has similarities to Mirostenella but differs from it in the absence of organic nodes at bifurcation points and the presence of a sympodial branching pattern. Moreover, a new subgenus, Verticillata, is also proposed to include Plumarella species with polyps arranged in whorls around branchlets.

  10. A revision of Ornithogalum subgenus Aspasia section Aspasia, the chincherinchees (Hyacinthaceae

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2007-08-01

    Full Text Available The species of Ornithogalum L. subgenus Aspasia section Aspasia are revised. Section Aspasia is defined by a rosette of  lanceolate to oblong leaves; large, boat-shaped, ± petaloid bracts; moderately-sized white, yellow or orange flowers, sometimes with dark central markings; thin-textured, ellipsoid capsules that are enclosed by and concealed within the persistent, papery perianth; and angular, colliculate to echinulate seeds. Twelve species are recognized in the section, separable into three series based on seed morphology. O. conicum is redefined to exclude specimens from the Eastern Cape, which are recognized as O. synanthifolium, and O. conicum subsp.  strictum is raised to species status as O. strictum. The circumscription of O. duhium is expanded to include O.fimbrimarginatum and O. subcoriaceum, previously distinguished on account of their longer styles.Collections from the Roggeveld Escarpment and Klein Roggeveld that were previously included in O. fimbrimaiginatum are recognized as the new species O. corticatum Mart.-Azarin, on the basis of their unusual, thick, cartilaginous outer tunics and puberulous adaxial leaf surface. O. ceresianum is removed from the synonomy of O. thyrsoides and recognized as a distinct species on account of its extensive glossy black tepal markings, winged inner filaments, and glossy black ovary. The poorly known  O. puberuhim is more ftilly described based on several recent collections, and  O. leeupoortense is neotypified in the absence of any original type material.  O. rupestre and O. multifolium are regarded as colour forms of the same species, for which  O. rupestre is the older name. Similarly, O. roussouwii is a depauperate, pale form of O. maculatum and is thus included in the synonomy of that species. The circumscription of O. pruinosum remains unchanged. The species O. haurii, O. diphyllum and O. sephtonii from the Drakensberg Mountains of Eastern Cape and KwaZulu-Natal are excluded from

  11. Ciscoes (Coregonus, subgenus Leucichthys) of the Laurentian Great Lakes and Lake Nipigon

    Science.gov (United States)

    Eshenroder, Randy L.; Vecsei, Paul; Gorman, Owen T.; Yule, Daniel; Pratt, Thomas C.; Mandrak, Nicholas E.; Bunnell, David B.; Muir, Andrew M.

    2016-01-01

    This study of the ciscoes (Coregonus, subgenus Leucichthys) of the Great Lakes and Lake Nipigon represents a furtherance through 2015 of field research initiated by Walter Koelz in 1917 and continued by Stanford Smith in the mid-1900s—a period spanning nearly a century. Like Koelz’s study, this work contains information on taxonomy, geographical distribution, ecology, and status of species (here considered forms). Of the seven currently recognized forms (C. artedi, C. hoyi, C. johannae, C. kiyi, C. nigripinnis, C. reighardi, and C. zenithicus) described by Koelz as major in his 1929 monograph, two (C. johannae and C. reighardi) are extinct. In addition, C. alpenae, described by Koelz but subsequently synonymized with C. zenithicus, although extinct, is recognized as valid making a total of eight major forms. Six of these forms, all but C. artedi and C. hoyi, have been lost from Lake Michigan, and seven have been lost from Lake Huron, leaving in Lake Huron only C. artedi and an introgressed deepwater form that we term a hybrid swarm. C. artedi appears, like its sister form C. alpenae, to have been lost from Lake Erie. Only C. artedi remains extant in Lake Ontario, its three sister forms (C. hoyi, C. kiyi, and C. reighardi) having disappeared long ago.Lakes Superior and Nipigon have retained their original species flocks consisting of four forms each: C. artedi, C. hoyi, and C. zenithicus in both lakes; C. kiyi in Lake Superior; and C. nigripinnis in Lake Nipigon. Morphological deviations from the morphotypes described by Koelz have been modest in contemporary samples. Overall, C. kiyi and C. artedi were the most morphologically stable forms while C. hoyi, C. nigripinnis, and C. zenithicus were the least stable. Although contemporary populations of C. artedi from Lakes Michigan and Huron are highly diverged from the morphotypes described by Koelz, the contemporary samples were of undescribed deep-bodied forms unlikely to have been sampled by Koelz because of

  12. The current challenges of dourine: difficulties in differentiating Trypanosoma equiperdum within the subgenus Trypanozoon.

    Science.gov (United States)

    Zablotskij, V T; Georgiu, C; de Waal, Th; Clausen, P H; Claes, F; Touratier, L

    2003-12-01

    During its 20th annual meeting in Paris in May 1999, the OIE (World organisation for animal health) Ad Hoc Group on Non-Tsetse Transmitted Animal Trypanosomoses expressed the following concerns about dourine: the discrepancies in some of the results of the complement fixation test (CFT), which is the only international diagnostic test officially recognised by the International Organisation for the Transportation of Equidae; the persistence of suspected cases of dourine in some Asian, European and African countries; the impossibility of differentiating Trypanosoma equiperdum from Trypanosoma evansi and of isolating new strains of T. equiperdum from clinical cases that have appeared in various parts of the world since 1982. In the light of these concerns, it was decided, in agreement with the Directorate of the Federal Veterinary Services of Russia in Moscow, to perform comparative trials on the value of CFT/dourine at the OIE Reference Laboratory for dourine in Moscow (The All-Russian Research Institute of Experimental Veterinary Medicine) using reagents (antigens and sera) from seven countries with extensive experience in the field of dourine diagnosis, namely, South Africa, France, Italy, Germany, Russia, the United States of America and the People's Republic of China. It is thanks to the successful co-operation of these countries that the trials were made possible. Results showed an overall concordance and were submitted for consideration to the OIE Biological Standards Commission, the commission which is in charge of the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals. These trials serve as a starting point for further study, particularly in the following areas: the isolation of new strains of T. equiperdum from clinical dourine cases; the identification of specific markers for T. equiperdum which would make it possible to differentiate it from among the other species within the subgenus Trypanozoon; the experimental infection of horses with

  13. A revision of Ornithogalum subgenus Aspasia section Aspasia, the chincherinchees (Hyacinthaceae

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2007-12-01

    Full Text Available The species of Ornithogalum L. subgenus Aspasia section Aspasia are revised. Section Aspasia is defined by a rosette of  lanceolate to oblong leaves; large, boat-shaped, ± petaloid bracts; moderately-sized white, yellow or orange flowers, sometimes with dark central markings; thin-textured, ellipsoid capsules that are enclosed by and concealed within the persistent, papery perianth; and angular, colliculate to echinulate seeds. Twelve species are recognized in the section, separable into three series based on seed morphology. O. conicum is redefined to exclude specimens from the Eastern Cape, which are recognized as O. synanthifolium, and O. conicum subsp.  strictum is raised to species status as O. strictum. The circumscription of O. duhium is expanded to include O.fimbrimarginatum and O. subcoriaceum, previously distinguished on account of their longer styles.Collections from the Roggeveld Escarpment and Klein Roggeveld that were previously included in O. fimbrimaiginatum are recognized as the new species O. corticatum Mart.-Azarin, on the basis of their unusual, thick, cartilaginous outer tunics and puberulous adaxial leaf surface. O. ceresianum is removed from the synonomy of O. thyrsoides and recognized as a distinct species on account of its extensive glossy black tepal markings, winged inner filaments, and glossy black ovary. The poorly known  O. puberuhim is more ftilly described based on several recent collections, and  O. leeupoortense is neotypified in the absence of any original type material.  O. rupestre and O. multifolium are regarded as colour forms of the same species, for which  O. rupestre is the older name. Similarly, O. roussouwii is a depauperate, pale form of O. maculatum and is thus included in the synonomy of that species. The circumscription of O. pruinosum remains unchanged. The species O. haurii, O. diphyllum and O. sephtonii from the Drakensberg Mountains of Eastern Cape and KwaZulu-Natal are excluded from

  14. Review of Cycadophila Xu, Tang & Skelley (Coleoptera: Erotylidae: Pharaxonothinae) inhabiting Cycas (Cycadaceae) in Asia, with descriptions of a new subgenus and thirteen new species.

    Science.gov (United States)

    Skelley, Paul; Xu, Guang; Tang, William; Lindström, Anders J; Marler, Thomas; Khuraijam, Jibankumar Singh; Singh, Rita; Radha, P; Rich, Stephen

    2017-05-12

    The genus Cycadophila Xu, Tang & Skelley (Coleoptera: Erotylidae: Pharaxonothinae) associated with Cycas L. (Cycadacaeae) in Asia is reviewed. Strobilophila, new subgenus, with five species is described: Cycadophila (Strobilophila) assamensis new species, C. (S.) hiepi new species, C. (S.) kwaiensis new species, C. (S.) tansachai new species and C. (S.) yangi new species, all associated with Cycas. For the nominate subgenus Cycadophila eight new species are described, Cycadophila (Cycadophila) abyssa new species, C. (C.) collina new species,C. (C.) samara new species, C. (C.) convexa new species, C. (C.) cyclochasma new species, C. (C.) eurynota new species, C. (C.) papua new species, and C. (C.) torquata new species and four new generic combinations are proposed: C. (C.) vittata (Arrow) new combination, C. (C.) discimaculata (Mader) new combination, C. (C.) intermedia (Chûjô) new combination, and C. (C.) lata (Grouvelle) new combination. Only the first three listed species of the nominate subgenus have known associations with Cycas. Species are distinguished on the basis of morphology and/or by analysis of 16S rRNA gene sequences. The larva of subgenus Strobilophila is described based on individuals collected together with adults and matched with analysis of 16S rRNA gene sequences. Keys to subgenera and species of known adults and larvae are provided.

  15. Capricious, or tied to history’s apron strings? Floristic regions in north-west European brambles (Rubus subgenus Rubus, Rosaceae)

    NARCIS (Netherlands)

    Haveman, R.; Bijlsma, R.J.; Ronde, de I.; Schaminee, J.H.J.

    2016-01-01

    Aim
    To classify and describe distributional patterns in apomictic Rubus subgenus Rubus in north-west Europe and to characterize the major regions by statistically derived character species.

    Location
    North-western Europe, in particular Ireland, the United Kingdom, the Netherlands,

  16. ITS2 secondary structure improves phylogeny estimation in a radiation of blue butterflies of the subgenus Agrodiaetus (Lepidoptera: Lycaenidae: Polyommatus

    Directory of Open Access Journals (Sweden)

    Wolf Matthias

    2009-12-01

    Full Text Available Abstract Background Current molecular phylogenetic studies of Lepidoptera and most other arthropods are predominantly based on mitochondrial genes and a limited number of nuclear genes. The nuclear genes, however, generally do not provide sufficient information for young radiations. ITS2 , which has proven to be an excellent nuclear marker for similarly aged radiations in other organisms like fungi and plants, is only rarely used for phylogeny estimation in arthropods, although universal primers exist. This is partly due to difficulties in the alignment of ITS2 sequences in more distant taxa. The present study uses ITS2 secondary structure information to elucidate the phylogeny of a species-rich young radiation of arthropods, the butterfly subgenus Agrodiaetus. One aim is to evaluate the efficiency of ITS2 to resolve the phylogeny of the subgenus in comparison with COI , the most important mitochondrial marker in arthropods. Furthermore, we assess the use of compensatory base changes in ITS2 for the delimitation of species and discuss the prospects of ITS2 as a nuclear marker for barcoding studies. Results In the butterfly family Lycaenidae, ITS2 secondary structure enabled us to successfully align sequences of different subtribes in Polyommatini and produce a Profile Neighbour Joining tree of this tribe, the resolution of which is comparable to phylogenetic trees obtained with COI+COII . The subgenus Agrodiaetus comprises 6 major clades which are in agreement with COI analyses. A dispersal-vicariance analysis (DIVA traced the origin of most Agrodiaetus clades to separate biogeographical areas in the region encompassing Eastern Anatolia, Transcaucasia and Iran. Conclusions With the inclusion of secondary structure information, ITS2 appears to be a suitable nuclear marker to infer the phylogeny of young radiations, as well as more distantly related genera within a diverse arthropod family. Its phylogenetic signal is comparable to the

  17. ITS2 secondary structure improves phylogeny estimation in a radiation of blue butterflies of the subgenus Agrodiaetus (Lepidoptera: Lycaenidae: Polyommatus ).

    Science.gov (United States)

    Wiemers, Martin; Keller, Alexander; Wolf, Matthias

    2009-12-26

    Current molecular phylogenetic studies of Lepidoptera and most other arthropods are predominantly based on mitochondrial genes and a limited number of nuclear genes. The nuclear genes, however, generally do not provide sufficient information for young radiations. ITS2 , which has proven to be an excellent nuclear marker for similarly aged radiations in other organisms like fungi and plants, is only rarely used for phylogeny estimation in arthropods, although universal primers exist. This is partly due to difficulties in the alignment of ITS2 sequences in more distant taxa. The present study uses ITS2 secondary structure information to elucidate the phylogeny of a species-rich young radiation of arthropods, the butterfly subgenus Agrodiaetus. One aim is to evaluate the efficiency of ITS2 to resolve the phylogeny of the subgenus in comparison with COI , the most important mitochondrial marker in arthropods. Furthermore, we assess the use of compensatory base changes in ITS2 for the delimitation of species and discuss the prospects of ITS2 as a nuclear marker for barcoding studies. In the butterfly family Lycaenidae, ITS2 secondary structure enabled us to successfully align sequences of different subtribes in Polyommatini and produce a Profile Neighbour Joining tree of this tribe, the resolution of which is comparable to phylogenetic trees obtained with COI+COII . The subgenus Agrodiaetus comprises 6 major clades which are in agreement with COI analyses. A dispersal-vicariance analysis (DIVA) traced the origin of most Agrodiaetus clades to separate biogeographical areas in the region encompassing Eastern Anatolia, Transcaucasia and Iran. With the inclusion of secondary structure information, ITS2 appears to be a suitable nuclear marker to infer the phylogeny of young radiations, as well as more distantly related genera within a diverse arthropod family. Its phylogenetic signal is comparable to the mitochondrial marker COI . Compensatory base changes are very rare

  18. Complete Mitochondrial Genome of Three Bactrocera Fruit Flies of Subgenus Bactrocera (Diptera: Tephritidae and Their Phylogenetic Implications.

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    Hoi-Sen Yong

    Full Text Available Bactrocera latifrons is a serious pest of solanaceous fruits and Bactrocera umbrosa is a pest of Artocarpus fruits, while Bactrocera melastomatos infests the fruit of Melastomataceae. They are members of the subgenus Bactrocera. We report here the complete mitochondrial genome of these fruit flies determined by next-generation sequencing and their phylogeny with other taxa of the subgenus Bactrocera. The whole mitogenomes of these three species possessed 37 genes namely, 13 protein-coding genes (PCGs, 2 rRNA and 22 tRNA genes. The mitogenome of B. latifrons (15,977 bp was longer than those of B. melastomatos (15,954 bp and B. umbrosa (15,898 bp. This difference can be attributed to the size of the intergenic spacers (283 bp in B. latifrons, 261 bp in B. melastomatos, and 211 bp in B. umbrosa. Most of the PCGs in the three species have an identical start codon, except for atp8 (adenosine triphosphate synthase protein 8, which had an ATG instead of GTG in B. umbrosa, whilst the nad3 (NADH dehydrogenase subunit 3 and nad6 (NADH dehydrogenase subunit 6 genes were characterized by an ATC instead of ATT in B. melastomatos. The three species had identical stop codon for the respective PCGs. In B. latifrons and B. melastomatos, the TΨC (thymidine-pseudouridine-cytidine-loop was absent in trnF (phenylalanine and DHU (dihydrouracil-loop was absent in trnS1 (serine S1. In B. umbrosa, trnN (asparagine, trnC (cysteine and trnF lacked the TψC-loop, while trnS1 lacked the DHU-stem. Molecular phylogeny based on 13 PCGs was in general concordant with 15 mitochondrial genes (13 PCGs and 2 rRNA genes, with B. latifrons and B. umbrosa forming a sister group basal to the other species of the subgenus Bactrocera which was monophyletic. The whole mitogenomes will serve as a useful dataset for studying the genetics, systematics and phylogenetic relationships of the many species of Bactrocera genus in particular, and tephritid fruit flies in general.

  19. Complete Mitochondrial Genome of Three Bactrocera Fruit Flies of Subgenus Bactrocera (Diptera: Tephritidae) and Their Phylogenetic Implications.

    Science.gov (United States)

    Yong, Hoi-Sen; Song, Sze-Looi; Lim, Phaik-Eem; Eamsobhana, Praphathip; Suana, I Wayan

    2016-01-01

    Bactrocera latifrons is a serious pest of solanaceous fruits and Bactrocera umbrosa is a pest of Artocarpus fruits, while Bactrocera melastomatos infests the fruit of Melastomataceae. They are members of the subgenus Bactrocera. We report here the complete mitochondrial genome of these fruit flies determined by next-generation sequencing and their phylogeny with other taxa of the subgenus Bactrocera. The whole mitogenomes of these three species possessed 37 genes namely, 13 protein-coding genes (PCGs), 2 rRNA and 22 tRNA genes. The mitogenome of B. latifrons (15,977 bp) was longer than those of B. melastomatos (15,954 bp) and B. umbrosa (15,898 bp). This difference can be attributed to the size of the intergenic spacers (283 bp in B. latifrons, 261 bp in B. melastomatos, and 211 bp in B. umbrosa). Most of the PCGs in the three species have an identical start codon, except for atp8 (adenosine triphosphate synthase protein 8), which had an ATG instead of GTG in B. umbrosa, whilst the nad3 (NADH dehydrogenase subunit 3) and nad6 (NADH dehydrogenase subunit 6) genes were characterized by an ATC instead of ATT in B. melastomatos. The three species had identical stop codon for the respective PCGs. In B. latifrons and B. melastomatos, the TΨC (thymidine-pseudouridine-cytidine)-loop was absent in trnF (phenylalanine) and DHU (dihydrouracil)-loop was absent in trnS1 (serine S1). In B. umbrosa, trnN (asparagine), trnC (cysteine) and trnF lacked the TψC-loop, while trnS1 lacked the DHU-stem. Molecular phylogeny based on 13 PCGs was in general concordant with 15 mitochondrial genes (13 PCGs and 2 rRNA genes), with B. latifrons and B. umbrosa forming a sister group basal to the other species of the subgenus Bactrocera which was monophyletic. The whole mitogenomes will serve as a useful dataset for studying the genetics, systematics and phylogenetic relationships of the many species of Bactrocera genus in particular, and tephritid fruit flies in general.

  20. Studies in the genus Riccia (Marchantiales from southern Africa. 21. R. stricta, R. purpurascens and R. fluitans, subgenus Ricciella

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    S. M. Perold

    1990-12-01

    Full Text Available Lindenberg (1836 regarded and published Riccia stricta as a variety of R. fluitans L. Subsequently, Nees (1838 and Gottsche et al. (1846 also treated it as a variety. Trevisan (1877 raised its rank and published the epithet,  Ricciella stricta Trevis.Ricciella is, however, regarded as a subgenus; Ricciella stricta is, therefore, transferred to Riccia stricta (Lindenb. Perold.It is described in detail and illustrated.  R. purpurascens Lehm. & Lindenb., a related endemic species, is also more fully described than before and illustrated.  R. fluitans L. apparently does not occur naturally in southern Africa. As far as is known, a single local specimen of it was introduced.

  1. Two new species and a new subgenus of toothed Brachyhypopomus electric knifefishes (Gymnotiformes, Hypopomidae) from the central Amazon and considerations pertaining to the evolution of a monophasic electric organ discharge

    OpenAIRE

    Sullivan,John P.; Zuanon,Jansen; Cox Fernandes,Cristina

    2013-01-01

    We describe two new, closely related species of toothed Brachyhypopomus (Hypopomidae: Gymnotiformes: Teleostei) from the central Amazon basin and create a new subgenus for them. Odontohypopomus, new subgenus of Brachyhypopomus, is diagnosed by (1) small teeth present on premaxillae; (2) medialmost two branchiostegal rays thin with blades oriented more vertically than remaining three rays; (3) background color in life (and to lesser extent in preservation) distinctly yellowish with head and si...

  2. Taxonomic review on the subgenus Tripodura Townes (Diptera: Chironomidae: Polypedilum) from China with eleven new species and a supplementary world checklist.

    Science.gov (United States)

    Zhang, Ruilei; Song, Chao; Qi, Xin; Wang, Xinhua

    2016-07-05

    The subgenus Tripodura Townes of Polypedilum Kieffer from China including 26 species is reviewed. Eleven new species, named P. (T.) absensilobum Zhang & Wang sp. n., P. (T.) apiculusetosum Zhang & Wang sp. n., P. (T.) arcuatum Zhang & Wang sp. n., P. (T.) bilamella Zhang & Wang sp. n., P. (T.) conghuaense Zhang & Wang sp. n., P. (T.) dengae Zhang & Wang sp. n., P. (T.) mengmanense Zhang & Wang sp. n., P. (T.) napahaiense Zhang & Wang sp. n., P. (T.) parallelum Zhang & Wang sp. n., P. (T.) pollicium Zhang & Wang sp. n. and P. (T.) trapezium Zhang & Wang sp. n. are described and illustrated based on male imagines. Three species, P. (T.) quadriguttatum Kieffer, P. (T.) unifascia (Tokunaga) and P. (T.) udominutum Niitsuma are firstly recorded in China. A key to known male imagines of Chinese species and an updated world checklist of subgenus Tripodura are presented.

  3. On the colour types in Lycodes nakamurae (Tanaka, 1914) and species composition of the subgenus Furcimanus (Perciformes: Zoarcidae: Lycodes) in the sea of Japan.

    Science.gov (United States)

    Saveliev, Pavel A; Balanov, Andrey A; Kukhlevskii, Andrey D

    2014-05-30

    Two colour types were revealed in a zoarcid fish of the subgenus Furcimanus, genus Lycodes, in the Sea of Japan. A comparison of morphometric, meristic and genetic characters in dark coloured and light coloured individuals suggests that the two colour morphs represent a single species, determined to be Lycodes nakamurae (Tanaka, 1914). Variability in colouration within L. nakamurae and a lack of morphological or molecular characters distinguishing L. nakamurae from L. nishimurai Shinohara & Shirai, 2005 suggest that the latter should be considered a synonym of L. nakamurae (Tanaka, 1914). A record of L. pectoralis in the waters of the Republic of Korea is regarded as a misidentification. Thus, we conclude that only one species of the Lycodes subgenus Furcimanus, L. nakamurae, with dark and light colour morphs as well as specimens of intermediate colouration, inhabits the Sea of Japan.

  4. A taxonomic review of Korean species of the Atheta Thomson subgenus Microdota Mulsant & Rey, with descriptions of two new species (Coleoptera, Staphylinidae, Aleocharinae

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    Seung-Gyu Lee

    2015-05-01

    Full Text Available A taxonomic review of the Atheta Thomson subgenus Microdota Mulsant & Rey in Korea is presented. The subgenus is represented in Korea by 15 species including two new species, Atheta (Microdota jangtaesanensis Lee & Ahn, sp. n. and A. (M. pasniki Lee & Ahn, sp. n. Four species [A. (M. kawachiensis Cameron, A. (M. muris Sawada, A. (M. spiniventris Bernhauer, and A. (M. spinula (Sawada] are new to the Korean Peninsula and two [A. (M. formicetorum Bernhauer and A. (M. subcrenulata Bernhauer] to South Korea. Two other species [A. (M. kobensis Cameron and A. (M. scrobicollis (Kraatz] previously recorded in North Korea had been identified incorrectly. A key, descriptions, habitus photographs and illustrations of the diagnostic features are provided. Species distributions and diversity in East Asia are discussed.

  5. The Mosquitoes of the Subgenus Culex in Southwestern Asia and Egypt (Diptera: Culicidae) (Contributions of the American Entomological Institute. Volume 24, Number 1, 1988)

    Science.gov (United States)

    1988-01-01

    data: “Type // Entebbe / Dr. Row // Culex / quasigelidus / (Type) Theobald // Entebbe. / bred from / larvae. / Sep . 20. 02”; left wing mounted on...Bigot, J.M.F. 1857. Dipteros, pp. 328-349. In: R. de la Sagra, Historia fisica, politica y natural de la lsla de Cuba. Vol. 7. Paris. 1859. Dipteres de...Naturaleza Mexico 7: 203-213. Harbach: Subgenus Culex in Southwestern Asia 135 Say, T. 1823. Descriptions of dipterous insects of the United States

  6. Rhynchelmis subgenus Sutroa Eisen new rank, with two new species from western North America (Annelida, Clitellata, Lumbriculidae).

    Science.gov (United States)

    Fend, Steven V; Carter, James L

    2014-01-31

    The lumbriculid Rhynchelmis subgenus Sutroa Eisen, 1888 new rank is defined for a group of Nearctic species having multiple diverticula originating at the spermathecal ducts and eversible penial bulbs. Characters are confirmed in specimens of the type species, Rhynchelmis (Sutroa) rostrata (Eisen, 1888), collected from the type locality. Rhynchelmis (Sutroa) klamathensis Fend n. sp. is described from open water benthic habitats in Upper Klamath Lake, Oregon, USA. It resembles other R. (Sutroa) species in the paired spermathecal diverticula, the spermathecal and penial bulbs, the histological structure of the atria, the nonfunctional anterior male funnels, and the arrangement of blood vessels. Rhynchelmis klamathensis differs from all Nearctic Rhynchelmis in lacking a filiform proboscis. The combination of large body size, the elongate spermathecal ducts with paired and usually unbranched diverticula, the highly contorted atria, and the complex male pores with conical penes also distinguish typical R. klamathensis from other Rhynchelmis species. Smaller specimens with otherwise similar morphology, from the Sacramento River Delta, California, are also assigned to this species. Rhynchelmis (Sutroa) diespluviae Fend n. sp. is described from several stream sites, mostly in northern Idaho, USA. Rhynchelmis diespluviae differs from closely related species in morphology of the conical penes, and in the structure and anterolateral position of the paired spermathecae.

  7. Species delimitation of three species within the Russula subgenus Compacta in Korea: R. eccentrica, R. nigricans, and R. subnigricans.

    Science.gov (United States)

    Park, Myung Soo; Lee, Hyun; Oh, Seung-Yoon; Jung, Paul Eunil; Seok, Soon Ja; Fong, Jonathan J; Lim, Young Woon

    2014-08-01

    Distinguishing individual Russula species can be very difficult due to extensive phenotypic plasticity and obscure morphological and anatomical discontinuities. In this study, we use the internal transcribed spacer (ITS) and 28S nuclear ribosomal large subunit (LSU) markers to identify and study the genetic diversity of species in the Russula subgenus Compacta in Korea. We focus on two morphologically similar species that are often misidentified for each other: R. nigricans and R. subnigricans. Based on molecular phylogenetic analyses, we identify three subgroups of R. nigricans, with two from Asia and one from Europe/North America. Surprisingly, we find Korean R. subnigricans are more closely related to R. eccentrica from North America than the type specimen of R. subnigricans from Japan. These molecular data, along with habitat data, reveal that Korean R. subnigricans had previously been misclassified and should now be recognized as R. eccentrica. Both ITS and LSU exhibit high interspecific and low intraspecific variation for R. eccentrica, R. nigricans, and R. subnigricans. These markers provide enough resolutional power to differentiate these species and uncover phylogeographic structure, and will be powerful tools for future ecological studies of Russula.

  8. Phylogeny and biogeography of pacific Rubus subgenus Idaeobatus (Rosaceae) species: Investigating the origin of the endemic Hawaiian raspberry R. macraei

    Science.gov (United States)

    Morden, C.W.; Gardner, D.E.; Weniger, D.A.

    2003-01-01

    The endemic Hawaiian raspberries Rubus hawaiensis and R. macraei (both subgenus Idaeobatus) had been thought to be closely related species until recent molecular studies demonstrated otherwise. These studies suggest that they are the products of separate colonizations to the Hawaiian Islands. Affinities of R. hawaiensis to R. spectabilis of western North America were clearly confirmed. However, no clear relation to R. macraei has been published. This study was initiated to examine species of subg. Idaeobatus from the surrounding Pacific region as well as species from other subgenera to better evaluate biogeographic and phylogenetic affinities of R. macraei by means of chromosome analysis and molecular data using the chloroplast gene ndbF. Results show that R. macraei clusters in a clade with species of blackberries, subg. Rubus, and of these it is most closely linked to R. ursinus. Chromosomally, R. macraei is 2n = 6x = 42, a number that would be a new report for subg. Idaeobatus. However, polyploidy is common in subg. Rubus. Analyses indicate that R. macraei and R. hawaiensis are derived from separate colonizations from North America and that similarities between them are due to convergent evolution in the Hawaiian environment.

  9. A new extinct dwarfed buffalo from Sulawesi and the evolution of the subgenus Anoa: An interdisciplinary perspective

    Science.gov (United States)

    Rozzi, Roberto

    2017-02-01

    The fossil and extant faunas of Sulawesi, the largest island within the Wallacea biogeographic region, exhibit a high degree of endemism. The lowland anoa Bubalus depressicornis and the mountain anoa Bubalus quarlesi, two closely-related dwarfed buffaloes, are among the most peculiar endemic mammals of the region. Here, I describe a new species, Bubalus grovesi, from the Late Pleistocene/Holocene of South Sulawesi and I give a revised diagnosis of Anoa. Bubalus grovesi sp. nov. differs from all previously described Bubalus in both the size and proportions of the skeleton and in possessing a unique combination of discrete character states. Body mass estimates suggest an average mass of 117 kg for Bubalus grovesi sp. nov. and a body size reduction of about 90% with respect to a typical water buffalo. A comprehensive overview of body mass estimates of dwarfed buffaloes and differences in their dental and postcranial features is included. Finally, new evidence on the taxonomy and island dwarfing of the anoas and available data from different disciplines are used to discuss the timing and mode of their evolution. The representatives of the subgenus Anoa would be dwarfed forms of the Asian water buffalo that arose following dispersal to Sulawesi during the Middle/Late Pleistocene.

  10. A revision of the species of the pseudoscorpion subgenus Chthonius (Ephippiochthonius) (Arachnida, Pseudoscorpiones, Chthoniidae) from Italy and neighbouring areas.

    Science.gov (United States)

    Gardini, Giulio

    2013-01-01

    A taxonomic revision and a key to the species of the subgenus Chthonius (Ephippiochthonius) Beier, 1930 from Italy, Corsica and the Swiss Canton of Ticino are provided. The species are arranged in two species-groups (tetrachelatus group and fuscimanus group) on the basis of the shape of pedipalpal hand and of the type of dentition of the fixed and movable chelal fingers. The following new species are described: i) in the tetrachelatus group: Chthonius (E.) altamurae n. sp. (♀, loc. typ.: Apulia, Bari Prov., Altamura, Grotta Lamalunga 1295 Pu/BA), C. (E.) elymus n. sp. (♂, loc. typ.: Sicily, Trapani Prov., Custonaci, Abisso del Purgatorio 8064 Si/TP), Chthonius (E.) messapicus n. sp. (♂, loc. typ.: Apulia, Brindisi Prov., San Pietro Vernotico, Cerano); ii) in the fuscimanus group: C. (E.) aeneae n. sp. (♂♀, loc. typ.: Liguria, Genoa Prov., Sestri Levante, Punta Manara), C. (E.) etruscus n. sp. (♂♀, loc. typ.: Tuscany, Grosseto Prov., Semproniano, Grotta di Montecchio 254 To/GR), C. (E.) gallii n. sp. (♂♀, loc. typ.: Liguria, Savona Prov., Bergeggi), C. (E.) intemelius n. sp. (♂♀, loc. typ.: Liguria, Imperia Prov., Apricale, Mt Cianela), C. (E.) latellai n. sp. (♂♀, loc. typ.: Latium, Latina Prov., Bassiano, Grotta di Fiume Coperto 1361 La/LT), C. (E.) ligur n. sp. (♂♀, loc. typ.: Liguria, Imperia Prov., near Baiardo), C. (E.) magrinii n. sp. (♂, loc. typ.: Latium, Frosinone Prov., San Giovanni Incarico, Grotta sulla strada per il Santuario della Madonna della Guardia n. c. La/FR), C. (E.) monguzzii n. sp. (♂♀, loc. typ.: Lombardia, Brescia Prov., Sulzano, Oricina de la Pofa del Giardì 438 Lo/BS), C. (E.) sulphureus n. sp. (♂♀, loc. typ.: Marche, Ancona Prov., Genga, Grotta di Frasassi 1 Ma/AN), C. (E.) tyrrhenicus n. sp. (♂♀, loc. typ.: Liguria, Genoa Prov., Genoa, Quinto al Mare, Mt Moro). The following new synonymies are proposed: Chthonius (E.) bauneensis Callaini, 1983 is a junior subjective synonym of C. (E

  11. Phylogeny of xerophilic aspergilli (subgenus Aspergillus ) and taxonomic revision of section Restricti

    DEFF Research Database (Denmark)

    Sklenář, F.; Jurjević, Ž.; Zalar, P.

    2017-01-01

    a multidisciplinary approach for definition of species boundaries in sect. Restricti. The monophyly of sections Aspergillus and Restricti was tested on a set of 102 isolates comprising all currently accepted species and was strongly supported by Maximum likelihood (ML) and Bayesian inferrence (BI) analysis based on β......-tubulin (benA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) loci. More than 300 strains belonging to sect. Restricti from various isolation sources and four continents were characterized by DNA sequencing, and 193 isolates were selected for phylogenetic analyses and phenotypic studies......Cl concentration from 0 to 25 %) and analysis of morphology including scanning electron microscopy. The micromorphology of conidial heads, vesicle dimensions, temperature profiles and growth parameters in osmotic gradient were useful criteria for species identification. The vast majority of species in sect...

  12. Identification of Sand flies of the Subgenus Larroussius based on Molecular and Morphological Characters in North Western Iran

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    A Absavaran

    2009-12-01

    Full Text Available Background: The adult female sand flies (Diptera: Psychodidae of the subgenus Larroussius are important vectors of Leishmania infantum (Kinetoplastida: Tripanosomatidae in Meshkinshahr district, Northwest of Iran. Four Phle­boto­mus (Larroussius species are present in this area, i.e. Phlebotomus (Larroussius kandelakii, P. (La. major, P. (La. perfiliewi and P. (La. tobbi. The objective of the present study was to identify and distinguish the females of P. per­filiewi, P. major and P. tobbi, in this district.Methods: Adult sand flies were collected with sticky papers, CDC light traps, and aspirator in 2006. Individual sand flies of this four species from thirty different locations were characterized morphologically and by comparative DNA se­quences analyses of a fragment of mitochondrial gene Cytochrome b (Cyt b and nuclear gene Elongation Factor 1- al­pha (EF-1α. PCR amplification was carried out for all three species P. major, P. perfiliewi and P. tobbi in the sub­ge­nus Larroussius.Results: Phylogenetic analyses of P. major populations in this study displayed two different populations and genetic di­ver­sity. Spermathecal segment number, pharyngeal armature and other morphological characters of these three spe­cies were examined and found to present consistent interspecific differences.Conclusion: According to our findings, the phylogeny of Cyt b and EF-1α haplotypes confirms the relationships be­tween P. major, P. tobbi and P. perfiliewi as already defined by their morphological similarities.

  13. Application of multiple DNA fingerprinting techniques to study the genetic relationships among three members of the subgenus Trypanozoon (Protozoa: Trypanosomatidae).

    Science.gov (United States)

    Li, Feng-Jun; Gasser, Robin B; Zheng, Jia-Yu; Claes, Filip; Zhu, Xing-Quan; Lun, Zhao-Rong

    2005-12-01

    Three different DNA fingerprinting techniques, the mobile genetic element (MGE)-PCR, simple sequence repeat (SSR)-PCR and random amplified polymorphic DNA (RAPD)-PCR, were used to define a large set of genetic markers to study genetic similarity within and among Trypanosoma brucei, Trypanosoma equiperdum and Trypanosoma evansi strains (n=18) from China, Africa and South America and to investigate their genetic relationships. Using the three fingerprinting techniques, >890 bands (ranging in size from 0.2 to 2kb) were defined for all 18 strains of Trypanosoma. Within each of the strains, 39-59 bands were defined. The similarity coefficients between strains ranged from approximately 41 to 94%, with a mean of 65%. There was more genetic similarity among strains within T. evansi (mean of approximately 79%) compared with T. equiperdum ( approximately 65%) and T. brucei ( approximately 59%). The similarity coefficient data were used to construct the dendrogram, which revealed that (irrespective of species) the majority of strains from China and South America grouped together to the exclusion of those from Africa. The exceptions were a T. brucei strain from Africa and a T. equiperdum strain of unknown origin. Hence, employing data sets generated using the three different fingerprinting methods, it was not possible to unequivocally distinguish among T. brucei, T. evansi and T. equiperdum, although there was a tendency for T. evansi strains to group together to the exclusion of T. brucei. The findings provide support for the hypothesis that T. evansi originated from a mutated form of T. equiperdum and stimulate further investigations of the genetic make-up and evolution of members of the subgenus Trypanozoon.

  14. New malaria parasites of the subgenus Novyella in African rainforest birds, with remarks on their high prevalence, classification and diagnostics.

    Science.gov (United States)

    Valkiūnas, Gediminas; Iezhova, Tatjana A; Loiseau, Claire; Smith, Thomas B; Sehgal, Ravinder N M

    2009-04-01

    Blood samples from 655 passerine birds were collected in rainforests of Ghana and Cameroon and examined both by microscopy and polymerase chain reaction (PCR)-based techniques. The overall prevalence of Plasmodium spp. was 46.6%, as determined by combining the results of both these diagnostic methods. In comparison to PCR-based diagnostics, microscopic examination of blood films was more sensitive in determining simultaneous infection of Plasmodium spp., but both detection methods showed similar trends of prevalence of malaria parasites in the same study sites. Plasmodium (Novyella) lucens n. sp., Plasmodium (Novyella) multivacuolaris n. sp. and Plasmodium (Novyella) parahexamerium n. sp. were found in the olive sunbird Cyanomitra olivacea (Nectariniidae), yellow-whiskered greenbul Andropadus latirostris (Picnonotidae), and white-tailed alethe Alethe diademata (Turdidae), respectively. These parasites are described based on the morphology of their blood stages and a segment of the mitochondrial cytochrome b (cyt b) gene, which can be used for molecular identification and diagnosis of these species. Illustrations of blood stages of new species are given, and phylogenetic analysis identifies DNA lineages closely related to these parasites. Malaria parasites of the subgenus Novyella with small erythrocytic meronts clearly predominate in African passerines. It is probable that the development of such meronts is a characteristic feature of evolution of Plasmodium spp. in African rainforest birds. Subgeneric taxonomy of avian Plasmodium spp. is discussed based on the recent molecular phylogenies of these parasites. It is concluded that a multi-genome phylogeny is needed before revising the current subgeneric classification of Plasmodium. We supported a hypothesis by Hellgren, Krizanauskiene, Valkiūnas, Bensch (J Parasitol 93:889-896, 2007), according to which, haemosporidian species with a genetic differentiation of over 5% in mitochondrial cyt b gene are expected to be

  15. A pilot study applying the plant Anchored Hybrid Enrichment method to New World sages (Salvia subgenus Calosphace; Lamiaceae).

    Science.gov (United States)

    Fragoso-Martínez, Itzi; Salazar, Gerardo A; Martínez-Gordillo, Martha; Magallón, Susana; Sánchez-Reyes, Luna; Moriarty Lemmon, Emily; Lemmon, Alan R; Sazatornil, Federico; Granados Mendoza, Carolina

    2017-12-01

    We conducted a pilot study using Anchored Hybrid Enrichment to resolve relationships among a mostly Neotropical sage lineage that may have undergone a recent evolutionary radiation. Conventional markers (ITS, trnL-trnF and trnH-psbA) have not been able to resolve the relationships among species nor within portions of the backbone of the lineage. We sampled 12 representative species of subgenus Calosphace and included one species of Salvia's s.l. closest relative, Lepechinia, as outgroup. Hybrid enrichment and sequencing were successful, yielding 448 alignments of individual loci with an average length of 704bp. The performance of the phylogenomic data in phylogenetic reconstruction was superior to that of conventional markers, increasing both support and resolution. Because the captured loci vary in the amount of net phylogenetic informativeness at different phylogenetic depths, these data are promising in phylogenetic reconstruction of this group and likely other lineages within Lamiales. However, special attention should be placed on the amount of phylogenetic noise that the data could potentially contain. A prior exploration step using phylogenetic informativeness profiles to detect loci with sites with disproportionately high substitution rates (showing "phantom" spikes) and, if required, the ensuing filtering of the problematic data is recommended. In our dataset, filtering resulted in increased support and resolution for the shallow nodes in maximum likelihood phylogenetic trees resulting from concatenated analyses of all the loci. Additionally, it is expected that an increase in sampling (loci and taxa) will aid in resolving weakly supported, short deep internal branches. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Carabus of Subgenus Cathoplius C.G. Thomson, 1875, with description of their life-way, life-cycle and pre-imaginal morphology (Coleoptera: Carabidae) .

