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Sample records for albilineans ashby dowson

  1. Xanthomonas albilineans(Ashby Dowson: cultivars susceptibility and effects in the sugar yield

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    Yosel Pérez Pérez

    2017-01-01

    Full Text Available The effects produced by the Xanthomonas albilineans (Ashby Dowson on stalks with acute symptoms of the disease have been addressed by different authors, however, is unknown the effects that may occur in seropositive asymptomatic stems to the bacteria. This work has as objective to study the impact of the presence of bacteria in the colonized tissues, as well as the relationship between the concentration of cells and the expression of symptoms. In 900 stems of 14 cultivars detected the bacteria by serology and identified the variables Brix of stem with handheld refractometer, as well as the contents of fructose, glucose and sucrose whit High Performance Liquid Chromatographic. The presence of the bacterium X. albilineans in asymptomatic stems affects the sugar content of the same, which constitutes a contribution to the knowledge of the pathogen - host relations for this disease. The stems are colonized by the bacteria, but the amount of UFC/g of tissue or per ml/juice does not mean that a cultivar is more or less susceptible. In stalks with symptoms the cell density increases toward the foliage, while that in the asymptomatic happens to the contrary.

  2. Caracterização molecular e patogênica de isolados de Xanthomonas albilineans (Ashby Dowson, agente causal da escaldadura das folhas da cana-de-açúcar Molecular and pathogenic characterization of isolates of Xanthomonas albilineans (Ashby Dowson, causal agent of sugarcane leaf scald

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    Mariana de Souza e Silva

    2007-12-01

    Full Text Available A escaldadura das folhas, causada pela bactéria Xanthomonas albilineans (Ashby Dowson, é uma das cinco doenças mais importantes da cana-de-açúcar e sua ocorrência reduz o rendimento e a longevidade da cultura. Variedades resistentes têm sido usadas para o controle, porém há evidências da ocorrência de variantes do patógeno. Em campos comerciais do Estado de São Paulo, tem sido observado que a mesma variedade de cana se apresenta como resistente em uma região e suscetível em outra, sugerindo a ocorrência de variantes na população do patógeno. Assim, o objetivo deste trabalho foi investigar a presença de diversidade genética da bactéria em áreas comerciais. Um total de 50 isolados foram obtidos em cultura pura a partir de plantas sintomáticas coletadas em Piracicaba (SP, Jaú (SP, região de Ribeirão Preto (SP e Iturama (MG. Os isolados foram confirmados como pertencentes à espécie X. albilineans por meio de características de colônias, serologia e PCR com 'primers' específicos. Para caracterização da diversidade genética, foi usado o método de Rep-PCR, a partir do DNA extraído de cada isolado. Oito isolados, provenientes dos diferentes grupos identificados por rep-PCR, foram usados em testes de patogenicidade, por meio de inoculação em duas variedades de cana. Os resultados confirmaram todos os isolados como pertencentes à espécie X. albilineans. Por meio de rep-PCR, foi demonstrada diversidade genética entre os isolados, os quais foram separados em três grupos: um grupo composto somente pelos isolados de Piracicaba; um segundo, contendo todos os isolados amostrados em Jaú e na região de Ribeirão Preto, e um isolado de Iturama; e, no terceiro, somente dois isolados coletados em Iturama. Os testes de patogenicidade revelaram diferenças na agressividade entre isolados, porém sem relação com sua região de origem. Este trabalho revelou a ocorrência de diversidade genética e de agressividade dentro da

  3. Genomic insights into strategies used by Xanthomonas albilineans with its reduced artillery to spread within sugarcane xylem vessels.

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    Pieretti, Isabelle; Royer, Monique; Barbe, Valérie; Carrere, Sébastien; Koebnik, Ralf; Couloux, Arnaud; Darrasse, Armelle; Gouzy, Jérôme; Jacques, Marie-Agnès; Lauber, Emmanuelle; Manceau, Charles; Mangenot, Sophie; Poussier, Stéphane; Segurens, Béatrice; Szurek, Boris; Verdier, Valérie; Arlat, Matthieu; Gabriel, Dean W; Rott, Philippe; Cociancich, Stéphane