    Science.gov (United States)

    Busato, Enrico; Ghittino, Claudio; Casale, Achille

    2014-09-25

    According to current taxonomy, Subgenus Cathoplius C.G. Thomson, 1875, within the Genus Carabus Linnaeus, 1758 (in the broad sense), includes two species: C. (Cathoplius) asperatus (Dejean, 1826), monotypic with a northern distribution, and the southern polytypic substitutive species C. (Cathoplius) stenocephalus Lucas, 1866. The authors describe the life-way, life-cycle and pre-imaginal characters of the taxa currently ascribed to Subgenus Cathoplius, with details never provided before. Cathoplius are ground beetles adapted to live in arid environments and extreme habitats such as sub-desert areas. All of them are strictly helicophagous, both during the pre-imaginal stages and as adults, and are localized in a narrow fringe along the Atlantic coast of northwestern Africa. Several data and observations on the eco-ethology of the different taxa, obtained both in field and in laboratory, are reported. The life-cycle of Cathoplius belongs to the winter breeding type, with an extremely high fecundity rate concentrated in a very short period of time, that has no similarity to any other Carabus species. Eggs, larvae and pupae of the different species and subspecies of Cathoplius are described and illustrated. Larval characters clearly place Subgenus Cathoplius into the lineage of Neocarabi, confirming it as a monophyletic and homogeneous assemblage. Hybridization trials between some taxa led to a reduced survival rate of the progeny, thus confirming their specific or subspecific differentiation as proposed by classical taxonomy. Furthermore, hybridization results suggest that C. (Cathoplius) stenocephalus aliai could be considered as a distinct species. Notes about the origin, biogeography and phylogeny of Cathoplius are also provided.

  17. Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae Are a Rich Source of Flavonoids and Related Non-Volatile Constituents.

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    Jason Q D Goodger

    Full Text Available The sub-dermal secretory cavities (glands embedded within the leaves of Eucalyptus (Myrtaceae were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the

  18. Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents.

    Science.gov (United States)

    Goodger, Jason Q D; Seneratne, Samiddhi L; Nicolle, Dean; Woodrow, Ian E

    2016-01-01

    The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone) was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone) was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the foliar glands

  19. Foliar Essential Oil Glands of Eucalyptus Subgenus Eucalyptus (Myrtaceae) Are a Rich Source of Flavonoids and Related Non-Volatile Constituents

    Science.gov (United States)

    Nicolle, Dean; Woodrow, Ian E.

    2016-01-01

    The sub-dermal secretory cavities (glands) embedded within the leaves of Eucalyptus (Myrtaceae) were once thought to be the exclusive repositories of monoterpene and sesquiterpene oils. Recent research has debunked this theory and shown that abundant non-volatile compounds also occur within foliar glands. In particular, glands of four species in subgenus Eucalyptus contain the biologically active flavanone pinocembrin. Pinocembrin shows great promise as a pharmaceutical and is predominantly plant-sourced, so Eucalyptus could be a potential commercial source of such compounds. To explore this we quantified and assessed the purity of pinocembrin in glands of 11 species of E. subg. Eucalyptus using Electro-Spray Ionisation Liquid Chromatography Mass Spectrometry of acetonitrile extracts and Gas Chromatography Mass Spectrometry analyses of hexane extracts of isolated glands which were free from other leaf tissues. Our results showed that the glands of subgenus Eucalyptus contain numerous flavanones that are structurally related to pinocembrin and often present in much greater abundance. The maximum concentration of pinocembrin was 2 mg g-1 dry leaf found in E. stellulata, whereas that of dimethylpinocembrin (5,7-dimethoxyflavanone) was 10 mg g-1 in E. oreades and that of pinostrobin (5-hydroxy-7-methoxyflavanone) was 12 mg g-1 in E. nitida. We also found that the flavanones are exclusively located within the foliar glands rather than distributed throughout leaf tissues. The flavanones differ from the non-methylated pinocembrin in the degree and positions of methylation. This finding is particularly important given the attractiveness of methylated flavonoids as pharmaceuticals and therapeutics. Another important finding was that glands of some members of the subgenus also contain flavanone O-glucosides and flavanone-β-triketone conjugates. In addition, glands contain free β-triketones, β-triketone heterodimers and chromone C-glucosides. Therefore, the foliar glands

  20. The Complete Chloroplast Genome Sequences of Aconitum pseudolaeve and Aconitum longecassidatum, and Development of Molecular Markers for Distinguishing Species in the Aconitum Subgenus Lycoctonum

    Directory of Open Access Journals (Sweden)

    Inkyu Park

    2017-11-01

    Full Text Available Aconitum pseudolaeve Nakai and Aconitum longecassidatum Nakai, which belong to the Aconitum subgenus Lycoctonum, are distributed in East Asia and Korea. Aconitum species are used in herbal medicine and contain highly toxic components, including aconitine. A. pseudolaeve, an endemic species of Korea, is a commercially valuable material that has been used in the manufacture of cosmetics and perfumes. Although Aconitum species are important plant resources, they have not been extensively studied, and genomic information is limited. Within the subgenus Lycoctonum, which includes A. pseudolaeve and A. longecassidatum, a complete chloroplast (CP genome is available for only one species, Aconitum barbatum Patrin ex Pers. Therefore, we sequenced the complete CP genomes of two Aconitum species, A. pseudolaeve and A. longecassidatum, which are 155,628 and 155,524 bp in length, respectively. Both genomes have a quadripartite structure consisting of a pair of inverted repeated regions (51,854 and 52,108 bp, respectively separated by large single-copy (86,683 and 86,466 bp and small single-copy (17,091 and 16,950 bp regions similar to those in other Aconitum CP genomes. Both CP genomes consist of 112 unique genes, 78 protein-coding genes, 4 ribosomal RNA (rRNA genes, and 30 transfer RNA (tRNA genes. We identified 268 and 277 simple sequence repeats (SSRs in A. pseudolaeve and A. longecassidatum, respectively. We also identified potential 36 species-specific SSRs, 53 indels, and 62 single-nucleotide polymorphisms (SNPs between the two CP genomes. Furthermore, a comparison of the three Aconitum CP genomes from the subgenus Lycoctonum revealed highly divergent regions, including trnK-trnQ, ycf1-ndhF, and ycf4-cemA. Based on this finding, we developed indel markers using indel sequences in trnK-trnQ and ycf1-ndhF. A. pseudolaeve, A. longecassidatum, and A. barbatum could be clearly distinguished using the novel indel markers AcoTT (Aconitum trnK-trnQ and Aco

  1. The Complete Chloroplast Genome Sequences of Aconitum pseudolaeve and Aconitum longecassidatum, and Development of Molecular Markers for Distinguishing Species in the Aconitum Subgenus Lycoctonum.

    Science.gov (United States)

    Park, Inkyu; Yang, Sungyu; Choi, Goya; Kim, Wook Jin; Moon, Byeong Cheol

    2017-11-21

    Aconitum pseudolaeve Nakai and Aconitum longecassidatum Nakai, which belong to the Aconitum subgenus Lycoctonum, are distributed in East Asia and Korea. Aconitum species are used in herbal medicine and contain highly toxic components, including aconitine. A. pseudolaeve, an endemic species of Korea, is a commercially valuable material that has been used in the manufacture of cosmetics and perfumes. Although Aconitum species are important plant resources, they have not been extensively studied, and genomic information is limited. Within the subgenus Lycoctonum, which includes A. pseudolaeve and A. longecassidatum, a complete chloroplast (CP) genome is available for only one species, Aconitum barbatum Patrin ex Pers. Therefore, we sequenced the complete CP genomes of two Aconitum species, A. pseudolaeve and A. longecassidatum, which are 155,628 and 155,524 bp in length, respectively. Both genomes have a quadripartite structure consisting of a pair of inverted repeated regions (51,854 and 52,108 bp, respectively) separated by large single-copy (86,683 and 86,466 bp) and small single-copy (17,091 and 16,950 bp) regions similar to those in other Aconitum CP genomes. Both CP genomes consist of 112 unique genes, 78 protein-coding genes, 4 ribosomal RNA (rRNA) genes, and 30 transfer RNA (tRNA) genes. We identified 268 and 277 simple sequence repeats (SSRs) in A. pseudolaeve and A. longecassidatum, respectively. We also identified potential 36 species-specific SSRs, 53 indels, and 62 single-nucleotide polymorphisms (SNPs) between the two CP genomes. Furthermore, a comparison of the three Aconitum CP genomes from the subgenus Lycoctonum revealed highly divergent regions, including trnK-trnQ, ycf1-ndhF, and ycf4-cemA. Based on this finding, we developed indel markers using indel sequences in trnK-trnQ and ycf1-ndhF. A. pseudolaeve, A. longecassidatum, and A. barbatum could be clearly distinguished using the novel indel markers AcoTT (Aconitum trnK-trnQ) and AcoYN (Aconitum

  2. Badister Clairville, 1806: A new species and new continental record for the nominate subgenus in Amazonian Perú (Coleoptera, Carabidae, Licinini

    Directory of Open Access Journals (Sweden)

    Terry Erwin

    2011-11-01

    Full Text Available Badister (Badister amazonus sp. n. is described from Perú, Loreto, 1.0 km SW Boca del Rio Samiria, Vigilante Post 1, 130m, “04°40.5`S, 074°18.9`W" its type locality. It is known also from two other localities in Loreto Department, Perú, in both the Varzea and Igapó river systems. This new species is sufficiently different that a new informal higher taxon, the amazonus species complex, is recognized. An updated key to the Western Hemisphere species of subgenus Badister is provided.

  3. Pollen morphology of Quercus (subgenus Quercus, section Quercus in Iran and its systematic implication

    Directory of Open Access Journals (Sweden)

    Parisa Panahi

    2012-03-01

    Full Text Available For the first time, pollen morphology of 9 (4 spp. and 5 subspp. taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for Quercus section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within Quercus section in Iran.

  4. Plastid genome evolution across the genus Cuscuta (Convolvulaceae): two clades within subgenus Grammica exhibit extensive gene loss.

    Science.gov (United States)

    Braukmann, Thomas; Kuzmina, Maria; Stefanovic, Sasa

    2013-02-01

    The genus Cuscuta (Convolvulaceae, the morning glory family) is one of the most intensely studied lineages of parasitic plants. Whole plastome sequencing of four Cuscuta species has demonstrated changes to both plastid gene content and structure. The presence of photosynthetic genes under purifying selection indicates that Cuscuta is cryptically photosynthetic. However, the tempo and mode of plastid genome evolution across the diversity of this group (~200 species) remain largely unknown. A comparative investigation of plastid genome content, grounded within a phylogenetic framework, was conducted using a slot-blot Southern hybridization approach. Cuscuta was extensively sampled (~56% of species), including groups previously suggested to possess more altered plastomes compared with other members of this genus. A total of 56 probes derived from all categories of protein-coding genes, typically found within the plastomes of flowering plants, were used. The results indicate that two clades within subgenus Grammica (clades 'O' and 'K') exhibit substantially more plastid gene loss relative to other members of Cuscuta. All surveyed members of the 'O' clade show extensive losses of plastid genes from every category of genes typically found in the plastome, including otherwise highly conserved small and large ribosomal subunits. The extent of plastid gene losses within this clade is similar in magnitude to that observed previously in some non-asterid holoparasites, in which the very presence of a plastome has been questioned. The 'K' clade also exhibits considerable loss of plastid genes. Unlike in the 'O' clade, in which all species seem to be affected, the losses in clade 'K' progress phylogenetically, following a pattern consistent with the Evolutionary Transition Series hypothesis. This clade presents an ideal opportunity to study the reduction of the plastome of parasites 'in action'. The widespread plastid gene loss in these two clades is hypothesized to be a

  5. Identification of Sand flies of the Subgenus Larroussius based on Molecular and Morphological Characters in North Western Iran

    Directory of Open Access Journals (Sweden)

    A Absavaran

    2009-12-01

    Full Text Available Background: The adult female sand flies (Diptera: Psychodidae of the subgenus Larroussius are important vectors of Leishmania infantum (Kinetoplastida: Tripanosomatidae in Meshkinshahr district, Northwest of Iran. Four Phle­boto­mus (Larroussius species are present in this area, i.e. Phlebotomus (Larroussius kandelakii, P. (La. major, P. (La. perfiliewi and P. (La. tobbi. The objective of the present study was to identify and distinguish the females of P. per­filiewi, P. major and P. tobbi, in this district."nMethods: Adult sand flies were collected with sticky papers, CDC light traps, and aspirator in 2006. Individual sand flies of this four species from thirty different locations were characterized morphologically and by comparative DNA se­quences analyses of a fragment of mitochondrial gene Cytochrome b (Cyt b and nuclear gene Elongation Factor 1- al­pha (EF-1α. PCR amplification was carried out for all three species P. major, P. perfiliewi and P. tobbi in the sub­ge­nus Larroussius."nResults: Phylogenetic analyses of P. major populations in this study displayed two different populations and genetic di­ver­sity. Spermathecal segment number, pharyngeal armature and other morphological characters of these three spe­cies were examined and found to present consistent interspecific differences."nConclusion: According to our findings, the phylogeny of Cyt b and EF-1α haplotypes confirms the relationships be­tween P. major, P. tobbi and P. perfiliewi as already defined by their morphological similarities.                                                                                  Keywords: Phlebotomus, Larroussius, Cytochrome b, Elongation Factor-1α, Morphology, Iran                 

  6. Pan-African phylogeny of Mus (subgenus Nannomys) reveals one of the most successful mammal radiations in Africa.

    Science.gov (United States)

    Bryja, Josef; Mikula, Ondřej; Šumbera, Radim; Meheretu, Yonas; Aghová, Tatiana; Lavrenchenko, Leonid A; Mazoch, Vladimír; Oguge, Nicholas; Mbau, Judith S; Welegerima, Kiros; Amundala, Nicaise; Colyn, Marc; Leirs, Herwig; Verheyen, Erik

    2014-12-14

    Rodents of the genus Mus represent one of the most valuable biological models for biomedical and evolutionary research. Out of the four currently recognized subgenera, Nannomys (African pygmy mice, including the smallest rodents in the world) comprises the only original African lineage. Species of this subgenus became important models for the study of sex determination in mammals and they are also hosts of potentially dangerous pathogens. Nannomys ancestors colonized Africa from Asia at the end of Miocene and Eastern Africa should be considered as the place of their first radiation. In sharp contrast with this fact and despite the biological importance of Nannomys, the specimens from Eastern Africa were obviously under-represented in previous studies and the phylogenetic and distributional patterns were thus incomplete. We performed comprehensive genetic analysis of 657 individuals of Nannomys collected at approximately 300 localities across the whole sub-Saharan Africa. Phylogenetic reconstructions based on mitochondrial (CYTB) and nuclear (IRBP) genes identified five species groups and three monotypic ancestral lineages. We provide evidence for important cryptic diversity and we defined and mapped the distribution of 27 molecular operational taxonomic units (MOTUs) that may correspond to presumable species. Biogeographical reconstructions based on data spanning all of Africa modified the previous evolutionary scenarios. First divergences occurred in Eastern African mountains soon after the colonization of the continent and the remnants of these old divergences still occur there, represented by long basal branches of M. (previously Muriculus) imberbis and two undescribed species from Ethiopia and Malawi. The radiation in drier lowland habitats associated with the decrease of body size is much younger, occurred mainly in a single lineage (called the minutoides group, and especially within the species M. minutoides), and was probably linked to aridification and

  7. DNA barcoding of the leaf-mining moth subgenus Ectoedemia s. str. (Lepidoptera: Nepticulidae) with COI and EF1-α: two are better than one in recognising cryptic species

    NARCIS (Netherlands)

    Nieukerken, E.J.; Doorenweerd, C.; Stokvis, F.R.; Groenenberg, D.S.J.

    2012-01-01

    We sequenced 665bp of the Cytochrome C Oxidase I (COI) barcoding marker for 257 specimens and 482bp of Elongation Factor 1-α (EF1-α) for 237 specimens belonging to the leafmining subgenus Ectoedemia (Ectoedemia) in the basal Lepidopteran family Nepticulidae. The dataset includes 45 out of 48 West

  8. A new subgenus of the weevil genus Otiorhynchus Germar, 1822 (Coleoptera: Curculionidae: Entiminae for a new species from Mediterranean Turkey associated with the carob tree, Ceratonia siliqua L. (Fabaceae

    Directory of Open Access Journals (Sweden)

    Genrik E. Davidian

    2017-03-01

    Full Text Available A new species Otiorhynchus ceratoniae Davidian, Gültekin & Korotyaev sp. nov. is described from eastern Mediterranean Turkey. A new monotypic subgenus Arnoldinus Davidian, Gültekin & Korotyaev subgen. nov. is erected for this species. The new species was found only under Ceratonia siliqua L. trees with lower leaves damaged by adults.

  9. Redefinition of the millipede subgenus Megaphyllum sensu stricto Verhoeff, 1894 and neotype designation for Megaphyllum austriacum (Latzel, 1884) (Myriapoda: Diplopoda: Julida: Julidae).

    Science.gov (United States)

    Lazányi, Eszter; Vagalinski, Boyan

    2013-11-26

    Megaphyllum sensu stricto, i.e. the nominotypical subgenus of the very complicated genus Megaphyllum Verhoeff, 1894, is redefined on the basis of examination of type and non-type material and literature data. Four species-groups including twenty species in all are listed, and the identity of M. austriacum (C. L. Koch, 1838) is clarified with a proposal of neotype designation under ICZN Article 75.6. in order to stabilize the current usage of the name. Prevailing usage of M. silvaticum (Verhoeff, 1898) syn. nov. (nomen protectum) over the senior synonym M. nigrescens (Latzel, 1884) (nomen oblitum) is maintained under ICZN Article 23.9. M. banaticum (Verhoeff, 1899) is syn. nov. of M. erythronotum (Latzel, 1884) comb. nov., M. bosniense cotinophilum (Loksa, 1962) syn. nov. of M. bosniense bosniense (Verhoeff, 1897) and M. transsylvanicum transdanubicum (Loksa, 1962) syn. nov. of M. transsylvanicum transsylvanicum (Verhoeff, 1897). M. unilineatum (C. L. Koch, 1838) is new to the fauna of Turkey.

  10. Molecular systematics of the phlebotomine sandflies of the subgenus Paraphlebotomus (diptera, psychodidae, phlebotomus) based on ITS2 rDNA sequences. Hypotheses Of dispersion and speciation.

    Science.gov (United States)

    Depaquit, J; Ferté, H; Léger, N; Killick-Kendrick, R; Rioux, J A; Killick-Kendrick, M; Hanafi, H A; Gobert, S

    2000-06-01

    Phylogenetic Paraphlebotomus relationships are inferred by a study based on the sequences of ITS2, which has been sequenced in nine Paraphlebotomus species: P. alexandri, P. andrejevi, P. jacusieli, P. kazeruni, P. mireillae, P. mongolensis, P. saevus, P. sergenti and P. similis and in two out-groups species of the subgenus Phlebotomus: P. papatasi and P. duboscqi. Paraphlebotomus alexandri appears as the sister group of all other Paraphlebotomus sandflies. Among the other species, three groupings are clearly highlighted: andrejevi and mongolensis; mireillae and saevus; jacusieli, kazeruni, sergenti and similis. These groupings are related to speculations about the migration of Paraphlebotomus from a centre of dispersion located in the Middle East sometime from the early Eocene to the late Miocene.

  11. Phylogeny of New World Salvia subgenus Calosphace (Lamiaceae) based on cpDNA (psbA-trnH) and nrDNA (ITS) sequence data.

    Science.gov (United States)

    Jenks, Aaron A; Walker, Jay B; Kim, Seung-Chul

    2013-07-01

    Salvia subgenus Calosphace (Lamiaceae) is economically and ethnomedicinally significant and comprised of more than 500 species. Although strongly supported as monophyletic, it has received no comprehensive systematic research since the initial establishment of 91 taxonomic sections in 1939. Representative taxa of 73 sections of Calosphace were sampled to investigate the phylogenetic relationships and identify major lineages using chloroplast (intergenic spacer psbA-trnH) and nuclear ribosomal DNA (internal transcribed spacer). Phylogenetic analysis of the combined data sets established monophyly of seven sections (Blakea, Corrugatae, Erythrostachys, Hastatae, Incarnatae, Microsphace, and Sigmoideae) and four major lineages (S. axillaris, "Hastatae clade", "Uliginosae clade", and "core Calosphace"). Sections spanning two or more centers of diversity are not supported by our results; rather, supported relationships exhibit significant geographic structure. Mexico is supported as the geographic origin of Calosphace, and no more than seven dispersal events to South America are required to account for current disjunct distributions.

  12. Traceability of marketable Japanese shoro in New Zealand: using multiplex PCR to exploit phylogeographic variation among taxa in the Rhizopogon subgenus Roseoli.

    Science.gov (United States)

    Visnovsky, Sandra B; Guerin-Laguette, Alexis; Wang, Yun; Pitman, Andrew R

    2010-01-01

    Rhizopogon roseolus Corda (synonym Rhizopogon rubescens Tul.), an economically important edible mushroom associated with the Pinaceae (mostly Pinus sp.), has a global distribution resulting from the introduction of exotic trees into the Southern Hemisphere for plantation forestry. However, the marketability of R. roseolus varies with the place of origin. R. roseolus strains cultivated in New Zealand from local carpophores for the Japanese market are morphologically and biologically distinct from those produced in Japan and are consequently considered less valuable. In this study, the ITS1-5.8S-ITS2 rRNA (internal transcribed spacer [ITS]) region was used to examine the phylogenetic relationships of R. roseolus and other closely related fungi belonging to Rhizopogon subgenus Roseoli to determine the genetic basis for phenotypic differences among R. roseolus isolates from different geographic regions. Phylogenetic comparison revealed phylogeographic variation within Rhizopogon subgenus Roseoli. Collections from the United States and Europe grouped into four distinct clades. Rhizopogon roseolus isolates found in New Zealand were closely related to those from the United States, likely due to introduction of Pinus radiata from its native California in the United States. In contrast, Japanese R. roseolus isolates clustered closely with European collections. Phylogenetic differences between Japanese and New Zealand R. roseolus isolates may explain the morphological and biological properties attributed to these geographical variants. The ITS region was subsequently used to design a multiplex PCR for the simultaneous identification of Japanese and New Zealand R. roseolus isolates to track the establishment of ectomycorrhiza on P. radiata seedlings inoculated with commercially valuable R. roseolus. This diagnostic demonstrated the first fruiting of Japanese shoro cultivated on P. radiata in the Southern Hemisphere.

  13. The Female Cibarial Armature of New World Culex, Subgenus Melanoconion and Related Subgenera with Notes on this Character in Subgenera Culex, Lutzia and Neoculex and Genera Galindomyia and Deinocerites (Diptera: Culicidae)

    Science.gov (United States)

    1978-01-01

    Peru ). deeZarator Dyar Subgenus lVeo&!ex: arixonensis Bohart (USA-Arizona), derivator Dyar and Knab (Costa Rica), territans Walker (USA-Maryland...apparently characteris- tic of aZbir,ensis. (d) batesi subtype (Fig. 3E). This subtype is apparently distinc- tive of batesi. The cibarial teeth...in the spissipes subtype (spissipes, eprmastasis, opisthopus, por- tesi , taeniopus and vomerifer) based on the cibarial armature as shown here and

  14. Notes on two species of the cavernicolous subgenus Neobisium (Blothrus) Schiödte, 1847 (Arachnida: Pseudoscorpiones) from Transylvania (Romania), with a key to the species of the Carpathian Mountains.

    Science.gov (United States)

    Novák, János

    2014-05-19

    Redescriptions of Neobisium (Blothrus) minutum (Tömösváry, 1882) and N. (B.) brevipes (Frivaldszky, 1865) are given, accompanied by new illustrations. Neobisium (B.) brevipes montanum is elevated to full species rank as N. (B.) montanum Beier, 1939. New records of N. (B.) minutum and N. (B.) brevipes from Romania are presented. A key to the members of the subgenus Blothrus occurring in the Carpathian Mountains is provided.

  15. Medical Entomology Studies - VI. A Revision of the Subgenus Lophoceraomyia of the Genus Culex in the Oriental Region (Diptera: Culicidae) (Contributions of the American Entomological Institute, Volume 13, Number 4, 1977)

    Science.gov (United States)

    1977-01-01

    cephalothorax and metanotum. Trumpet. Brownish, short, stout, sausage -like, apex slightly projecting beyond margin of middorsal ridge in flat preparation...Subgenus LoPhoceraow2yia in the Oriental Region 137 lighter or yellowish white. Trumpet. Dark brown, short, stout, sausage -like. Complete chaetotaxy...Publ. 20: 1-147. Les moustiques de la Cochinchine et du Sud-Annam. Arch. Inst. Pasteur d’Indochine 3-4: 75-121. Les moustiques de la Cochinchine

  16. Medical Entomolgy Studies - VI. A Revision of the Subgenus Lophoceraomyia of the Genus Culex in the Oriental Region (Diptera: Culicidae) (Contributions of the American Entomological Institute. Volume 13, Number 4)

    Science.gov (United States)

    1977-01-01

    cephalothorax and metanotum. Trumpet. Brownish, short, stout, sausage -like, apex slightly projecting beyond margin of middorsal ridge in flat preparation...Subgenus LoPhoceraow2yia in the Oriental Region 137 lighter or yellowish white. Trumpet. Dark brown, short, stout, sausage -like. Complete chaetotaxy...Publ. 20: 1-147. Les moustiques de la Cochinchine et du Sud-Annam. Arch. Inst. Pasteur d’Indochine 3-4: 75-121. Les moustiques de la Cochinchine

  17. A new species of Reithrodontomys, subgenus Aporodon (Cricetidae: Neotominae), from the highlands of Costa Rica, with comments on Costa Rican and Panamanian Reithrodontomys

    Science.gov (United States)

    Gardner, Alfred L.; Carleton, Michael D.

    2009-01-01

    A new species of the rodent genus Reithrodontomys (Cricetidae: Neotominae) is described from Cerro Asuncion in the western Cordillera de Talamanca, Costa Rica. The long tail, elongate rostrum, bulbous braincase, and complex molars of the new species associate it with members of the subgenus Aporodon, tenuirostris species group. In its diminutive size and aspects of cranial shape, the new species (Reithrodontomys musseri, sp. nov.) most closely resembles R. microdon, a form known from highlands in Guatemala and Chiapas, Mexico. In the course of differentially diagnosing the new species, we necessarily reviewed the Costa Rican and Panamanian subspecies of R. mexicanus based on morphological comparisons, study of paratypes and vouchers used in recent molecular studies, and morphometric analyses. We recognize Reithrodontomys cherrii (Allen, 1891) and R. garichensis finders and Pearson, 1940, as valid species, and allocate R. mexicanus potrerograndei Goodwin, 1945, as a subjective synonym of R. brevirostris Goodwin, 1943. Critical review of museum specimens collected subsequent to Hooper's (1952) revision is needed and would do much to improve understanding of Reithrodontomys taxonomy and distribution in Middle America.

  18. Albucacrispa and A. grandis (Hyacinthaceae: Omithogaloideae, two new species of subgenus Albuca, the rediscovery of A. albucoides (sub­ genus Osmyne, and the identity of A. reflexa

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2009-08-01

    Full Text Available Albuca crispa is a new species of section Falconera series Trianthera with crispulate leaves from the Great Karoo, known  at least since 1947 but overlooked until now. A second new species. A grandis. from the southwestern Cape was previously included in  A. fragrans Jacq. (section  Falconera series  Falconera. It is a robust species that flowers in winter and early spring and the styles are rugulose with ± isodiametric epidermal cells, unlike typical  A. fragrans which is a more slender species flowering in early summer and with derived, smooth styles with fusiform epidermal cells. The recent discovery of a flowering population matching the type of A. albucoides (Aiton J.C.Manning & Goldblatt (subgenus Osmyne allows for a full description and illustration of this poorly know n and taxonomically neglected species that has often been included in A. suaveolens (Jacq. J.C.Manning & Goldblatt. Lastly, examination of the type  of A. reflexa Krause & Dinter from Namibia shows it to be conspecific w ith Drimia indica (Roxb. Jessop.

  19. Albucacrispa and A. grandis (Hyacinthaceae: Omithogaloideae, two new species of subgenus Albuca, the rediscovery of A. albucoides (sub­ genus Osmyne, and the identity of A. reflexa

    Directory of Open Access Journals (Sweden)

    J. C. Manning

    2009-12-01

    Full Text Available Albuca crispa is a new species of section Falconera series Trianthera with crispulate leaves from the Great Karoo, known  at least since 1947 but overlooked until now. A second new species. A grandis. from the southwestern Cape was previously included in  A. fragrans Jacq. (section  Falconera series  Falconera. It is a robust species that flowers in winter and early spring and the styles are rugulose with ± isodiametric epidermal cells, unlike typical  A. fragrans which is a more slender species flowering in early summer and with derived, smooth styles with fusiform epidermal cells. The recent discovery of a flowering population matching the type of A. albucoides (Aiton J.C.Manning & Goldblatt (subgenus Osmyne allows for a full description and illustration of this poorly know n and taxonomically neglected species that has often been included in A. suaveolens (Jacq. J.C.Manning & Goldblatt. Lastly, examination of the type  of A. reflexa Krause & Dinter from Namibia shows it to be conspecific w ith Drimia indica (Roxb. Jessop.

  20. Scratching the surface? Taxonomic revision of the subgenus Schizoptera (Odontorhagus) reveals vast undocumented biodiversity in the largest litter bug genus Schizoptera Fieber (Hemiptera: Dipsocoromorpha).

    Science.gov (United States)

    Leon, Stephanie; Weirauch, Christiane

    2016-11-03

    Schizoptera Fieber, currently the largest genus of litter bugs (Hemiptera: Dipsocoromorpha), comprises 61 extant species in 4 subgenera. Specimens are abundant in New World bulk and residue samples. Schizoptera species showcase stunning morphology including intricate, asymmetrical genitalia in males that have proven to provide excellent species diagnostic features in the past. Recent bulk sample sorting efforts have revealed a vast number of Schizoptera specimens from across the New World, with the majority representing undescribed species. We here taxonomically revise the subgenus Schizoptera (Odontorhagus) that has recently been shown to form a monophyletic group within Schizoptera. Characterized by the blunt tooth on the posterior margin of the propleuron, Schizoptera (Odontorhagus) previously comprised 10 species from Central and the northern part of South America. We here describe 20 new species in S. (Odontorhagus): S. acuta, n. sp., S. angularis, n. sp., S. ansata, n. sp., S. aspera, n. sp., S. brevis, n. sp., S. dentata, n. sp., S. dolosa, n. sp., S. enigmatica, n. sp., S. exacta, n. sp., S. gorgonensis, n. sp., S. insidiosa, n. sp., S. monstrosa, n. sp., S. piscicaudata, n. sp., S. quasicompleta, n. sp., S. radicata, n. sp., S. serrata, n. sp., S. simpla, n. sp., S. singularis, n. sp., S. trivialis, n. sp., S. ungulata, n. sp., increasing the species count of Schizoptera to 81. We provide morphological documentation including digital habitus images and genitalic drawings for all new species and document and redescribe existing species where feasible. Distribution maps and a key to the species of Schizoptera (Odontorhagus) are also presented. We predict that similar increases in species numbers are to be expected for the remaining subgenera of Schizoptera, making this genus a very diverse lineage of minute litter bugs.

  1. The comparison of molecular and morphology-based phylogenies of trichaline net-winged beetles (Coleoptera: Lycidae: Metriorrhynchini with description of a new subgenus

    Directory of Open Access Journals (Sweden)

    Matej Bocek

    2017-10-01

    Full Text Available Separate morphological and molecular phylogenetic analyses are presented and the classification of trichaline net-winged beetles is revised. The clade, earlier given a subfamily, tribe or subtribe rank, is a terminal lineage in Metriorrhynchina and contains Diatrichalus Kleine, 1926, Eniclases Waterhouse, 1879, Flabellotrichalus Pic, 1921, Lobatang Bocak, 1998, Microtrichalus Pic, 1921, Schizotrichalus Kleine, 1926, and Trichalus Waterhouse, 1877. Maibrius subgen. nov. is proposed in Flabellotrichalus with the type-species Flabellotrichalus (Maibrius horaki sp. nov. Unlike previous studies, Lobatang is included in the trichaline clade. Further, Spinotrichalus Kazantsev, 2010, stat. nov. is down-ranked to the subgenus in Lobatang Bocak, 1998 and a new combination, Lobatang (Spinotrichalus telnovi (Kazantsev, 2010 comb. nov., is proposed. The morphology does not provide a sufficient support for robust phylogeny due to the intrageneric variability of most phenotypic traits and the limited number of characters supporting deep relationships. Most morphological generic diagnoses must be based on the shape of male genitalia. Other characters, such as the shapes of pronotum and antennae are commonly variable within genera. The fronto-lateral pronotal ridges of Eniclases + Schizotrichalus resemble the ancestral condition in Metriorrhynchini and they re-evolved in the terminal clade and do not indicate the early split of Eniclases + Schizotrichalus from other trichaline genera. The evolution of morphological traits and the conflict in the morphological and molecular phylogenetic signal are discussed in details. We suggest that the general appearance is affected by the evolution of mimetic complexes, the patterns of elytral costae by their strengthening function, and the presence of flabellate antennae by their role in sexual communication. Then, similar phenotypic traits evolve in unrelated lineages. The results demonstrate that phylogenetic

  2. Population genetic structure, genetic diversity, and natural history of the South American species of Nothofagus subgenus Lophozonia (Nothofagaceae) inferred from nuclear microsatellite data.

    Science.gov (United States)

    Vergara, Rodrigo; Gitzendanner, Matthew A; Soltis, Douglas E; Soltis, Pamela S

    2014-06-01

    The effect of glaciation on the levels and patterns of genetic variation has been well studied in the Northern Hemisphere. However, although glaciation has undoubtedly shaped the genetic structure of plants in the Southern Hemisphere, fewer studies have characterized the effect, and almost none of them using microsatellites. Particularly, complex patterns of genetic structure might be expected in areas such as the Andes, where both latitudinal and altitudinal glacial advance and retreat have molded modern plant communities. We therefore studied the population genetics of three closely related, hybridizing species of Nothofagus (N. obliqua, N. alpina, and N. glauca, all of subgenus Lophozonia; Nothofagaceae) from Chile. To estimate population genetic parameters and infer the influence of the last ice age on the spatial and genetic distribution of these species, we examined and analyzed genetic variability at seven polymorphic microsatellite DNA loci in 640 individuals from 40 populations covering most of the ranges of these species in Chile. Populations showed no significant inbreeding and exhibited relatively high levels of genetic diversity (H E = 0.502-0.662) and slight, but significant, genetic structure (R ST = 8.7-16.0%). However, in N. obliqua, the small amount of genetic structure was spatially organized into three well-defined latitudinal groups. Our data may also suggest some introgression of N. alpina genes into N. obliqua in the northern populations. These results allowed us to reconstruct the influence of the last ice age on the genetic structure of these species, suggesting several centers of genetic diversity for N. obliqua and N. alpina, in agreement with the multiple refugia hypothesis.

  3. Two new species and a new subgenus of toothed Brachyhypopomus electric knifefishes (Gymnotiformes, Hypopomidae) from the central Amazon and considerations pertaining to the evolution of a monophasic electric organ discharge.

    Science.gov (United States)

    Sullivan, John P; Zuanon, Jansen; Cox Fernandes, Cristina

    2013-01-01

    We describe two new, closely related species of toothed Brachyhypopomus (Hypopomidae: Gymnotiformes: Teleostei) from the central Amazon basin and create a new subgenus for them. Odontohypopomus, new subgenus of Brachyhypopomus, is diagnosed by (1) small teeth present on premaxillae; (2) medialmost two branchiostegal rays thin with blades oriented more vertically than remaining three rays; (3) background color in life (and to lesser extent in preservation) distinctly yellowish with head and sides peppered with small, widely spaced, very dark brown stellate chromatophores that greatly contrast with light background coloration; (4) a dark blotch or bar of subcutaneous pigment below the eye; (5) electric organ discharge waveform of very long duration (head-positive phase approx. 2 milliseconds or longer, head-negative phase shorter or absent) and slow pulse repetition rate (3-16 Hz). The type species of the new subgenus, Brachyhypopomus (Odontohypopomus) walteri sp. n., is diagnosed by the following additional character states: (1) subcutaneous dark pigment at base of orbit particularly prominent, (2) body semi-translucent and nearly bright yellow background coloration in life, (3) a biphasic electric organ discharge (EOD) waveform of very long duration (between 3.5 and 4 milliseconds at 25° C) with head-positive first phase significantly longer than second head-negative phase in both sexes. Brachyhypopomus (Odontohypopomus) bennetti sp. n. is diagnosed by two character states in addition to those used to diagnose the subgenus Odontohypopomus: (1) a deep electric organ, visible as large semi-transparent area, occupying approximately 14-17% body depth directly posterior to the abdominal cavity in combination with a short, but deep, caudal filament, and (2) a monophasic, head-positive EOD waveform, approximately 2.1 milliseconds in duration in both sexes. These are the only described rhamphichthyoid gymnotiforms with oral teeth, and Brachyhypopomus bennetti is the first

  4. Two new species and a new subgenus of toothed Brachyhypopomus electric knifefishes (Gymnotiformes, Hypopomidae from the central Amazon and considerations pertaining to the evolution of a monophasic electric organ discharge

    Directory of Open Access Journals (Sweden)

    John Sullivan

    2013-08-01

    Full Text Available We describe two new, closely related species of toothed Brachyhypopomus (Hypopomidae: Gymnotiformes: Teleostei from the central Amazon basin and create a new subgenus for them. Odontohypopomus, new subgenus of Brachyhypopomus, is diagnosed by (1 small teeth present on premaxillae; (2 medialmost two branchiostegal rays thin with blades oriented more vertically than remaining three rays; (3 background color in life (and to lesser extent in preservation distinctly yellowish with head and sides peppered with small, widely spaced, very dark brown stellate chromatophores that greatly contrast with light background coloration; (4 a dark blotch or bar of subcutaneous pigment below the eye; (5 electric organ discharge waveform of very long duration (head-positive phase approx. 2 milliseconds or longer, head-negative phase shorter or absent and slow pulse repetition rate (3–16 Hz. The type species of the new subgenus, Brachyhypopomus (Odontohypopomus walteri sp. n., is diagnosed by the following additional character states: (1 subcutaneous dark pigment at base of orbit particularly prominent, (2 body semi-translucent and nearly bright yellow background coloration in life, (3 a biphasic electric organ discharge (EOD waveform of very long duration (between 3.5 and 4 milliseconds at 25° C with head-positive first phase significantly longer than second head-negative phase in both sexes. Brachyhypopomus (Odontohypopomus bennetti sp. n. is diagnosed by two character states in addition to those used to diagnose the subgenus Odontohypopomus: (1 a deep electric organ, visible as large semi-transparent area, occupying approximately 14–17% body depth directly posterior to the abdominal cavity in combination with a short, but deep, caudal filament, and (2 a monophasic, head-positive EOD waveform, approximately 2.1 milliseconds in duration in both sexes. These are the only described rhamphichthyoid gymnotiforms with oral teeth, and B. bennetti is the first

  5. Electronics and electronic systems

    CERN Document Server

    Olsen, George H

    1987-01-01

    Electronics and Electronic Systems explores the significant developments in the field of electronics and electronic devices. This book is organized into three parts encompassing 11 chapters that discuss the fundamental circuit theory and the principles of analog and digital electronics. This book deals first with the passive components of electronic systems, such as resistors, capacitors, and inductors. These topics are followed by a discussion on the analysis of electronic circuits, which involves three ways, namely, the actual circuit, graphical techniques, and rule of thumb. The remaining p

  6. In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus - doi: 10.4025/actascibiolsci.v33i4.6482 In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus - doi: 10.4025/actascibiolsci.v33i4.6482

    Directory of Open Access Journals (Sweden)

    Sueli Fumie Yamada-Ogatta

    2011-09-01

    Full Text Available The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 µg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 µg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 µg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 µg mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 µg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 µg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was 275 µg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a

  7. Development of Chloroplast and Nuclear DNA Markers for Chinese Oaks (Quercus Subgenus Quercus and Assessment of Their Utility as DNA Barcodes

    Directory of Open Access Journals (Sweden)

    Jia Yang

    2017-05-01

    Full Text Available Chloroplast DNA (cpDNA is frequently used for species demography, evolution, and species discrimination of plants. However, the lack of efficient and universal markers often brings particular challenges for genetic studies across different plant groups. In this study, chloroplast genomes from two closely related species (Quercus rubra and Castanea mollissima in Fagaceae were compared to explore universal cpDNA markers for the Chinese oak species in Quercus subgenus Quercus, a diverse species group without sufficient molecular differentiation. With the comparison, nine and 14 plastid markers were selected as barcoding and phylogeographic candidates for the Chinese oaks. Five (psbA-trnH, matK-trnK, ycf3-trnS, matK, and ycf1 of the nine plastid candidate barcodes, with the addition of newly designed ITS and a single-copy nuclear gene (SAP, were then tested on 35 Chinese oak species employing four different barcoding approaches (genetic distance-, BLAST-, character-, and tree-based methods. The four methods showed different species identification powers with character-based method performing the best. Of the seven barcodes tested, a barcoding gap was absent in all of them across the Chinese oaks, while ITS and psbA-trnH provided the highest species resolution (30.30% with the character- and BLAST-based methods, respectively. The six-marker combination (psbA-trnH + matK-trnK + matK + ycf1 + ITS + SAP showed the best species resolution (84.85% using the character-based method for barcoding the Chinese oaks. The barcoding results provided additional implications for taxonomy of the Chinese oaks in subg. Quercus, basically identifying three major infrageneric clades of the Chinese oaks (corresponding to Groups Quercus, Cerris, and Ilex referenced to previous phylogenetic classification of Quercus. While the morphology-based allocations proposed for the Chinese oaks in subg. Quercus were challenged. A low variation rate of the chloroplast genome, and

  8. Development of Chloroplast and Nuclear DNA Markers for Chinese Oaks (Quercus Subgenus Quercus) and Assessment of Their Utility as DNA Barcodes

    Science.gov (United States)

    Yang, Jia; Vázquez, Lucía; Chen, Xiaodan; Li, Huimin; Zhang, Hao; Liu, Zhanlin; Zhao, Guifang

    2017-01-01

    Chloroplast DNA (cpDNA) is frequently used for species demography, evolution, and species discrimination of plants. However, the lack of efficient and universal markers often brings particular challenges for genetic studies across different plant groups. In this study, chloroplast genomes from two closely related species (Quercus rubra and Castanea mollissima) in Fagaceae were compared to explore universal cpDNA markers for the Chinese oak species in Quercus subgenus Quercus, a diverse species group without sufficient molecular differentiation. With the comparison, nine and 14 plastid markers were selected as barcoding and phylogeographic candidates for the Chinese oaks. Five (psbA-trnH, matK-trnK, ycf3-trnS, matK, and ycf1) of the nine plastid candidate barcodes, with the addition of newly designed ITS and a single-copy nuclear gene (SAP), were then tested on 35 Chinese oak species employing four different barcoding approaches (genetic distance-, BLAST-, character-, and tree-based methods). The four methods showed different species identification powers with character-based method performing the best. Of the seven barcodes tested, a barcoding gap was absent in all of them across the Chinese oaks, while ITS and psbA-trnH provided the highest species resolution (30.30%) with the character- and BLAST-based methods, respectively. The six-marker combination (psbA-trnH + matK-trnK + matK + ycf1 + ITS + SAP) showed the best species resolution (84.85%) using the character-based method for barcoding the Chinese oaks. The barcoding results provided additional implications for taxonomy of the Chinese oaks in subg. Quercus, basically identifying three major infrageneric clades of the Chinese oaks (corresponding to Groups Quercus, Cerris, and Ilex) referenced to previous phylogenetic classification of Quercus. While the morphology-based allocations proposed for the Chinese oaks in subg. Quercus were challenged. A low variation rate of the chloroplast genome, and complex

  9. Gracilaria, Subgenus Textoriella (Gracilariaceae, Rhodophyta in the Gulf of Mexico and the Mexican Caribbean Gracilaria, subgénero Textoriella (Gracilariaceae, Rhodophyta en el golfo de México y el Caribe mexicano

    Directory of Open Access Journals (Sweden)

    Kurt M. Dreckmann

    2009-12-01

    Full Text Available Four species of Gracilaria (Gracilariaceae, Rhodophyta with textorii-type spermatangial conceptacles (subgenus Textoriella Yamamoto are recorded for the Gulf of Mexico and the Mexican Caribbean: Gracilaria blodgettii, G. cervicornis, G. mammillaris, and G. tikvahiae. The general distribution of the subgenus for Central America, both Pacific and Atlantic, displays a disjunct pattern explainable based on the geologic vicariant events that interrupted the connection between Pacific and Atlantic at the Isthmuses of Panama (closed 3.1-2.8 million years ago, and Tehuantepec (southern Mexico, closed 4-3.5 million years ago. Gracilaria cuneata/G. crispata, and G. mammillaris (G. hayi/G. veleroae are 2 pairs of sibling species, or sister taxa, that diverged as a result of the final emergence of the Isthmus, and of the same age as the Central American Isthmus itself.Se registran 4 especies de Gracilaria (Gracilariaceae, Rhodophyta con conceptáculos espematangiales tipo textorii- (subgénero Textoriella Yamamoto para el golfo de México y Caribe mexicano: Gracilaria blodgettii, G. cervicornis, G. mammillaris y G. tikvahiae. La distribución general del subgénero para Atlántico y Pacífico de Centroamérica despliega un patrón disyunto explicable por los eventos geológicos vicariantes que interrumpieron la conexión entre Pacífico y Atlántico en los istmos de Panamá (cerrado hace aprox. 3.1-2.8 millones de años y Tehuantepec (sur de México, cerrado hace aprox. 4-3.5 millones de años. Gracilaria cuneata/G. crispata y G. mammillaris (= G. hayi/ G. veleroae corresponden a 2 pares de especies hermanas que divergieron como resultado de la emersión del istmo, y con aproximadamente la misma edad del istmo centroamericano.

  10. The Electron

    Energy Technology Data Exchange (ETDEWEB)

    Thomson, George

    1972-01-01

    Electrons are elementary particles of atoms that revolve around and outside the nucleus and have a negative charge. This booklet discusses how electrons relate to electricity, some applications of electrons, electrons as waves, electrons in atoms and solids, the electron microscope, among other things.

  11. Wild Allium species (Alliaceae used in folk medicine of Tajikistan and Uzbekistan

    Directory of Open Access Journals (Sweden)

    Kurbonova Parvina A

    2006-04-01

    Full Text Available Abstract Background Hitherto available sources from literature mentioned several wild growing Allium species as "edible" or "medicinally used" but without any further specification. Methods New data were gained during recent research missions: Allium plants were collected and shown to the local population which was asked for names and usage of these plants. Results Information was collected about current medical applications of sixteen wild species, nine of which belong to different sections of Allium subgenus Melanocrommyum. These plants are used against headache, cold, and stomach problems, and are mostly applied fresh or after boiling. Conclusion Close taxonomic relatives of the common onion were used similar to cultivated onion species, but medical use like garlic was mostly reported for species taxonomically not related to garlic.

  12. Electron radiography

    Science.gov (United States)

    Merrill, Frank E.; Morris, Christopher

    2005-05-17

    A system capable of performing radiography using a beam of electrons. Diffuser means receive a beam of electrons and diffuse the electrons before they enter first matching quadrupoles where the diffused electrons are focused prior to the diffused electrons entering an object. First imaging quadrupoles receive the focused diffused electrons after the focused diffused electrons have been scattered by the object for focusing the scattered electrons. Collimator means receive the scattered electrons and remove scattered electrons that have scattered to large angles. Second imaging quadrupoles receive the collimated scattered electrons and refocus the collimated scattered electrons and map the focused collimated scattered electrons to transverse locations on an image plane representative of the electrons' positions in the object.

  13. Anatomia do escapo floral de espécies brasileiras de Paepalanthus subgênero Platycaulon (Eriocaulaceae Anatomy of the inflorescence scape of Brazilian species of the Paepalanthus subgenus Platycaulon (Eriocaulaceae

    Directory of Open Access Journals (Sweden)

    Vera Lucia Scatena

    1998-08-01

    Full Text Available Foi estudada a anatomia dos escapos de 17 espécies de Paepalanthus subgênero Platycaulon, sendo 10 da sect. Divisi e sete da sect. Conferti. O trabalho foi realizado para caracterizar anatomicamente os escapos. como contribuição para o entendimento do grupo, uma vez que. morfologicamente, esse é o caráter laxonômico mais importante. Procurou-se, também, confirmar ou não o reconhecimento das duas seções dentro do subgênero. Para os estudos anatômicos utilizou-se material proveniente do Brasil, obtido de exsicatas de diferentes herbários e/ou coletado na Serra do Cipó, MG. Neste trabalho observou-se que Paepalanthus subg. Platycaulon é caracterizado morfologicamente por apresentar escapos pluricapitulados no ápice. Anatomicamente, as espécies estudadas da sect. Divisi apresentam escapos com vários cilindros vasculares, na região mediana e, ainda apresentam, em Paepalanthus vellozioides e P. spixianus, feixes vasculares corticais, características únicas na família. Diferentemente, as espécies avaliadas da sect. Conferti apresentam escapos com cilindro vascular único na região mediana, padrão análogo ao das demais Eriocaulaccae, e ainda apresentam, em Paepalanthus itatiaiensis, P. planifolius e P. paulensis, feixes vasculares medulares, que até então não haviam sido referidos para a família.The scape anatomy of 17 taxa of Paepalanthus subgenus Platycaylon were studied, being 10 taxa of sect. Divisi and seven of sect. Conferti. The study was carried out to see whether scape morphology and anatomy provide valid taxonomic characters at the subgeneric level in Paepalanthus and to lest a proposal to recognize two sections within Paepalanthus subgenus Platycaylon: sect. Divisi and sect. Conferti. The material for anatomical study was collected in Brazil, partly from herbarium specimens and partly from fresh material collected in the field, from the Serra do Cipó. Minas Gerais State. In this work, we observe that

  14. Electron Microscopy.

    Science.gov (United States)

    Beer, Michael

    1980-01-01

    Reviews technical aspects of structure determination in biological electron microscopy (EM). Discusses low dose EM, low temperature microscopy, electron energy loss spectra, determination of mass or molecular weight, and EM of labeled systems. Cites 34 references. (CS)

  15. Electronic Commerce

    OpenAIRE

    Slavko Đerić

    2016-01-01

    Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks...

  16. Understand electronics

    CERN Document Server

    Bishop, Owen

    2013-01-01

    Understand Electronics provides a readable introduction to the exciting world of electronics for the student or enthusiast with little previous knowledge. The subject is treated with the minimum of mathematics and the book is extensively illustrated.This is an essential guide for the newcomer to electronics, and replaces the author's best-selling Beginner's Guide to Electronics.The step-by-step approach makes this book ideal for introductory courses such as the Intermediate GNVQ.

  17. Vacuum electronics

    CERN Document Server

    Eichmeier, Joseph A

    2008-01-01

    Nineteen experts from the electronics industry, research institutes and universities have joined forces to prepare this book. ""Vacuum Electronics"" covers the electrophysical fundamentals, the present state of the art and applications, as well as the future prospects of microwave tubes and systems, optoelectronics vacuum devices, electron and ion beam devices, light and X-ray emitters, particle accelerators and vacuum interrupters. These topics are supplemented by useful information about the materials and technologies of vacuum electronics and vacuum technology.

  18. Electronic components

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Components provides a basic grounding in the practical aspects of using and selecting electronics components. The book describes the basic requirements needed to start practical work on electronic equipment, resistors and potentiometers, capacitance, and inductors and transformers. The text discusses semiconductor devices such as diodes, thyristors and triacs, transistors and heat sinks, logic and linear integrated circuits (I.C.s) and electromechanical devices. Common abbreviations applied to components are provided. Constructors and electronics engineers will find the book useful

  19. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    'electronic signature' means data attached to, incorporated in, or logically associated with other data and which is intended by the user to serve as a signature;. The suggested new definition for an electronic signature reads as follows: 'electronic signature' means a sound, symbol or process that is (i) uniquely linked to the ...

  20. ELECTRONIC SIGNATURES

    African Journals Online (AJOL)

    10332324

    (a) facilitate ecommerce;2. (b) remove and prevent barriers to electronic communications in South Africa;3. (c) ensure that electronic transactions in the Republic conform to the highest international standards;4. (d) promote the development of electronic transactions services which are responsive to the needs of users and ...

  1. Sticker electronics

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-09-08

    Electronic stickers may be manufactured on flexible substrates (110, 120, 130) as layers and packaged together. The package may then have an adhesive applied to one side to provide capability for sticking the electronic devices to surfaces. The stickers can be wrappable, placed on surfaces, glued on walls or mirrors or wood or stone, and have electronics (112, 122, 132) which may or may not be ultrathin. Packaging for the electronic sticker can use polymer on cellulose manufacturing and/or three dimensional (3-D) printing. The electronic stickers may provide lighting capability, sensing capability, and/or recharging capabilities.

  2. Basic electronics

    CERN Document Server

    Holbrook, Harold D

    1971-01-01

    Basic Electronics is an elementary text designed for basic instruction in electricity and electronics. It gives emphasis on electronic emission and the vacuum tube and shows transistor circuits in parallel with electron tube circuits. This book also demonstrates how the transistor merely replaces the tube, with proper change of circuit constants as required. Many problems are presented at the end of each chapter. This book is comprised of 17 chapters and opens with an overview of electron theory, followed by a discussion on resistance, inductance, and capacitance, along with their effects on t

  3. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E.; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K.; Gascó, M.; Klievink, A.J.; Lindgren, I.; Milano, M.; Panagiotopoulos, P.; Pardo, T.A.; Parycek, P.; Sæbø, O.

    2015-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies. This book presents papers from the 14th International Federation for Information

  4. Electronic Government and Electronic Participation

    NARCIS (Netherlands)

    Tambouris, E; Scholl, H.J.; Janssen, M.F.W.H.A.; Wimmer, M.A.; Tarabanis, K; Gascó, M; Klievink, A.J.; Lindgren, I; Milano, M; Panagiotopoulos, P; Pardo, T.A.; Parycek, P; Sæbø, Ø

    2016-01-01

    Electronic government and electronic participation continue to transform the public sector and society worldwide and are constantly being transformed themselves by emerging information and communication technologies.This book presents papers from the 14th International Federation for Information

  5. Electron Tree

    DEFF Research Database (Denmark)

    Appelt, Ane L; Rønde, Heidi S

    2013-01-01

    The photo shows a close-up of a Lichtenberg figure – popularly called an “electron tree” – produced in a cylinder of polymethyl methacrylate (PMMA). Electron trees are created by irradiating a suitable insulating material, in this case PMMA, with an intense high energy electron beam. Upon discharge......, during dielectric breakdown in the material, the electrons generate branching chains of fractures on leaving the PMMA, producing the tree pattern seen. To be able to create electron trees with a clinical linear accelerator, one needs to access the primary electron beam used for photon treatments. We...... appropriated a linac that was being decommissioned in our department and dismantled the head to circumvent the target and ion chambers. This is one of 24 electron trees produced before we had to stop the fun and allow the rest of the accelerator to be disassembled....

  6. Fine-scale phylogenetic structure and major events in the history of the current wild soybean (Glycine soja) and taxonomic assignment of semi-wild type (Glycine gracilis Skvortz.) within the Chinese subgenus Soja.

    Science.gov (United States)

    Wang, Ke-Jing; Li, Xiang-Hua; Liu, Yang

    2012-01-01

    Wild and cultivated species of soybeans have coexisted for 5000 years in China. Despite this long history, there is very little information on the genetic relationship of Glycine soja and G. max. To gain insight into the major events in the history of the subgenus Soja, we examined 20 simple sequence repeat (SSR) markers of a large number of accessions (910). The results showed no significant differences between wild and semi-wild soybeans in genetic diversity but significant differences between G. soja and G. max. Ancestry and cluster analyses revealed that semi-wild soybeans should belong to the wild category and not to G. max. Our results also showed that differentiation had occurred not only among G. soja, G. gracilis, and G. max but also within G. soja and within G. gracilis. Glycine soja had 3 clear genetic categories: typical small-seeded (≤2.0 g 100-seed weight), dual-origin middle-seeded (2.0-2.5 g), and large-seeded plants (2.51-3.0 g). These last were genetically close to G. gracilis, their defining some traits having been acquired mainly by introgression from soybeans. Small-seeded G. gracilis (3.01-3.5 g) were genetically different from larger seeded ones (from 3.51 to 4.0 to over 10 g). Seed size predominated over seed coat color in evolutionary degree. Typical and large-seeded G. soja were found to have 0.7% and 12% introgressive cultivar genes, respectively. The genetic boundary of G. gracilis was at the range of 2.51-3.0 g of G. soja. In the great majority of wild accessions, traits such as white flowers, gray pubescences, no-seed bloom, and colored seed coats were likely introgressive from domesticated soybeans.

  7. Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Slavko Đerić

    2016-12-01

    Full Text Available Electronic commerce can be defined in different ways. Any definition helps to understand and explain that concept as better as possible.. Electronic commerce is a set of procedures and technologies that automate the tasks of financial transactions using electronic means. Also, according to some authors, electronic commerce is defined as a new concept, which is being developed and which includes process of buying and selling or exchanging products, services or information via computer networks, including the Internet. Electronic commerce is not limited just to buying and selling, but it also includes all pre-sales and after-sales ongoing activities along the supply chain. Introducing electronic commerce, using the Internet and Web services in business, realizes the way to a completely new type of economy - internet economy.

  8. Micropower electronics

    CERN Document Server

    Keonjian, Edward

    1964-01-01

    Micropower Electronics deals with the operation of modern electronic equipment at micropower levels and the problems associated with micropower electronics. Topics covered include the relations between minimum required power density and frequency response for semiconductor triode amplifiers; physical realization of digital logic circuits; micropower microelectronic subsystems; and metal-oxide-semiconductor field-effect devices for micropower logic circuitry. This book is comprised of 10 chapters and begins with an analysis of fundamental relationships and basic requirements pertinent to the ph

  9. Microfluidic electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2012-08-21

    Microfluidics, a field that has been well-established for several decades, has seen extensive applications in the areas of biology, chemistry, and medicine. However, it might be very hard to imagine how such soft microfluidic devices would be used in other areas, such as electronics, in which stiff, solid metals, insulators, and semiconductors have previously dominated. Very recently, things have radically changed. Taking advantage of native properties of microfluidics, advances in microfluidics-based electronics have shown great potential in numerous new appealing applications, e.g. bio-inspired devices, body-worn healthcare and medical sensing systems, and ergonomic units, in which conventional rigid, bulky electronics are facing insurmountable obstacles to fulfil the demand on comfortable user experience. Not only would the birth of microfluidic electronics contribute to both the microfluidics and electronics fields, but it may also shape the future of our daily life. Nevertheless, microfluidic electronics are still at a very early stage, and significant efforts in research and development are needed to advance this emerging field. The intention of this article is to review recent research outcomes in the field of microfluidic electronics, and address current technical challenges and issues. The outlook of future development in microfluidic electronic devices and systems, as well as new fabrication techniques, is also discussed. Moreover, the authors would like to inspire both the microfluidics and electronics communities to further exploit this newly-established field.

  10. Electron Bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Peters, John W.; Miller, Anne-Frances; Jones, Anne K.; King, Paul W.; Adams, Michael W. W.

    2016-04-01

    Electron bifurcation is the recently recognized third mechanism of biological energy conservation. It simultaneously couples exergonic and endergonic oxidation-reduction reactions to circumvent thermodynamic barriers and minimize free energy loss. Little is known about the details of how electron bifurcating enzymes function, but specifics are beginning to emerge for several bifurcating enzymes. To date, those characterized contain a collection of redox cofactors including flavins and iron-sulfur clusters. Here we discuss the current understanding of bifurcating enzymes and the mechanistic features required to reversibly partition multiple electrons from a single redox site into exergonic and endergonic electron transfer paths.

  11. Polymer electronics

    CERN Document Server

    Hsin-Fei, Meng

    2013-01-01

    Polymer semiconductor is the only semiconductor that can be processed in solution. Electronics made by these flexible materials have many advantages such as large-area solution process, low cost, and high performance. Researchers and companies are increasingly dedicating time and money in polymer electronics. This book focuses on the fundamental materials and device physics of polymer electronics. It describes polymer light-emitting diodes, polymer field-effect transistors, organic vertical transistors, polymer solar cells, and many applications based on polymer electronics. The book also disc

  12. Electron holography

    CERN Document Server

    Tonomura, Akira

    1993-01-01

    Holography was devised for breaking through the resolution limit of electron microscopes The advent of a "coherent" field emission electron beam has enabled the use of Electron Holography in various areas of magnetic domain structures observation, fluxon observation in superconductors, and fundamental experiments in physics which have been inaccessible using other techniques After examining the fundamentals of electron holography and its applications to the afore mentioned fields, a detailed discussion of the Aharonov-Bohm effect and the related experiments is presented Many photographs and illustrations are included to elucidate the text

  13. Printed Electronics

    Science.gov (United States)

    Crain, John M. (Inventor); Lettow, John S. (Inventor); Aksay, Ilhan A. (Inventor); Korkut, Sibel (Inventor); Chiang, Katherine S. (Inventor); Chen, Chuan-Hua (Inventor); Prud'Homme, Robert K. (Inventor)

    2016-01-01

    Printed electronic device comprising a substrate onto at least one surface of which has been applied a layer of an electrically conductive ink comprising functionalized graphene sheets and at least one binder. A method of preparing printed electronic devices is further disclosed.

  14. Electronic Cereal.

    Science.gov (United States)

    Frentrup, Julie R.; Phillips, Donald B.

    1996-01-01

    Describes activities that use Froot Loops breakfast cereal to help students master the concepts of valence electrons and chemical bonding and the implications of the duet and octet rules. Involves students working in groups to create electron dot structures for various compounds. (JRH)

  15. Digital electronics

    CERN Document Server

    Morris, John

    2013-01-01

    An essential companion to John C Morris's 'Analogue Electronics', this clear and accessible text is designed for electronics students, teachers and enthusiasts who already have a basic understanding of electronics, and who wish to develop their knowledge of digital techniques and applications. Employing a discovery-based approach, the author covers fundamental theory before going on to develop an appreciation of logic networks, integrated circuit applications and analogue-digital conversion. A section on digital fault finding and useful ic data sheets completes th

  16. Electronic diagrams

    CERN Document Server

    Colwell, Morris A

    1976-01-01

    Electronic Diagrams is a ready reference and general guide to systems and circuit planning and in the preparation of diagrams for both newcomers and the more experienced. This book presents guidelines and logical procedures that the reader can follow and then be equipped to tackle large complex diagrams by recognition of characteristic 'building blocks' or 'black boxes'. The goal is to break down many of the barriers that often seem to deter students and laymen in learning the art of electronics, especially when they take up electronics as a spare time occupation. This text is comprised of nin

  17. Electronic identity

    CERN Document Server

    de Andrade, Norberto Nuno Gomes; Argles, David

    2014-01-01

    With the increasing availability of electronic services, security and a reliable means by which identity is verified is essential.Written by Norberto Andrade the first chapter of this book provides an overview of the main legal and regulatory aspects regarding electronic identity in Europe and assesses the importance of electronic identity for administration (public), business (private) and, above all, citizens. It also highlights the role of eID as a key enabler of the economy.In the second chapter Lisha Chen-Wilson, David Argles, Michele Schiano di Zenise and Gary Wills discuss the user-cent

  18. Polymer electronics

    CERN Document Server

    Geoghegan, Mark

    2013-01-01

    Polymer electronics is the science behind many important new developments in technology, such as the flexible electronic display (e-ink) and many new developments in transistor technology. Solar cells, light-emitting diodes, and transistors are all areas where plastic electronics is likely to, or is already having, a serious impact on our daily lives. With polymer transistors and light-emitting diodes now being commercialised, there is a clear need for a pedagogic text thatdiscusses the subject in a clear and concise fashion suitable for senior undergraduate and graduate students. The content

  19. Stretchable electronics

    CERN Document Server

    Someya, Takao

    2012-01-01

    With its comprehensive coverage this handbook and ready reference brings together some of the most outstanding scientists in the field to lay down the undisputed knowledge on how to make electronics stretchable.As such, it focuses on gathering and evaluating the materials, designs, models and technologies that enable the fabrication of fully elastic electronic devices which can sustain high strain. Furthermore, it provides a review of those specific applications that directly benefit from highly compliant electronics, including transistors, photonic devices and sensors. In addition to stre

  20. Electron optics

    CERN Document Server

    Grivet, Pierre; Bertein, F; Castaing, R; Gauzit, M; Septier, Albert L

    1972-01-01

    Electron Optics, Second English Edition, Part I: Optics is a 10-chapter book that begins by elucidating the fundamental features and basic techniques of electron optics, as well as the distribution of potential and field in electrostatic lenses. This book then explains the field distribution in magnetic lenses; the optical properties of electrostatic and magnetic lenses; and the similarities and differences between glass optics and electron optics. Subsequent chapters focus on lens defects; some electrostatic lenses and triode guns; and magnetic lens models. The strong focusing lenses and pris

  1. Starting electronics

    CERN Document Server

    Brindley, Keith

    2005-01-01

    Starting Electronics is unrivalled as a highly practical introduction for hobbyists, students and technicians. Keith Brindley introduces readers to the functions of the main component types, their uses, and the basic principles of building and designing electronic circuits. Breadboard layouts make this very much a ready-to-run book for the experimenter; and the use of multimeter, but not oscilloscopes, puts this practical exploration of electronics within reach of every home enthusiast's pocket. The third edition has kept the simplicity and clarity of the original. New material

  2. Single step polymerase chain reaction (PCR for the diagnosis of the Leishmania (Viannia subgenus Reação de polimerização em cadeia (PCR em etapa única para diagnóstico de Leishmania do subgênero (Viannia

    Directory of Open Access Journals (Sweden)

    Byanca Regina Paiva

    2004-04-01

    Full Text Available In Brazil, the main etiologic agent of Leishmaniasis that frequently presents with mucosal involvement belongs to the Viannia subgenus. The therapeutic conduct in this disease depends on the parasitological diagnosis, and classical methods are restricted in identifying the agent. In this paper we describe a polymerase chain reaction (PCR, which uses primers designed from mini-exons repetitive sequences. The PCR amplifies a 177bp fragment that can distinguish (Viannia from (Leishmania subgenus. This test could be a useful diagnostic tool.No Brasil, o principal agente etiológico da leishmaniose, apresentando freqüentemente comprometimento das mucosas, pertence ao subgênero (Viannia. A conduta terapêutica no tratamento da leishmaniose depende de seu diagnóstico parasitológico e os métodos clássicos restringem sua identificação. Neste trabalho, descrevemos uma reação de PCR, utilizando primers desenhados a partir de seqüências repetitivas de mini-exons, que amplificam um fragmento de 177pb e que são capazes de distinguir o subgênero (Viannia do subgênero (Leishmania, tornando-se uma ferramenta útil no diagnóstico desta doença.

  3. Paper electronics.

    Science.gov (United States)

    Tobjörk, Daniel; Österbacka, Ronald

    2011-05-03

    Paper is ubiquitous in everyday life and a truly low-cost substrate. The use of paper substrates could be extended even further, if electronic applications would be applied next to or below the printed graphics. However, applying electronics on paper is challenging. The paper surface is not only very rough compared to plastics, but is also porous. While this is detrimental for most electronic devices manufactured directly onto paper substrates, there are also approaches that are compatible with the rough and absorptive paper surface. In this review, recent advances and possibilities of these approaches are evaluated and the limitations of paper electronics are discussed. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Electronic Cigarettes

    Science.gov (United States)

    ... Campaigns Infogallery Be Tobacco Free Search betobaccofree.gov Menu Search ABOUT TOBACCO Tobacco Facts and Figures Tobacco and Nicotine Smoked Tobacco Products Smokeless Tobacco Products Electronic Cigarettes New FDA Regulations HEALTH EFFECTS Nicotine Addiction ...

  5. Electronic Elections

    DEFF Research Database (Denmark)

    Schürmann, Carsten

    2009-01-01

    Electronic voting technology is a two edged sword. It comes with many risks but brings also many benefits. Instead of flat out rejecting the technology as uncontrollably dangerous, we advocate in this paper a different technological angle that renders electronic elections trustworthy beyond...... the usual levels of doubt. We exploit the trust that voters currently have into the democratic process and model our techniques around that observation accordingly. In particular, we propose a technique of trace emitting computations to record the individual steps of an electronic voting machine...... for a posteriori validation on an acceptably small trusted computing base. Our technology enables us to prove that an electronic elections preserves the voter’s intent, assuming that the voting machine and the trace verifier are independent....

  6. Electronic plants.

    Science.gov (United States)

    Stavrinidou, Eleni; Gabrielsson, Roger; Gomez, Eliot; Crispin, Xavier; Nilsson, Ove; Simon, Daniel T; Berggren, Magnus

    2015-11-01

    The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analogous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants' "circuitry" has never been directly merged with electronics. We report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions. With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization.

  7. Electron Microprobe

    Data.gov (United States)

    Federal Laboratory Consortium — The JEOL JXA-8600 is a conventional hairpin filament thermal emission electron microprobe that is more than 20 years old. It is capable of performing qualitative and...

  8. Spin electronics

    CERN Document Server

    Buhrman, Robert; Daughton, James; Molnár, Stephan; Roukes, Michael

    2004-01-01

    This report is a comparative review of spin electronics ("spintronics") research and development activities in the United States, Japan, and Western Europe conducted by a panel of leading U.S. experts in the field. It covers materials, fabrication and characterization of magnetic nanostructures, magnetism and spin control in magnetic nanostructures, magneto-optical properties of semiconductors, and magnetoelectronics and devices. The panel's conclusions are based on a literature review and a series of site visits to leading spin electronics research centers in Japan and Western Europe. The panel found that Japan is clearly the world leader in new material synthesis and characterization; it is also a leader in magneto-optical properties of semiconductor devices. Europe is strong in theory pertaining to spin electronics, including injection device structures such as tunneling devices, and band structure predictions of materials properties, and in development of magnetic semiconductors and semiconductor heterost...

  9. Electronic Commerce

    Energy Technology Data Exchange (ETDEWEB)

    Laird, N. [NRG Information Services Inc., Calgary, AB (Canada)

    1995-11-01

    The concept of electronic commerce in the gas industry was discussed. It was defined as the integration of communication technology, advanced information processing capability and business standards, to improve effectiveness of the business process. Examples of electronic data interchange from the automotive, airline, and banking industry were given. The objective of using this technology in the gas industry was described as the provision of one electronic facility to make seamless contractual and operational arrangements for moving natural gas across participating pipelines. The benefit of seamless integration - one readily available standard system used by several companies - was highlighted. A list of value-added services such as the free movement of bulletins, directories, nominations,and other documents was provided.

  10. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e-government/e-governance...

  11. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due to po...

  12. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e...

  13. Power electronics

    Indian Academy of Sciences (India)

    Kishore Chatterjee

    This special issue of Sadhana is a compilation of papers selected from those presented at the 7th National Power. Electronics Conference (NPEC), held at the Indian Institute of Technology, Bombay, on 21–23 December 2015. From among the papers presented in NPEC-2017, selected papers were peer-reviewed for ...

  14. Electronic Money.

    Science.gov (United States)

    Schilling, Tim

    Thirty years ago a cashless society was predicted for the near future; paper currency and checks would be an antiquated symbol of the past. Consumers would embrace a new alternative for making payments: electronic money. But currency is still used for 87% of payments, mainly for "nickel and dime" purchases. And checks are the payment…

  15. Electronic spectroscopies

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Schoonheydt, R.A.

    2000-01-01

    Diffuse reflectance spectroscopy (DRS) in the ultraviolet, visible and near-infrared region is a versatile spectroscopic technique, as both d-d and charge transfer transitions of supported TMI can be probed. One of the advantages of electronic spectroscopy is that the obtained information is

  16. Greening Electronics

    DEFF Research Database (Denmark)

    Pizzol, Massimo; Søes Kokborg, Morten; Thomsen, Marianne

    Based on a literature review with focus on hazardous substances in waste electric and electronic equipment (WEEE) and numbers from a Danish treatment facility a flow analysis for specific substances has been conducted. Further, the accessible knowledge on human and environmental effects due...

  17. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; McMullan, G

    2011-08-01

    Electron microscopy (EM) is an important tool for high-resolution structure determination in applications ranging from condensed matter to biology. Electronic detectors are now used in most applications in EM as they offer convenience and immediate feedback that is not possible with film or image plates. The earliest forms of electronic detector used routinely in transmission electron microscopy (TEM) were charge coupled devices (CCDs) and for many applications these remain perfectly adequate. There are however applications, such as the study of radiation-sensitive biological samples, where film is still used and improved detectors would be of great value. The emphasis in this review is therefore on detectors for use in such applications. Two of the most promising candidates for improved detection are: monolithic active pixel sensors (MAPS) and hybrid pixel detectors (of which Medipix2 was chosen for this study). From the studies described in this review, a back-thinned MAPS detector appears well suited to replace film in for the study of radiation-sensitive samples at 300 keV, while Medipix2 is suited to use at lower energies and especially in situations with very low count rates. The performance of a detector depends on the energy of electrons to be recorded, which in turn is dependent on the application it is being used for; results are described for a wide range of electron energies ranging from 40 to 300 keV. The basic properties of detectors are discussed in terms of their modulation transfer function (MTF) and detective quantum efficiency (DQE) as a function of spatial frequency.

  18. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF...... transistors (Part 2). The synthetic protocols rely on stepwise Sonogashira coupling reactions. Conductivity studies on various OPE-based molecular wires reveal that mere OPE compounds have a higher electrical resistance compared to the cruciform based wires (up to 9 times higher). The most spectacular result...... be potential candidates for future molecular electronics Synthesis of a new donor-acceptor chromophore based on a benzoquinone- TTF motif (QuinoneDTF) is also described herein (Part 2). Reaction of this molecule with acid induces a colour change from purple to orange. The purple colour can be restored...

  19. Electronic Nose and Electronic Tongue

    Science.gov (United States)

    Bhattacharyya, Nabarun; Bandhopadhyay, Rajib

    Human beings have five senses, namely, vision, hearing, touch, smell and taste. The sensors for vision, hearing and touch have been developed for several years. The need for sensors capable of mimicking the senses of smell and taste have been felt only recently in food industry, environmental monitoring and several industrial applications. In the ever-widening horizon of frontier research in the field of electronics and advanced computing, emergence of electronic nose (E-Nose) and electronic tongue (E-Tongue) have been drawing attention of scientists and technologists for more than a decade. By intelligent integration of multitudes of technologies like chemometrics, microelectronics and advanced soft computing, human olfaction has been successfully mimicked by such new techniques called machine olfaction (Pearce et al. 2002). But the very essence of such research and development efforts has centered on development of customized electronic nose and electronic tongue solutions specific to individual applications. In fact, research trends as of date clearly points to the fact that a machine olfaction system as versatile, universal and broadband as human nose and human tongue may not be feasible in the decades to come. But application specific solutions may definitely be demonstrated and commercialized by modulation in sensor design and fine-tuning the soft computing solutions. This chapter deals with theory, developments of E-Nose and E-Tongue technology and their applications. Also a succinct account of future trends of R&D efforts in this field with an objective of establishing co-relation between machine olfaction and human perception has been included.

  20. Electronic Government

    DEFF Research Database (Denmark)

    Wimmer, Maria A.; Traunmüller, Roland; Grönlund, Åke

    This book constitutes the refereed proceedings of the 4th International Conference on Electronic Government, EGOV 2005, held in Copenhagen, Denmark, in August 2005. The 30 revised papers presented were carefully reviewed and selected from numerous submissions, and assess the state-of-the-art in e......-government/e-governance and provide guidance for research, development and application of this emerging field. The papers are arranged in topical sections on challenges, performance, strategy, knowledge, and technology....

  1. Electronic Aggression

    Centers for Disease Control (CDC) Podcasts

    2007-11-20

    Aggression is no longer limited to the school yard. New forms of electronic media, such as blogs, instant messaging, chat rooms, email, text messaging, and the internet are providing new arenas for youth violence to occur.  Created: 11/20/2007 by National Center for Injury Prevention and Control, Division of Violence Prevention.   Date Released: 11/28/2007.

  2. Electronic discourse

    OpenAIRE

    Locher, Miriam A.

    2014-01-01

    This chapter deals with electronic discourse by discussing the pragmatics of language use in computer-mediated settings. In many so-called first world countries, accessing the Internet by means of a computer or a smartphone, etc. has become an everyday activity for many people. In only little more than twenty years of publicly accessible Internet access, the use of computer-mediated forms of communication has developed from primarily information websites and email exchanges to highly interact...

  3. FILOGENIA DE ESPECIES DEL SUBGENERO Parides (LEPIDOPTERA: PAPILIONIDAE BASADA EN SECUENCIAS DEL GEN CITOCROMO OXIDASA I Species phylogeny of the Subgenus Parides (Lepidoptera: Papilionidae Based in Sequences of Citochrome Oxidase I Gene

    Directory of Open Access Journals (Sweden)

    INGRID MARCELA GUTIÉRREZ R

    2012-12-01

    Colombia where the biota of North and South America converge. This work presents a phylogenetic hypothesis of these butterflies and proposes a more robust definition of some taxa. For this, 15 taxa of the subgenus Parides were analyzed as ingroup; species of other two genera of Troidini, closer to Parides , were used as out-group. DNA was extracted using the Pascual et al. (1997 protocol and Quiagen DNAeasy kit. A terminal fragment of Cytochrome Oxidase I gen (476 bp were amplified. We obtained a phylogenetic approximation using maximum parsimony and evaluated the branch support with Jackknife and absolute Bremer support. We also conducted a bayesian analysis. The resulting phylogenetic hypothesis suggested that Parides is a paraphyletic group; the molecular evidence support one species and five subspecies. The analyzed taxa were divided in three principal groups coincident with the Lysander (group 1 and Aeneas (groups 1 and 2 groups proposed by Rothschild and Jordan (1906.

  4. ELECTRON GUN

    Science.gov (United States)

    Christofilos, N.C.; Ehlers, K.W.

    1960-04-01

    A pulsed electron gun capable of delivering pulses at voltages of the order of 1 mv and currents of the order of 100 amperes is described. The principal novelty resides in a transformer construction which is disposed in the same vacuum housing as the electron source and accelerating electrode structure of the gun to supply the accelerating potential thereto. The transformer is provided by a plurality of magnetic cores disposed in circumferentially spaced relation and having a plurality of primary windings each inductively coupled to a different one of the cores, and a helical secondary winding which is disposed coaxially of the cores and passes therethrough in circumferential succession. Additional novelty resides in the disposition of the electron source cathode filament input leads interiorly of the transformer secondary winding which is hollow, as well as in the employment of a half-wave filament supply which is synchronously operated with the transformer supply such that the transformer is pulsed during the zero current portions of the half-wave cycle.

  5. Electronic detectors for electron microscopy.

    Science.gov (United States)

    Faruqi, A R; Henderson, R

    2007-10-01

    Due to the increasing popularity of electron cryo-microscopy (cryoEM) in the structural analysis of large biological molecules and macro-molecular complexes and the need for simple, rapid and efficient readout, there is a persuasive need for improved detectors. Commercial detectors, based on phosphor/fibre optics-coupled CCDs, provide adequate performance for many applications, including electron diffraction. However, due to intrinsic light scattering within the phosphor, spatial resolution is limited. Careful measurements suggest that CCDs have superior performance at lower resolution while all agree that film is still superior at higher resolution. Consequently, new detectors are needed based on more direct detection, thus avoiding the intermediate light conversion step required for CCDs. Two types of direct detectors are discussed in this review. First, there are detectors based on hybrid technology employing a separate pixellated sensor and readout electronics connected with bump bonds-hybrid pixel detectors (HPDs). Second, there are detectors, which are monolithic in that sensor and readout are all in one plane (monolithic active pixel sensor, MAPS). Our discussion is centred on the main parameters of interest to cryoEM users, viz. detective quantum efficiency (DQE), resolution or modulation transfer function (MTF), robustness against radiation damage, speed of readout, signal-to-noise ratio (SNR) and the number of independent pixels available for a given detector.

  6. Basic electronics

    CERN Document Server

    Tayal, DC

    2010-01-01

    The second edition of this book incorporates the comments and suggestions of my friends and students who have critically studied the first edition. In this edition the changes and additions have been made and subject matter has been rearranged at some places. The purpose of this text is to provide a comprehensive and up-to-date study of the principles of operation of solid state devices, their basic circuits and application of these circuits to various electronic systems, so that it can serve as a standard text not only for universities and colleges but also for technical institutes. This book

  7. Electronic materials

    CERN Document Server

    Kwok, H L

    2010-01-01

    The electronic properties of solids have become of increasing importance in the age of information technology. The study of solids and materials, while having originated from the disciplines of physics and chemistry, has evolved independently over the past few decades. The classical treatment of solid-state physics, which emphasized classifications, theories and fundamental physical principles, is no longer able to bridge the gap between materials advances and applications. In particular, the more recent developments in device physics and technology have not necessarily been driven by new conc

  8. Direct electron detection in transmission electron microscopy

    OpenAIRE

    Jin, Liang

    2009-01-01

    Since the first prototype of a transmission electron microscope was built in 1931 by Ernst Ruska and Max Knoll, Transmission Electron Microscopy (TEM) has proved to be an essential imaging tool for physicists, material scientists, and biologists. To record the TEM images for analysis, electron microscopists have used specialized electron micrograph film for a long time, until the new developments in TEM, such as electron tomography and cryo- electron microscopy, pushed for the needs of digita...