    2012-11-21

    Xanthomonas albilineans causes leaf scald, a lethal disease of sugarcane. X. albilineans exhibits distinctive pathogenic mechanisms, ecology and taxonomy compared to other species of Xanthomonas. For example, this species produces a potent DNA gyrase inhibitor called albicidin that is largely responsible for inducing disease symptoms; its habitat is limited to xylem; and the species exhibits large variability. A first manuscript on the complete genome sequence of the highly pathogenic X. albilineans strain GPE PC73 focused exclusively on distinctive genomic features shared with Xylella fastidiosa-another xylem-limited Xanthomonadaceae. The present manuscript on the same genome sequence aims to describe all other pathogenicity-related genomic features of X. albilineans, and to compare, using suppression subtractive hybridization (SSH), genomic features of two strains differing in pathogenicity. Comparative genomic analyses showed that most of the known pathogenicity factors from other Xanthomonas species are conserved in X. albilineans, with the notable absence of two major determinants of the "artillery" of other plant pathogenic species of Xanthomonas: the xanthan gum biosynthesis gene cluster, and the type III secretion system Hrp (hypersensitive response and pathogenicity). Genomic features specific to X. albilineans that may contribute to specific adaptation of this pathogen to sugarcane xylem vessels were also revealed. SSH experiments led to the identification of 20 genes common to three highly pathogenic strains but missing in a less pathogenic strain. These 20 genes, which include four ABC transporter genes, a methyl-accepting chemotaxis protein gene and an oxidoreductase gene, could play a key role in pathogenicity. With the exception of hypothetical proteins revealed by our comparative genomic analyses and SSH experiments, no genes potentially involved in any offensive or counter-defensive mechanism specific to X. albilineans were identified, supposing

  4. Genomic insights into strategies used by Xanthomonas albilineans with its reduced artillery to spread within sugarcane xylem vessels

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    Pieretti Isabelle

    2012-11-01

    Full Text Available Abstract Background Xanthomonas albilineans causes leaf scald, a lethal disease of sugarcane. X. albilineans exhibits distinctive pathogenic mechanisms, ecology and taxonomy compared to other species of Xanthomonas. For example, this species produces a potent DNA gyrase inhibitor called albicidin that is largely responsible for inducing disease symptoms; its habitat is limited to xylem; and the species exhibits large variability. A first manuscript on the complete genome sequence of the highly pathogenic X. albilineans strain GPE PC73 focused exclusively on distinctive genomic features shared with Xylella fastidiosa—another xylem-limited Xanthomonadaceae. The present manuscript on the same genome sequence aims to describe all other pathogenicity-related genomic features of X. albilineans, and to compare, using suppression subtractive hybridization (SSH, genomic features of two strains differing in pathogenicity. Results Comparative genomic analyses showed that most of the known pathogenicity factors from other Xanthomonas species are conserved in X. albilineans, with the notable absence of two major determinants of the “artillery” of other plant pathogenic species of Xanthomonas: the xanthan gum biosynthesis gene cluster, and the type III secretion system Hrp (hypersensitive response and pathogenicity. Genomic features specific to X. albilineans that may contribute to specific adaptation of this pathogen to sugarcane xylem vessels were also revealed. SSH experiments led to the identification of 20 genes common to three highly pathogenic strains but missing in a less pathogenic strain. These 20 genes, which include four ABC transporter genes, a methyl-accepting chemotaxis protein gene and an oxidoreductase gene, could play a key role in pathogenicity. With the exception of hypothetical proteins revealed by our comparative genomic analyses and SSH experiments, no genes potentially involved in any offensive or counter-defensive mechanism

  5. STS-93 Pilot Ashby suits up for launch

    Science.gov (United States)

    1999-01-01

    In the Operations and Checkout Building during final launch preparations for the third time, STS-93 Pilot Jeffrey S. Ashby pulls on his glove, part of his launch and entry suit. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Eileen Collins, Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  6. STS-93 Pilot Ashby suits up before launch

    Science.gov (United States)

    1999-01-01

    In the Operations and Checkout Building during final launch preparations for the second time, STS-93 Pilot Jeffrey S. Ashby waves after donning his launch and entry suit while a suit tech adjusts his boot. After Space Shuttle Columbia's July 20 launch attempt was scrubbed at the T-7 second mark in the countdown, the launch was rescheduled for Thursday, July 22, at 12:28 a.m. EDT. The target landing date is July 26, 1999, at 11:24 p.m. EDT. STS- 93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  7. Occurrence of Xanthomonas campestris pv. campestris (Pammel, 1895 Dowson 1939, on Brassicas in Montenegro