  9. Power Electronics

    DEFF Research Database (Denmark)

    Iov, Florin; Ciobotaru, Mihai; Blaabjerg, Frede

    2008-01-01

    The global electrical energy consumption is still rising and there is an urgent demand to increase the power capacity. It is expected that the power capacity has to be doubled within 20 years. The production, distribution and use of energy should be as efficient as possible and incentives to save...... energy at the end-user should also be set up. Deregulation of energy has in the past lowered the investment in larger power plants, which means the need for new electrical power sources will be high in the near future. Two major technologies will play important roles to solve the future problems. One...... is to change the electrical power production sources from the conventional, fossil (and short term) based energy sources to renewable energy resources. The other is to use high efficient power electronics in power generation, power transmission/distribution and end-user application. This paper discuss the most...

  10. Scanning transmission electron microscope

    OpenAIRE

    Kruit, P.

    2006-01-01

    The invention relates to a scanning transmission electron microscope comprising an electron source, an electron accelerator and deflection means for directing electrons emitted by the electron source at an object to be examined, and in addition a detector for detecting electrons coming from the object and, connected to the detector, a device for processing the detected electrons so as to form an object image, wherein a beam splitter is provided for dividing the electron beam from the electron...

  11. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    2013-01-01

    Practical Electronics Handbook, Third Edition provides the frequently used and highly applicable principles of electronics and electronic circuits.The book contains relevant information in electronics. The topics discussed in the text include passive and active discrete components; linear and digital I.C.s; microprocessors and microprocessor systems; digital-analogue conversions; computer aids in electronics design; and electronic hardware components.Electronic circuit constructors, service engineers, electronic design engineers, and anyone with an interest in electronics will find the book ve

  12. Sustainable Management of Electronics

    Science.gov (United States)

    To provide information on EPAs strategy for electronics stewardship, certified electronics recyclers and the Challenge; as well as where to donate unwanted electronics, how to calculate benefits, and what's going on with electronics mgmt in their states.

  13. EDITORIAL: Synaptic electronics Synaptic electronics

    Science.gov (United States)

    Demming, Anna; Gimzewski, James K.; Vuillaume, Dominique

    2013-09-01

    Conventional computers excel in logic and accurate scientific calculations but make hard work of open ended problems that human brains handle easily. Even von Neumann—the mathematician and polymath who first developed the programming architecture that forms the basis of today's computers—was already looking to the brain for future developments before his death in 1957 [1]. Neuromorphic computing uses approaches that better mimic the working of the human brain. Recent developments in nanotechnology are now providing structures with very accommodating properties for neuromorphic approaches. This special issue, with guest editors James K Gimzewski and Dominique Vuillaume, is devoted to research at the serendipitous interface between the two disciplines. 'Synaptic electronics', looks at artificial devices with connections that demonstrate behaviour similar to synapses in the nervous system allowing a new and more powerful approach to computing. Synapses and connecting neurons respond differently to incident signals depending on the history of signals previously experienced, ultimately leading to short term and long term memory behaviour. The basic characteristics of a synapse can be replicated with around ten simple transistors. However with the human brain having around 1011 neurons and 1015 synapses, artificial neurons and synapses from basic transistors are unlikely to accommodate the scalability required. The discovery of nanoscale elements that function as 'memristors' has provided a key tool for the implementation of synaptic connections [2]. Leon Chua first developed the concept of the 'The memristor—the missing circuit element' in 1971 [3]. In this special issue he presents a tutorial describing how memristor research has fed into our understanding of synaptic behaviour and how they can be applied in information processing [4]. He also describes, 'The new principle of local activity, which uncovers a minuscule life-enabling "Goldilocks zone", dubbed the

  14. Scanning transmission electron microscope

    NARCIS (Netherlands)

    Kruit, P.

    2006-01-01

    The invention relates to a scanning transmission electron microscope comprising an electron source, an electron accelerator and deflection means for directing electrons emitted by the electron source at an object to be examined, and in addition a detector for detecting electrons coming from the

  15. Carbon Nanotube Electron Gun

    Science.gov (United States)

    Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

    2013-01-01

    An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

  16. A sugar pine consensus map: Comparative mapping between the Pinus subgenus Pinus and the subgenus Strobus

    Science.gov (United States)

    Kathleen D. Jermstad; Andrew J. Eckert; Bohun B. Kinloch; Dean A. Davis; Deems C. Burton; Annette D. Mix; Jill L. Wegrzyn; David B. Neale

    2011-01-01

    We have constructed a consensus genetic linkage map for sugar pine using three mapping populations that segregate for resistance to white pine blister rust, a disease caused by the fungal pathogen Cronartium ribicola. The major gene of resistance, Cr1, was mapped in two of the populations and included in the consensus map, which contains 400 markers organized into 19...

  17. Electronics for LHC Experiments

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    This document gathers the abstracts of most presentations made at this workshop on electronics for the large hadron collider (LHC) experiments. The presentations were arranged into 6 sessions: 1) electronics for tracker, 2) trigger electronics, 3) detector control systems, 4) data acquisition, 5) electronics for calorimeters and electronics for muons, and 6) links, power systems, grounding and shielding, testing and quality assurance.

  18. Electronic Design Automation Using Object Oriented Electronics

    OpenAIRE

    Walid M. Aly; Mohamed S. Abuelnasr

    2010-01-01

    Problem statement: Electronic design automation is the usage of computer technology and software tools for designing integrated electronic system and creating electrical schematics. Approach: An approach is presented for modeling of various electronic and electric devices using object oriented design, aiming on building a library of devices (classes) which can be used for electronic design automation. Results: The presented library was implemented using Java programming language to form an El...

  19. Electron Microscopy Center (EMC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

  20. Hybrid printed electronics

    NARCIS (Netherlands)

    Koetse, M.; Smits, E.; Rubingh, E.; Teunissen, P.; Kusters, R.; Abbel, R.; Brand, J. van den

    2016-01-01

    Although many electronic functionalities can be realized by printed or organic electronics, short-term marketable products often require robust, reproducible, and nondisturbing technologies. In this chapter we show how hybrid electronics, a combination of printed circuitry, thin-film electronics,

  1. Concepts in spin electronics

    CERN Document Server

    2006-01-01

    A new branch of physics and nanotechnology called spin electronics has emerged, which aims at simultaneously exploiting the charge and spin of electrons in the same device. The aim of this book is to present new directions in the development of spin electronics in both the basic physics and the future electronics.

  2. Introduction to Electronic Marketing.

    Science.gov (United States)

    Dilbeck, Lettie

    These materials for a five-unit course were developed to introduce secondary and postsecondary students to the use of electronic equipment in marketing. The units cover the following topics: electronic marketing as a valid marketing approach; telemarketing; radio electronic media marketing; television electronic media marketing; and cable TV…

  3. Introduction to electronics

    CERN Multimedia

    CERN. Geneva

    2005-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  4. Introduction to Electronics course

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    Electronics in HEP experiments: specificities and evolution The Art of Electronics: is there something beyond Ohm's law? Basic building blocks of Analog electronics: quickly understanding a schematic Charge preamps, current preamps and future preamps, shaping and the rest Electronics noise: fundamental and practical Evolution of technology: ASICs, FPGAs...

  5. Atomicity in Electronic Commerce,

    Science.gov (United States)

    1996-01-01

    Atomicity in Electronic Commerce J. D. Tygar January 1996 CMU-CS-96-112 School of Computer Science Carnegie Mellon University Pittsburgh, PA 15213...other research sponsor. Keywords: electronic commerce , atomicity, NetBill, IBIP, cryptography, transaction pro- cessing, ACID, franking, electronic ...goods over networks. Electronic commerce has inspired a large variety of work. Unfortunately, much of that work ignores traditional transaction

  6. The leaf surface strucure of the species from the subgenus Sedum of the genus Sedum L. (Crassulaceae DC. from the protected soil collections of A.V. Fomin Botanical Garden

    Directory of Open Access Journals (Sweden)

    Mykola V. Yatsenko

    2013-04-01

    Full Text Available By means of light and scanning electron microscopy (SEM the structure of leaf ’s epidermis of 8 species of genus SedumL. was investigated. A number of common (amphistomatics, anisocytic type of stomatal complex, strum cuticle and different signs have been revealed in the structure of the leaf ’s tissue. The results acquired on the basis of micromorphology of a leaf ’s epidermis can be used in the taxonomy of the investigated Sedumspecies.

  7. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  8. Electronics engineer's reference book

    CERN Document Server

    Mazda, F F

    1989-01-01

    Electronics Engineer's Reference Book, Sixth Edition is a five-part book that begins with a synopsis of mathematical and electrical techniques used in the analysis of electronic systems. Part II covers physical phenomena, such as electricity, light, and radiation, often met with in electronic systems. Part III contains chapters on basic electronic components and materials, the building blocks of any electronic design. Part IV highlights electronic circuit design and instrumentation. The last part shows the application areas of electronics such as radar and computers.

  9. Scanning ultrafast electron microscopy

    OpenAIRE

    Yang, Ding-Shyue; Mohammed, Omar F.; Zewail, Ahmed H.

    2010-01-01

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for whic...

  10. Practical microwave electron devices

    CERN Document Server

    Meurant, Gerard

    2013-01-01

    Practical Microwave Electron Devices provides an understanding of microwave electron devices and their applications. All areas of microwave electron devices are covered. These include microwave solid-state devices, including popular microwave transistors and both passive and active diodes; quantum electron devices; thermionic devices (including relativistic thermionic devices); and ferrimagnetic electron devices. The design of each of these devices is discussed as well as their applications, including oscillation, amplification, switching, modulation, demodulation, and parametric interactions.

  11. Electronics engineer's reference book

    CERN Document Server

    Turner, L W

    1976-01-01

    Electronics Engineer's Reference Book, 4th Edition is a reference book for electronic engineers that reviews the knowledge and techniques in electronics engineering and covers topics ranging from basics to materials and components, devices, circuits, measurements, and applications. This edition is comprised of 27 chapters; the first of which presents general information on electronics engineering, including terminology, mathematical equations, mathematical signs and symbols, and Greek alphabet and symbols. Attention then turns to the history of electronics; electromagnetic and nuclear radiatio

  12. Electron-electron interactions in disordered systems

    CERN Document Server

    Efros, AL

    1985-01-01

    ``Electron-Electron Interactions in Disordered Systems'' deals with the interplay of disorder and the Coulomb interaction. Prominent experts give state-of-the-art reviews of the theoretical and experimental work in this field and make it clear that the interplay of the two effects is essential, especially in low-dimensional systems.

  13. Single electron-ics with carbon nanotubes

    NARCIS (Netherlands)

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for

  14. VIRTUAL ELECTRONIC COMPONENTS OF THE ELECTRONIC EQUIPMENT

    Directory of Open Access Journals (Sweden)

    E. Lazarevich

    2013-01-01

    Full Text Available The article is present new idea of the creation, developments and improvements of the electronic equipment of complex systems by means of the virtual electronic components. The idea of the virtual electronic components is a presentation and perception of the creation and developments of the equipment on two forming: real – in the manner of standard marketed block of the intellectual property and image – in the manner of virtual component. The real component in most cases slows the development of the electronic equipment. The imaginary component is the «locomotive» of development of the electronic equipment. The Imaginary component contains the scientific has brushed against developer. The scientific has brushed against developer reveals of itself in the manner of virtual component on the modern level of the design rates of microelectronics.

  15. Electronics for dummies

    CERN Document Server

    Shamieh

    2015-01-01

    Explore the basic concepts of electronics, build your electronics workbench, and begin creating fun electronics projects right away! Electronics For Dummies, 3rd Edition is your guide to the world of electronics. Spanning circuitry, wiring, robotics, transmitters, amplifiers, and more, this book demystifies electricity basics and beyond. The third edition offers new content revised to reflect the latest advancements in the electronics field, and it offers full color project examples to spark your creativity and inspire you to put your new skills to use! Packed with projects that can be comple

  16. Laboratory Handbook Electronics

    CERN Multimedia

    1966-01-01

    Laboratory manual 1966 format A3 with the list of equipment cables, electronic tubes, chassis, diodes transistors etc. One of CERN's first material catalogue for construction components for mechanical and electronic chassis.

  17. Certified Electronics Recyclers

    Science.gov (United States)

    Learn how EPA encourages all electronics recyclers become certified by demonstrating to an accredited, independent third-party auditor and that they meet specific standards to safely recycle and manage electronics.

  18. Electronic Science Seminar

    Directory of Open Access Journals (Sweden)

    Geidarov P.Sh.

    2015-09-01

    Full Text Available The structure of electronic scientific seminar, which provides a high level of quality of the objectivity in the evaluation of scientific papers, including dissertations, is described. Conditions for the implementation of electronic scientific seminar are also considered.

  19. THE ELECTRONIC SIGNATURE

    Directory of Open Access Journals (Sweden)

    Voiculescu Madalina Irena

    2009-05-01

    Full Text Available Article refers to significance and the digital signature in electronic commerce. Internet and electronic commerce open up many new opportunities for the consumer, yet, the security (or perceived lack of security of exchanging personal and financial data

  20. Joint Services Electronics Program.

    Science.gov (United States)

    1983-09-30

    Compound Semiconductors." 4 ......... I-*. Univesity of California. Berkeley Electronics Research Laboratory Joint Services Electronics Program August 15...reduction techniques [SCH-66,MCG- 73,HAM-75], for essentially i educing the proportionality constant. A significant portion of the probabilistic literature

  1. Extreme environment electronics

    CERN Document Server

    Cressler, John D

    2012-01-01

    Unfriendly to conventional electronic devices, circuits, and systems, extreme environments represent a serious challenge to designers and mission architects. The first truly comprehensive guide to this specialized field, Extreme Environment Electronics explains the essential aspects of designing and using devices, circuits, and electronic systems intended to operate in extreme environments, including across wide temperature ranges and in radiation-intense scenarios such as space. The Definitive Guide to Extreme Environment Electronics Featuring contributions by some of the world's foremost exp

  2. Netiquette in Electronic Communication

    OpenAIRE

    Tomáš Kozík; Jozefína Slivová

    2014-01-01

    Electronic mail and electronic communications systems are considered significant and effective tools of communication. One of the most widespread electronic communication tools is e - mail communication. In order to avoid misinterpretation of the report on the side of the recipient, it is need to pay attention to the writing of e - mail messages as well as to their content. With the continuous expansion of the use of electronic communication there have gradually developed certain rules of...

  3. Handbook on electronic commerce

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, M. [Illinois Univ., Urbana, IL (United States). Beckman Inst. for Advanced Science and Technology; Blanning, R. [Vanderbilt Univ., Nashville, TN (United States). Owen Graduate School of Management; Strader, T. [Iowa State Univ., Ames, IA (United States). Management Information Systems; Whinston, A. [eds.] [Texas Univ., Austin, TX (United States). Dept. of Management Science and Information Systems

    2000-07-01

    The world is undergoing a revolution to a digital economy, with pronounced implications for corporate strategy, marketing, operations, information systems, customer services, global supply-chain management, and product distribution. This handbook examines the aspects of electronic commerce, including electronic storefront, on-line business, consumer interface, business-to-business networking, digital payment, legal issues, information product development, and electronic business models. Indispensable for academics, students and professionals who are interested in Electronic Commerce and Internet Business. (orig.)

  4. Electronics and computer acronyms

    CERN Document Server

    Brown, Phil

    1988-01-01

    Electronics and Computer Acronyms presents a list of almost 2,500 acronyms related to electronics and computers. The material for this book is drawn from a number of subject areas, including electrical, electronics, computers, telecommunications, fiber optics, microcomputers/microprocessors, audio, video, and information technology. The acronyms also encompass avionics, military, data processing, instrumentation, units, measurement, standards, services, organizations, associations, and companies. This dictionary offers a comprehensive and broad view of electronics and all that is associated wi

  5. Electronic Toll System

    OpenAIRE

    Kotěšovec, Václav

    2017-01-01

    This thesis deals with the functioning of the electronic toll system. The first section describes the electronic fee collection, the architecture of the electronic toll collection system and the EU transport policy. The next section describes the electronic fee collection in the Czech republic and neighbouring countries. As a conclusion is a personal recommendation for a better functioning of the system in the Czech republic.

  6. Syringe-injectable electronics.

    Science.gov (United States)

    Liu, Jia; Fu, Tian-Ming; Cheng, Zengguang; Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M

    2015-07-01

    Seamless and minimally invasive three-dimensional interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating the syringe injection (and subsequent unfolding) of sub-micrometre-thick, centimetre-scale macroporous mesh electronics through needles with a diameter as small as 100 μm. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with >90% device yield. We demonstrate several applications of syringe-injectable electronics as a general approach for interpenetrating flexible electronics with three-dimensional structures, including (1) monitoring internal mechanical strains in polymer cavities, (2) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (3) in vivo multiplexed neural recording. Moreover, syringe injection enables the delivery of flexible electronics through a rigid shell, the delivery of large-volume flexible electronics that can fill internal cavities, and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics.

  7. Syringe injectable electronics

    Science.gov (United States)

    Hong, Guosong; Zhou, Tao; Jin, Lihua; Duvvuri, Madhavi; Jiang, Zhe; Kruskal, Peter; Xie, Chong; Suo, Zhigang; Fang, Ying; Lieber, Charles M.

    2015-01-01

    Seamless and minimally-invasive three-dimensional (3D) interpenetration of electronics within artificial or natural structures could allow for continuous monitoring and manipulation of their properties. Flexible electronics provide a means for conforming electronics to non-planar surfaces, yet targeted delivery of flexible electronics to internal regions remains difficult. Here, we overcome this challenge by demonstrating syringe injection and subsequent unfolding of submicrometer-thick, centimeter-scale macroporous mesh electronics through needles with a diameter as small as 100 micrometers. Our results show that electronic components can be injected into man-made and biological cavities, as well as dense gels and tissue, with > 90% device yield. We demonstrate several applications of syringe injectable electronics as a general approach for interpenetrating flexible electronics with 3D structures, including (i) monitoring of internal mechanical strains in polymer cavities, (ii) tight integration and low chronic immunoreactivity with several distinct regions of the brain, and (iii) in vivo multiplexed neural recording. Moreover, syringe injection enables delivery of flexible electronics through a rigid shell, delivery of large volume flexible electronics that can fill internal cavities and co-injection of electronics with other materials into host structures, opening up unique applications for flexible electronics. PMID:26053995

  8. EFFECTIVE ELECTRONIC TUTORIAL

    Directory of Open Access Journals (Sweden)

    Andrei A. Fedoseev

    2014-01-01

    Full Text Available The article analyzes effective electronic tutorials creation and application based on the theory of pedagogy. Herewith the issues of necessary electronic tutorial functional, ways of the educational process organization with the use of information and communication technologies and the logistics of electronic educational resources are touched upon. 

  9. Arduino electronics blueprints

    CERN Document Server

    Wilcher, Don

    2015-01-01

    This book is intended for those who want to learn about electronics and coding by building amazing devices and gadgets with Arduino. If you are an experienced developer who understands the basics of electronics, then you can quickly learn how to build smart devices using Arduino. The only experience needed is a desire to learn about electronics, circuit breadboarding, and coding.

  10. Electronic recordkeeping: An introduction

    Energy Technology Data Exchange (ETDEWEB)

    Deken, J.M.

    2000-01-19

    This paper begins with a brief overview of records and archival management before the advent of the electronic era; then describe the ways in which the definitions and constructs of archives and records management have been altered in the electronic environment; and outlines the various approaches to the challenges of electronic recordkeeping that are currently being investigated and applied.

  11. ELECTRONS IN NONPOLAR LIQUIDS.

    Energy Technology Data Exchange (ETDEWEB)

    HOLROYD,R.A.

    2002-10-22

    Excess electrons can be introduced into liquids by absorption of high energy radiation, by photoionization, or by photoinjection from metal surfaces. The electron's chemical and physical properties can then be measured, but this requires that the electrons remain free. That is, the liquid must be sufficiently free of electron attaching impurities for these studies. The drift mobility as well as other transport properties of the electron are discussed here as well as electron reactions, free-ion yields and energy levels, Ionization processes typically produce electrons with excess kinetic energy. In liquids during thermalization, where this excess energy is lost to bath molecules, the electrons travel some distance from their geminate positive ions. In general the electrons at this point are still within the coulombic field of their geminate ions and a large fraction of the electrons recombine. However, some electrons escape recombination and the yield that escapes to become free electrons and ions is termed G{sub fi}. Reported values of G{sub fi} for molecular liquids range from 0.05 to 1.1 per 100 eV of energy absorbed. The reasons for this 20-fold range of yields are discussed here.

  12. Single electron-ics with carbon nanotubes

    OpenAIRE

    Götz, G.T.J.

    2010-01-01

    We experimentally investigate Quantum Dots, formed in Carbon Nanotubes. The first part of this thesis deals with charge sensing on such quantum dots. The charge sensor is a metallic Single-electron-transistor, sensitive to the charge of a single electron on the quantum dot. We use this technique for real-time charge readout and precise tuning of the tunnel barriers of the quantum dot. The second part of this thesis describes the realization of exceptionally clean Carbon Nanotube quantum dots....

  13. Soldering in electronics assembly

    CERN Document Server

    Judd, Mike

    2013-01-01

    Soldering in Electronics Assembly discusses several concerns in soldering of electronic assemblies. The book is comprised of nine chapters that tackle different areas in electronic assembly soldering. Chapter 1 discusses the soldering process itself, while Chapter 2 covers the electronic assemblies. Chapter 3 talks about solders and Chapter 4 deals with flux. The text also tackles the CS and SC soldering process. The cleaning of soldered assemblies, solder quality, and standards and specifications are also discussed. The book will be of great use to professionals who deal with electronic assem

  14. Automotive electronics design fundamentals

    CERN Document Server

    Zaman, Najamuz

    2015-01-01

    This book explains the topology behind automotive electronics architectures and examines how they can be profoundly augmented with embedded controllers. These controllers serve as the core building blocks of today’s vehicle electronics. Rather than simply teaching electrical basics, this unique resource focuses on the fundamental concepts of vehicle electronics architecture, and details the wide variety of Electronic Control Modules (ECMs) that enable the increasingly sophisticated "bells & whistles" of modern designs.  A must-have for automotive design engineers, technicians working in automotive electronics repair centers and students taking automotive electronics courses, this guide bridges the gap between academic instruction and industry practice with clear, concise advice on how to design and optimize automotive electronics with embedded controllers.

  15. Electronic equipment packaging technology

    CERN Document Server

    Ginsberg, Gerald L

    1992-01-01

    The last twenty years have seen major advances in the electronics industry. Perhaps the most significant aspect of these advances has been the significant role that electronic equipment plays in almost all product markets. Even though electronic equipment is used in a broad base of applications, many future applications have yet to be conceived. This versatility of electron­ ics has been brought about primarily by the significant advances that have been made in integrated circuit technology. The electronic product user is rarely aware of the integrated circuits within the equipment. However, the user is often very aware of the size, weight, mod­ ularity, maintainability, aesthetics, and human interface features of the product. In fact, these are aspects of the products that often are instrumental in deter­ mining its success or failure in the marketplace. Optimizing these and other product features is the primary role of Electronic Equipment Packaging Technology. As the electronics industry continues to pr...

  16. Scanning ultrafast electron microscopy.

    Science.gov (United States)

    Yang, Ding-Shyue; Mohammed, Omar F; Zewail, Ahmed H

    2010-08-24

    Progress has been made in the development of four-dimensional ultrafast electron microscopy, which enables space-time imaging of structural dynamics in the condensed phase. In ultrafast electron microscopy, the electrons are accelerated, typically to 200 keV, and the microscope operates in the transmission mode. Here, we report the development of scanning ultrafast electron microscopy using a field-emission-source configuration. Scanning of pulses is made in the single-electron mode, for which the pulse contains at most one or a few electrons, thus achieving imaging without the space-charge effect between electrons, and still in ten(s) of seconds. For imaging, the secondary electrons from surface structures are detected, as demonstrated here for material surfaces and biological specimens. By recording backscattered electrons, diffraction patterns from single crystals were also obtained. Scanning pulsed-electron microscopy with the acquired spatiotemporal resolutions, and its efficient heat-dissipation feature, is now poised to provide in situ 4D imaging and with environmental capability.

  17. Engineered phages for electronics.

    Science.gov (United States)

    Cui, Yue

    2016-11-15

    Phages are traditionally widely studied in biology and chemistry. In recent years, engineered phages have attracted significant attentions for functionalization or construction of electronic devices, due to their specific binding, catalytic, nucleating or electronic properties. To apply the engineered phages in electronics, these are a number of interesting questions: how to engineer phages for electronics? How are the engineered phages characterized? How to assemble materials with engineered phages? How are the engineered phages micro or nanopatterned? What are the strategies to construct electronics devices with engineered phages? This review will highlight the early attempts to address these questions and explore the fundamental and practical aspects of engineered phages in electronics, including the approaches for selection or expression of specific peptides on phage coat proteins, characterization of engineered phages in electronics, assembly of electronic materials, patterning of engineered phages, and construction of electronic devices. It provides the methodologies and opens up ex-cit-ing op-por-tu-ni-ties for the development of a variety of new electronic materials and devices based on engineered phages for future applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Electronic Publishing or Electronic Information Handling?

    Science.gov (United States)

    Heck, A.

    The current dramatic evolution in information technology is bringing major modifications in the way scientists communicate. The concept of 'electronic publishing' is too restrictive and has often different, sometimes conflicting, interpretations. It is thus giving way to the broader notion of 'electronic information handling' encompassing the diverse types of information, the different media, as well as the various communication methodologies and technologies. New problems and challenges result also from this new information culture, especially on legal, ethical, and educational grounds. The procedures for validating 'published material' and for evaluating scientific activities will have to be adjusted too. 'Fluid' information is becoming a common concept. Electronic publishing cannot be conceived without link to knowledge bases nor without intelligent information retrieval tools.

  19. Colliding Electrons - Workhorses of Gaseous Electronics

    Science.gov (United States)

    McConkey, Bill

    2004-09-01

    The need for electron scattering data to explain the various observed phenomena encountered in electric discharges through gases and indeed in plasmas of all types, has provided strong motivation to collision physicists over the years to carry out the appropriate measurements and calculations. The field has been continually stimulated by new discoveries in such diverse areas as planetary atmosphere processes, low and high temperature plasma physics, lasers and radiation chemistry. In addition, electron collisions undergird the efficient operation of a multitude of practical devices and industrial processes. This talk will seek to give a flavor of what has been happening in this field, particularly over the past half-century.

  20. Electron transfer in proteins

    DEFF Research Database (Denmark)

    Farver, O; Pecht, I

    1991-01-01

    Electron migration between and within proteins is one of the most prevalent forms of biological energy conversion processes. Electron transfer reactions take place between active centers such as transition metal ions or organic cofactors over considerable distances at fast rates and with remarkable...... specificity. The electron transfer is attained through weak electronic interaction between the active sites, so that considerable research efforts are centered on resolving the factors that control the rates of long-distance electron transfer reactions in proteins. These factors include (in addition......-containing proteins. These proteins serve almost exclusively in electron transfer reactions, and as it turns out, their metal coordination sites are endowed with properties uniquely optimized for their function....

  1. Introduction to printed electronics

    CERN Document Server

    Suganuma, Katsuaki

    2014-01-01

    This book describes in detail modern technologies for printed electronics, explaining how nanotechnology and modern printing technology are merging to revolutionize electronics fabrication of thin, lightweight, large, and inexpensive products. Readers will benefit from the explanations of materials, devices and circuits used to design and implement the latest applications of printed electronics, such as thin flexible OLED displays, organic solar cells, OLED lighting, smart wallpaper, sensors, logic, memory and more.

  2. Electrons in silicon microstructures.

    Science.gov (United States)

    Howard, R E; Jackel, L D; Mankiewich, P M; Skocpol, W J

    1986-01-24

    Silicon microstructures only a few hundred atoms wide can be fabricated and used to study electron transport in narrow channels. Spatially localized voltage probes as close together as 0.1 micrometer can be used to investigate a variety of physical phenomena, including velocity saturation due to phonon emission, the local potentials caused by scattering from a single trapped electron, and quantum tunneling or hopping among very few electron states.

  3. Green and biodegradable electronics

    OpenAIRE

    Irimia-Vladu, Mihai; Głowacki, Eric. D.; Voss, Gundula; Bauer, Siegfried; Sariciftci, Niyazi Serdar

    2012-01-01

    We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials sugg...

  4. Technology of Electronic Signatur

    Directory of Open Access Journals (Sweden)

    Jaroslav Sadovsky

    2004-01-01

    Full Text Available An electronic signature uses a hash of message and an asymetrical algorithm of encryption for its generation. During verification of message on receiver side the hash of original message must be identical with the hash of received message. Electronic message is secured autentization of author and integrity of transmission date. By electronic signature it is possible to sign everything what is in digital form.

  5. Modern electronic materials

    CERN Document Server

    Watkins, John B

    2013-01-01

    Modern Electronic Materials focuses on the development of electronic components. The book first discusses the history of electronic components, including early developments up to 1900, developments up to World War II, post-war developments, and a comparison of present microelectric techniques. The text takes a look at resistive materials. Topics include resistor requirements, basic properties, evaporated film resistors, thick film resistors, and special resistors. The text examines dielectric materials. Considerations include basic properties, evaporated dielectric materials, ceramic dielectri

  6. Electronic collection management

    CERN Document Server

    Mcginnis, Suzan D

    2013-01-01

    Build and manage your collection of digital resources with these successful strategies! This comprehensive volume is a practical guide to the art and science of acquiring and organizing electronic resources. The collections discussed here range in size from small college libraries to large research libraries, but all are facing similar problems: shrinking budgets, increasing demands, and rapidly shifting formats. Electronic Collection Management offers new ideas for coping with these issues. Bringing together diverse aspects of collection development, Electronic Collection

  7. Introduction to electronics

    CERN Document Server

    Korneff, Theodore

    1966-01-01

    Introduction to Electronics focuses on the study of electronics and electronic devices. Composed of 14 chapters, the book starts with discussions on dc circuits, including resistance, voltmeter, ammeter, galvanometer, internal resistance, and positive and negative currents. This topic is followed by discussions on ac circuits, particularly addressing voltage and current, average power, resistive load, complex plane, and parallel circuits. Discussions also focus on filters and tuned circuits, diodes, and power supplies. Particularly given attention are the processes, diagrams, and analyses

  8. Nonadiabatic electron heat pump

    OpenAIRE

    Rey, Miguel; Strass, Michael; Kohler, Sigmund; Hänggi, Peter; Sols, Fernando

    2006-01-01

    We investigate a mechanism for extracting heat from metallic conductors based on the energy-selective transmission of electrons through a spatially asymmetric resonant structure subject to ac driving. This quantum refrigerator can operate at zero net electronic current as it replaces hot by cold electrons through two energetically symmetric inelastic channels. We present numerical results for a specific heterostructure and discuss general trends. We also explore the conditions under which the...

  9. Fundamentals of electronics

    CERN Document Server

    Schubert, Thomas F

    2015-01-01

    This book, Electronic Devices and Circuit Application, is the first of four books of a larger work, Fundamentals of Electronics. It is comprised of four chapters describing the basic operation of each of the four fundamental building blocks of modern electronics: operational amplifiers, semiconductor diodes, bipolar junction transistors, and field effect transistors. Attention is focused on the reader obtaining a clear understanding of each of the devices when it is operated in equilibrium. Ideas fundamental to the study of electronic circuits are also developed in the book at a basic level to

  10. Electron correlation in molecules

    CERN Document Server

    Wilson, S

    2007-01-01

    Electron correlation effects are of vital significance to the calculation of potential energy curves and surfaces, the study of molecular excitation processes, and in the theory of electron-molecule scattering. This text describes methods for addressing one of theoretical chemistry's central problems, the study of electron correlation effects in molecules.Although the energy associated with electron correlation is a small fraction of the total energy of an atom or molecule, it is of the same order of magnitude as most energies of chemical interest. If the solution of quantum mechanical equatio

  11. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2007-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Each chapter ends with a set

  12. Electronics circuits and systems

    CERN Document Server

    Bishop, Owen

    2011-01-01

    The material in Electronics - Circuits and Systems is a truly up-to-date textbook, with coverage carefully matched to the electronics units of the 2007 BTEC National Engineering and the latest AS and A Level specifications in Electronics from AQA, OCR and WJEC. The material has been organized with a logical learning progression, making it ideal for a wide range of pre-degree courses in electronics. The approach is student-centred and includes: numerous examples and activities; web research topics; Self Test features, highlighted key facts, formulae and definitions. Ea

  13. Flexible Electronics Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Flexible Electronics Research Facility designs, synthesizes, tests, and fabricates materials and devices compatible with flexible substrates for Army information...

  14. Electronic signal conditioning

    CERN Document Server

    NEWBY, BRUCE

    1994-01-01

    At technician level, brief references to signal conditioning crop up in a fragmented way in various textbooks, but there has been no single textbook, until now!More advanced texts do exist but they are more mathematical and presuppose a higher level of understanding of electronics and statistics. Electronic Signal Conditioning is designed for HNC/D students and City & Guilds Electronics Servicing 2240 Parts 2 & 3. It will also be useful for BTEC National, Advanced GNVQ, A-level electronics and introductory courses at degree level.

  15. Electronics pocket book

    CERN Document Server

    Parr, E A

    1981-01-01

    Electronics Pocket Book, Fourth Edition is a nonmathematical presentation of the many varied topics covered by electronics. The book tackles electron physics, electronic components (i.e. resistors, capacitors, and conductors), integrated circuits, and the principles of a.c. and d.c. amplifiers. The text also discusses oscillators, digital circuits, digital computers, and optoelectronics (i.e., sensors, emitters, and devices that utilize light). Communications (such as line and radio communications, transmitters, receivers, and digital techniques); the principles and examples of servosystems; a

  16. Flying Electronic Warfare Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Provides NP-3D aircraft host platforms for Effectiveness of Navy Electronic Warfare Systems (ENEWS) Program antiship missile (ASM) seeker simulators used...

  17. Analytical Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — The Titan 80-300 is a transmission electron microscope (TEM) equipped with spectroscopic detectors to allow chemical, elemental, and other analytical measurements to...

  18. High-power electronics

    CERN Document Server

    Kapitsa, Petr Leonidovich

    1966-01-01

    High-Power Electronics, Volume 2 presents the electronic processes in devices of the magnetron type and electromagnetic oscillations in different systems. This book explores the problems of electronic energetics.Organized into 11 chapters, this volume begins with an overview of the motion of electrons in a flat model of the magnetron, taking into account the in-phase wave and the reverse wave. This text then examines the processes of transmission of electromagnetic waves of various polarization and the wave reflection from grids made of periodically distributed infinite metal conductors. Other

  19. Electronic circuits fundamentals & applications

    CERN Document Server

    Tooley, Mike

    2015-01-01

    Electronics explained in one volume, using both theoretical and practical applications.New chapter on Raspberry PiCompanion website contains free electronic tools to aid learning for students and a question bank for lecturersPractical investigations and questions within each chapter help reinforce learning Mike Tooley provides all the information required to get to grips with the fundamentals of electronics, detailing the underpinning knowledge necessary to appreciate the operation of a wide range of electronic circuits, including amplifiers, logic circuits, power supplies and oscillators. The

  20. Smart Electronic Textiles.

    Science.gov (United States)

    Weng, Wei; Chen, Peining; He, Sisi; Sun, Xuemei; Peng, Huisheng

    2016-05-17

    This Review describes the state-of-the-art of wearable electronics (smart textiles). The unique and promising advantages of smart electronic textiles are highlighted by comparing them with the conventional planar counterparts. The main kinds of smart electronic textiles based on different functionalities, namely the generation, storage, and utilization of electricity, are then discussed with an emphasis on the use of functional materials. The remaining challenges are summarized together with important new directions to provide some useful clues for the future development of smart electronic textiles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Electron caustic lithography

    Directory of Open Access Journals (Sweden)

    S. M. Kennedy

    2012-06-01

    Full Text Available A maskless method of electron beam lithography is described which uses the reflection of an electron beam from an electrostatic mirror to produce caustics in the demagnified image projected onto a resist–coated wafer. By varying the electron optics, e.g. via objective lens defocus, both the morphology and dimensions of the caustic features may be controlled, producing a range of bright and tightly focused projected features. The method is illustrated for line and fold caustics and is complementary to other methods of reflective electron beam lithography.

  2. Electronics Environmental Benefits Calculator

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Electronics Environmental Benefits Calculator (EEBC) was developed to assist organizations in estimating the environmental benefits of greening their purchase,...

  3. Electronic Service Statistics - Quarterly Report

    Data.gov (United States)

    Social Security Administration — This is a quarterly report that compares electronic data vs non-electronic data for electronic services. Report contains six main sections namely, electronic access,...

  4. NanoElectronics and BioElectronics

    Science.gov (United States)

    Srivastava, Deepak

    2001-01-01

    This viewgraph presentation reviews the use of Carbon Nanotube electronics in the bioelectronics. Included is a brief review of the carbon nanotube manufacturing, the use of carbon nanotubes in Atomic Force Microscopy (AFM), and Computational Nanotechnology, that allows designers to understand nanotube characteristics and serves as a design tool.

  5. Electrons in Condensed Matter

    Indian Academy of Sciences (India)

    entire liquid or solid. The variety of electronic behaviour which ... sity of electronic behaviour in condensed matter, ego ferro- ..... a big dog? We do not know the reasons yet. As it turns out for many fundamentally interesting phenomena, colossal magneto- resistance may also find applications, this time in magnetic recording.

  6. Managing electronic records

    CERN Document Server

    McLeod, Julie

    2005-01-01

    For records management courses, this book covers the theory and practice of managing electronic records as business and information assets. It focuses on the strategies, systems and procedures necessary to ensure that electronic records are appropriately created, captured, organized and retained over time to meet business and legal requirements.

  7. Free-electron lasers

    CERN Document Server

    Schmüser, P

    2006-01-01

    The synchrotron radiation of relativistic electrons in undulator magnets and the low-gain Free-Electron Laser (FEL) are discussed in some detail. The highgain FEL based on the principle of Self Amplified Spontaneous Emission is treated on a qualitative level.

  8. Single particle electron microscopy

    NARCIS (Netherlands)

    Boekema, Egbert J.; Folea, Mihaela; Kouril, Roman

    2009-01-01

    Electron microscopy (EM) in combination with image analysis is a powerful technique to study protein structures at low, medium, and high resolution. Since electron micrographs of biological objects are very noisy, improvement of the signal-to-noise ratio by image processing is an integral part of

  9. Cooling of electronic equipment

    DEFF Research Database (Denmark)

    A. Kristensen, Anders Schmidt

    2003-01-01

    Cooling of electronic equipment is studied. The design size of electronic equipment decrease causing the thermal density to increase. This affect the cooling which can cause for example failures of critical components due to overheating or thermal induced stresses. Initially a pin fin heat sink...

  10. ELECTRON CYCLOTRON WAVES

    NARCIS (Netherlands)

    Westerhof, E.

    2010-01-01

    This lecture gives an overview of heating and current drive with electron cyclotron waves. We present the main theoretical aspects of wave propagation, wave absorption, and non-inductive current drive, as well as important technical aspects for the application of high power electron cyclotron waves,

  11. Electron cyclotron waves

    NARCIS (Netherlands)

    Westerhof, E.

    2012-01-01

    This lecture gives an overview of heating and current drive with electron cyclotron waves. We present the main theoretical aspects of wave propagation, wave absorption, and non-inductive current drive, as well as important technical aspects for the application of high power electron cyclotron waves,

  12. Electron cyclotron waves

    NARCIS (Netherlands)

    Westerhof, E.

    2008-01-01

    This lecture gives an overview of heating and current drive with electron cyclotron waves. We present the main theoretical aspects of wave propagation, wave absorption, and non-inductive current drive, as well as important technical aspects for the application of high power electron cyclotron waves,

  13. ELECTRONIC FILE MONITORING SYSTEM

    African Journals Online (AJOL)

    GBUBEMI

    2014-11-06

    Nov 6, 2014 ... integrated seamlessly in a global electronic business environment that includes centralized storage of all documents and related content, with the flexibility to distribute any document in the system electronically or to print, fax, or mail it as a hard copy. Things to be considered for this upgrade are Document ...

  14. Basic Electronics I.

    Science.gov (United States)

    Robertson, L. Paul

    Designed for use in basic electronics programs, this curriculum guide is comprised of twenty-nine units of instruction in five major content areas: Orientation, Basic Principles of Electricity/Electronics, Fundamentals of Direct Current, Fundamentals of Alternating Current, and Applying for a Job. Each instructional unit includes some or all of…

  15. Electrons in Molecules

    Indian Academy of Sciences (India)

    “What are electrons doing in molecules?” This is a deceptively simple question that scientists have been trying to answer for more than eighty years. With the advent of quantum mechanics in 1926, it became clear that we must understand the dynamics of electronic motion in atoms, molecules and solids in order to explain ...

  16. Electron scattering violates parity

    CERN Multimedia

    2004-01-01

    Parity violation has been observed in collisions between electrons at the Stanford Linear Accelerator Center (SLAC) in the US. The resuls, which are in agreement with the Stanford Model of particle physics, also provide a new measurement of the weak charge of the electron (½ page)

  17. Electronics and Lithuanian Terminology

    Directory of Open Access Journals (Sweden)

    Stasys Zajankauskas

    2011-04-01

    Full Text Available It is found that the vacuum triode, transistor, monolithic circuit and microprocessor were the most important inventions of traditional electronics. Thus, the origins of the traditional electronics should be associated with the invention of the vacuum triode, but not with the invention of vacuum diode. It is shown that the science of electronics is not as young as computer science or up-to-date information technologies: electronics, including active electronics, had already celebrated the centenary, and the period of 2004–2008 is the period of numerous already solid jubilees. Thus, the terminology of electronics is not at initial stage of evolution as well – general terms should be already systematized and normalized. However, Lithuanian terms for electronic devices invented before tens of years and terms for old-defined notions associated with these devices are still varying, some are worsened. Especially, the incorrectly motivated terms used for variations of transistors and microcircuits are analyzed in the article. It is motivated which terms are preferable, systematic and exact. The paper is dedicated to the 50th anniversary of monolithic circuit, as well as the 60th anniversary of transistor, the 40th jubilee of microprocessor and centenary of electronics.

  18. Practical electronics for inventors

    CERN Document Server

    Scherz, Paul

    2013-01-01

    Spark your creativity and gain the electronics skills required to transform your innovative ideas into functioning gadgets. This hands-on, updated guide outlines electrical principles and provides thorough, easy-to-follow instructions, schematics, and illustrations. Findout how to select components, safely assemble circuits, perform error tests, and build plug-and-play prototypes. Practical Electronics for Inventors, Third Edition, features all-new chapters on sensors, microcontrollers, modular electronics, and the latest software tools. Coverage includes: Resistors, capacitors, inductors, and transformers Diodes, transistors, and integrated circuits Optoelectronics, solar cells, and phototransistors Sensors, GPS modules, and touch screens Op amps, regulators, and power supplies Digital electronics, LCD displays, and logic gates Microcontrollers and prototyping platforms, including Arduino DC motors, RC servos, and stepper motors Microphones, audio amps, and speakers Modular electronics and prototyping.

  19. Silicon Carbide Electronic Devices

    Science.gov (United States)

    Neudeck, P. G.

    2001-01-01

    The status of emerging silicon carbide (SiC) widebandgap semiconductor electronics technology is briefly surveyed. SiC-based electronic devices and circuits are being developed for use in high-temperature, high-power, and/or high-radiation conditions under which conventional semiconductors cannot function. Projected performance benefits of SiC electronics are briefly illustrated for several applications. However, most of these operational benefits of SiC have yet to be realized in actual systems, primarily owing to the fact that the growth techniques of SiC crystals are relatively immature and device fabrication technologies are not yet sufficiently developed to the degree required for widespread, reliable commercial use. Key crystal growth and device fabrication issues that limit the performance and capability of high-temperature and/or high-power SiC electronics are identified. The electrical and material quality differences between emerging SiC and mature silicon electronics technology are highlighted.

  20. Electronic crystal growth

    Science.gov (United States)

    Sato, T.; Miyagawa, K.; Kanoda, K.

    2017-09-01

    Interacting atoms or molecules condense into liquid, and, when cooled further, they form a crystal. The time evolution of the atomic or molecular ordering has been widely studied as a nonequilibrium emergence of order from a supercooled liquid or a glass. Interacting electrons in a variety of correlated electron systems also form crystals, but observing the time evolution of electronic crystallization has been experimentally challenging. Here, working with an organic conductor exhibiting a supercooled charge liquid or charge glass as a metastable state, we observed electronic crystal growth through resistivity and nuclear magnetic resonance measurements. The temperature profile of the crystal growth is similar to those observed in classical systems and reveals two distinct regimes for the mechanism of electronic crystallization.

  1. Electrons in Nanostructures

    DEFF Research Database (Denmark)

    Flindt, Christian

    2007-01-01

    This thesis concerns theoretical aspects of electrons in man-made nanostruc- tures. Advances in nanofabrication technology during recent decades have made it possible to produce electrical devices on the nano-scale, whose func- tionality is determined by the quantum mechanical nature of a single...... in the possibilities o®ered by the quantum mechanical behavior of electrons when it comes to informa- tion processing. This branch of research is also concerned with fundamental questions in physics. Besides an introduction to the above-mentioned subjects, the thesis con- tains a number of contributions to the ¯elds...... of coherent electron manip- ulation and the statistical description of electron transport through nano- devices. The physics of the electrons are described with a combination of numerical methods, developed and applied in the thesis, and more analytical approaches, which are also discussed. The thesis...

  2. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.; AHRENS,L.; BRENNAN,M.; HARRISON,M.; KEWISCH,J.; MACKAY,W.; PEGGS,S.; ROSER,T.; SATOGATA,T.; TRBOJEVIC,D.; YAKIMENKO,V.

    2001-06-18

    We introduce plans for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This project has a number of new features as electron coolers go: It will cool 100 GeV/nucleon ions with 50 MeV electrons; it will be the first attempt to cool a collider at storage-energy; and it will be the first cooler to use a bunched beam and a linear accelerator as the electron source. The linac will be superconducting with energy recovery. The electron source will be based on a photocathode gun. The project is carried out by the Collider-Accelerator Department at BNL in collaboration with the Budker Institute of Nuclear Physics.

  3. In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus = Atividade in vitro do ácido 2-piridinocarboxílico em tripanossoma do subgênero Schizotrypanum isolado do morcego Phyllostomus hastatus

    Directory of Open Access Journals (Sweden)

    Paulo Roberto Ceridóreo Corrêa

    2011-09-01

    Full Text Available The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 ƒÊg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 ƒÊg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was275 ƒÊg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 ƒÊg mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.O efeito do acido 2- piridinocarboxilico (acido picolinico sobre um tripanossoma do subgenero Schizotrypanum isolado do morcego Phyllostomus hastatus foi determinado neste estudo. O acido picolinico, na concentracao de 50 ƒÊg mL-1, inibiu 99% do crescimento de epimastigotas apos 12 dias de incubacao. Alem disso, houve um decrescimo de 50 e 100% na mobilidade dos tripomastigotas apos 6 e 24h, respectivamente, em presenca de acido picolinico na concentracao de 50 ƒÊg mL-1. A concentracao citotoxica 50% para celulas HEp-2 foi de 275 ƒÊg mL-1 apos quatro dias de incubacao. Esses resultados indicam maior toxicidade contra os tripanossomas. O efeito inibitoriodo acido picolinico sobre o crescimento de

  4. Simulations of Gaussian electron guns for RHIC electron lens

    Energy Technology Data Exchange (ETDEWEB)

    Pikin, A. [Brookhaven National Lab. (BNL), Upton, NY (United States). Collider-Accelerator Dept.

    2014-02-28

    Simulations of two versions of the electron gun for RHIC electron lens are presented. The electron guns have to generate an electron beam with Gaussian radial profile of the electron beam density. To achieve the Gaussian electron emission profile on the cathode we used a combination of the gun electrodes and shaping of the cathode surface. Dependence of electron gun performance parameters on the geometry of electrodes and the margins for electrodes positioning are presented.

  5. Developing electronic textbooks

    Energy Technology Data Exchange (ETDEWEB)

    Zadoks, R.I. [Texas Univ., El Paso, TX (United States). Mechanical and Industrial Engineering Dept.; Ratner, J.A. [Sandia National Labs., Albuquerque, NM (United States)

    1996-03-01

    This paper discusses a new approach to the development of engineering education materials. The ``Electronic Textbook`` represents the logical progression of the printed textbook in the Electronic Age. The concept behind this approach is simple; to place all of the information contained in a textbook in electronic form. Currently, paper texts exist on the market with electronic supplements, however, this Electronic Textbook would include supplements fully integrated in the whole text. The computer hardware and software needed to make this advance possible have existed for nearly ten years, and they have been readily available to engineering educators and students for over three years. Computer based ``tools`` in engineering textbooks as are prevalent today range from computer styled algorithms and code snippets, to fully developed software applications with graphical user interfaces on floppy disks attached to the back covers of books. The next logical step in publishing is to dispense with the paper book entirely, by distributing textbooks via electronic media such as CD-ROM. Electronic Textbooks use the full range of multi-media technologies in the learning and teaching process including video clips, computer animations and fully functional numerical engines as integral parts of the textbook material. This is very appealing since interactive media provide teaching tools that appeal to divergent learning styles. The advantages of Electronic Textbooks lead to several challenges. Special attention must be paid to the development of user interfaces; navigation is of particular importance when non- linear exploration is encouraged. These issues are being addressed at the Sandia National Laboratories by an electronic documentation development team. This team includes experts in engineering, in human factors, and in computer hardware and software development. Guidelines for the development of electronic textbooks based on the experiences of this team are provided.

  6. Electronic Collection Management and Electronic Information Services

    Science.gov (United States)

    2003-04-01

    TITLE: Electronic Information Management for PfP Nations [La gestion electronique des informations pour les pays du PfP] To order the complete...and information centers As a key institutional structure for providing information "collection" and "services" to users, the library or information...including the specialized staff, to select, structure , offer intellectual access to, interpret, distribute, preserve the integrity of, and ensure the

  7. Electron heat flux instability

    Science.gov (United States)

    Saeed, Sundas; Sarfraz, M.; Yoon, P. H.; Lazar, M.; Qureshi, M. N. S.

    2017-02-01

    The heat flux instability is an electromagnetic mode excited by a relative drift between the protons and two-component core-halo electrons. The most prominent application may be in association with the solar wind where drifting electron velocity distributions are observed. The heat flux instability is somewhat analogous to the electrostatic Buneman or ion-acoustic instability driven by the net drift between the protons and bulk electrons, except that the heat flux instability operates in magnetized plasmas and possesses transverse electromagnetic polarization. The heat flux instability is also distinct from the electrostatic counterpart in that it requires two electron species with relative drifts with each other. In the literature, the heat flux instability is often called the 'whistler' heat flux instability, but it is actually polarized in the opposite sense to the whistler wave. This paper elucidates all of these fundamental plasma physical properties associated with the heat flux instability starting from a simple model, and gradually building up more complexity towards a solar wind-like distribution functions. It is found that the essential properties of the instability are already present in the cold counter-streaming electron model, and that the instability is absent if the protons are ignored. These instability characteristics are highly reminiscent of the electron firehose instability driven by excessive parallel temperature anisotropy, propagating in parallel direction with respect to the ambient magnetic field, except that the free energy source for the heat flux instability resides in the effective parallel pressure provided by the counter-streaming electrons.

  8. Electron Cooling of RHIC

    CERN Document Server

    Ben-Zvi, Ilan; Barton, Donald; Beavis, Dana; Blaskiewicz, Michael; Bluem, Hans; Brennan, Joseph M; Bruhwiler, David L; Burger, Al; Burov, Alexey; Burrill, Andrew; Calaga, Rama; Cameron, Peter; Chang, Xiangyun; Cole, Michael; Connolly, Roger; Delayen, Jean R; Derbenev, Yaroslav S; Eidelman, Yury I; Favale, Anthony; Fedotov, Alexei V; Fischer, Wolfram; Funk, L W; Gassner, David M; Hahn, Harald; Harrison, Michael; Hershcovitch, Ady; Holmes, Douglas; Hseuh Hsiao Chaun; Johnson, Peter; Kayran, Dmitry; Kewisch, Jorg; Kneisel, Peter; Koop, Ivan; Lambiase, Robert; Litvinenko, Vladimir N; MacKay, William W; Mahler, George; Malitsky, Nikolay; McIntyre, Gary; Meng, Wuzheng; Merminga, Lia; Meshkov, Igor; Mirabella, Kerry; Montag, Christoph; Nagaitsev, Sergei; Nehring, Thomas; Nicoletti, Tony; Oerter, Brian; Parkhomchuk, Vasily; Parzen, George; Pate, David; Phillips, Larry; Preble, Joseph P; Rank, Jim; Rao, Triveni; Rathke, John; Roser, Thomas; Russo, Thomas; Scaduto, Joseph; Schultheiss, Tom; Sekutowicz, Jacek; Shatunov, Yuri; Sidorin, Anatoly O; Skrinsky, Aleksander Nikolayevich; Smirnov, Alexander V; Smith, Kevin T; Todd, Alan M M; Trbojevic, Dejan; Troubnikov, Grigory; Wang, Gang; Wei, Jie; Williams, Neville; Wu, Kuo-Chen; Yakimenko, Vitaly; Zaltsman, Alex; Zhao, Yongxiang; ain, Animesh K

    2005-01-01

    We report progress on the R&D program for electron-cooling of the Relativistic Heavy Ion Collider (RHIC). This electron cooler is designed to cool 100 GeV/nucleon at storage energy using 54 MeV electrons. The electron source will be a superconducting RF photocathode gun. The accelerator will be a superconducting energy recovery linac. The frequency of the accelerator is set at 703.75 MHz. The maximum electron bunch frequency is 9.38 MHz, with bunch charge of 20 nC. The R&D program has the following components: The photoinjector and its photocathode, the superconducting linac cavity, start-to-end beam dynamics with magnetized electrons, electron cooling calculations including benchmarking experiments and development of a large superconducting solenoid. The photoinjector and linac cavity are being incorporated into an energy recovery linac aimed at demonstrating ampere class current at about 20 MeV. A Zeroth Order Design Report is in an advanced draft state, and can be found on the web at http://www.ags...

  9. Introduction to electron crystallography

    Energy Technology Data Exchange (ETDEWEB)

    Hovmoeller, S.; Zou, Xiaodong [Department of Materials and Environmental Chemistry, Stockholm University and Berzeeli Center Exselent 10691 Stockholm (Sweden)

    2011-06-15

    Everything in Nature, macroscopic or microscopic, inorganic, organic or biological, has its specific properties. Most properties of matter depend on the atomic structures, and many techniques have been developed over the centuries for structure analysis. The greatest of them all, structure analysis of single crystals by X-ray diffraction, X-ray crystallography, was founded in 1912, and remains the most important technique for studying structures of periodically ordered objects at atomic resolution. Electron diffraction of single crystals was discovered fifteen years later by Thomson, Davisson and Germer. The wave property of electrons was exploited in the invention of the electron microscope by Knoll and Ruska in 1932. Since then, electron microscopes have been used in many fields as a tool for exploring and visualising the microscopic world in all its beauty. Between the first blurred images and today's sharp atomic resolution lies seventy years of untiring engineering. More recently, the unprecedented power of computers has made it possible to analyse quantitatively, and even further improve, these images. The amalgamation of electron diffraction and atomic resolution electron microscopy with crystallographic image processing has created a new powerful tool for structure analysis - electron crystallography. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  10. Electron Beam Materials Irradiators

    Science.gov (United States)

    Cleland, Marshall R.

    2012-06-01

    Radiation processing is a well established method for enhancing the properties of materials and commercial products by treating them with ionizing energy in the form of high-energy electrons, X-rays, and gamma rays. Beneficial effects include polymerizing, cross-linking, grafting and degrading plastics, sterilizing single-use medical devices, disinfecting and disinfesting fresh foods, purifying drinking water, treating wastewater and other toxic waste materials that harm the environment, and many other applications that are still being evaluated. Industrial electron accelerators of several types have been developed and are being used for these applications. More than 1800 electron accelerators are presently installed in facilities worldwide for these purposes.

  11. VLSI electronics microstructure science

    CERN Document Server

    1982-01-01

    VLSI Electronics: Microstructure Science, Volume 4 reviews trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the silicon-on-insulator for VLSI and VHSIC, X-ray lithography, and transient response of electron transport in GaAs using the Monte Carlo method. The technology and manufacturing of high-density magnetic-bubble memories, metallic superlattices, challenge of education for VLSI, and impact of VLSI on medical signal processing are also elaborated. This text likewise covers the impact of VLSI t

  12. Semiconductor opto-electronics

    CERN Document Server

    Moss, TS; Ellis, B

    1972-01-01

    Semiconductor Opto-Electronics focuses on opto-electronics, covering the basic physical phenomena and device behavior that arise from the interaction between electromagnetic radiation and electrons in a solid. The first nine chapters of this book are devoted to theoretical topics, discussing the interaction of electromagnetic waves with solids, dispersion theory and absorption processes, magneto-optical effects, and non-linear phenomena. Theories of photo-effects and photo-detectors are treated in detail, including the theories of radiation generation and the behavior of semiconductor lasers a

  13. Consulting in Electronic Commerce

    Directory of Open Access Journals (Sweden)

    Florentina Loredana Tache

    2010-10-01

    Full Text Available Economic development of electronic services provide advice and many agents of existingreferral systems to recommend and provide products, information and customized views of thecommunity through a personalized interaction in real time. Distributed systems of autonomous agentsare becoming increasingly important in electronic comet because the basic decisions of agents adviceon trust and reputation are taken in a similar way human society. If these decisions will be as a realconsumer protection, when new aspects of online consumer legislation will become usefulinformation in advice and consulting of electronic commerce.

  14. Power Electronics for Microgrids

    DEFF Research Database (Denmark)

    Dragicevic, Tomislav; Blaabjerg, Frede

    2016-01-01

    A microgrid (MG) is a stand-alone or grid-connected hybrid renewable system that uses distributed renewable and nonrenewable energy sources and energy storage systems (ESSs) to supply power to local loads. The system is ordinarily based on power electronics, with interface converters allowing...... a continuous supply of power in the presence of variable RES production. This chapter describes some specific features of DC MGs in terms of power architecture, control, and protection. It also reviews several uncommon power electronic interfaces. Regarding control, operation without critical communication...... are explained in this chapter. The chapter concludes with a review of power electronic intensive protection solutions for DC MGs....

  15. Electronic components and systems

    CERN Document Server

    Dennis, W H

    2013-01-01

    Electronic Components and Systems focuses on the principles and processes in the field of electronics and the integrated circuit. Covered in the book are basic aspects and physical fundamentals; different types of materials involved in the field; and passive and active electronic components such as capacitors, inductors, diodes, and transistors. Also covered in the book are topics such as the fabrication of semiconductors and integrated circuits; analog circuitry; digital logic technology; and microprocessors. The monograph is recommended for beginning electrical engineers who would like to kn

  16. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1968-01-01

    Electronic Devices and Circuits, Volume 1 deals with the design and applications of electronic devices and circuits such as passive components, diodes, triodes and transistors, rectification and power supplies, amplifying circuits, electronic instruments, and oscillators. These topics are supported with introductory network theory and physics. This volume is comprised of nine chapters and begins by explaining the operation of resistive, inductive, and capacitive elements in direct and alternating current circuits. The theory for some of the expressions quoted in later chapters is presented. Th

  17. Polarized electron sources

    Energy Technology Data Exchange (ETDEWEB)

    Prepost, R. [Univ. of Wisconsin, Madison, WI (United States)

    1994-12-01

    The fundamentals of polarized electron sources are described with particular application to the Stanford Linear Accelerator Center. The SLAC polarized electron source is based on the principle of polarized photoemission from Gallium Arsenide. Recent developments using epitaxially grown, strained Gallium Arsenide cathodes have made it possible to obtain electron polarization significantly in excess of the conventional 50% polarization limit. The basic principles for Gallium and Arsenide polarized photoemitters are reviewed, and the extension of the basic technique to strained cathode structures is described. Results from laboratory measurements of strained photocathodes as well as operational results from the SLAC polarized source are presented.

  18. Principles of quantum electronics

    CERN Document Server

    Marcuse, Dietrich

    1980-01-01

    Principles of Quantum Electronics focuses on the concept of quantum electronics as the application of quantum theory to engineering problems. It examines the principles that govern specific quantum electronics devices and presents their theoretical applications to typical problems. Comprised of 10 chapters, this book starts with an overview of the Dirac formulation of quantum mechanics. This text then considers the derivation of the formalism of field quantization and discusses the properties of photons and phonons. Other chapters examine the interaction between the electromagnetic field and c

  19. Electron paramagnetic resonance

    CERN Document Server

    Al'tshuler, S A

    2013-01-01

    Electron Paramagnetic Resonance is a comprehensive text on the field of electron paramagnetic resonance, covering both the theoretical background and the results of experiment. This book is composed of eight chapters that cover theoretical materials and experimental data on ionic crystals, since these are the materials that have been most extensively studied by the methods of paramagnetic resonance. The opening chapters provide an introduction to the basic principles of electron paramagnetic resonance and the methods of its measurement. The next chapters are devoted to the theory of spectra an

  20. Socorro Electronic Structure Software

    Energy Technology Data Exchange (ETDEWEB)

    2017-08-03

    Socorro can be used to compute the ground-state electron density for a periodically repeated simulation cell in which the external potential is obtained from norm-conserving pseudopotentials or projector-augmented-wave functions. The ground-state electron density is computed by summation over one-electron orbitals which are obtained using the Kohn-Sham formulation of density-functional theory and which are expanded in a plane-wave basis. Various quantities can be computed from the ground-state solution, including atomic forces which can be used to optimize atom positions in the simulation cell and to perform molecular dynamics simulations.

  1. Field emission electronics

    CERN Document Server

    Egorov, Nikolay

    2017-01-01

    This book is dedicated to field emission electronics, a promising field at the interface between “classic” vacuum electronics and nanotechnology. In addition to theoretical models, it includes detailed descriptions of experimental and research techniques and production technologies for different types of field emitters based on various construction principles. It particularly focuses on research into and production of field cathodes and electron guns using recently developed nanomaterials and carbon nanotubes. Further, it discusses the applications of field emission cathodes in new technologies such as light sources, flat screens, microwave and X-ray devices.

  2. Quantum electronics basic theory

    CERN Document Server

    Fain, V M; Sanders, J H

    1969-01-01

    Quantum Electronics, Volume 1: Basic Theory is a condensed and generalized description of the many research and rapid progress done on the subject. It is translated from the Russian language. The volume describes the basic theory of quantum electronics, and shows how the concepts and equations followed in quantum electronics arise from the basic principles of theoretical physics. The book then briefly discusses the interaction of an electromagnetic field with matter. The text also covers the quantum theory of relaxation process when a quantum system approaches an equilibrium state, and explai

  3. Electronics Modernization Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Current electronic packaging designs used in our most recent spacecraft are comprised of technologies from the 1980’s and 1990’s. The current approach...

  4. Electronic Universal Vote

    Directory of Open Access Journals (Sweden)

    Cristian USCATU

    2008-01-01

    Full Text Available In the days of informational society everything is going online. Most aspects of our lives have online components. Since democracy is a big issue, it could not escape this trend. Governments themselves are moving to the online environment for the purpose of improving their internal efficiency and their availability to the citizens, businesses and other parties interested. Since governments are the result of elections, elections have also been touched by the electronic fever. New electronic voting solutions arise and each one brings new debates with many arguments in their favor and against them. Accessibility and ease of use leads the arguments in favor of electronic voting over the internet, while fear of fraud is the main reason people are avoiding electronics and clinging on classic paper ballots.

  5. Electron and Photon ID

    CERN Document Server

    Hryn'ova, Tetiana; The ATLAS collaboration

    2017-01-01

    The identification of prompt photons and the rejection of background coming mostly from photons from hadron decays relies on the high granularity of the ATLAS calorimeter. The electron identification used in ATLAS for run 2 is based on a likelihood discrimination to separate isolated electron candidates from candidates originating from photon conversions, hadron misidentification and heavy flavor decays. In addition, isolation variables are used as further handles to separate signal and background. Several methods are used to measure with data the efficiency of the photon identification requirements, to cover a broad energy spectrum. At low energy, photons from radiative Z decays are used. In the medium energy range, similarities between electrons and photon showers are exploited using Z->ee decays. At high energy, inclusive photon samples are used. The measurement of the efficiencies of the electron identification and isolation cuts are performed with the data using tag and probe techniques with large statis...

  6. Sheet electron beam tester

    Science.gov (United States)

    Spear, Alexander Grenbeaux

    The DARPA HiFIVE project uses a pulsed electron sheet beam gun to power a traveling wave tube amplifier operating at 220 GHz. Presented is a method for characterizing the high current density 0.1 mm by 1 mm sheet electron beam. A tungsten tipped probe was scanned through the cross section of the sheet electron beam inside of a vacuum vessel. The probe was controlled with sub-micron precision using stepper motors and LabView computer control while boxcar averaging hardware sampled the pulsed beam. Matlab algorithms were used to interpret the data, calculate beam dimensions and current density, and create 2-dimensional cross section images. Full characterization of two separate HiFIVE sheet electron guns was accomplished and is also presented.

  7. Electronics for guitarists

    CERN Document Server

    Dailey, Denton J

    2014-01-01

    Electronics for Guitarists focuses on analog circuitry, and is written for the guitarist interested in transistor and vacuum tube-based amplifiers. Topics include discrete transistors and diodes, classical filter circuits, and vacuum tube-based amplifiers.

  8. Single molecule electronic devices.

    Science.gov (United States)

    Song, Hyunwook; Reed, Mark A; Lee, Takhee

    2011-04-12

    Single molecule electronic devices in which individual molecules are utilized as active electronic components constitute a promising approach for the ultimate miniaturization and integration of electronic devices in nanotechnology through the bottom-up strategy. Thus, the ability to understand, control, and exploit charge transport at the level of single molecules has become a long-standing desire of scientists and engineers from different disciplines for various potential device applications. Indeed, a study on charge transport through single molecules attached to metallic electrodes is a very challenging task, but rapid advances have been made in recent years. This review article focuses on experimental aspects of electronic devices made with single molecules, with a primary focus on the characterization and manipulation of charge transport in this regime. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Improved electron transport layer

    DEFF Research Database (Denmark)

    2012-01-01

    The present invention provides: a method of preparing a coating ink for forming a zinc oxide electron transport layer, comprising mixing zinc acetate and a wetting agent in water or methanol; a coating ink comprising zinc acetate and a wetting agent in aqueous solution or methanolic solution......; a method of preparing a zinc oxide electron transporting layer, which method comprises: i) coating a substrate with the coating ink of the present invention to form a film; ii) drying the film; and iii) heating the dry film to convert the zinc acetate substantially to ZnO; a method of preparing an organic...... photovoltaic device or an organic LED having a zinc oxide electron transport layer, the method comprising, in this order: a) providing a substrate bearing a first electrode layer; b) forming an electron transport layer according to the following method: i) coating a coating ink comprising an ink according...

  10. Advanced Electron Linacs

    Energy Technology Data Exchange (ETDEWEB)

    Siemann, R.

    2005-02-14

    The research into advanced acceleration concepts for electron linear accelerators being pursued at SLAC is reviewed. This research includes experiments in laser acceleration, plasma wakefield acceleration, and mmwavelength RF driven accelerators.

  11. Maps for electron clouds

    Directory of Open Access Journals (Sweden)

    Ubaldo Iriso

    2005-02-01

    Full Text Available The electron cloud effect has been studied by means of detailed simulation codes that typically track the particles' evolution under the influence of the corresponding electromagnetic forces and fields. In this paper we show that, for the RHIC case, the electron cloud can be treated from an abstract point of view as a bunch to bunch evolution using simple maps. Secondly, we show how this treatment yields a useful conclusion, which is otherwise difficult to obtain: for a fixed number of bunches and total beam current in RHIC, it is possible to determine the best way to distribute the bunch pattern around the ring to minimize the electron cloud formation. This application is an example of how maps become a useful tool for exploring the electron cloud evolution in parameter space.

  12. Scanning Auger Electron Microscope

    Data.gov (United States)

    Federal Laboratory Consortium — A JEOL model 7830F field emission source, scanning Auger microscope.Specifications / Capabilities:Ultra-high vacuum (UHV), electron gun range from 0.1 kV to 25 kV,...

  13. Lasers in Electronic Warfare

    Science.gov (United States)

    Manke, Gerald C.

    2014-10-01

    The use of lasers for Electronic Warfare applications will be discussed and reviewed. Specific examples of deployed EW systems which include lasers will be presented along with a discussion of their most salient features.

  14. PREFACE: Spin Electronics

    Science.gov (United States)

    Dieny, B.; Sousa, R.; Prejbeanu, L.

    2007-04-01

    Conventional electronics has in the past ignored the spin on the electron, however things began to change in 1988 with the discovery of giant magnetoresistance in metallic thin film stacks which led to the development of a new research area, so called spin-electronics. In the last 10 years, spin-electronics has achieved a number of breakthroughs from the point of view of both basic science and application. Materials research has led to several major discoveries: very large tunnel magnetoresistance effects in tunnel junctions with crystalline barriers due to a new spin-filtering mechanism associated with the spin-dependent symmetry of the electron wave functions new magnetic tunnelling barriers leading to spin-dependent tunnelling barrier heights and acting as spin-filters magnetic semiconductors with increasingly high ordering temperature. New phenomena have been predicted and observed: the possibility of acting on the magnetization of a magnetic nanostructure with a spin-polarized current. This effect, due to a transfer of angular momentum between the spin polarized conduction electrons and the local magnetization, can be viewed as the reciprocal of giant or tunnel magnetoresistance. It can be used to switch the magnetization of a magnetic nanostructure or to generate steady magnetic excitations in the system. the possibility of generating and manipulating spin current without charge current by creating non-equilibrium local accumulation of spin up or spin down electrons. The range of applications of spin electronics materials and phenomena is expanding: the first devices based on giant magnetoresistance were the magnetoresistive read-heads for computer disk drives. These heads, introduced in 1998 with current-in plane spin-valves, have evolved towards low resistance tunnel magnetoresistice heads in 2005. Besides magnetic recording technology, these very sensitive magnetoresistive sensors are finding applications in other areas, in particular in biology. magnetic

  15. ELECTRONIC BANKING AND ELECTRONIC COMMERCE IN SERBIA

    Directory of Open Access Journals (Sweden)

    Ivana B. Petrevska

    2014-10-01

    Full Text Available Nowadays, we may witness to dramatic and visible changes in our life environment. Business ambient for companies is different every day, and it is very hard to predict a direction of future changes. There is an environment characterized by sharp competition and increasing number of competitors, fast technological improvements and highly sophisticated and informed costumers. Technological process influences the humanity strongly, changing the way that people live, work and spend. Electronic commerce and electronic banking has become incontinent, and makes a great part of today's total transactions. There are an increasing number of companies that perform their business that way and make profit. Social networks are proven to be the least expensive way of information exchange, and they are present in almost every part of the world. The globalization has reached the most distant parts of the Earth. Every resistance to new technologies is dangerous and may lead to bankruptcy. Due to the EU expansion, Internet users are to be expected, and prosperity of the e-commerce business models at the same time. In Serbia, electronic commerce is present, but not as developed as in EU countries. E-commerce, however it might be successful throughout the world, it is somewhat slow in its growth in Serbia. The reasons are numerous, and main obstacles are the lack of trust, still limited usage of banking cards, avoiding of e-payments by older population etc. Also, the recent scandals over the misuse of personal data, and e-crime are discouraging factors for the growth of e-trade and ebanking. The younger generations are ever more ready to use e-commerce, since they are open to new technologies and do not have the defensive attitude towards it. E-commerce and e-banking has growing potential even among older population, if the society prevents them from fear and mistrust.

  16. Electronics 3 checkbook

    CERN Document Server

    Knight, S A; May, A J C

    2013-01-01

    Electronics 3 Checkbook provides a concise coverage of the theories and definitions of concepts in electronics. The book provides problems and worked examples to supplement fuller textbooks of the same subject. The coverage of the text includes decibel measurement, operational amplifiers, DA and AD converters, controlled rectifiers, triggering devices, optoelectronic devices, fiber optics, and power amplifiers. The text will be of great use to electrical engineering students who wish to enhance their understanding of the basics of mechanical and electrical science.

  17. The Recycler Electron Cooler

    Energy Technology Data Exchange (ETDEWEB)

    Shemyakin, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Prost, L. R. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)

    2013-03-19

    The Recycler Electron cooler was the first (and so far, the only) cooler working at a relativistic energy (γ = 9.5). It was successfully developed in 1995-2004 and was in operation at Fermilab in 2005-2011, providing cooling of antiprotons in the Recycler ring. This paper describes the cooler, difficulties in achieving the required electron beam parameters and the ways to overcome them, cooling measurements, and details of operation.

  18. Electrical and electronic principles

    CERN Document Server

    Knight, SA

    1988-01-01

    Electrical and Electronic Principles, 3 focuses on the principles involved in electrical and electronic circuits, including impedance, inductance, capacitance, and resistance.The book first deals with circuit elements and theorems, D.C. transients, and the series circuits of alternating current. Discussions focus on inductance and resistance in series, resistance and capacitance in series, power factor, impedance, circuit magnification, equation of charge, discharge of a capacitor, transfer of power, and decibels and attenuation. The manuscript then examines the parallel circuits of alternatin

  19. Newnes electronics assembly handbook

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Newnes Electronics Assembly Handbook: Techniques, Standards and Quality Assurance focuses on the aspects of electronic assembling. The handbook first looks at the printed circuit board (PCB). Base materials, basic mechanical properties, cleaning of assemblies, design, and PCB manufacturing processes are then explained. The text also discusses surface mounted assemblies and packaging of electromechanical assemblies, as well as the soldering process. Requirements for the soldering process; solderability and protective coatings; cleaning of PCBs; and mass solder/component reflow soldering are des

  20. Electronic discharge summaries.

    Science.gov (United States)

    Stetson, Peter D; Keselman, Alla; Rappaport, Daniel; Van Vleck, Tielman; Cooper, Mary; Boyer, Aurelia; Hripcsak, George

    2005-01-01

    Timely completion of Discharge Summaries is a requirement of high quality care. We developed a system for writing electronic Discharge Summaries. DSUM Writer has generated 2464 of 7349 total summaries (34%) and has paid for itself during its first 8 weeks in production. DSUM Writer is a component of a suite of tools (eNote) for electronic physician documentation used to support clinical care, billing and narrative analysis research.

  1. Electron Beam Materials Processing

    Science.gov (United States)

    Powers, Donald E.

    2012-06-01

    In electron beam processing, a well-defined beam of relatively energetic electrons produced by a high voltage acceleration gap is used to transmit thermal energy into a material in a precise manner. This controlled deposition of heat is employed in a wide variety of industrial applications for precision cutting, drilling, and welding of materials as well as annealing, glazing, and surface hardening. This chapter will describe the equipment used and the most prominent industrial applications for this process.

  2. Mathematics for electronic technology

    CERN Document Server

    Howson, D P

    1975-01-01

    Mathematics for Electronic Technology is a nine-chapter book that begins with the elucidation of the introductory concepts related to use of mathematics in electronic engineering, including differentiation, integration, partial differentiation, infinite series, vectors, vector algebra, and surface, volume and line integrals. Subsequent chapters explore the determinants, differential equations, matrix analysis, complex variable, topography, graph theory, and numerical analysis used in this field. The use of Fourier method for harmonic analysis and the Laplace transform is also described. The ma

  3. Newnes electronics toolkit

    CERN Document Server

    Phillips, Geoff

    2013-01-01

    Newnes Electronics Toolkit brings together fundamental facts, concepts, and applications of electronic components and circuits, and presents them in a clear, concise, and unambiguous format, to provide a reference book for engineers. The book contains 10 chapters that discuss the following concepts: resistors, capacitors, inductors, semiconductors, circuit concepts, electromagnetic compatibility, sound, light, heat, and connections. The engineer's job does not end when the circuit diagram is completed; the design for the manufacturing process is just as important if volume production is to be

  4. Electronic Portfolios for Scientists

    OpenAIRE

    Dahn, I.; Christmann, A

    2007-01-01

    Electronic portfolios (ePortfolios) are electronic versions of paper based portfolios. They are increasingly applied in education. Software for building and maintaining ePortfolios is emerging; open specifications for the exchange of ePortfolios exist. They show the potential to serve as a standard tool for documenting achievements in lifelong learning. In this paper we explore the potential of ePortfolios for scientists.

  5. Thermionics basic principles of electronics

    CERN Document Server

    Jenkins, J; Ashhurst, W

    2013-01-01

    Basic Principles of Electronics, Volume I : Thermionics serves as a textbook for students in physics. It focuses on thermionic devices. The book covers topics on electron dynamics, electron emission, and the themionic vacuum diode and triode. Power amplifiers, oscillators, and electronic measuring equipment are studied as well. The text will be of great use to physics and electronics students, and inventors.

  6. Netiquette in Electronic Communication

    Directory of Open Access Journals (Sweden)

    Tomáš Kozík

    2014-06-01

    Full Text Available Electronic mail and electronic communications systems are considered significant and effective tools of communication. One of the most widespread electronic communication tools is e - mail communication. In order to avoid misinterpretation of the report on the side of the recipient, it is need to pay attention to the writing of e - mail messages as well as to their content. With the continuous expansion of the use of electronic communication there have gradually developed certain rules of etiquette in electronic communications. The existing rules of the propriety ones are expressed in the term " etiqutte " and are not automatically applied in the new communications environment - media. For electronic communication, the new rules of etiquette have been stabilised into a term NETIQUETTE. The word netiquette was created by combining words NET (net and ETIKETA (a set of rules of social behavior and habits. Netiquette constitutes the rules of the behavior of users on a network. Although the netiquette is merely "an unwritten set of rules", their not using can be understood as a type of disrespect. Analysis of knowledge of domestic and foreign sources as well as results of a survey confirmed the justification of paying attention to the education of individuals in NETIQUETTE, irrespective of the degree of education.

  7. Relativistic Electron Vortices.

    Science.gov (United States)

    Barnett, Stephen M

    2017-03-17

    The desire to push recent experiments on electron vortices to higher energies leads to some theoretical difficulties. In particular the simple and very successful picture of phase vortices of vortex charge ℓ associated with ℓℏ units of orbital angular momentum per electron is challenged by the facts that (i) the spin and orbital angular momentum are not separately conserved for a Dirac electron, which suggests that the existence of a spin-orbit coupling will complicate matters, and (ii) that the velocity of a Dirac electron is not simply the gradient of a phase as it is in the Schrödinger theory suggesting that, perhaps, electron vortices might not exist at a fundamental level. We resolve these difficulties by showing that electron vortices do indeed exist in the relativistic theory and show that the charge of such a vortex is simply related to a conserved orbital part of the total angular momentum, closely related to the familiar situation for the orbital angular momentum of a photon.

  8. Good Security Practices for Electronic Commerce, Including Electronic Data Interchange

    Science.gov (United States)

    1993-12-01

    FROM - TO) xx-xx-2002 to xx-xx-2002 4. TITLE AND SUBTITLE Good Security Practices for Electronic Commerce , Including Electronic Data Interchange...Report 12/1/1993 4. TITLE AND SUBTITLE Good Security Practices for Electronic Commerce , Including Electronic Data Interchange 5. FUNDING NUMBERS 6...Maximum 200 Words) Electronic commerce (EC) is the use of documents in electronic form, rather than paper, for carrying out functions of business or

  9. Runaway electrons and ITER

    Science.gov (United States)

    Boozer, Allen H.

    2017-05-01

    The potential for damage, the magnitude of the extrapolation, and the importance of the atypical—incidents that occur once in a thousand shots—make theory and simulation essential for ensuring that relativistic runaway electrons will not prevent ITER from achieving its mission. Most of the theoretical literature on electron runaway assumes magnetic surfaces exist. ITER planning for the avoidance of halo and runaway currents is focused on massive-gas or shattered-pellet injection of impurities. In simulations of experiments, such injections lead to a rapid large-scale magnetic-surface breakup. Surface breakup, which is a magnetic reconnection, can occur on a quasi-ideal Alfvénic time scale when the resistance is sufficiently small. Nevertheless, the removal of the bulk of the poloidal flux, as in halo-current mitigation, is on a resistive time scale. The acceleration of electrons to relativistic energies requires the confinement of some tubes of magnetic flux within the plasma and a resistive time scale. The interpretation of experiments on existing tokamaks and their extrapolation to ITER should carefully distinguish confined versus unconfined magnetic field lines and quasi-ideal versus resistive evolution. The separation of quasi-ideal from resistive evolution is extremely challenging numerically, but is greatly simplified by constraints of Maxwell’s equations, and in particular those associated with magnetic helicity. The physics of electron runaway along confined magnetic field lines is clarified by relations among the poloidal flux change required for an e-fold in the number of electrons, the energy distribution of the relativistic electrons, and the number of relativistic electron strikes that can be expected in a single disruption event.