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    Dragana Radunović

    2012-01-01

    Full Text Available Brassicas form the most important group of vegetable crops in Montenegro. The cabbage(Brassica oleracea var. capitata is most commonly grown, although other brassicas,particularly kale, Brussels sprout, cauliflower and broccoli, have been increasingly producedsince recently. One of the specialties of vegetable production in Montenegro is growing ofcollard (Brassica oleracea var. acephala, which is the simplest variety of the Brassica oleraceaspecies and in the nearest relation with their wild ancestor – the sylvestris variety.Diseases are the main restrictive factors for successful production of these vegetables.Susceptibility of the cultivars and inadequate control often result in more or less damagedcrops in some plots.Causal agents of brassica diseases, especially bacterial, have not been investigated inMontenegro until 2009. Since the symptoms observed in 2009 were „V” shaped leaf edgenecrosis and black rot of vascular tissue, it was assumed that they were caused by plantpathogenic bacterium Xanthomonas campestris pv. campestris.Samples of the infected plants were collected from different localities in Montenegro.Isolation and identification of the bacterium were performed using laboratory methodsaccording to Schaad (1980, Lelliott and Stead (1987 and Arsenijević (1997. Examinationof chosen bacterial isolates was conducted using both, classical bacteriological methods(examination of their pathogenic, morphological, cultivation and biochemical and physiologicalcharacteristics, and ELISA test.The obtained results confirmed the presence of X.campestris pv. campestris (Pammel,1895 Dowson 1939, on cabbage, kale, broccoli and collard in Montenegro. This is the firstexperimental evidence that collard is the host of X. campestris pv. campestris in Montenegro.

  8. The RpfCG two-component system negatively regulates the colonization of sugar cane stalks by Xanthomonas albilineans.

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    Rott, Philippe; Fleites, Laura A; Mensi, Imène; Sheppard, Lauren; Daugrois, Jean-Heinrich; Dow, J Maxwell; Gabriel, Dean W

    2013-06-01

    The genome of Xanthomonas albilineans, the causal agent of sugar cane leaf scald, carries a gene cluster encoding a predicted quorum sensing system that is highly related to the diffusible signalling factor (DSF) systems of the plant pathogens Xylella fastidiosa and Xanthomonas campestris. In these latter pathogens, a cluster of regulation of pathogenicity factors (rpf) genes encodes the DSF system and is involved in control of various cellular processes. Mutation of Xanthomonas albilineans rpfF, encoding a predicted DSF synthase, in Florida strain XaFL07-1 resulted in a small reduction of disease severity (DS). Single-knockout mutations of rpfC and rpfG (encoding a predicted DSF sensor and regulator, respectively) had no effect on DS or swimming motility of the pathogen. However, capacity of the pathogen to cause disease was slightly reduced and swimming motility was severely affected when rpfG and rpfC were both deleted. Similar results were obtained when the entire rpfGCF region was deleted. Surprisingly, when the pathogen was mutated in rpfG or rpfC (single or double mutations) it was able to colonize sugar cane spatially more efficiently than the wild-type. Mutation in rpfF alone did not affect the degree of spatial invasion. We conclude that the DSF signal contributes to symptom expression but not to invasion of sugar cane stalks by Xanthomonas albilineans strain XaFL07-1, which is mainly controlled by the RpfCG two-component system.

  9. [Occurrence of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in the state of Maranhão, Brazil].

    Science.gov (United States)

    de Lemos, Raimunda N S; da Silva, Gilson S; Araújo, José R G; Das Chagas, Evandro F; Moreira, Aldenise A; Soares, Ana T M

    2006-01-01

    Aleurocanthus woglumi Ashby in citrus and mango crops in the state of Maranhão, Brazil, is recorded. Samples of 2003 and 2004 from several counties were identified and deposited in the Insect Collection of the Laboratório de Entomologia of the Núcleo de Biotecnologia Agronômica, Universidade Estadual do Maranhão.