  10. Electron-electron attraction in an engineered electromechanical system

    Science.gov (United States)

    Széchenyi, Gábor; Pályi, András; Droth, Matthias

    2017-12-01

    Two electrons in a quantum dot repel each other: their interaction can be characterized by a positive interaction energy. From the theory of superconductivity, we also know that mechanical vibrations of the crystal lattice can make the electron-electron interaction attractive. Analogously, if a quantum dot interacts with a mechanical degree of freedom, the effective interaction energy can be negative; that is, the electron-electron interaction might be attractive. In this work, we propose and theoretically study an engineered electromechanical system that exhibits electron-electron attraction: a quantum dot suspended on a nonlinear mechanical resonator, tuned by a bottom and a top gate electrode. We focus on the example of a dot embedded in a suspended graphene ribbon, for which we identify conditions for electron-electron attraction. Our results suggest the possibility of electronic transport via tunneling of packets of multiple electrons in such devices, similar to that in superconducting nanostructures, but without the use of any superconducting elements.

  11. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  12. Electronic Commerce and Competitive Procurement

    Science.gov (United States)

    1991-06-01

    AD-A238 831 " ELECTRONIC COMMERCE AND COMPETITIVE PROCUREMENT Report PL006R1 June 1991 DTIC AJUL 2 9 1991"M Daniel J. Drake John A. Ciucci Prepared...TITLE AND SUBTITLE 5. FUNDING NUMBERS Electronic Commerce and Competitive Procurement C MDA903-90-C-0006 PE 0902198D 6. AUTHOR(S) Daniel J. Drake and... electronic commerce techniques ( electronic Jata interchange (EDI). electronic mail (E-mail), electronic bulletin boards and facsimile] to competitive

  13. A new subgenus of the Coleopterous family Drilidae

    NARCIS (Netherlands)

    Gorham, H.S.

    1883-01-01

    Generi Diplocladon Gorham 1) valde affine, sed antennae simpliciter pectinatae. Antennae duodecimi-articulatae, articulo basali valido subquadrato, secundo brevi quam hoc dimidio minore, tertio triangulari, angulo interno ramum emittente; quarto ad undecimum perbrevibus, latitudine haud longioribus,

  14. Electron microscope phase enhancement

    Science.gov (United States)

    Jin, Jian; Glaeser, Robert M.

    2010-06-15

    A microfabricated electron phase shift element is used for modifying the phase characteristics of an electron beam passing though its center aperture, while not affecting the more divergent portion of an incident beam to selectively provide a ninety-degree phase shift to the unscattered beam in the back focal plan of the objective lens, in order to realize Zernike-type, in-focus phase contrast in an electron microscope. One application of the element is to increase the contrast of an electron microscope for viewing weakly scattering samples while in focus. Typical weakly scattering samples include biological samples such as macromolecules, or perhaps cells. Preliminary experimental images demonstrate that these devices do apply a ninety degree phase shift as expected. Electrostatic calculations have been used to determine that fringing fields in the region of the scattered electron beams will cause a negligible phase shift as long as the ratio of electrode length to the transverse feature-size aperture is about 5:1. Calculations are underway to determine the feasibility of aspect smaller aspect ratios of about 3:1 and about 2:1.

  15. Microfluidic stretchable RF electronics.

    Science.gov (United States)

    Cheng, Shi; Wu, Zhigang

    2010-12-07

    Stretchable electronics is a revolutionary technology that will potentially create a world of radically different electronic devices and systems that open up an entirely new spectrum of possibilities. This article proposes a microfluidic based solution for stretchable radio frequency (RF) electronics, using hybrid integration of active circuits assembled on flex foils and liquid alloy passive structures embedded in elastic substrates, e.g. polydimethylsiloxane (PDMS). This concept was employed to implement a 900 MHz stretchable RF radiation sensor, consisting of a large area elastic antenna and a cluster of conventional rigid components for RF power detection. The integrated radiation sensor except the power supply was fully embedded in a thin elastomeric substrate. Good electrical performance of the standalone stretchable antenna as well as the RF power detection sub-module was verified by experiments. The sensor successfully detected the RF radiation over 5 m distance in the system demonstration. Experiments on two-dimensional (2D) stretching up to 15%, folding and twisting of the demonstrated sensor were also carried out. Despite the integrated device was severely deformed, no failure in RF radiation sensing was observed in the tests. This technique illuminates a promising route of realizing stretchable and foldable large area integrated RF electronics that are of great interest to a variety of applications like wearable computing, health monitoring, medical diagnostics, and curvilinear electronics.

  16. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD`s Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases & Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  17. Electronic Commerce user manual

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-10

    This User Manual supports the Electronic Commerce Standard System. The Electronic Commerce Standard System is being developed for the Department of Defense of the Technology Information Systems Program at the Lawrence Livermore National Laboratory, operated by the University of California for the Department of Energy. The Electronic Commerce Standard System, or EC as it is known, provides the capability for organizations to conduct business electronically instead of through paper transactions. Electronic Commerce and Computer Aided Acquisition and Logistics Support, are two major projects under the DoD's Corporate Information Management program, whose objective is to make DoD business transactions faster and less costly by using computer networks instead of paper forms and postage. EC runs on computers that use the UNIX operating system and provides a standard set of applications and tools that are bound together by a common command and menu system. These applications and tools may vary according to the requirements of the customer or location and may be customized to meet the specific needs of an organization. Local applications can be integrated into the menu system under the Special Databases Applications option on the EC main menu. These local applications will be documented in the appendices of this manual. This integration capability provides users with a common environment of standard and customized applications.

  18. Electronic Spectroscopy & Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Mark Maroncelli, Nancy Ryan Gray

    2010-06-08

    The Gordon Research Conference (GRC) on Electronic Spectroscopy and Dynamics was held at Colby College, Waterville, NH from 07/19/2009 thru 07/24/2009. The Conference was well-attended with participants (attendees list attached). The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students. The GRC on Electronic Spectroscopy & Dynamics showcases some of the most recent experimental and theoretical developments in electronic spectroscopy that probes the structure and dynamics of isolated molecules, molecules embedded in clusters and condensed phases, and bulk materials. Electronic spectroscopy is an important tool in many fields of research, and this GRC brings together experts having diverse backgrounds in physics, chemistry, biophysics, and materials science, making the meeting an excellent opportunity for the interdisciplinary exchange of ideas and techniques. Topics covered in this GRC include high-resolution spectroscopy, biological molecules in the gas phase, electronic structure theory for excited states, multi-chromophore and single-molecule spectroscopies, and excited state dynamics in chemical and biological systems.

  19. Reversibly Bistable Flexible Electronics

    KAUST Repository

    Alfaraj, Nasir

    2015-05-01

    Introducing the notion of transformational silicon electronics has paved the way for integrating various applications with silicon-based, modern, high-performance electronic circuits that are mechanically flexible and optically semitransparent. While maintaining large-scale production and prototyping rapidity, this flexible and translucent scheme demonstrates the potential to transform conventionally stiff electronic devices into thin and foldable ones without compromising long-term performance and reliability. In this work, we report on the fabrication and characterization of reversibly bistable flexible electronic switches that utilize flexible n-channel metal-oxide-semiconductor field-effect transistors. The transistors are fabricated initially on rigid (100) silicon substrates before they are peeled off. They can be used to control flexible batches of light-emitting diodes, demonstrating both the relative ease of scaling at minimum cost and maximum reliability and the feasibility of integration. The peeled-off silicon fabric is about 25 µm thick. The fabricated devices are transferred to a reversibly bistable flexible platform through which, for example, a flexible smartphone can be wrapped around a user’s wrist and can also be set back to its original mechanical position. Buckling and cyclic bending of such host platforms brings a completely new dimension to the development of flexible electronics, especially rollable displays.

  20. Phasor power electronics

    CERN Document Server

    Rim, Chun T

    2016-01-01

    This book presents a comprehensive introduction to the principles of power electronics, focusing on the switched transformer concept and phasor transformation techniques as employed in the analysis and design of power electronic circuits. Phasor transformations, as introduced in this book, make the time-varying nature of a switching converter simple and easy to handle, transforming it into an equivalent time-invariant circuit. The book starts with an introduction to the philosophy and fundamental principles of power electronics. The switched transformer concept, which is applicable to any switching converter, is introduced, and it is shown how DC-DC converters analyses are then so straightforward that very little equational manipulation is needed. Then the phasor transformation techniques are comprehensively explained over three parts. Single phase and multi-phase AC systems are dealt with through the single phase phasor transformation and circuit DQ transformation, respectively. A general unified phasor tran...

  1. Understanding the Electron

    CERN Document Server

    Knuth, Kevin H

    2015-01-01

    Well over a century after the discovery of the electron, we are still faced with serious conceptual issues regarding precisely what an electron is. Since the development of particle physics and the Standard Model, we have accumulated a great deal of knowledge about the relationships among various subatomic particles. However, this knowledge has not significantly aided in our understanding of the fundamental nature of any particular elementary subatomic particle. The fact that many particle properties, such as position, time, speed, energy, momentum, and component of spin, are observer-dependent suggests that these relevant variables do not represent properties per se, but rather the relationship between the observer and the observed. That is, they reflect details about how the electron influences the observer, and vice versa. Here we attempt to understand this by considering a simple model where particles influence one another in a discrete and direct fashion. The resulting framework, referred to as Influence...

  2. Wireless Biological Electronic Sensors.

    Science.gov (United States)

    Cui, Yue

    2017-10-09

    The development of wireless biological electronic sensors could open up significant advances for both fundamental studies and practical applications in a variety of areas, including medical diagnosis, environmental monitoring, and defense applications. One of the major challenges in the development of wireless bioelectronic sensors is the successful integration of biosensing units and wireless signal transducers. In recent years, there are a few types of wireless communication systems that have been integrated with biosensing systems to construct wireless bioelectronic sensors. To successfully construct wireless biological electronic sensors, there are several interesting questions: What types of biosensing transducers can be used in wireless bioelectronic sensors? What types of wireless systems can be integrated with biosensing transducers to construct wireless bioelectronic sensors? How are the electrical sensing signals generated and transmitted? This review will highlight the early attempts to address these questions in the development of wireless biological electronic sensors.

  3. Electronics for Extreme Environments

    Science.gov (United States)

    Patel, J. U.; Cressler, J.; Li, Y.; Niu, G.

    2001-01-01

    Most of the NASA missions involve extreme environments comprising radiation and low or high temperatures. Current practice of providing friendly ambient operating environment to electronics costs considerable power and mass (for shielding). Immediate missions such as the Europa orbiter and lander and Mars landers require the electronics to perform reliably in extreme conditions during the most critical part of the mission. Some other missions planned in the future also involve substantial surface activity in terms of measurements, sample collection, penetration through ice and crust and the analysis of samples. Thus it is extremely critical to develop electronics that could reliably operate under extreme space environments. Silicon On Insulator (SOI) technology is an extremely attractive candidate for NASA's future low power and high speed electronic systems because it offers increased transconductance, decreased sub-threshold slope, reduced short channel effects, elimination of kink effect, enhanced low field mobility, and immunity from radiation induced latch-up. A common belief that semiconductor devices function better at low temperatures is generally true for bulk devices but it does not hold true for deep sub-micron SOI CMOS devices with microscopic device features of 0.25 micrometers and smaller. Various temperature sensitive device parameters and device characteristics have recently been reported in the literature. Behavior of state of the art technology devices under such conditions needs to be evaluated in order to determine possible modifications in the device design for better performance and survivability under extreme environments. Here, we present a unique approach of developing electronics for extreme environments to benefit future NASA missions as described above. This will also benefit other long transit/life time missions such as the solar sail and planetary outposts in which electronics is out open in the unshielded space at the ambient space

  4. Determination of electron temperature and electron density in ...

    African Journals Online (AJOL)

    The electron temperatures and electron densities of air and argon have been measured at various pds (pressure times distance). The electron temperatures have been computed using the Johnson-Malter double-probe method. The electron densities have been computed using the total positive ion current and the ...

  5. Electron kinetics in capacitively coupled plasmas modulated by electron injection

    Science.gov (United States)

    Zhang, Ya; Peng, Yanli; Innocenti, Maria Elena; Jiang, Wei; Wang, Hong-yu; Lapenta, Giovanni

    2017-09-01

    The controlling effect of an electron injection on the electron energy distribution function (EEDF) and on the energetic electron flux, in a capacitive radio-frequency argon plasma, is studied using a one-dimensional particle-in-cell/Monte Carlo collisions model. The input power of the electron beam is as small as several tens of Watts with laboratory achievable emission currents and energies. With the electron injection, the electron temperature decreases but with a significant high energy tail. The electron density, electron temperature in the sheath, and electron heating rate increase with the increasing emission energy. This is attributed to the extra heating of the energetic electrons in the EEDF tail. The non-equilibrium EEDF is obtained for strong non-local distributions of the electric field, electron heating rate, excitation, and ionization rate, indicating the discharge has transited from a volume heating (α-mode dominated) into a sheath heating (γ-mode dominated) type. In addition, the electron injection not only modifies the self-bias voltage, but also enhances the electron flux that can reach the electrodes. Moreover, the relative population of energetic electrons significantly increases with the electron injection compared to that without the electron injection, relevant for modifying the gas and surface chemistry reactions.

  6. Electron-electron correlations in liquid s-p metals

    CERN Document Server

    Leys, F E

    2003-01-01

    We present calculations for the valence electron-electron structure factor in liquid Mg near freezing, assuming knowledge of the jellium result. On the basis of this, we predict significant corrections to jellium short-range correlations in liquid s-p metals and in particular an increase in the electron-electron contact probability.

  7. Electronics 2 checkbook

    CERN Document Server

    Knight, S A

    2013-01-01

    Electronics 2 Checkbook is an 11-chapter text that presents problems and worked examples to establish and exemplify the theory contained in technical syllabuses, with a particular emphasis on electronics.The introductory chapters review the elementary theory of semiconductors and the p-n junction diode. The subsequent chapters deal with the applications of diode, the characteristics of bipolar transistors, and the mode of operation of small signal amplifiers. These topics are followed by discussions of the function of the field-effect transistor and power supplies. The concluding chapters expl

  8. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  9. Stretchability of encapsulated electronics

    Science.gov (United States)

    Wu, J.; Liu, Z. J.; Song, J.; Huang, Y.; Hwang, K.-C.; Zhang, Y. W.; Rogers, J. A.

    2011-08-01

    Stretchable and flexible electronics offer the performance of conventional wafer-based systems but can be stretched like a rubber band, twisted like a rope, and bent over a pencil. Such a technology offers new application opportunities, in areas of surgical and diagnostic implements that naturally integrate with the human body to provide advanced capabilities, to curvilinear devices such as hemispherical "eyeball" cameras. In practice, stretchable and flexible electronic systems require encapsulation layers to provide mechanical and environmental protection. This paper establishes a simple, analytical model for the optimal design of encapsulation.

  10. Corrosion in Electronics

    DEFF Research Database (Denmark)

    Ambat, Rajan; Gudla, Helene Virginie Conseil; Verdingovas, Vadimas

    2017-01-01

    and high density packing combined with the use of several materials, which can undergo electrochemical corrosion in the presence of water film formed due to humidity exposure and bias conditions on the PCBA surface. This article provides a short review of the corrosion reliability issues of electronics due...... to the use of electronics under varying humidity conditions. Important PCBA aspects, which are fundamental to the corrosion cell formation under humid conditions, are discussed. Effect of hygroscopic residues from the process and service and their role in assisting water film build up and corrosion...... is presented. Various failure modes resulting from the corrosion and influence factors are discussed including humid and gaseous conditions....

  11. Modern electronic maintenance principles

    CERN Document Server

    Garland, DJ

    2013-01-01

    Modern Electronic Maintenance Principles reviews the principles of maintaining modern, complex electronic equipment, with emphasis on preventive and corrective maintenance. Unfamiliar subjects such as the half-split method of fault location, functional diagrams, and fault finding guides are explained. This book consists of 12 chapters and begins by stressing the need for maintenance principles and discussing the problem of complexity as well as the requirements for a maintenance technician. The next chapter deals with the connection between reliability and maintenance and defines the terms fai

  12. An electronic quantum eraser.

    Science.gov (United States)

    Weisz, E; Choi, H K; Sivan, I; Heiblum, M; Gefen, Y; Mahalu, D; Umansky, V

    2014-06-20

    The quantum eraser is a device that illustrates the quantum principle of complementarity and shows how a dephased system can regain its lost quantum behavior by erasing the "which-path" information already obtained about it. Thus far, quantum erasers were constructed predominantly in optical systems. Here, we present a realization of a quantum eraser in a mesoscopic electronic device. The use of interacting electrons, instead of noninteracting photons, allows control over the extracted information and a smooth variation of the degree of quantum erasure. The demonstrated system can serve as a first step toward a variety of more complex setups. Copyright © 2014, American Association for the Advancement of Science.

  13. Electronics for technicians

    CERN Document Server

    Crane, P W

    2013-01-01

    Electronics for Technicians covers the basic fundamentals of electronics, including the operation of devices and circuits. The book is meant to help the technician to obtain numerical answers to actual circuit problems. This volume consists of seven chapters, the first of which introduces the reader to the basic rules for circuits containing resistive and reactive elements. Charge and discharge of a capacitor through a resistor is discussed, along with charge and discharge of an inductance through a resistance, application of sinusoidal voltages to simple networks, and series and parallel LCR

  14. VLSI electronics microstructure science

    CERN Document Server

    1981-01-01

    VLSI Electronics: Microstructure Science, Volume 3 evaluates trends for the future of very large scale integration (VLSI) electronics and the scientific base that supports its development.This book discusses the impact of VLSI on computer architectures; VLSI design and design aid requirements; and design, fabrication, and performance of CCD imagers. The approaches, potential, and progress of ultra-high-speed GaAs VLSI; computer modeling of MOSFETs; and numerical physics of micron-length and submicron-length semiconductor devices are also elaborated. This text likewise covers the optical linewi

  15. Basic Electron Transport

    Science.gov (United States)

    Hickey, B. J.; Morgan, G. J.; Howson, M. A.

    This chapter will take you through a simple introduction to transport theory covering the Boltzmann equation, the Fuchs-Sondheimer model for thin films, the normal magnetoresistance and quantum interference effects in metals with strong electron scattering. At the end of the chapter we will also introduce you to a number of the basic techniques involved in electron transport measurements. All of this is by way of introduction to basic transport properties common to all metals. In later chapters these ideas will be developed and applied to systems in which spin dependent transport is important.

  16. Advances in electronic materials

    CERN Document Server

    Kasper, Erich; Grimmeiss, Hermann G

    2008-01-01

    This special-topic volume, Advances in Electronic Materials, covers various fields of materials research such as silicon, silicon-germanium hetero-structures, high-k materials, III-V semiconductor alloys and organic materials, as well as nano-structures for spintronics and photovoltaics. It begins with a brief summary of the formative years of microelectronics; now the keystone of information technology. The latter remains one of the most important global technologies, and is an extremely complex subject-area. Although electronic materials are primarily associated with computers, the internet

  17. The Electron Enters Industry

    Science.gov (United States)

    Wise, George

    1997-04-01

    The electron occupies a crucial intersection of science, technology, business, and government. It is not at all surprising that it became an object of value in all four realms. It is more surprising that it escaped capture by the institutions dominating the realms. This paper will show the electron in its first half century demonstrating its value in such areas as telephony, radio, X-ray tubes, industrial control, fluorescent lamps, television and radar. In the process, it appeared to fall under the control of a few giant institutions. However, its protean nature, which had attracted the giants, turned out to be its means for escaping them.

  18. Electronic health record

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross border...... and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increases the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...

  19. Innovations in electronic services

    Directory of Open Access Journals (Sweden)

    Dagmara Wach

    2011-12-01

    Full Text Available Summarry Existence in electronic business has become increasingly difficult. High competition and considerable financial resources needed to enter electronic market are the problems of most micro and small sized enterprises, starting or developing their business. Nevertheless, there is a market niche for them, which can ensure success and grant partial financing of the business. This niche are small web projects, providing the customer with personalized service, hitting his tastes and meeting immediate needs. A projects that large websites are unable to perform. Financial sourcing of those projects comes from EU subsidies, in the framework of the Działanie 8.1. PO IG, 2007-2013.

  20. Precision electron polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Chudakov, Eugene A. [JLAB

    2013-11-01

    A new generation of precise Parity-Violating experiments will require a sub-percent accuracy of electron beam polarimetry. Compton polarimetry can provide such accuracy at high energies, but at a few hundred MeV the small analyzing power limits the sensitivity. M{\\o}ller polarimetry provides a high analyzing power independent on the beam energy, but is limited by the properties of the polarized targets commonly used. Options for precision polarimetry at ~300 MeV will be discussed, in particular a proposal to use ultra-cold atomic hydrogen traps to provide a 100\\%-polarized electron target for M{\\o}ller polarimetry.

  1. Practical electronics handbook

    CERN Document Server

    Sinclair, Ian R

    1988-01-01

    Practical Electronics Handbook, Second Edition covers information useful in electronics, with focus on mathematical conventions. The handbook discusses the passive (resistors, capacitors, band coding, and inductors) and active discrete (diodes, transistors and negative feedback) components; discrete component circuits; and transferring digital data. Linear I.C.s, which are the single-chip arrangements of amplifier circuits that are intended to be biased and operated in a linear way, and digital I.C.s, which process signals and consist of two significant voltage levels, are also considered. T

  2. A revision of the genus Inocybe in Europe. I. Subgenus Inosperma and the smooth-spored species of subgenus Inocybe

    NARCIS (Netherlands)

    Kuyper, Th.W.

    1986-01-01

    Fries (1821: 11) established Agaricus series Derminus tribus Inocybe, which was later elevated by him to generic rank (Fries, 1863: 346). Originally Fries based his circumscription of Inocybe solely on macroscopical characters; when it was raised to generic status Fries added that the spores of all

  3. Using Electronic Portfolios

    Science.gov (United States)

    Page, Deb

    2012-01-01

    The digitized collections of artifacts known as electronic portfolios are creating solutions to a variety of performance improvement needs in ways that are cost-effective and improve both individual and group learning and performance. When social media functionality is embedded in e-portfolios, the tools support collaboration, social learning,…

  4. Electrons in Condensed Matter

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. Electrons in Condensed Matter. T V Ramakrishnan. General Article Volume 2 Issue 12 December 1997 pp 17-32. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/002/12/0017-0032 ...

  5. Polymer Electronics, Quo Vadis?

    NARCIS (Netherlands)

    Chiechi, Ryan C.; Hummelen, Jan C.

    2012-01-01

    At the heart of polymer electronics lies more than three decades of research into conjugated polymers. The future of these materials is intimately tied to the development of organic photovoltaic (OPV) devices that can compete with traditional, inorganic devices in efficiency and cost. In addition to

  6. Educating for Electronic Resources

    Science.gov (United States)

    Grogg, Jill E.

    2008-01-01

    While mission statements for various libraries and information centers necessarily vary, all librarians face "two very pressing charges: make voluminous numbers of electronic resources as visible as possible in a landscape of multiple access points and simultaneously manage all the technology, tasks, and data necessary to facilitate such…

  7. ALICE physics with electrons

    CERN Document Server

    Schicker, R

    2005-01-01

    The ALICE potential for measurements of dielectron decays of quarkonia J/psi and of the Upsilon-family is discussed. The electron trigger capability of the ALICE transition radiation detector (TRD) is reviewed, and the anticipated pion rejection power is given. Furthermore, the invariant mass resolution achieved for quarkonia states is given and the signal to background ratio is presented.

  8. Power Electronics Thermal Management

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, Gilberto [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-08-07

    Thermal modeling was conducted to evaluate and develop thermal management strategies for high-temperature wide-bandgap (WBG)-based power electronics systems. WBG device temperatures of 175 degrees C to 250 degrees C were modeled under various under-hood temperature environments. Modeling result were used to identify the most effective capacitor cooling strategies under high device temperature conditions.

  9. Electronic waste recycling techniques

    CERN Document Server

    Bernardes, Andréa

    2015-01-01

    This book presents an overview of the characterization of electronic waste. In addition, processing techniques for the recovery of metals, polymers and ceramics are described. This book serves as a source of information and as an educational technical reference for practicing scientists and engineers, as well as for students.

  10. Quantum Hall Electron Nematics

    Science.gov (United States)

    MacDonald, Allan

    In 2D electron systems hosted by crystals with hexagonal symmetry, electron nematic phases with spontaneously broken C3 symmetry are expected to occur in the quantum Hall regime when triplets of Landau levels associated with three different Fermi surface pockets are partially filled. The broken symmetry state is driven by intravalley Coulombic exchange interactions that favor spontaneously polarized valley occupations. I will discuss three different examples of 2D electron systems in which this type of broken symmetry state is expected to occur: i) the SnTe (111) surface, ii) the Bi (111) surface. and iii) unbalanced bilayer graphene. This type of quantum Hall electron nematic state has so far been confirmed only in the Bi (111) case, in which the anisotropic quasiparticle wavefunctions of the broken symmetry state were directly imaged. In the SnTe case the nematic state phase boundary is controlled by a competition between intravalley Coulomb interactions and intervalley scattering processes that increase in relative strength with magnetic field. An in-plane Zeeman field alters the phase diagram by lifting the three-fold Landau level degeneracy, yielding a ground state energy with 2 π/3 periodicity as a function of Zeeman-field orientation angle. I will comment on the possibility of observing similar states in the absence of a magnetic field. Supported by DOE Division of Materials Sciences and Engineering Grant DE-FG03-02ER45958.

  11. and transmission electron microscopy

    African Journals Online (AJOL)

    Administrator

    immune-electron microscopy (IEM) from patients' feces. They reported this virus particle as the causative agent of winter vomiting outbreaks in Norwalk (Kapikian et al.,. 1972). This is the remarkable landmark study of non- bacterial gastroenteritis viruses, especially for small round structured viruses (SRSVs). After that, many.

  12. Inventing the Electronic University

    Science.gov (United States)

    Lewis, David W.

    2015-01-01

    Higher education is confronting a fundamental change. The transition from print on paper to digital and electronic technologies is transforming instruction, scholarly communication, and the storage and preservation of knowledge. What is required is not the automation of old systems, but the restructuring of institutions. The drive for autonomy,…

  13. Readily Made Solvated Electrons

    Science.gov (United States)

    Ibanez, Jorge G.; Guerra-Millan, Francisco J.; Hugerat, Muhamad; Vazquez-Olavarrieta, Jorge L.; Basheer, Ahmad; Abu-Much, Riam

    2011-01-01

    The existence of solvated electrons has been known for a long time. Key methods for their production (i.e., photoionization of reducing ions, water radiolysis, and the reaction between H[middle dot] and OH[superscript -]) are unsuitable for most school laboratories. We describe a simple experiment to produce liquid ammonia and solvated electrons…

  14. The electronic neighbourhood

    DEFF Research Database (Denmark)

    Rüdiger, Bjarne; Tournay, Bruno

    2004-01-01

    This paper presents the results of a 3-year research project. The Electronic Neighbourhood (2000-2004). Researchers have developed and tested a digital model of the urban area and other digital tools for supporting the dialogue and cooperation between professionals and citizens in an urban...... regeneration project in Copenhagen....

  15. Electronic Resource Management Systems

    Directory of Open Access Journals (Sweden)

    Mark Ellingsen

    2004-10-01

    Full Text Available Computer applications which deal with electronic resource management (ERM are quite a recent development. They have grown out of the need to manage the burgeoning number of electronic resources particularly electronic journals. Typically, in the early years of e-journal acquisition, library staff provided an easy means of accessing these journals by providing an alphabetical list on a web page. Some went as far as categorising the e-journals by subject and then grouping the journals either on a single web page or by using multiple pages. It didn't take long before it was recognised that it would be more efficient to dynamically generate the pages from a database rather than to continually edit the pages manually. Of course, once the descriptive metadata for an electronic journal was held within a database the next logical step was to provide administrative forms whereby that metadata could be manipulated. This in turn led to demands for incorporating more information and more functionality into the developing application.

  16. Joint Services Electronics Program.

    Science.gov (United States)

    1986-09-30

    34 Int. J. Infrared and Millimeter Waves, Vol. 2, pp. 883-904, 1981. 2. H. Shichijo, K. Hess and B.G. Streetman, "Real-Space Electron Transfer by...Huachuca, AZ 85613 Dr. Rudolf G. Buser Night Vision & Electro-Optics LabsU.S. Army Research, Development ATTN: DELNL-L and Standardization Group - CA Fort

  17. Quantitative Electron Nanodiffraction.

    Energy Technology Data Exchange (ETDEWEB)

    Spence, John [Arizona State Univ., Mesa, AZ (United States)

    2015-01-30

    This Final report summarizes progress under this award for the final reporting period 2002 - 2013 in our development of quantitive electron nanodiffraction to materials problems, especially devoted to atomistic processes in semiconductors and electronic oxides such as the new artificial oxide multilayers, where our microdiffraction is complemented with energy-loss spectroscopy (ELNES) and aberration-corrected STEM imaging (9). The method has also been used to map out the chemical bonds in the important GaN semiconductor (1) used for solid state lighting, and to understand the effects of stacking sequence variations and interfaces in digital oxide superlattices (8). Other projects include the development of a laser-beam Zernike phase plate for cryo-electron microscopy (5) (based on the Kapitza-Dirac effect), work on reconstruction of molecular images using the scattering from many identical molecules lying in random orientations (4), a review article on space-group determination for the International Tables on Crystallography (10), the observation of energy-loss spectra with millivolt energy resolution and sub-nanometer spatial resolution from individual point defects in an alkali halide, a review article for the Centenary of X-ray Diffration (17) and the development of a new method of electron-beam lithography (12). We briefly summarize here the work on GaN, on oxide superlattice ELNES, and on lithography by STEM.

  18. ELECTRON COOLING FOR RHIC.

    Energy Technology Data Exchange (ETDEWEB)

    BEN-ZVI,I.

    2001-05-13

    The Accelerator Collider Department (CAD) at Brookhaven National Laboratory is operating the Relativistic Heavy Ion Collider (RHIC), which includes the dual-ring, 3.834 km circumference superconducting collider and the venerable AGS as the last part of the RHIC injection chain. CAD is planning on a luminosity upgrade of the machine under the designation RHIC II. One important component of the RHIC II upgrade is electron cooling of RHIC gold ion beams. For this purpose, BNL and the Budker Institute of Nuclear Physics in Novosibirsk entered into a collaboration aimed initially at the development of the electron cooling conceptual design, resolution of technical issues, and finally extend the collaboration towards the construction and commissioning of the cooler. Many of the results presented in this paper are derived from the Electron Cooling for RHIC Design Report [1], produced by the, BINP team within the framework of this collaboration. BNL is also collaborating with Fermi National Laboratory, Thomas Jefferson National Accelerator Facility and the University of Indiana on various aspects of electron cooling.

  19. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    IAS Admin

    Recently, electron paramagnetic resonance (EPR) spectros- copy has emerged as a powerful tool to study the structure and dynamics of biological macromolecules such as proteins, protein aggregates, RNA and DNA. It is used in combination with molecular modelling to study complex systems such as soluble proteins ...

  20. Electron Paramagnetic Resonance Spectroscopy

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Electron Paramagnetic Resonance Spectroscopy: Biological Applications. B G Hegde. General Article Volume 20 Issue 11 November 2015 pp 1017-1032. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    IAS Admin

    Electron Paramagnetic Resonance Imaging. 2. Radiofrequency FT-EPR Imaging. Sankaran Subramanian and Murali C Krishna. Keywords. FT-EPR, Hahn-echo, acquisition delay, single-point imaging (SPI), gradient-echo, k-space, echo-SPI, carbogen, oxygen relaxivity, T2*. T2- and T1-based oximetry, co- registration ...

  2. Electronic states of myricetin

    DEFF Research Database (Denmark)

    Vojta, Danijela; Karlsen, Eva; Spanget-Larsen, Jens

    2017-01-01

    Myricetin (3,3',4',5,5',7'-hexahydroxyflavone) was investigated by linear dichroism spectroscopy on molecular samples partially aligned in stretched poly(vinyl alcohol) (PVA). At least five electronic transitions in the range 40000 – 20000 cm–1 were characterized with respect to their wavenumbers...

  3. Electron Paramagnetic Resonance Imaging

    Indian Academy of Sciences (India)

    Twentieth century bore witness to remarkable scientists whohave advanced our understanding of the brain. Among them,EPR (Electron Paramagnetic Resonance) imaging is particularlyuseful in monitoring hypoxic zones in tumors which arehighly resistant to radiation and chemotherapeutic treatment.This first part of the ...

  4. Electronic Equipment Cold Plates

    Science.gov (United States)

    1976-04-01

    appear to be best suited for electronic-cooling applications are the silicons, fluorinated organics, and the ethylene - glycnl-water solution. The...with power dissipa- tion of 30 watts frui each transistor. The SMximsi allowable Junction teaperature of the transistors is given as tj - 135*C

  5. Newnes electronics assembly pocket book

    CERN Document Server

    Brindley, Keith

    2013-01-01

    Produced in association with the Engineering Training Authority with contributions from dozens of people in the electronics industry. The material covers common skills in electrical and electronic engineering and concentrates mainly on wiring and assembly. 'Newnes Electronics Assembly Pocket Book' is for electronics technicians, students and apprentices.

  6. Non-diffracting multi-electron vortex beams balancing their electron-electron interactions.

    Science.gov (United States)

    Mutzafi, Maor; Kaminer, Ido; Harari, Gal; Segev, Mordechai

    2017-09-21

    The wave-like nature of electrons has been known for almost a century, but only in recent years has the ability to shape the wavefunction of EBeams (Electron-Beams) become experimentally accessible. Various EBeam wavefunctions have been demonstrated, such as vortex, self-accelerating, Bessel EBeams etc. However, none has attempted to manipulate multi-electron beams, because the repulsion between electrons rapidly alters the beam shape. Here, we show how interference effects of the quantum wavefunction describing multiple electrons can be used to exactly balance both the repulsion and diffraction-broadening. We propose non-diffracting wavepackets of multiple electrons, which can also carry orbital angular momentum. Such wavefunction shaping facilitates the use of multi-electron beams in electron microscopy with higher current without compromising on spatial resolution. Simulating the quantum evolution in three-dimensions and time, we show that imprinting such wavefunctions on electron pulses leads to shape-preserving multi-electrons ultrashort pulses. Our scheme applies to any beams of charged particles, such as protons and ion beams.Vortex electron beams are generated using single electrons but their low beam-density is a limitation in electron microscopy. Here the authors propose a scheme for the realization of non-diffracting electron beams by shaping wavepackets of multiple electrons and including electron-electron interactions.

  7. The electronic structures of solids

    CERN Document Server

    Coles, B R

    2013-01-01

    The Electronic Structures of Solids aims to provide students of solid state physics with the essential concepts they will need in considering properties of solids that depend on their electronic structures and idea of the electronic character of particular materials and groups of materials. The book first discusses the electronic structure of atoms, including hydrogen atom and many-electron atom. The text also underscores bonding between atoms and electrons in metals. Discussions focus on bonding energies and structures in the solid elements, eigenstates of free-electron gas, and electrical co

  8. Electron Jet of Asymmetric Reconnection

    Science.gov (United States)

    Khotyaintsev, Yu. V.; Graham, D. B.; Norgren, C.; Eriksson, E.; Li, W.; Johlander, A.; Vaivads, A.; Andre, M.; Pritchett, P. L.; Retino, A.; hide

    2016-01-01

    We present Magnetospheric Multiscale observations of an electron-scale current sheet and electron outflow jet for asymmetric reconnection with guide field at the subsolar magnetopause. The electron jet observed within the reconnection region has an electron Mach number of 0.35 and is associated with electron agyrotropy. The jet is unstable to an electrostatic instability which generates intense waves with E(sub parallel lines) amplitudes reaching up to 300 mV/m and potentials up to 20% of the electron thermal energy. We see evidence of interaction between the waves and the electron beam, leading to quick thermalization of the beam and stabilization of the instability. The wave phase speed is comparable to the ion thermal speed, suggesting that the instability is of Buneman type, and therefore introduces electron-ion drag and leads to braking of the electron flow. Our observations demonstrate that electrostatic turbulence plays an important role in the electron-scale physics of asymmetric reconnection.

  9. Diamondoid monolayers as electron emitters

    Science.gov (United States)

    Yang, Wanli [El Cerrito, CA; Fabbri, Jason D [San Francisco, CA; Melosh, Nicholas A [Menlo Park, CA; Hussain, Zahid [Orinda, CA; Shen, Zhi-Xun [Stanford, CA

    2012-04-10

    Provided are electron emitters based upon diamondoid monolayers, preferably self-assembled higher diamondoid monolayers. High intensity electron emission has been demonstrated employing such diamondoid monolayers, particularly when the monolayers are comprised of higher diamondoids. The application of such diamondoid monolayers can alter the band structure of substrates, as well as emit monochromatic electrons, and the high intensity electron emissions can also greatly improve the efficiency of field-effect electron emitters as applied to industrial and commercial applications.

  10. Electronic Commerce Removing Regulatory Impediments

    Science.gov (United States)

    1992-05-01

    AD-A252 691 ELECTRONIC COMMERCE Removing Regulatory Impediments ~DuiG A% ELECTE I JUL1 8 1992 0 C D Daniel J. Drake John A. Ciucci ... - ""N ST AT KE...Management Institute 6400 Goldsboro Road Bethesda, Maryland 20817-5886 92 LMI Executive Summary ELECTRONIC COMMERCE : REMOVING REGULATORY IMPEDIMENTS... Electronic Commerce techniques, such as electronic mail and electronic data interchange (EDI), enable Government agencies to conduct business without the

  11. Decal electronics for printed high performance cmos electronic systems

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-11-23

    High performance complementary metal oxide semiconductor (CMOS) electronics are critical for any full-fledged electronic system. However, state-of-the-art CMOS electronics are rigid and bulky making them unusable for flexible electronic applications. While there exist bulk material reduction methods to flex them, such thinned CMOS electronics are fragile and vulnerable to handling for high throughput manufacturing. Here, we show a fusion of a CMOS technology compatible fabrication process for flexible CMOS electronics, with inkjet and conductive cellulose based interconnects, followed by additive manufacturing (i.e. 3D printing based packaging) and finally roll-to-roll printing of packaged decal electronics (thin film transistors based circuit components and sensors) focusing on printed high performance flexible electronic systems. This work provides the most pragmatic route for packaged flexible electronic systems for wide ranging applications.

  12. Electron Structure of Francium

    Science.gov (United States)

    Koufos, Alexander

    2012-02-01

    This talk presents the first calculations of the electronic structure of francium for the bcc, fcc and hcp structures, using the Augmented Plane Wave (APW) method in its muffin-tin and linearized general potential forms. Both the Local Density Approximation (LDA) and Generalized Gradient Approximation (GGA), were used to calculate the electronic structure and total energy of francium (Fr). The GGA and LDA both found the total energy of the hcp structure slightly below that of the fcc and bcc structure, respectively. This is in agreement with similar results for the other alkali metals using the same methodology. The equilibrium lattice constant, bulk modulus and superconductivity parameters were calculated. We found that under pressures, in the range of 1-5 GPa, Fr could be a superconductor at a critical temperature of about 4K.

  13. Electronic Word of Behavior

    DEFF Research Database (Denmark)

    Kunst, Katrine; Vatrapu, Ravi; Hussain, Abid

    2017-01-01

    In this research in progress-paper, we introduce the notion of ‘Electronic Word of Behavior’ (eWOB) to describe the phenomenon of consumers’ product-related behaviors increasingly made observable by online social environments. We employ Observational Learning theory to conceptualize the notion of...... how the presence of individual-specific behavior-based social information in a movie streaming service affects potential users’ attitude towards and intentions to use the service.......In this research in progress-paper, we introduce the notion of ‘Electronic Word of Behavior’ (eWOB) to describe the phenomenon of consumers’ product-related behaviors increasingly made observable by online social environments. We employ Observational Learning theory to conceptualize the notion of e...

  14. Semiconductor Physical Electronics

    CERN Document Server

    Li, Sheng

    2006-01-01

    Semiconductor Physical Electronics, Second Edition, provides comprehensive coverage of fundamental semiconductor physics that is essential to an understanding of the physical and operational principles of a wide variety of semiconductor electronic and optoelectronic devices. This text presents a unified and balanced treatment of the physics, characterization, and applications of semiconductor materials and devices for physicists and material scientists who need further exposure to semiconductor and photonic devices, and for device engineers who need additional background on the underlying physical principles. This updated and revised second edition reflects advances in semicondutor technologies over the past decade, including many new semiconductor devices that have emerged and entered into the marketplace. It is suitable for graduate students in electrical engineering, materials science, physics, and chemical engineering, and as a general reference for processing and device engineers working in the semicondi...

  15. Engineering limitations with electrons

    CERN Document Server

    Gröbner, Oswald

    1992-01-01

    The vacuum required for electron machines is determined by the beam lifetime and must be in the ultrahigh vacuum range. Since the emission of intense synchrotron radiation by the electron beam produces strong dynamic outgassing from the vacuum chamber, this gas load must be removed by a powerful, distributed pumping system. To achieve good beam lifetimes an extended in-situ cleaning (beam conditioning) by synchrotron radiation must be applied. High pumping speeds can be obtained using a distributed pumping system, e.g. based on linear, non-evaporable getter pumps. The absorption of the synchrotron radiation power, either by the vacuum chamber directly or on local aborbers,is closely linked to the design of the global system and to the choice of the vacuum chamber material.

  16. Electronics for Satellite Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Robert P.; /UC, Santa Cruz

    2006-05-16

    The tracking detector for the LAT science instrument on the GLAST mission is an example of a large-scale particle detection system built primarily by particle physicists for space flight within the context of a NASA program. The design and fabrication model in most ways reflected practice and experience from particle physics, but the quality assurance aspects were guided by NASA. Similarly, most of the electronics in the LAT as a whole were designed and built by staff at a particle physics lab. This paper reports on many of the challenges and lessons learned in the experience of designing and building the tracking detector and general LAT electronics for use in the NASA GLAST mission.

  17. Conversion electron surface imaging

    CERN Document Server

    Irwin, G M; Wehner, A

    1999-01-01

    A method of imaging the Moessbauer absorption over the surface of a sample based on counting conversion electrons emitted from the surface following resonant absorption of gamma radiation is described. This Conversion Electron Surface Imaging (CESI) method is somewhat analogous to Magnetic Resonance Imaging (MRI), particularly chemical shift imaging, and similar tomographic reconstruction techniques are involved in extracting the image. The theory behind the technique and a prototype device is described, as well as the results of proof-of-principle experiments which demonstrate the function of the device. Eventually this same prototype device will be part of a system to determine the spatial variation of the Moessbauer spectrum over the surface of a sample. Applications include imaging of variations of surface properties of steels and other iron containing alloys, as well as other surfaces over which sup 5 sup 7 Fe has been deposited.

  18. Electron-molecule collisions

    CERN Document Server

    Takayanagi, Kazuo

    1984-01-01

    Scattering phenomena play an important role in modern physics. Many significant discoveries have been made through collision experiments. Amongst diverse kinds of collision systems, this book sheds light on the collision of an electron with a molecule. The electron-molecule collision provides a basic scattering problem. It is scattering by a nonspherical, multicentered composite particle with its centers having degrees of freedom of motion. The molecule can even disintegrate, Le., dissociate or ionize into fragments, some or all of which may also be molecules. Although it is a difficult problem, the recent theoretical, experimental, and computational progress has been so significant as to warrant publication of a book that specializes in this field. The progress owes partly to technical develop­ ments in measurements and computations. No less important has been the great and continuing stimulus from such fields of application as astrophysics, the physics of the earth's upper atmosphere, laser physics, radiat...

  19. High Power Electronics

    Science.gov (United States)

    Pendharker, Sameer

    High Power Electronics Future Trends: New process, circuit and packaging technologies over the last 5 years have led to significant innovation and technological developments in high power electronics. In this topic, the trends and performance improvements achieved in the industry will be discussed with focus on gallium-nitride (GaN) and silicon carbide (SiC). Both GaN and SiC technologies have been around for many years but have seen limited adoption and proliferation in high power systems. With the improved transistor performance, power conversion efficiencies and densities previously unrealizable are now available leading to new applications and new system. Trends in these technologies will also be reviewed and remaining challenges to overcome before true mass market adoption can be expected.

  20. Electron beam silicon purification

    Energy Technology Data Exchange (ETDEWEB)

    Kravtsov, Anatoly [SIA ' ' KEPP EU' ' , Riga (Latvia); Kravtsov, Alexey [' ' KEPP-service' ' Ltd., Moscow (Russian Federation)

    2014-11-15

    Purification of heavily doped electronic grade silicon by evaporation of N-type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150-300 kg) and yield solar grade silicon. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Electronic health records

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2011-01-01

    The European Commission wants to boost the digital economy by enabling all Europeans to have access to online medical records anywhere in Europe by 2020. With the newly enacted Directive 2011/24/EU on patients’ rights in cross-border healthcare due for implementation by 2013, it is inevitable...... that a centralised European health record system will become a reality even before 2020. However, the concept of a centralised supranational central server raises concern about storing electronic medical records in a central location. The privacy threat posed by a supranational network is a key concern. Cross......-border and Interoperable electronic health record systems make confidential data more easily and rapidly accessible to a wider audience and increase the risk that personal data concerning health could be accidentally exposed or easily distributed to unauthorised parties by enabling greater access to a compilation...

  2. PAMELA and electrons

    Energy Technology Data Exchange (ETDEWEB)

    Mocchiutti, E., E-mail: Emiliano.Mocchiutti@ts.infn.i [INFN, Sezione di Trieste, Padriciano 99, I-34012 Trieste (Italy); Adriani, O. [University of Florence, Department of Physics, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); INFN, Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); Barbarino, G.C. [University of Naples ' Federico II' , Department of Physics, Via Cintia, I-80126 Naples (Italy); INFN, Sezione di Napoli, Via Cintia, I-80126 Naples (Italy); Bazilevskaya, G.A. [Lebedev Physical Institute, Leninsky Prospekt 53, RU-119991 Moscow (Russian Federation); Bellotti, R. [University of Bari, Department of Physics, Via Amendola 173, I-70126 Bari (Italy); INFN, Sezione di Bari, Via Amendola 173, I-70126 Bari (Italy); Boezio, M. [INFN, Sezione di Trieste, Padriciano 99, I-34012 Trieste (Italy); Bogomolov, E.A. [Ioffe Physical Technical Institute, Polytekhnicheskaya 26, RU-194021 St. Petersburg (Russian Federation); Bonechi, L.; Bongi, M. [University of Florence, Department of Physics, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); INFN, Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); Bonvicini, V. [INFN, Sezione di Trieste, Padriciano 99, I-34012 Trieste (Italy); Borisov, S. [INFN, Sezione di Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, I-00133 Rome (Italy); Moscow Engineering and Physics Institute, Kashirskoe Shosse 31, RU-11540 Moscow (Russian Federation); Bottai, S. [INFN, Sezione di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino, Florence (Italy); Bruno, A. [University of Bari, Department of Physics, Via Amendola 173, I-70126 Bari (Italy); INFN, Sezione di Bari, Via Amendola 173, I-70126 Bari (Italy); Cafagna, F. [INFN, Sezione di Bari, Via Amendola 173, I-70126 Bari (Italy); Campana, D. [INFN, Sezione di Napoli, Via Cintia, I-80126 Naples (Italy)

    2011-02-21

    The 15th of June 2006, the PAMELA satellite-borne experiment was launched from the Baikonur cosmodrome and it has been collecting data since July 2006. The apparatus comprises a time-of-flight system, a silicon-microstrip magnetic spectrometer, a silicon-tungsten electromagnetic calorimeter, an anticoincidence system, a shower tail counter scintillator and a neutron detector. The combination of these devices allows precision studies of the charged cosmic radiation to be conducted over a wide energy range (100 MeV-100's GeV) with high statistics. The measurement of the positron to electron fraction and of the electron energy spectrum in order to search for exotic sources, such as dark matter particle annihilations, are within the PAMELA primary scientific goal.

  3. Recycling of electronic scrap

    DEFF Research Database (Denmark)

    Legarth, Jens Brøbech

    This Ph.D. thesis deals with the growingly important field of electronics recycling with special attention to the problem of printed circuit board recycling. A literature survey of contemporary electronics recycling and printed circuit board recycling is presented.Further, an analysis of the role...... of recycling in the modern quest for a sustainable global society is performed, clearly showing that without intensified focus on recycling, the global community cannot hope to reach even the most modest goals for sustainability in resource use. A general method for finding new recycling alternatives...... resource recovery is largest. It is clearly shown with the two printed circuit board scrap cases that the currently used copper recycling scenario is environmentally inferior to the tin and lead primary production scenarios. The method is a novelty, since no-one has previously put forward a method...

  4. CERN Electronics Pool presentations

    CERN Multimedia

    2011-01-01

    The CERN Electronics Pool has organised a series of presentations in collaboration with oscilloscope manufacturers. The last one will take place according to the schedule below.   Time will be available at the end of the presentation to discuss your personal needs. The Agilent presentation had to be postponed and will be organised later. -     Lecroy: Thursday, 24 November 2011, in 530-R-030, 14:00 to 16:30.

  5. Implantable electronic medical devices

    CERN Document Server

    Fitzpatrick, Dennis

    2014-01-01

    Implantable Electronic Medical Devices provides a thorough review of the application of implantable devices, illustrating the techniques currently being used together with overviews of the latest commercially available medical devices. This book provides an overview of the design of medical devices and is a reference on existing medical devices. The book groups devices with similar functionality into distinct chapters, looking at the latest design ideas and techniques in each area, including retinal implants, glucose biosensors, cochlear implants, pacemakers, electrical stimulation t

  6. Electrical and electronic principles

    CERN Document Server

    Knight, S A

    1991-01-01

    Electrical and Electronic Principles, 2, Second Edition covers the syllabus requirements of BTEC Unit U86/329, including the principles of control systems and elements of data transmission. The book first tackles series and parallel circuits, electrical networks, and capacitors and capacitance. Discussions focus on flux density, electric force, permittivity, Kirchhoff's laws, superposition theorem, arrangement of resistors, internal resistance, and powers in a circuit. The text then takes a look at capacitors in circuit, magnetism and magnetization, electromagnetic induction, and alternating v

  7. Xyce parallel electronic simulator.

    Energy Technology Data Exchange (ETDEWEB)

    Keiter, Eric R; Mei, Ting; Russo, Thomas V.; Rankin, Eric Lamont; Schiek, Richard Louis; Thornquist, Heidi K.; Fixel, Deborah A.; Coffey, Todd S; Pawlowski, Roger P; Santarelli, Keith R.

    2010-05-01

    This document is a reference guide to the Xyce Parallel Electronic Simulator, and is a companion document to the Xyce Users Guide. The focus of this document is (to the extent possible) exhaustively list device parameters, solver options, parser options, and other usage details of Xyce. This document is not intended to be a tutorial. Users who are new to circuit simulation are better served by the Xyce Users Guide.

  8. Electronic Braille Document Reader

    OpenAIRE

    Arif, Shahab; Holmes, Violeta

    2013-01-01

    This paper presents an investigation into developing a portable Braille device which would allow visually impaired individuals to read electronic documents by actuating Braille text on a finger. Braille books tend to be bulky in size due to the minimum size requirements for each Braille cell. E-books can be read in Braille using refreshable Braille displays connected to a computer. However, the refreshable Braille displays are expensive, bulky and are not portable. These factors restrict blin...

  9. FRAUD IN ELECTRONIC COMMERCE

    OpenAIRE

    Valentin-Stelian Badescu

    2013-01-01

    Electronic commerce is experiencing a great extent, and about the same extent fraud seeks - and sometimes is the place to impressive levels. Moreover, computer fraud and, the actors' they do not seem to suffer from the global economic recession and get as sophisticated as a legitimate business model and one of the most important dimensions of the work of modern organizations is the manipulation of information (collection, processing, storage, distribution, etc.). This component informational ...

  10. Electronics Technician 3

    Science.gov (United States)

    1957-01-01

    grade of of a strong, pliable wood strip and securing sandpaper (No. 00) may be used. Sandpapering the canvas with rivets, as shown in figure is also...and use properly personnel. insulated tools; cover the deck with an approved All electronics personnel must become thor- insulating material; and make...not struction, the worker must be insulated from be broken except when absolutely necessary and accidental grounding by the use of approved authorized

  11. Electronic Health Services

    OpenAIRE

    Khalil, Mounir M; Jones, Ray

    2007-01-01

    Information and communication technologies have made dramatic changes in our lives. Healthcare communities also made use of these technologies. Using computerized medical knowledge, electronic patients’ information and telecommunications a lot of applications are now established throughout the world. These include better ways of information management, remote education, telemedicine and public services. Yet, a lot of people don't know about these technologies and their applications. Understan...

  12. Chemistry of fast electrons

    Science.gov (United States)

    Maximoff, Sergey N.; Head-Gordon, Martin P.

    2009-01-01

    A chemicurrent is a flux of fast (kinetic energy ≳ 0.5−1.3 eV) metal electrons caused by moderately exothermic (1−3 eV) chemical reactions over high work function (4−6 eV) metal surfaces. In this report, the relation between chemicurrent and surface chemistry is elucidated with a combination of top-down phenomenology and bottom-up atomic-scale modeling. Examination of catalytic CO oxidation, an example which exhibits a chemicurrent, reveals 3 constituents of this relation: The localization of some conduction electrons to the surface via a reduction reaction, 0.5 O2 + δe− → Oδ− (Red); the delocalization of some surface electrons into a conduction band in an oxidation reaction, Oδ− + CO → CO2δ− → CO2 + δe− (Ox); and relaxation without charge transfer (Rel). Juxtaposition of Red, Ox, and Rel produces a daunting variety of metal electronic excitations, but only those that originate from CO2 reactive desorption are long-range and fast enough to dominate the chemicurrent. The chemicurrent yield depends on the universality class of the desorption process and the distribution of the desorption thresholds. This analysis implies a power-law relation with exponent 2.66 between the chemicurrent and the heat of adsorption, which is consistent with experimental findings for a range of systems. This picture also applies to other oxidation-reduction reactions over high work function metal surfaces. PMID:19561296

  13. ELECTRONIC HUMAN RESOURCE MANAGEMENT

    OpenAIRE

    Dr. M. Panneerselvam

    2017-01-01

    Electronic Human Resource Management is an essence the revolution of human resource functions to management and employees. These functions are typically used via intranet and web technology. This helps the organization to improve their standards where they can able to review and forward. All those documents can be viewed within a fraction of second with help of client and server links. The phenomenon of E- HRM deserves closer and more fundamental roots to HR activity. The E-HRM develops and b...

  14. Electronic Collaboration Logbook

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    At FNAL, we developed an Electronic Collaboration Logbook (ECL) application which is used by about 20 different collaborations, experiments and groups at FNAL. ECL is the latest iteration of the project formerly known as Control Room Logbook (CRL). We have been working on mobile (IOS and Android) clients for ECL. We will present history, current status and future plans of the project, as well as design, implementation and support solutions made by the project.

  15. Dealing with electronics

    CERN Document Server

    Drosg, Manfred

    2014-01-01

    By using a holistic approach in the understanding of the various circuits and by taking ample advantage of the duality between the electrical quantities voltage and current the understanding of the properties of electronic circuits is made easier. This approach reduces the amount of mathematics needed for a deeper understanding. This graduate textbook aims at completeness regarding the construction of possible circuits and their classification.

  16. Plasmonic-Electronic Transduction

    Science.gov (United States)

    2012-01-31

    output continue to rely on bulky free space optics and inefficient couplers such as prisms . The objective of this project was to study direct electronic...output continue to rely on bulky free space optics and inefficient couplers such as prisms . The objective of this project was to study direct...JOSA B 27, 730 (2010). 3. “Long-wave infrared surface plasmon grating coupler ,” J. W. Cleary, G. Medhi, R. E. Peale, and W. R. Buchwald, Appl. Optics

  17. Electronic healthcare information security

    CERN Document Server

    Dube, Kudakwashe; Shoniregun, Charles A

    2010-01-01

    The ever-increasing healthcare expenditure and pressing demand for improved quality and efficiency of patient care services are driving innovation in healthcare information management. The domain of healthcare has become a challenging testing ground for information security due to the complex nature of healthcare information and individual privacy. ""Electronic Healthcare Information Security"" explores the challenges of e-healthcare information and security policy technologies. It evaluates the effectiveness of security and privacy implementation systems for anonymization methods and techniqu

  18. Electronic Noses and Applications

    Directory of Open Access Journals (Sweden)

    Martine LUMBRERAS

    2014-05-01

    Full Text Available Electronic noses are customized devices employed to detect and to identify gaseous mixtures, even to give the concentration of the atmosphere components. Nowadays, the research in this domain is more and more growing, in Europe and other countries in the world, for many applications, such as environmental protection, food industries, perfumery, public safety, medicine, and pharmacy. Electronic noses allow to detect many organic volatile compounds, for which there is no specific detector. They constitute an alternative to complex, long, and too expensive existing methods, unable to ensure continuous monitoring. Their conception deals with many related areas (metrology, chemistry, physics, electronics, informatics, statistics, modelisation as well as areas related to the molecules to be detected. The system training is a primary step: during a measurement under a gaseous atmosphere, we must record the sensor time-responses in a treatment system, while specifying the name of the concerned odor. This process must be repeated many times for each studied atmosphere, and for all the chosen atmospheres. So a learning data base can be created, made from representative parameters of all the realized measures. After this training stage, clustering software will classify the data analysis in “concentration” or “nature” groups. Using the group separation rules given by this supervised classification, the system will be able to find itself the name of an odor or a concentration.

  19. Graphene Electronic Tattoo Sensors.

    Science.gov (United States)

    Kabiri Ameri, Shideh; Ho, Rebecca; Jang, Hongwoo; Tao, Li; Wang, Youhua; Wang, Liu; Schnyer, David M; Akinwande, Deji; Lu, Nanshu

    2017-08-22

    Tattoo-like epidermal sensors are an emerging class of truly wearable electronics, owing to their thinness and softness. While most of them are based on thin metal films, a silicon membrane, or nanoparticle-based printable inks, we report sub-micrometer thick, multimodal electronic tattoo sensors that are made of graphene. The graphene electronic tattoo (GET) is designed as filamentary serpentines and fabricated by a cost- and time-effective "wet transfer, dry patterning" method. It has a total thickness of 463 ± 30 nm, an optical transparency of ∼85%, and a stretchability of more than 40%. The GET can be directly laminated on human skin just like a temporary tattoo and can fully conform to the microscopic morphology of the surface of skin via just van der Waals forces. The open-mesh structure of the GET makes it breathable and its stiffness negligible. A bare GET is able to stay attached to skin for several hours without fracture or delamination. With liquid bandage coverage, a GET may stay functional on the skin for up to several days. As a dry electrode, GET-skin interface impedance is on par with medically used silver/silver-chloride (Ag/AgCl) gel electrodes, while offering superior comfort, mobility, and reliability. GET has been successfully applied to measure electrocardiogram (ECG), electromyogram (EMG), electroencephalogram (EEG), skin temperature, and skin hydration.

  20. Transformational silicon electronics

    KAUST Repository

    Rojas, Jhonathan Prieto

    2014-02-25

    In today\\'s traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry\\'s most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications. © 2014 American Chemical Society.

  1. Nonadiabatic anharmonic electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, P. P. [Molecular Physics Research, 6547 Kristina Ursula Court, Falls Church, Virginia 22044 (United States)

    2013-03-28

    The effect of an inner sphere, local mode vibration on an electron transfer is modeled using the nonadiabatic transition probability (rate) expression together with both the anharmonic Morse and the harmonic oscillator potential. For an anharmonic inner sphere mode, a variational analysis uses harmonic oscillator basis functions to overcome the difficulties evaluating Morse-model Franck-Condon overlap factors. Individual matrix elements are computed with the use of new, fast, robust, and flexible recurrence relations. The analysis therefore readily addresses changes in frequency and/or displacement of oscillator minimums in the different electron transfer states. Direct summation of the individual Boltzmann weighted Franck-Condon contributions avoids the limitations inherent in the use of the familiar high-temperature, Gaussian form of the rate constant. The effect of harmonic versus anharmonic inner sphere modes on the electron transfer is readily seen, especially in the exoergic, inverted region. The behavior of the transition probability can also be displayed as a surface for all temperatures and values of the driving force/exoergicity {Delta}=-{Delta}G. The temperature insensitivity of the transfer rate is clearly seen when the exoergicity equals the collective reorganization energy ({Delta}={Lambda}{sub s}) along a maximum ln (w) vs. {Delta} ridge of the surface. The surface also reveals additional regions for {Delta} where ln (w) appears to be insensitive to temperature, or effectively activationless, for some kinds of inner sphere contributions.

  2. The SPEDE electron spectrometer

    CERN Document Server

    O'Neill, George

    This thesis presents SPEDE (SPectrometer for Electron DEtection) and documents its construction, testing and performance during commissioning at Jyvaskyla, Finland, before deployment at the HIE-ISOLDE facility at CERN coupled with the MINIBALL array to perform in-beam electron-gamma spectroscopy using post-accelerated radioactive ion beams. Commissioning experiments took place in two two-day stints during spring 2015, coupled with several JUROGAMII gamma-detectors. This spectrometer will help aid in fully understanding exotic regions of the nuclear chart such as regions with a high degree of octupole deformation, and in those nuclei exhibiting shape coexistence. For the rst time, electron spectroscopy has been performed at the target position from states populated in accelerated nuclei via Coulomb excitation. The FWHM of SPEDE is approximately 7 keV at 320 keV, and Doppler correction was possible to improve Doppler broadened peaks. The results are intended to give the reader a full understanding of the dete...

  3. Transformational silicon electronics.

    Science.gov (United States)

    Rojas, Jhonathan Prieto; Torres Sevilla, Galo Andres; Ghoneim, Mohamed Tarek; Inayat, Salman Bin; Ahmed, Sally M; Hussain, Aftab Mustansir; Hussain, Muhammad Mustafa

    2014-02-25

    In today's traditional electronics such as in computers or in mobile phones, billions of high-performance, ultra-low-power devices are neatly integrated in extremely compact areas on rigid and brittle but low-cost bulk monocrystalline silicon (100) wafers. Ninety percent of global electronics are made up of silicon. Therefore, we have developed a generic low-cost regenerative batch fabrication process to transform such wafers full of devices into thin (5 μm), mechanically flexible, optically semitransparent silicon fabric with devices, then recycling the remaining wafer to generate multiple silicon fabric with chips and devices, ensuring low-cost and optimal utilization of the whole substrate. We show monocrystalline, amorphous, and polycrystalline silicon and silicon dioxide fabric, all from low-cost bulk silicon (100) wafers with the semiconductor industry's most advanced high-κ/metal gate stack based high-performance, ultra-low-power capacitors, field effect transistors, energy harvesters, and storage to emphasize the effectiveness and versatility of this process to transform traditional electronics into flexible and semitransparent ones for multipurpose applications.

  4. Electronic Recruitment at CERN

    CERN Multimedia

    2004-01-01

    The Human Resources Department switches to electronic recruitment. From now on whenever you are involved in a recruitment action you will receive an e-mail giving you access to a Web folder. Inside you will find a shortlist of applications drawn up by the Human Resources Department. This will allow you to consult the folder, at the same time as everyone else involved in the recruitment process, for the vacancy you are interested in. This new electronic recruitment system, known as e-RT, will be introduced in a presentation given at 10 a.m. on 11 February in the Main Auditorium. Implemented by AIS (Administrative Information Services) and the Human Resources Department, e-RT will cover vacancies open in all of CERN's recruitment programmes. The electronic application system was initially made available to technical students in July 2003. By December it was extended to summer students, fellows, associates and Local Staff. Geraldine Ballet from the Recruitment Service prefers e-RT to mountains of paper! The Hu...

  5. Electrons in Flatland

    Science.gov (United States)

    MacDonald, Allan

    2007-04-01

    Like the classical squares and triangles in Edwin Abbott's 19th century social satire and science fiction novel Flatland, electrons and other quantum particles behave differently when confined to a two-dimensional world. Condensed matter physicists have been intrigued and regularly suprised by two-dimensional electron systems since they were first studied in semiconductor field-effect-transistor devices over forty years ago. I will discuss some important milestones in the study of two-dimensional electrn systems, from the discoveries of the integer and fractional quantum Hall effects in the 1980's to recent quantum Hall effect work on quasiparticles with non-Abelian quantum statistics. Special attention will be given to a new electronic Flatland that has risen to prominence recently, graphene, which consists of a single sheet of carbon atoms in a honeycomb lattice arrangement. Graphene provides a realization of two-dimensional massless Dirac fermions which interact via nearly instantaneous Coulomb interactions. Early research on graphene has demonstrated yet again that Flatland exceeds expectations.

  6. Nanotechnology in paper electronics

    Science.gov (United States)

    Demming, Anna; Österbacka, Professor Ronald; Han, Jin-Woo, Dr

    2014-03-01

    The ability to put cutting edge technology on paper—not in words but in a working physical form—has been attracting an increasing number of researchers over the past decade. Paper has many advantages that make it attractive for flexible electronics: it is relatively environmentally benign; it is renewable; it can be recycled; it is light weight; production processes for paper are well advanced; and it is inexpensive. This special issue, with guest editors Ronald Österbacka from Åbo Akademi University in Finland and Jin-Woo Han from the NASA AMES Research Center, features some of the latest in paper electronics research, including developments towards applications in displays, sensing and alternative energy sources, as well as fundamental studies to further our understanding of how paper can be most effectively used in electronics. As Andrew Steckl and colleagues in the US point out, 'Cellulose-based paper substrates were implemented as an electronic substrate as early as 1969, with most advancement occurring in the past decade largely due to technology improvements in thin film deposition and organic materials' [1, 2]. They report a detailed comparison between paper, standard liquid crystal display rigid glass and flexible glass for hosting pentacene organic thin film transistors, and obtain promising results for future paper-based devices. As most meaningful electronic devices rely on transistors to function, transistors feature quite prominently in this special issue. Rodrigo Martins and colleagues in France and Portugal study the effect of fibre type, structure and dimension on paper-based transistors and reveal further insights into how paper properties affect device performance [3]. Qing Wan and colleagues in China bring the state of the art in transistor technology to paper substrates [4], fabricating indium-zinc-oxide (IZO)-based protonic/electronic hybrid thin film transistors on paper and showing that they can be used as artificial synapses. Like the

  7. Practical analog electronics for technicians

    CERN Document Server

    Kimber, W A

    2013-01-01

    'Practical Analog Electronics for Technicians' not only provides an accessible introduction to electronics, but also supplies all the problems and practical activities needed to gain hands-on knowledge and experience. This emphasis on practice is surprisingly unusual in electronics texts, and has already gained Will Kimber popularity through the companion volume, 'Practical Digital Electronics for Technicians'. Written to cover the Advanced GNVQ optional unit in electronics, this book is also ideal for BTEC National, A-level electronics and City & Guilds courses. Together with 'Practical Digit

  8. Electron Cooling Study for MEIC

    Energy Technology Data Exchange (ETDEWEB)

    He, Zhang [Jefferson Lab., Newport News, VA (United States); Douglas, David R. [Jefferson Lab., Newport News, VA (United States); Derbenev, Yaroslav S. [Jefferson Lab., Newport News, VA (United States); Zhang, Yuhong [Jefferson Lab., Newport News, VA (United States)

    2015-09-01

    Electron cooling of the ion beams is one critical R&D to achieve high luminosities in JLab's MEIC proposal. In the present MEIC design, a multi-staged cooling scheme is adapted, which includes DC electron cooling in the booster ring and bunched beam electron cooling in the collider ring at both the injection energy and the collision energy. We explored the feasibility of using both magnetized and non-magnetized electron beam for cooling, and concluded that a magnetized electron beam is necessary. Electron cooling simulation results for the newly updated MEIC design is also presented.

  9. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1993-01-01

    Advances in Electron Transfer Chemistry, Volume 3 presents studies that discuss findings in the various aspects of electron chemistry. The book is comprised of four chapters; each chapter reviews a work that tackles an issue in electron transfer chemistry. Chapter 1 discusses the photoinduced electron transfer in flexible biaryl donor-acceptor molecules. Chapter 2 tackles light-induced electron transfer in inorganic systems in homogeneous and heterogeneous phases. The book also covers internal geometry relaxation effects on electron transfer rates of amino-centered systems. The sequential elec

  10. Understand electrical and electronics maths

    CERN Document Server

    Bishop, Owen

    1993-01-01

    Understand Electrical and Electronics Maths covers elementary maths and the aspects of electronics. The book discusses basic maths including quotients, algebraic fractions, logarithms, types of equations and balancing of equations. The text also describes the main features and functions of graphs and the solutions to simpler types of electronics problems. The book then tackles the applications of polar coordinates in electronics, limits, differentiation and integration, and the applications of maths of rates of change in electronics. The activities of an electronic circuit; techniques of math

  11. Two-Electron Transfer Pathways.

    Science.gov (United States)

    Lin, Jiaxing; Balamurugan, D; Zhang, Peng; Skourtis, Spiros S; Beratan, David N

    2015-06-18

    The frontiers of electron-transfer chemistry demand that we develop theoretical frameworks to describe the delivery of multiple electrons, atoms, and ions in molecular systems. When electrons move over long distances through high barriers, where the probability for thermal population of oxidized or reduced bridge-localized states is very small, the electrons will tunnel from the donor (D) to acceptor (A), facilitated by bridge-mediated superexchange interactions. If the stable donor and acceptor redox states on D and A differ by two electrons, it is possible that the electrons will propagate coherently from D to A. While structure-function relations for single-electron superexchange in molecules are well established, strategies to manipulate the coherent flow of multiple electrons are largely unknown. In contrast to one-electron superexchange, two-electron superexchange involves both one- and two-electron virtual intermediate states, the number of virtual intermediates increases very rapidly with system size, and multiple classes of pathways interfere with one another. In the study described here, we developed simple superexchange models for two-electron transfer. We explored how the bridge structure and energetics influence multielectron superexchange, and we compared two-electron superexchange interactions to single-electron superexchange. Multielectron superexchange introduces interference between singly and doubly oxidized (or reduced) bridge virtual states, so that even simple linear donor-bridge-acceptor systems have pathway topologies that resemble those seen for one-electron superexchange through bridges with multiple parallel pathways. The simple model systems studied here exhibit a richness that is amenable to experimental exploration by manipulating the multiple pathways, pathway crosstalk, and changes in the number of donor and acceptor species. The features that emerge from these studies may assist in developing new strategies to deliver multiple

  12. Contribution of backscattered electrons to the total electron yield ...

    Indian Academy of Sciences (India)

    It is shown experimentally that under energetic electron bombardment the backscattered electrons from solid targets contribute significantly (∼ 80%) to the observed total electron yield, even for targets of high backscattering coefficients. It is further found that for tungsten ( = 74) with a backscattering coefficient of about 0.50 ...

  13. Attainment of Electron Beam Suitable for Medium Energy Electron Cooling

    Energy Technology Data Exchange (ETDEWEB)

    Seletskiy, Sergei M. [Univ. of Rochester, NY (United States)

    2005-01-01

    Electron cooling of charged particle beams is a well-established technique at electron energies of up to 300 keV. However, up to the present time the advance of electron cooling to the MeV-range energies has remained a purely theoretical possibility. The electron cooling project at Fermilab has recently demonstrated the ¯rst cooling of 8.9 GeV/c antiprotons in the Recycler ring, and therefore, has proved the validity of the idea of relativistic electron cool- ing. The Recycler Electron Cooler (REC) is the key component of the Teva- tron Run II luminosity upgrade project. Its performance depends critically on the quality of electron beam. A stable electron beam of 4.3 MeV car- rying 0.5 A of DC current is required. The beam suitable for the Recycler Electron Cooler must have an angular spread not exceeding 200 ¹rad. The full-scale prototype of the REC was designed, built and tested at Fermilab in the Wideband laboratory to study the feasibility of attaining the high-quality electron beam. In this thesis I describe various aspects of development of the Fermilab electron cooling system, and the techniques used to obtain the electron beam suitable for the cooling process. In particular I emphasize those aspects of the work for which I was principally responsible.

  14. Electron-excited molecule interactions

    Energy Technology Data Exchange (ETDEWEB)

    Christophorou, L.G. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA). Dept. of Physics)

    1991-01-01

    In this paper the limited but significant knowledge to date on electron scattering from vibrationally/rotationally excited molecules and electron scattering from and electron impact ionization of electronically excited molecules is briefly summarized and discussed. The profound effects of the internal energy content of a molecule on its electron attachment properties are highlighted focusing in particular on electron attachment to vibrationally/rotationally and to electronically excited molecules. The limited knowledge to date on electron-excited molecule interactions clearly shows that the cross sections for certain electron-molecule collision processes can be very different from those involving ground state molecules. For example, optically enhanced electron attachment studies have shown that electron attachment to electronically excited molecules can occur with cross sections 10{sup 6} to 10{sup 7} times larger compared to ground state molecules. The study of electron-excited molecule interactions offers many experimental and theoretical challenges and opportunities and is both of fundamental and technological significance. 54 refs., 15 figs.

  15. Holography and transmission electron microscopy

    OpenAIRE

    Matteucci, G.; Pozzi, G.; Tonomura, A.

    1993-01-01

    The basic principles and methods of off-axis electron holography are presented and illustrated by means of three examples related to its application in high resolution electron microscopy and the investigation of electric and magnetic fields in thin specimens.

  16. Workflow Management in Electronic Commerce

    NARCIS (Netherlands)

    Grefen, P.W.P.J.; Spaccapietra, S.; March, S.T.; Kambayashi, Y.

    In electronic commerce scenarios, effectiveness and efficiency of business process execution are of paramount importance for business success. Even more than in traditional commerce scenarios, they determine the chances of survival of organizations in fast moving, highly competitive electronic

  17. Electronic Services Monthly MI Report

    Data.gov (United States)

    Social Security Administration — This electronic services monthly MI report contains monthly MI data for most public facing online online applications such as iClaim, electronic access, Mobile wage...

  18. Getting started with electronic projects

    CERN Document Server

    Pretty, Bill

    2015-01-01

    This book is aimed at hobbyists with basic knowledge of electronics circuits. Whether you are a novice electronics project builder, a ham radio enthusiast, or a BeagleBone tinkerer, you will love this book.

  19. Electron avalanches in inhomogeneous media

    CERN Document Server

    Byrne, J

    2002-01-01

    We derive a general expression for the cumulant generating function describing the propagation of electron avalanches in inhomogeneous media. The results have applications in the theory of particle counting devices which rely on signal amplification by electron multiplication.

  20. Diamond bio electronics.

    Science.gov (United States)

    Linares, Robert; Doering, Patrick; Linares, Bryant

    2009-01-01

    The use of diamond for advanced applications has been the dream of mankind for centuries. Until recently this dream has been realized only in the use of diamond for gemstones and abrasive applications where tons of diamonds are used on an annual basis. Diamond is the material system of choice for many applications, but its use has historically been limited due to the small size, high cost, and inconsistent (and typically poor) quality of available diamond materials until recently. The recent development of high quality, single crystal diamond crystal growth via the Chemical Vapor Deposition (CVD) process has allowed physcists and increasingly scientists in the life science area to think beyond these limitations and envision how diamond may be used in advanced applications ranging from quantum computing, to power generation and molecular imaging, and eventually even diamond nano-bots. Because of diamond's unique properties as a bio-compatible material, better understanding of diamond's quantum effects and a convergence of mass production, semiconductor-like fabrication process, diamond now promises a unique and powerful key to the realization of the bio-electronic devices being envisioned for the new era of medical science. The combination of robust in-the-body diamond based sensors, coupled with smart bio-functionalized diamond devices may lead to diamond being the platform of choice for bio-electronics. This generation of diamond based bio-electronic devices would contribute substantially to ushering in a paradigm shift for medical science, leading to vastly improved patient diagnosis, decrease of drug development costs and risks, and improved effectiveness of drug delivery and gene therapy programs through better timed and more customized solutions.

  1. EMC in power electronics

    CERN Document Server

    Tihanyi, Laszlo

    1995-01-01

    Electronics professionals will find this book invaluable when designing power equipment, because it describes in detail how to cope with the problem of electromagnetic interference. The author shows how to meet the exacting US and European EMC standards for conducted emissions.The book includes a wide range of EMI analysis techniques. An important focus is on the energy content of interference transient signals (traditional analysis concentrates on amplitude and frequency). This provides a more accurate picture of the EMI situation. For those who do not want or need detailed analysis technique

  2. Electronic Cigarette Toxicity.

    Science.gov (United States)

    Payne, J Drew; Michaels, David; Orellana-Barrios, Menfil; Nugent, Kenneth

    2017-04-01

    Electronic cigarettes (e-cigarettes) are often advertised as a healthier product when compared with traditional cigarettes. Currently, there are limited data to support this and only a threat of federal regulation from the US Food and Drug Administration. Calls to poison control centers about e-cigarette toxicity, especially in children, and case reports of toxic exposures have increased over the past 3 years. This research letter reports the frequency of hazardous exposures to e-cigarettes and characterizes the reported adverse health effects associated with e-cigarette toxicity.

  3. Electronic phase transitions

    CERN Document Server

    Kopaev, YuV

    1992-01-01

    Electronic Phase Transitions deals with topics, which are presently at the forefront of scientific research in modern solid-state theory. Anderson localization, which has fundamental implications in many areas of solid-state physics as well as spin glasses, with its influence on quite different research activities such as neural networks, are two examples that are reviewed in this book. The ab initio statistical mechanics of structural phase transitions is another prime example, where the interplay and connection of two unrelated disciplines of solid-state theory - first principle ele

  4. Joint Services Electronics Program.

    Science.gov (United States)

    1982-05-01

    Dr. W. Paul Dr. P. Crouch Dr. P.S. Pershan Dr. H. Ehrenreich Dr. B. von Roedern Dr. P.N. Habbal Dr. B. Sandler Dr. 0. Hijab Dr. W.J. Skocpol Dr. Y.C...ELECTRONICS Personnel * Prof. H. Ehrenreich Mr. D.W. Abraham Prof. W. Paul Mr. J. Aponte Prof. P.S. Pershan Mr. G.E. Blonder Assoc. Prof. W.J. Skocpol ...Reference 1. W.J. Skocpol , M.R. Beasley, and M. Tinkham, "Phase-Slip Centers and Nonequilibrium Processes in Superconducting Tin Microbridges," J. Low Temp

  5. Hermeticity of electronic packages

    CERN Document Server

    Greenhouse, Hal; Romenesco, Bruce

    2011-01-01

    This is a book about the integrity of sealed packages to resist foreign gases and liquids penetrating the seal or an opening (crack) in the packageùespecially critical to the reliability and longevity of electronics. The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to so

  6. Joint Services Electronics Program

    Science.gov (United States)

    1991-07-01

    quality I-V data, showing the "Coulomb blockade," the "Coulomb staircase," and "single-electron transistor action" in a double junction configuration. We...asymmetries in the I-V curves, and which also controls the " transistor action" by modulating the small signal conductance of the device from zero to a...consists of a 5 by 5 array of photodetectors. The photodetectors are implemented by using the parasitic bipolar junction transis- tors ( BJT ) available in

  7. Hermeticity of electronic packages

    CERN Document Server

    Greenhouse, Hal

    2000-01-01

    This is a book about the integrity of sealed packages to resist foreign gases and liquids penetrating the seal or an opening (crack) in the package-especially critical to the reliability and longevity of electronics. The author explains how to predict the reliability and the longevity of the packages based on leak rate measurements and the assumptions of impurities. Non-specialists in particular will benefit from the author's long involvement in the technology. Hermeticity is a subject that demands practical experience, and solving one problem does not necessarily give one the background to so

  8. Joint Services Electronics Program.

    Science.gov (United States)

    1985-12-31

    HgCdTe and Related No)ii-\\1:i m I HgZnTe, CdZnTe , K.C. Hass 5. Chemical Trends in Diluted Magnetic Sernicoridiitr- 11. I’lir, I Larson, and K.C. Hass...34 J. Vac. Sci. Technol. A3, 2, 367 (1985). 1.4 Electronic Structure of HgCdTe and Related Non-Magnetic I-VI Alloys: HgZnTe, CdZnTe . K.C. Hass, Contract

  9. High Availability Electronics standards

    CERN Document Server

    Larsen, Ray

    2007-01-01

    Availability modeling of the proposed International Linear Collider (ILC) predicts unacceptably low uptime with current electronics systems designs. High Availability (HA) analysis is being used as a guideline for all major machine systems including sources, utilities, cryogenics, magnets, power supplies, instrumentation and controls. R&D teams are seeking to achieve total machine high availability with nominal impact on system cost. The focus of this paper is the investigation of commercial standard HA architectures and packaging for Accelerator Controls and Instrumentation. Application of HA design principles to power systems and detector instrumentation are also discussed.