  10. Genes diferencialmente expressos em cana-de-açúcar inoculada com Xanthomonas albilineans, o agente causal da escaldadura da folha Diferential gene expression in sugar cane infected with Xanthomonas albilineans, causal agent of leaf scald

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    Karina Maia Dabbas

    2006-09-01

    Full Text Available A escaldadura da folha, causada pela bactéria Xanthomonas albilineans colonizadora do xilema, é uma das principais doenças da cana-de-açúcar. A sintomatologia na fase crônica é caracterizada principalmente pelo aparecimento de uma faixa branca paralela à nervura central da folha, que evolui até queimar totalmente, sendo também observado brotação de gemas laterais no colmo. Neste trabalho, a técnica de macroarranjos de cDNA foi empregada para o estudo da expressão de 3.575 ESTs (espressed sequence tags em folhas de cana-de-açúcar. Foram utilizadas duas variedades, uma resistente (SP82-1176 e outra suscetível (SP78-4467 a Xanthomonas albilineans as quais foram infectadas mecanicamente por ferimentos. As membranas dos macroarranjos foram confeccionadas a partir de ESTs de bibliotecas de folha e cartucho de cana-de-açúcar provenientes do projeto SUCEST e hibridizadas contra sondas de cDNA de plantas infectadas e controle marcadas com isótopos radioativos. Analisando os resultados dos macroarranjos foi possível verificar um comportamento diferenciado para cada variedade durante o ataque do patógeno. Após realizadas análises estatísticas identificamos na variedade resistente ESTs com expressão induzida relacionadas com biossíntese de isoprenoides, proteínas LRR transmembrânica, "ziper" de leucina, lignificação, tolerância ao frio, diferenciação de plastídeos, sistemas de defesa e de adaptação da planta ao meio ambiente. As ESTs reprimidas na variedade resistente foram àquelas relacionadas com genes responsáveis pela síntese de proteínas do controle da expansão da parede celular, detoxificação e transporte de auxina. Na variedade susceptível foram reprimidas ESTs relacionadas a genes de proteínas das respostas de defesa da planta, biossíntese de Etileno e regulação da transcrição.The leaf scald disease, caused by the xylem-invading pathogen Xanthomonas albilineans, is one of the most devastating

  11. Actividad antimicrobiana y cinética de fermentación de weissella confusa contra xanthomonas albilineans

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    Serna Cock, Liliana; Camargo Guarnizo, Andres Felipe; Rengifo Guerrero, Carlos Andres

    2014-01-01

    Se evaluó la actividad antimicrobiana de Weissella confusa, una bacteria ácido láctica, contra Xanthomonas albilineans, microrganismo productor de la escaldadura de la hoja en la caña de azúcar. Se midió la cinética de fermentación de la bacteria ácido láctica en sustrato comercial (MRS) y en residuos agrícolas de cosecha de caña de azúcar (RAC) provenientes de semilleros con 7 meses de edad. Se realizaron fermentaciones sumergidas a 32 °C, cada hora hasta 4 horas, a pH 6 y 100 r.p.m. de agit...

  12. Gamma irradiation as a quarantine treatment against eggs of Citrus black fly (Aleurocanthus woglumi Ashby)

    International Nuclear Information System (INIS)

    Villavicencio, Anna Lucia C.H.; Araujo, Michel M.; Fanaro, Gustavo B.; Costa, Helbert H.S.F.; Silva, Priscila P.V.; Arthur, Valter

    2009-01-01

    The citrus black fruit fly (Aleurocanthus woglumi Ashby) is an important pest of citrus originated in Southeast Asia and its first record in the new world was in Jamaica in 1913. In Brazil, it was detected in 2001 in the state of Para and more recently it was detected in Sao Paulo in 2008. This pest that attacks over 300 species of plants, but its main host are citrus. It is an A2 quarantine pest, because it is not spread throughout the country. The objective of this study was to test doses of 0 (control), 25, 50, 75, 100, 125, 150, 175 and 200 Gy of gamma irradiation for disinfection of eggs of the citrus black fruit fly in leaves of citrus plants. Treatment consisted of 5 replicates with 60 eggs each. Evaluations were performed in the following periods: 1, 3, 5, 7 and 10 days after irradiation. Under the conditions assayed, it could be concluded that a dose of 200 Gy caused 100% mortality of Aleurocanthus woglumi Ashby eggs and could be recommended as a successful quarantine processing against infested plants. (author)

  13. Xanthomonas albilineans OmpA1 appears to be functionally modular and both the OMC and C-like domains are necessary for leaf scald disease of sugarcane.

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    Fleites, Laura A; Mensi, Imène; Gargani, Daniel; Zhang, Shujian; Rott, Philippe; Gabriel, Dean W

    2013-10-01

    Several EZ-Tn5 insertions in gene locus XALc_0557 (OmpA1) of the sugarcane leaf scald pathogen Xanthomonas albilineans XaFL07-1 were previously found to strongly affect pathogenicity and endophytic stalk colonization. XALc_0557 has a predicted OmpA N-terminal outer membrane channel (OMC) domain and an OmpA C-like domain. Further analysis of mutant M468, with an EZ-Tn5 insertion in the upstream OMC domain coding region, revealed impaired epiphytic and endophytic leaf survival, impaired resistance to sodium dodecyl sulfate (SDS), structural defects in the outer membrane (OM), and hyperproduction of OM vesicles. Cloned full-length XALc_0557 complemented M468 for all phenotypes tested, including pathogenicity, resistance to SDS, and ability to survive both endophytically and epiphytically. Another construct, pCT47.3, which expressed only the C-like domain of XALc_0557, restored resistance to SDS in M468 but failed to complement any other mutant phenotype, indicating that the C-like domain functioned independently of the OMC domain to help maintain OM integrity. pCT47.3 also complemented pathogenicity, resistance to SDS, and stalk colonization in mutant M1152, which carries an EZ-Tn5 insert in the C-like coding region, indicating that both predicted domains are modular and necessary but neither is sufficient for X. albilineans pathogenicity, endophytic survival in, and epiphytic survival on sugarcane.

  14. Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants

    International Nuclear Information System (INIS)

    Pena, Marcia R.; Silva, Neliton M. da

    2009-01-01

    The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

  15. Biology of the citrus blackfly, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), in three host plants; Biologia da mosca-negra-dos-citros, Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae), em tres plantas hospedeiras

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    Pena, Marcia R.; Silva, Neliton M. da [Universidade Federal do Amazonas (UFAM), Manaus, AM (Brazil).Lab. de Entomologia Agricola], e-mail: marciarpena@yahoo.com.br, e-mail: nmarques@ufam.edu.br; Venframim, Jose D.; Haddad, Marineia de L. [Escola Superior de Agricultura Luiz de Queiroz (ESALQ/USP), Piracicaba, SP (Brazil). Lab. de Resistencia de Plantas e Plantas Inseticidas], e-mail: jdvendra@esalq.usp.br, e-mail: mlhaddad@esalq.usp.br; Lourencao, Andre L. [Instituto Agronomico de Campinas (IAC), SP (Brazil)], e-mail: andre@iac.sp.gov.br

    2009-03-15

    The citrus blackfly, Aleurocanthus woglumi Ashby, was detected in Brazil in 2001. The aim of this research was to evaluate the biology, biometry and host preference of A. woglumi in sweet orange, acid lime Tahiti and mango. Experiments were set in laboratory conditions with insects collected in rangpur lime plants in Manaus, State of Amazonas, from January to June of 2006. The following parameters were evaluated: number of spirals (ovo positions) and eggs per plant, number of eggs by spiral per plant, survival of the immature (eggs, 1st, 2nd, 3rd and 4th instars), and length and survival of the immature stage. The mean embrionary period was 15 days for the three hosts. The 4th nymph (puparium) was the longest during nymph development. Second and third instars had the highest survival. The mean length of the egg-adult cycle was 70 days for the three hosts evaluated. The eggs were laid in a spiral shape on the adaxial leaf surface. The 1st instars moved to short distances from the spiral, while the 2nd, 3rd and 4th are sessile and have bristles on the whole body. Based on the highest oviposition and the highest survival of the immature stage of the citrus blackfly in acid lime Tahiti, this plant can be considered the most suitable host to A. woglumi. (author)

  16. First record of occurrence of mosca-negra-dos-citrus, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Sternorrhyncha: Aleyrodidae in Roraima, Brazil = Primeiro registro da ocorrência de mosca-negra-dos-citros, Aleurocanthus woglumi Ashby, 1915 (Hemiptera: Aleyrodidae em Roraima

    Directory of Open Access Journals (Sweden)