  10. Security electronics circuits manual

    CERN Document Server

    MARSTON, R M

    1998-01-01

    Security Electronics Circuits Manual is an invaluable guide for engineers and technicians in the security industry. It will also prove to be a useful guide for students and experimenters, as well as providing experienced amateurs and DIY enthusiasts with numerous ideas to protect their homes, businesses and properties.As with all Ray Marston's Circuits Manuals, the style is easy-to-read and non-mathematical, with the emphasis firmly on practical applications, circuits and design ideas. The ICs and other devices used in the practical circuits are modestly priced and readily available ty

  11. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  12. Electronics I essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electronics I covers fundamentals of semiconductor devices, junction diodes, bipolar junction transistors, power supplies, multitransistor circuits, small signals, low-frequency anal

  13. Electronic Word of Behavior

    DEFF Research Database (Denmark)

    Kunst, Katrine

    that recent years have seen a social media-facilitated move from opinion-centric eWOM (e.g. reviews) to behavior-centric (e.g. information about friends’ music consumption on Spotify). A review of the concepts of WOM and eWOM and a netnographic study reveal that the current definitions and understandings...... of the concepts do not capture this new kind of consumer-to-consumer information transfer about products and services. Consequently, we suggest an extension of those concepts: Electronic Word of Behavior....

  14. Electronics II essentials

    CERN Document Server

    REA, The Editors of

    2012-01-01

    REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Electronics II covers operational amplifiers, feedback and frequency compensation of OP amps, multivibrators, logic gates and families, Boolean algebra, registers, counters, arithmet

  15. The uniform electron gas

    CERN Document Server

    Loos, Pierre-François

    2016-01-01

    The uniform electron gas or UEG (also known as jellium) is one of the most fundamental models in condensed-matter physics and the cornerstone of the most popular approximation --- the local-density approximation --- within density-functional theory. In this article, we provide a detailed review on the energetics of the UEG at high, intermediate and low densities, and in one, two and three dimensions. We also report the best quantum Monte Carlo and symmetry-broken Hartree-Fock calculations available in the literature for the UEG and discuss the phase diagrams of jellium.

  16. Transmission electron microscope CCD camera

    Science.gov (United States)

    Downing, Kenneth H.

    1999-01-01

    In order to improve the performance of a CCD camera on a high voltage electron microscope, an electron decelerator is inserted between the microscope column and the CCD. This arrangement optimizes the interaction of the electron beam with the scintillator of the CCD camera while retaining optimization of the microscope optics and of the interaction of the beam with the specimen. Changing the electron beam energy between the specimen and camera allows both to be optimized.

  17. Rf Feedback free electron laser

    Science.gov (United States)

    Brau, Charles A.; Swenson, Donald A.; Boyd, Jr., Thomas J.

    1981-01-01

    A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

  18. Unbalanced field RF electron gun

    Science.gov (United States)

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  19. A fluorescence scanning electron microscope

    OpenAIRE

    Kanemaru, Takaaki; Hirata, Kazuho; Takasu, Shin-ichi; Isobe, Shin-Ichiro; Mizuki, Keiji; Mataka, Shuntaro; Nakamura, Kei-ichiro

    2010-01-01

    Fluorescence techniques are widely used in biological research to examine molecular localization, while electron microscopy can provide unique ultrastructural information. To date, correlative images from both fluorescence and electron microscopy have been obtained separately using two different instruments, i.e. a fluorescence microscope (FM) and an electron microscope (EM). In the current study, a scanning electron microscope (SEM) (JEOL JXA8600 M) was combined with a fluorescence digital c...

  20. Electronic kits in physics education

    OpenAIRE

    Hnyk, Michal

    2015-01-01

    Title: Electronic kits in physics education Author: Michal Hnyk Department: Department of physics education Supervisor: RNDr. Peter Žilavý, Ph.D., Department of physics education Abstract: This diploma thesis named Electronic kits in physics education contains five main parts. It deals with the use of electronic kits in the physics education and references a research of literature discussing this problem in the first part. Thesis offers a brief overview of types of electronic kits, which are ...

  1. New trend in electron holography

    Science.gov (United States)

    Tanigaki, Toshiaki; Harada, Ken; Murakami, Yasukazu; Niitsu, Kodai; Akashi, Tetsuya; Takahashi, Yoshio; Sugawara, Akira; Shindo, Daisuke

    2016-06-01

    Electron holography using a coherent electron wave is a promising technique for high-resolution visualization of electromagnetic fields in and around objects. The capability of electron holography has been enhanced by the development of new technologies and has thus become an even more powerful tool for exploring scientific frontiers. This review introduces these technologies including split-illumination electron holography and vector-field electron tomography. Split-illumination electron holography, which uses separated coherent waves, overcomes the limits imposed by the lateral coherence requirement for electron waves in electron holography. Areas that are difficult to observe using conventional electron holography are now observable. Exemplified applications include observing a singular magnetic domain wall in electrical steel sheets, local magnetizations at anti-phase boundaries, and electrostatic potentials in metal-oxide-semiconductor field-effect transistors. Vector-field electron tomography can be used to visualize magnetic vectors in three dimensions. Two components of the vectors are reconstructed using dual-axis tomography, and the remaining one is calculated using div B   =  0. A high-voltage electron microscope can be used to achieve precise magnetic reconstruction. For example, magnetic vortices have been visualized using a 1 MV holography electron microscope.

  2. New methods for electron tomography

    NARCIS (Netherlands)

    Ziese, Ulrike

    2002-01-01

    Electron tomography is a method for obtaining three-dimensional structural information from electron micrographs. It can be applied to a wide range of samples that can be prepared for transmission electron microscopy (TEM)—may they be of biological origin like e.g. cryo or thin plastic sections of

  3. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

  4. Electronic Books for Secondary Students.

    Science.gov (United States)

    Anderson-Inman, Lynne; Horney, Mark

    1997-01-01

    Discusses the definition, purposes, and advantages and disadvantages of electronic books. Notes the types of embedded resources present in them, offers an example of an electronic book, and suggests three steps to evaluate and select electronic books for the curriculum. (SR)

  5. Electron attachment to boron trichloride

    Science.gov (United States)

    Tav, Cumali; Datskos, Panos G.; Pinnaduwage, Lal A.

    1998-11-01

    Low-energy electron attachment to BCl3 was measured using an electron swarm technique. The parent negative ion, BCl3-, was observed within a narrow electron range close to thermal energy. Previous negative ion measurements in BCl3 discharges, which yielded seemingly inconsistent results, can be shown to be self-consistent based on the present observations.

  6. Freeform electronics for advanced healthcare

    KAUST Repository

    Hussain, Muhammad Mustafa

    2017-02-16

    Freeform (physically flexible, stretchable and reconfigurable) electronics can be critical enabler for advanced personalized healthcare. With increased global population and extended average lifetime of mankind, it is more important than ever to integrate advanced electronics into our daily life for advanced personalized healthcare. In this paper, we discuss some critical criteria to design such electronics with enabling applications.

  7. Electron microscopy of viruses.

    Science.gov (United States)

    Laue, Michael

    2010-01-01

    Electron microscopy is widely used in virology because viruses are generally too small for a direct inspection by light microscopy. Analysis of virus morphology is necessary in many circumstances, e.g., for the diagnosis of a virus in particular clinical situations or the analysis of virus entry and assembly. Moreover, quality control of virus particle integrity is required if a virus is propagated in cell culture, particularly if the virus genome has changed. In most cases already the basic methodology for transmission electron microscopy, i.e., negative staining and ultrathin sectioning, is sufficient to give relevant information on virus ultrastructure. This chapter gives detailed information on the principles of these basic methodologies and provides simple but reliable protocols for a quick start. Moreover, the description of standard protocols for negative staining and ultrathin sectioning are supplemented by protocols on immuno-negative staining and rapid ultrathin sectioning. Finally, principles of methods for an extended ultrastructural research using more elaborate techniques, such as cryotechniques or methods to reveal the three-dimensional virus architecture, are briefly reviewed. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Modular Lego-Electronics

    KAUST Repository

    Shaikh, Sohail F.

    2017-10-24

    Electronic system components have thousands of individual field effect transistors (FETs) interconnected executing dedicated functions. Assembly yield of >80% will guarantee system failure since a single interconnect failure will result in undesired performance. Hence, a paradigm shift is needed in the self-assembly or integration of state-of-the-art integrated circuits (ICs) for a physically compliant system. Traditionally, most ICs share same geometry with only variations in dimensions and packaging. Here, a generic manufacturable method of converting state-of-the-art complementary metal oxide semiconductor-based ICs into modular Lego-electronics is shown with unique geometry that is physically identifiable to ease manufacturing and enhance throughput. Various geometries at the backside of the silicon die and on the destination site having the same geometry with relaxed dimension (up to 50 µm extra) allow targeted site binding like DNA assembly. Different geometries, angles, and heights for different modules provide a unique identity to each of the ICs. A two-level geometric combination presented here helps in maintaining the uniqueness of individual module to assemble at exact matching site like a perfect lock-and-key model. The assembled ICs offer uncompromised electrical performance, higher yield, and fabrication ease. In future, this method can further be expanded for fluidic assisted self-assembly.

  9. The ALICE trigger electronics

    CERN Document Server

    Krivda, M; Evans, D; Jones, G T; Jovanovic, P; Jusko, A; Králik, I; Lazzeroni, C; Lietava, R; Scott, H; Sándor, L; Tapia Takaki, D; Urbán, J; Villalobos Baillie, O

    2007-01-01

    The ALICE trigger system (TRG) consists of a Central Trigger Processor (CTP) and up to 24 Local Trigger Units (LTU) for each sub-detector. The CTP receives and processes trigger signals from trigger detectors and the outputs from the CTP are 3 levels of hardware triggers: L0, L1 and L2. The 24 sub-detectors are dynamically partitioned in up to 6 independent clusters. The trigger information is propagated through the LTUs to the Front-end electronics (FEE) of each sub-detector via LVDS cables and optical fibres. The trigger information sent from LTU to FEE can be monitored online for possible errors using the newly developed TTCit board. After testing and commissioning of the trigger system itself on the surface, the ALICE trigger electronics has been installed and tested in the experimental cavern with appropriate ALICE experimental software. Testing the Alice trigger system with detectors on the surface and in the experimental cavern in parallel is progressing very well. Currently one setup is used for testi...

  10. Electronic Nicotine Delivery Systems.

    Science.gov (United States)

    Walley, Susan C; Jenssen, Brian P

    2015-11-01

    Electronic nicotine delivery systems (ENDS) are rapidly growing in popularity among youth. ENDS are handheld devices that produce an aerosolized mixture from a solution typically containing concentrated nicotine, flavoring chemicals, and propylene glycol to be inhaled by the user. ENDS are marketed under a variety of names, most commonly electronic cigarettes and e-cigarettes. In 2014, more youth reported using ENDS than any other tobacco product. ENDS pose health risks to both users and nonusers. Nicotine, the major psychoactive ingredient in ENDS solutions, is both highly addictive and toxic. In addition to nicotine, other toxicants, carcinogens, and metal particles have been detected in solutions and aerosols of ENDS. Nonusers are involuntarily exposed to the emissions of these devices with secondhand and thirdhand aerosol. The concentrated and often flavored nicotine in ENDS solutions poses a poisoning risk for young children. Reports of acute nicotine toxicity from US poison control centers have been increasing, with at least 1 child death reported from unintentional exposure to a nicotine-containing ENDS solution. With flavors, design, and marketing that appeal to youth, ENDS threaten to renormalize and glamorize nicotine and tobacco product use. There is a critical need for ENDS regulation, legislative action, and counter promotion to protect youth. ENDS have the potential to addict a new generation of youth to nicotine and reverse more than 50 years of progress in tobacco control. Copyright © 2015 by the American Academy of Pediatrics.

  11. Electron spectroscopy of crystals

    CERN Document Server

    Nemoshkalenko, V V

    1979-01-01

    This book is conceived as a monograph, and represents an up-to-date collection of information concerning the use of the method of X-ray photoelectron spec­ troscopy in the study of the electron structure of crystals, as well as a personal interpretation of the subject by the authors. In a natural way, the book starts in Chapter 1 with a recapitulation of the fundamentals of the method, basic relations, principles of operation, and a com­ parative presentation of the characteristics and performances of the most com­ monly used ESCA instruments (from the classical ones-Varian, McPherson, Hewlett Packard, and IEEE-up to the latest model developed by Professor Siegbahn in Uppsala), and continues with a discussion of some of the difficult problems the experimentalist must face such as calibration of spectra, prepara­ tion of samples, and evaluation of the escape depth of electrons. The second chapter is devoted to the theory of photoemission from crystal­ line solids. A discussion of the methods of Hartree-Fo...

  12. Flexible electronic eardrum

    Institute of Scientific and Technical Information of China (English)

    Yang Gu; Xuewen Wang; Wen Gu; Yongjin Wu; Tie Li; Ting Zhang

    2017-01-01

    Flexible mechanosensors with a high sensitivity and fast response speed may advance the wearable and implantable applications of healthcare devices,such as real-time heart rate,pulse,and respiration monitoring.In this paper,we introduce a novel flexible electronic eardrum (EE) based on single-walled carbon nanotubes,polyethylene,and polydimethylsiloxane with micro-structured pyramid arrays.The EE device shows a high sensitivity,high signal-to-noise ratio (approximately 55 dB),and fast response time (76.9 μs) in detecting and recording sound within a frequency domain of 20-13,000 Hz.The mechanism for sound detection is investigated and the sensitivity is determined using the micro-structure,thickness,and strain state.We also demonstrated that the device is able to distinguish human voices.This unprecedented performance of the flexible electronic eardrum has implications for many applications such as implantable acoustical bioelectronics and personal voice recognition.

  13. Electronics via waveform analysis

    CERN Document Server

    Craig, Edwin C

    1993-01-01

    The author believes that a good basic understanding of electronics can be achieved by detailed visual analyses of the actual voltage waveforms present in selected circuits. The voltage waveforms included in this text were photographed using a 35-rrun camera in an attempt to make the book more attractive. This book is intended for the use of students with a variety of backgrounds. For this reason considerable material has been placed in the Appendix for those students who find it useful. The Appendix includes many basic electricity and electronic concepts as well as mathematical derivations that are not vital to the understanding of the circuit being discussed in the text at that time. Also some derivations might be so long that, if included in the text, it could affect the concentration of the student on the circuit being studied. The author has tried to make the book comprehensive enough so that a student could use it as a self-study course, providing one has access to adequate laboratory equipment.

  14. Magnetic electron lenses

    CERN Document Server

    1982-01-01

    No single volume has been entirely devoted to the properties of magnetic lenses, so far as I am aware, although of course all the numerous textbooks on electron optics devote space to them. The absence of such a volume, bringing together in­ formation about the theory and practical design of these lenses, is surprising, for their introduction some fifty years ago has created an entirely new family of commercial instruments, ranging from the now traditional transmission electron microscope, through the reflection and transmission scanning microscopes, to co­ lumns for micromachining and microlithography, not to mention the host of experi­ mental devices not available commercially. It therefore seemed useful to prepare an account of the various aspects of mag­ netic lens studies. These divide naturally into the five chapters of this book: the theoretical background, in which the optical behaviour is described and formu­ lae given for the various aberration coefficients; numerical methods for calculat­ ing...

  15. The ALICE Electronic Logbook

    Science.gov (United States)

    Altini, V.; Carena, F.; Carena, W.; Chapeland, S.; Chibante Barroso, V.; Costa, F.; Divià, R.; Fuchs, U.; Makhlyueva, I.; Roukoutakis, F.; Schossmaier, K.; Soòs, C.; Vande Vyvre, P.; Von Haller, B.; ALICE Collaboration

    2010-04-01

    All major experiments need tools that provide a way to keep a record of the events and activities, both during commissioning and operations. In ALICE (A Large Ion Collider Experiment) at CERN, this task is performed by the Alice Electronic Logbook (eLogbook), a custom-made application developed and maintained by the Data-Acquisition group (DAQ). Started as a statistics repository, the eLogbook has evolved to become not only a fully functional electronic logbook, but also a massive information repository used to store the conditions and statistics of the several online systems. It's currently used by more than 600 users in 30 different countries and it plays an important role in the daily ALICE collaboration activities. This paper will describe the LAMP (Linux, Apache, MySQL and PHP) based architecture of the eLogbook, the database schema and the relevance of the information stored in the eLogbook to the different ALICE actors, not only for near real time procedures but also for long term data-mining and analysis. It will also present the web interface, including the different used technologies, the implemented security measures and the current main features. Finally it will present the roadmap for the future, including a migration to the web 2.0 paradigm, the handling of the database ever-increasing data volume and the deployment of data-mining tools.

  16. Effective electron-electron and electron-phonon interactions in the Hubbard-Holstein model

    Energy Technology Data Exchange (ETDEWEB)

    Aprea, G. [INFM-CNR SMC Center, and Dipartimento di Fisica, Universita di Roma ' La Sapienza' , piazzale Aldo Moro 5, I-00185 Rome (Italy); Di Castro, C. [INFM-CNR SMC Center, and Dipartimento di Fisica, Universita di Roma ' La Sapienza' , piazzale Aldo Moro 5, I-00185 Rome (Italy); Grilli, M. [INFM-CNR SMC Center, and Dipartimento di Fisica, Universita di Roma ' La Sapienza' , piazzale Aldo Moro 5, I-00185 Rome (Italy)]. E-mail marco.grilli@roma1.infn.it; Lorenzana, J. [INFM-CNR SMC Center, and Dipartimento di Fisica, Universita di Roma ' La Sapienza' , piazzale Aldo Moro 5, I-00185 Rome (Italy)

    2006-06-12

    We investigate the interplay between the electron-electron and the electron-phonon interaction in the Hubbard-Holstein model. We implement the flow-equation method to investigate within this model the effect of correlation on the electron-phonon effective coupling and, conversely, the effect of phonons in the effective electron-electron interaction. Using this technique we obtain analytical momentum-dependent expressions for the effective couplings and we study their behavior for different physical regimes. In agreement with other works on this subject, we find that the electron-electron attraction mediated by phonons in the presence of Hubbard repulsion is peaked at low transferred momenta. The role of the characteristic energies involved is also analyzed.

  17. The art of linear electronics

    CERN Document Server

    Hood, John Linsley

    2013-01-01

    The Art of Linear Electronics presents the principal aspects of linear electronics and techniques in linear electronic circuit design. The book provides a wide range of information on the elucidation of the methods and techniques in the design of linear electronic circuits. The text discusses such topics as electronic component symbols and circuit drawing; passive and active semiconductor components; DC and low frequency amplifiers; and the basic effects of feedback. Subjects on frequency response modifying circuits and filters; audio amplifiers; low frequency oscillators and waveform generato

  18. Power electronics and motor drives

    CERN Document Server

    Wilamowski, Bogdan M

    2011-01-01

    Universities throughout the world typically provide an excellent education in the various aspects of electronics, however their focus is normally on traditional low power electronics. In contrast, in the industrial environment, there is a need for high power electronics that is used to control electromechanical systems in addition to the low power electronics typically employed for analog and digital systems. To address this need, Section 1 of this volume in The Industrial Electronics Handbook, Second Edition, is focused on special high power semiconductor devices. Section 2 not only describes

  19. Relativistic electron beams above thunderclouds

    DEFF Research Database (Denmark)

    Füellekrug, M.; Roussel-Dupre, R.; Symbalisty, E. M. D.

    2011-01-01

    Non-luminous relativistic electron beams above thunderclouds have been detected by the radio signals of low frequency similar to 40-400 kHz which they radiate. The electron beams occur similar to 2-9 ms after positive cloud-to-ground lightning discharges at heights between similar to 22-72 km above...... thunderclouds. Intense positive lightning discharges can also cause sprites which occur either above or prior to the electron beam. One electron beam was detected without any luminous sprite which suggests that electron beams may also occur independently of sprites. Numerical simulations show that beams...... of electrons partially discharge the lightning electric field above thunderclouds and thereby gain a mean energy of similar to 7MeV to transport a total charge of similar to-10mC upwards. The impulsive current similar to 3 x 10(-3) Am-2 associated with relativistic electron beams above thunderclouds...

  20. Diffusive scattering of electrons by electron holes around injection fronts

    Science.gov (United States)

    Vasko, I. Y.; Agapitov, O. V.; Mozer, F. S.; Artemyev, A. V.; Krasnoselskikh, V. V.; Bonnell, J. W.

    2017-03-01

    Van Allen Probes have detected nonlinear electrostatic spikes around injection fronts in the outer radiation belt. These spikes include electron holes (EH), double layers, and more complicated solitary waves. We show that EHs can efficiently scatter electrons due to their substantial transverse electric fields. Although the electron scattering driven by EHs is diffusive, it cannot be evaluated via the standard quasi-linear theory. We derive analytical formulas describing local electron scattering by a single EH and verify them via test particle simulations. We show that the most efficiently scattered are gyroresonant electrons (crossing EH on a time scale comparable to the local electron gyroperiod). We compute bounce-averaged diffusion coefficients and demonstrate their dependence on the EH spatial distribution (latitudinal extent and spatial filling factor) and individual EH parameters (amplitude of electrostatic potential, velocity, and spatial scales). We show that EHs can drive pitch angle scattering of ≲5 keV electrons at rates 10-2-10-4 s-1 and, hence, can contribute to electron losses and conjugated diffuse aurora brightenings. The momentum and pitch angle scattering rates can be comparable, so that EHs can also provide efficient electron heating. The scattering rates driven by EHs at L shells L ˜ 5-8 are comparable to those due to chorus waves and may exceed those due to electron cyclotron harmonics.

  1. FRAUD IN ELECTRONIC COMMERCE

    Directory of Open Access Journals (Sweden)

    Valentin – Stelian Bădescu

    2013-11-01

    Full Text Available Electronic commerce is experiencing a great extent, and about the same extent fraud seeks - and sometimes is the place to impressive levels. Moreover, computer fraud and, the actors' they do not seem to suffer from the global economic recession and get as sophisticated as a legitimate business model and one of the most important dimensions of the work of modern organizations is the manipulation of information (collection, processing, storage, distribution, etc.. This component informational increasingly involves broader and more complex, with the technological advancement of computer science and globalization of human society, special measures to ensure the security of information. Cyber-crime is an illegal act committed by using a computer network (especially Internet. Cyber-crime is a subset of cybercrime.

  2. Electronic cigarette: A review

    Directory of Open Access Journals (Sweden)

    Vinay Mahishale

    2014-01-01

    Full Text Available The principal addictive component of tobacco smoke is nicotine. The mechanisms of nicotine addiction are highly complex and are responsible for maintenance of smoking behaviour. Use of electronic cigarettes (E-cigarettes, devices that deliver a nicotine containing vapor has increased rapidly across the world. They are marketed as a "healthier alternatives" to conventional cigarettes. There is extensive debate over long-term safety and efficacy of these devices on public health. Studies show that the vapor generated from the E-cigarettes has a variable amount of nicotine and potential harmful toxins. Until robust research demonstrates the safety of E-cigarettes and efficacy in the treatment of tobacco dependence, their role as safe smoking cessation tool is unclear. This review highlights the recent data regarding E-cigarettes toxicity, impact on lung function, and efficacy in smoking reduction and cessation.

  3. de electrones localizados

    Directory of Open Access Journals (Sweden)

    John Jairo Hoyos Quintero

    2005-01-01

    Full Text Available La refrigeración magnética es una de las tecnologías con mayor potencial comercial. Reduce el consumo de energía en los sistemas de refrigeración y el impacto ambiental provocado por los gases de invernadero. En este artículo se presentan los aspectos fundamentales del efecto magnetocalórico. También se analiza la aplicación real del modelo de electrones localizados a la refrigeración magnética. En la vecindad de la temperatura de transformación magnética, el modelo sólo sirve para describir el comportamiento cualitativo del efecto magnetocalórico.

  4. Electronics for embedded systems

    CERN Document Server

    Bindal, Ahmet

    2017-01-01

    This book provides semester-length coverage of electronics for embedded systems, covering most common analog and digital circuit-related issues encountered while designing embedded system hardware. It is written for students and young professionals who have basic circuit theory background and want to learn more about passive circuits, diode and bipolar transistor circuits, the state-of-the-art CMOS logic family and its interface with older logic families such as TTL, sensors and sensor physics, operational amplifier circuits to condition sensor signals, data converters and various circuits used in electro-mechanical device control in embedded systems. The book also provides numerous hardware design examples by integrating the topics learned in earlier chapters. The last chapter extensively reviews the combinational and sequential logic design principles to be able to design the digital part of embedded system hardware.

  5. MDT DCS Electronics System

    CERN Document Server

    Tsarouchas, Charilaos; Gazis, Evangelos; Tsipolitis, Georgios

    This note has the aim to present the Detector Control System for the Monitor- ing of the electronics values of MDT chambers in ATLAS experiment in CERN. This system is decided to be called in short ELTX. The principal task of DCS is to enable and ensure the coherent and safe oper- ation of the detector. The interaction of detector expers, users or shifters to the detector hardware is also done via DCS. This is the responsible system of moni- toring the operational parameters and the overall state of the detector, the alarm generation and handling, the connection of hardware values to databases and the interaction with the DAQ system. Through this thesis, one can see what ELTX system has to offer as a Detector Control System and in detail, what is the hardware to be controlled and monitored. Moreover it is presented the mainstream of central Atlas DCS concerning the active interfaces.ELTX is a system following these standards.

  6. Optical Rewritable Electronic Paper

    Science.gov (United States)

    Muravsky, Alexander; Murauski, Anatoli; Chigrinov, Vladimir; Kwok, Hoi-Sing

    We developed new principle of electronic paper that is one side (for 2D image) or double side (for stereoscopic 3D image) light printable rewritable matter with polarization dependent gray scale. It consists of one or two liquid crystal displays based on Optical Rewritable (ORW) technology, which is the development of rotation azo-dye photoalignment. Each ORW display uses bare plastic or polarizers as substrates. The conductor is not required, as the image is formed by rewritable states of azimuthal direction, which results in 2D pattern of the liquid crystal twist angle. Continuous grey image maintains proper performance even when the device is bent. Simple construction provides durability and low cost, thin substrates minimize parallax for 3D image. Fluorescent dye dopant of liquid crystal partly absorbs light in blue and re-emit in green specter range improving photopic reflection and enhancing color of the ORW e-paper.

  7. Joint services electronics program

    Science.gov (United States)

    Peters, Leon, Jr.

    1990-11-01

    The transfer of the compact range and target identification technology initiated under JSEP support for time domain studies continues to make large advances. Using other sources of support, design for a mini-chamber has now been generated and has been constructed. This range is designed to study smaller targets at higher frequencies. The research has proven to be of intense interest to DoD and the aerospace industry and our compact range consortium represents a major cross section of the aerospace and electronic industries, including additional major support from several DoD agencies. In fact, the total support in these experimental studies substantially exceeds our JSEP support. This research is truly guiding a major portion of this technology in the USA and has been extremely important for stealth technology advances.

  8. Basic electronic circuits

    CERN Document Server

    Buckley, P M

    1980-01-01

    In the past, the teaching of electricity and electronics has more often than not been carried out from a theoretical and often highly academic standpoint. Fundamentals and basic concepts have often been presented with no indication of their practical appli­ cations, and all too frequently they have been illustrated by artificially contrived laboratory experiments bearing little relationship to the outside world. The course comes in the form of fourteen fairly open-ended constructional experiments or projects. Each experiment has associated with it a construction exercise and an explanation. The basic idea behind this dual presentation is that the student can embark on each circuit following only the briefest possible instructions and that an open-ended approach is thereby not prejudiced by an initial lengthy encounter with the theory behind the project; this being a sure way to dampen enthusiasm at the outset. As the investigation progresses, questions inevitably arise. Descriptions of the phenomena encounte...

  9. Electronics for Guitarists

    CERN Document Server

    Dailey, Denton J

    2013-01-01

    In the second edition of Electronics for Guitarists author Denton Dailey teaches the basic theory of operation and design principles of analog guitar signal processing circuits and amplifiers. The design and operation of common effects circuits such as tone controls, preamps, phasers, flangers, envelope followers, distortion and overdrives are covered, as are both solid-state amplifiers and power supplies. Written primarily for the guitarist, this book balances coverage of theoretical analysis and design while providing many examples of practical experimental circuits. The main thrust of the material is analog circuitry, focusing on fundamental principles of transistors, integrated circuit and vacuum tube-based amplifier operation and theory, and operation of typical guitar signal processing effects circuits. Updated to the new edition include: • New coverage of tone control circuits, MOSFETS and their applications as small-signal amplifiers, rail splitters and charge pumps, amplifiers using germanium trans...

  10. Automated electronic filter design

    CERN Document Server

    Banerjee, Amal

    2017-01-01

    This book describes a novel, efficient and powerful scheme for designing and evaluating the performance characteristics of any electronic filter designed with predefined specifications. The author explains techniques that enable readers to eliminate complicated manual, and thus error-prone and time-consuming, steps of traditional design techniques. The presentation includes demonstration of efficient automation, using an ANSI C language program, which accepts any filter design specification (e.g. Chebyschev low-pass filter, cut-off frequency, pass-band ripple etc.) as input and generates as output a SPICE(Simulation Program with Integrated Circuit Emphasis) format netlist. Readers then can use this netlist to run simulations with any version of the popular SPICE simulator, increasing accuracy of the final results, without violating any of the key principles of the traditional design scheme.

  11. Creep in electronic ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Routbort, J. L.; Goretta, K. C.; Arellano-Lopez, A. R.

    2000-04-27

    High-temperature creep measurements combined with microstructural investigations can be used to elucidate deformation mechanisms that can be related to the diffusion kinetics and defect chemistry of the minority species. This paper will review the theoretical basis for this correlation and illustrate it with examples from some important electronic ceramics having a perovskite structure. Recent results on BaTiO{sub 3}, (La{sub 1{minus}x}Sr){sub 1{minus}y}MnO{sub 3+{delta}}, YBa{sub 2}Cu{sub 3}O{sub x}, Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub x}, (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} and Sr(Fe,Co){sub 1.5}O{sub x} will be presented.

  12. Electron microprobe petrochronology

    Science.gov (United States)

    Williams, Michael; Jercinovic, Michael; Mahan, Kevin

    2017-04-01

    Petrochronology involves the incorporation of chronometer phases into the petrologic (and tectonic) evolution of their host rocks, such that direct age constraints can be placed on petrologic and structural processes. The electron microprobe has a central and critical role to play in establishing the linkage between chronometer phases and their host assemblage. In addition to characterizing the composition of the major silicate phases, the probe can be used to locate and map compositional zonation in accessory phases including chronometers such as monazite, xenotime, zircon, titanite, etc. One particularly effective technique for integrating petrology and geochronology is to combine high-resolution images of chronometer phases with large-scale images of polished sections. Chronometers can be evaluated in the context of their local compositional environment. This has proven to be useful for placing the chronometer domains within the reaction history of the host rock. Key chronometer domains, once selected, can be dated by the most appropriate tool, or by multiple techniques. For relatively old or small domains in monazite or xenotime, EPMA can provide precise age constraints. However, the analysis strategy must be designed as a trace element analysis from the beginning. Unlike major element analysis, background analysis is both critical and challenging, and new methodology is required, currently either wavelength scanning or multipoint analysis. Errors on the order of 2% are possible with standard instruments, and errors of 1% or better can be achieved with optimized instruments. Future improvements in electron microprobe hardware, software, and procedures will further enhance EPMA characterization of chronometer phases and petrochronological relationships. New thermodynamic modeling and experimental data will increasingly allow accessory chronometer phases to be integrated in petrological calculations and render petrochronology a routine part of petrologic analysis.

  13. Nanoelectromechanical Heat Engine Based on Electron-Electron Interaction.

    Science.gov (United States)

    Vikström, A; Eriksson, A M; Kulinich, S I; Gorelik, L Y

    2016-12-09

    We theoretically show that a nanoelectromechanical system can be mechanically actuated by a heat flow through it via an electron-electron interaction. In contrast to most known actuation mechanisms in similar systems, this new mechanism does not involve an electronic current nor external ac fields. Instead, the mechanism relies on deflection-dependent tunneling rates and a heat flow which is mediated by an electron-electron interaction while an electronic current through the device is prohibited by, for instance, a spin-valve effect. Therefore, the system resembles a nanoelectromechanical heat engine. We derive a criterion for the mechanical instability and estimate the amplitude of the resulting self-sustained oscillations. Estimations show that the suggested phenomenon can be studied using available experimental techniques.

  14. Impact of electron irradiation on electron holographic potentiometry

    Energy Technology Data Exchange (ETDEWEB)

    Park, J. B.; Niermann, T.; Lehmann, M. [Technische Universität Berlin, Institut für Optik und Atomare Physik, Straße des 17. Juni 135, 10623 Berlin (Germany); Berger, D. [Technische Universität Berlin, Zentraleinrichtung für Elektronenmikroskopie, Strae des 17. Juni 135, 10623 Berlin (Germany); Knauer, A.; Weyers, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Koslow, I.; Kneissl, M. [Ferdinand-Braun-Institut, Leibnitz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 4, 12489 Berlin (Germany); Technische Universität Berlin, Institut für Festkörperphysik, Hardenbergstr. 36, 10623 Berlin (Germany)

    2014-09-01

    While electron holography in the transmission electron microscope offers the possibility to measure maps of the electrostatic potential of semiconductors down to nanometer dimensions, these measurements are known to underestimate the absolute value of the potential, especially in GaN. We have varied the dose rates of electron irradiation over several orders of magnitude and observed strong variations of the holographically detected voltages. Overall, the results indicate that the electron beam generates electrical currents within the specimens primarily by the photovoltaic effect and due to secondary electron emission. These currents have to be considered for a quantitative interpretation of electron holographic measurements, as their negligence contributes to large parts in the observed discrepancy between the measured and expected potential values in GaN.

  15. Electron and ion induced electron emission from metals and insulators

    CERN Document Server

    Steinbatz, M

    2001-01-01

    gradually exposed to oxygen as an experimental probe. The experimental data are fitted with an analytical model, that is able to describe the observed kinetics. The fit parameters give absolute values of sticking probabilities and of surface reaction rates. During oxidation of aluminum and magnesium also spontaneous emission of electrons (exoelectrons) is observed. This effect is quantitatively studied for different oxygen partial pressures. The experimental data also indicate a significant influence of the surface morphology on the exoemission process. An important consequence of atomic collisions in solids is ionization leading to electron ejection from the target atoms with subsequent migration through the solid. A certain fraction of these electrons finally reaches the surface and is ejected into vacuum. A standard measurement of this phenomenon is the observation of the particle (electron, ion) induced electron emission yield g, defined as the average number of ejected electrons per incoming projectile. ...

  16. Femtosecond gas phase electron diffraction with MeV electrons.

    Science.gov (United States)

    Yang, Jie; Guehr, Markus; Vecchione, Theodore; Robinson, Matthew S; Li, Renkai; Hartmann, Nick; Shen, Xiaozhe; Coffee, Ryan; Corbett, Jeff; Fry, Alan; Gaffney, Kelly; Gorkhover, Tais; Hast, Carsten; Jobe, Keith; Makasyuk, Igor; Reid, Alexander; Robinson, Joseph; Vetter, Sharon; Wang, Fenglin; Weathersby, Stephen; Yoneda, Charles; Wang, Xijie; Centurion, Martin

    2016-12-16

    We present results on ultrafast gas electron diffraction (UGED) experiments with femtosecond resolution using the MeV electron gun at SLAC National Accelerator Laboratory. UGED is a promising method to investigate molecular dynamics in the gas phase because electron pulses can probe the structure with a high spatial resolution. Until recently, however, it was not possible for UGED to reach the relevant timescale for the motion of the nuclei during a molecular reaction. Using MeV electron pulses has allowed us to overcome the main challenges in reaching femtosecond resolution, namely delivering short electron pulses on a gas target, overcoming the effect of velocity mismatch between pump laser pulses and the probe electron pulses, and maintaining a low timing jitter. At electron kinetic energies above 3 MeV, the velocity mismatch between laser and electron pulses becomes negligible. The relativistic electrons are also less susceptible to temporal broadening due to the Coulomb force. One of the challenges of diffraction with relativistic electrons is that the small de Broglie wavelength results in very small diffraction angles. In this paper we describe the new setup and its characterization, including capturing static diffraction patterns of molecules in the gas phase, finding time-zero with sub-picosecond accuracy and first time-resolved diffraction experiments. The new device can achieve a temporal resolution of 100 fs root-mean-square, and sub-angstrom spatial resolution. The collimation of the beam is sufficient to measure the diffraction pattern, and the transverse coherence is on the order of 2 nm. Currently, the temporal resolution is limited both by the pulse duration of the electron pulse on target and by the timing jitter, while the spatial resolution is limited by the average electron beam current and the signal-to-noise ratio of the detection system. We also discuss plans for improving both the temporal resolution and the spatial resolution.

  17. The experimental study of neutralized electron beams for electron cooling

    CERN Document Server

    Bosser, Jacques; MacCaferri, R; Molinari, G; Tranquille, G; Varenne, F; Korotaev, Yu V; Meshkov, I N; Polyakov, V A; Smirnov, A; Syresin, E M

    1996-01-01

    In this report we present the latest experimental results on electron beam neutralization. These experiments have been made at LEAR and on the JINR test bench. The main difficulty in obtaining neutralized beams resides in an instability which is dependent on the electron beam current. A number of methods have been developed in order to overcome this instability and have enabled us to further investigate the possibility of generating intense low energy electron beams for the cooling of Pb ions.

  18. Radiation damage in electron cryomicroscopy.

    Science.gov (United States)

    Baker, Lindsay A; Rubinstein, John L

    2010-01-01

    In an electron microscope, the electron beam used to determine the structures of biological tissues, cells, and molecules destroys the specimen as the image is acquired. This destruction occurs before a statistically well-defined image can be obtained and is consequently the fundamental limit to resolution in biological electron cryomicroscopy (cryo-EM). Damage from the destructive interaction of electrons with frozen-hydrated specimens occurs in three stages: primary damage, as electrons ionize the sample, break bonds, and produce secondary electrons and free radicals; secondary damage, as the secondary electrons and free radicals migrate through the specimen and cause further chemical reactions; and tertiary damage, as hydrogen gas is evolved within the sample, causing gross morphological changes to the specimen. The deleterious effects of radiation are minimized in cryo-EM by limiting the exposure of the specimen to incident electrons and cooling the sample to reduce secondary damage. This review emphasizes practical considerations for minimizing radiation damage, including measurement of electron exposure, estimation of absorbed doses of energy, selection of microscope voltage and specimen temperature, and selection of electron exposure to optimize images. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Application of electron accelerator worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Machi, Sueo [Japan Atomic Industrial Forum, Inc., Tokyo (Japan)

    2003-02-01

    Electron accelerator is an important radiation source for radiation technology, which covers broad fields such as industry, health care, food and environmental protection. There are about 1,000 electron accelerators for radiation processing worldwide. Electron accelerator has advantage over Co-60 irradiator in term of high dose rate and power, assurance of safety, and higher economic performance at larger volume of irradiation. Accelerator generating higher energy in the range of 10 MeV and high power electron beam is now commercially available. There is a trend to use high-energy electron accelerator replacing Co-60 in case of large through-put of medical products. Irradiated foods, in particular species, are on the commercial market in 35 countries. Electron accelerator is used efficiently and economically for production of new or modified polymeric materials through radiation-induced cross-linking, grafting and polymerization reaction. Another important application of electron beam is the curing of surface coatings in the manufacture of products. Electron accelerators of large capacity are used for cleaning exhaust gases in industrial scale. Economic feasibility studies of this electron beam process have shown that this technology is more cost effective than the conventional process. It should be noted that the conventional limestone process produce gypsum as a by-product, which cannot be used in some countries. By contrast, the by-product of the electron beam process is a valuable fertilizer. (Y. Tanaka)

  20. Quantum tomography of an electron

    Science.gov (United States)

    Jullien, T.; Roulleau, P.; Roche, B.; Cavanna, A.; Jin, Y.; Glattli, D. C.

    2014-10-01

    The complete knowledge of a quantum state allows the prediction of the probability of all possible measurement outcomes, a crucial step in quantum mechanics. It can be provided by tomographic methods which have been applied to atomic, molecular, spin and photonic states. For optical or microwave photons, standard tomography is obtained by mixing the unknown state with a large-amplitude coherent photon field. However, for fermions such as electrons in condensed matter, this approach is not applicable because fermionic fields are limited to small amplitudes (at most one particle per state), and so far no determination of an electron wavefunction has been made. Recent proposals involving quantum conductors suggest that the wavefunction can be obtained by measuring the time-dependent current of electronic wave interferometers or the current noise of electronic Hanbury-Brown/Twiss interferometers. Here we show that such measurements are possible despite the extreme noise sensitivity required, and present the reconstructed wavefunction quasi-probability, or Wigner distribution function, of single electrons injected into a ballistic conductor. Many identical electrons are prepared in well-controlled quantum states called levitons by repeatedly applying Lorentzian voltage pulses to a contact on the conductor. After passing through an electron beam splitter, the levitons are mixed with a weak-amplitude fermionic field formed by a coherent superposition of electron-hole pairs generated by a small alternating current with a frequency that is a multiple of the voltage pulse frequency. Antibunching of the electrons and holes with the levitons at the beam splitter changes the leviton partition statistics, and the noise variations provide the energy density matrix elements of the levitons. This demonstration of quantum tomography makes the developing field of electron quantum optics with ballistic conductors a new test-bed for quantum information with fermions. These results may