    Francisco Clemilto da Silva Maciel

    2011-12-01

    Full Text Available The Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae is an important pest of citrus. Originated in Asia, this pest was detected in Brazil for the first time in the State of Para, Brazil in 2001. In the culture of citrus fruits the black fly carries direct and indirect damage, impeding the development and production of plants. In addition to restricting trade in local areas from its occurrence to the presence of the plague, since the A. woglumi quarantine pest is considered present (A2 of high alert in accordance with Instruction No 23, April 29, 2008, established by the Ministério da Agricultura, Pecuária e Abastecimento of the Brazil. The objective of this paper was to record the first occurrence of Aleurocanthus woglumi in the State of Roraima, Brazil.= A mosca-negra-dos-citros, Aleurocanthus woglumi Ashb, (Hemiptera: Aleyrodidae é uma importante praga dos citros. De origem asiática, esta praga foi detectada no Brasil pela primeira vez no estado do Pará no ano de 2001. Na cultura dos citros a mosca-negra acarreta danos diretos e indiretos, prejudicando o desenvolvimento e produção das plantas. Além de restringir o comércio de locais de sua ocorrência para áreas livres da presença da praga, visto que o A. woglumi é considerado praga quarentenária presente (A2 de alerta máximo de acordo com a instrução normativa No 23, de 29 de abril de 2008; estabelecida pelo Ministério da Agricultura, Pecuária e Abastecimento. Objetivou-se com o presente trabalho registrar a primeira ocorrência de mosca-negra-dos-citros no estado de Roraima.

  17. Use of first ratoon as categorized seed of sugarcane

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    Héctor Jorge Suárez

    2016-04-01

    Full Text Available The results obtained on commercial seedbeds of Factory Ofelina (Panamá are presented. Were you sampled 289.55 ha in 13 fields planted with ten varieties in plant cane, ratoon and second shoot those who underwent first molecular diagnosis (PCR for stunting diseases shoot and leaf scald, then staining was performed vascular xylem vessels with safranin whose purpose was to determine the percentage of functional vessels. The molecular diagnosis offered the 49 and 6 % of the samples had the presence of bacteria Leifsonia xyli (subsp xyli and Xanthomonas albilineans (Ashby Dowson respectively, while 92.7 % of the area evaluat- ed showed values ​​ higher than 85 % functionality xylem vessels. In Cuba the total cost of production of regis- tered seed II hovers around $ 8 188 724.2, using the 20 % of ratoon in the country would save approximately $ 1 066 370.7. The use of ratoon as seed is a common practice in countries like Brazil, Colombia, Argentina and Costa Rica, among others, its use is depending on the effectiveness of treatments to be given to the seed through the chain seed and varieties resistance to use.

  18. Influência de Fatores Abióticos na Infestação de Mosca-Negra-dos-Citros (Aleurocanthus woglumi Ashby em Plantio de Citros em Sistema Agroflorestal no Estado do Pará

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    Anderson Silva

    2011-03-01

    Abstract. An important part of citrus production at Pará state is planted by Agroforestry System (AFS, that presents, amongst major phytosanitary problems, the citrus blackfly, that by severe attacks cause estimated redution of 80% in its’ production. Beside that, it constitutes a quarentenary pest of maximun alert level A2. Given the relevance of this sucking insect and the lack of basic knowledge, as well pest studies associated to agroforestry planting, the objective of this study was to evaluate the abiotic factors influence on blackfly infestation in citrus planting by agroforestry planting at Pará state. This study was carried out at Capitão Poço county, northeast mesoregion of Pará. 12 samplings were made evaluating the presence or abscence of Aleurocanthus woglumi Ashby alive nymphs and/or adults. Correlation analisys was carried out to evaluate abiotic parameters (temperature and precipitation and kriging maps to evaluate Teca plants shading effects on the pest under study infestation. Amongst the main results obtained, there was pest infestation in every evaluated moth; there was temperature influence onto citrus blackfly population regulation and high precipitations reduced the number of plants with A. woglumi presence. Still, it can be inferred that the citrus blackfly infestations present preference for moderate shading intensity. However, changes occuring by the forestry species introduction onto agricultural cultivations must be better investigated.

  19. Work Loop and Ashby Charts of Active Materials

    Science.gov (United States)

    2013-10-17

    was  below  the middle  of  the  electromagnet.  The  sample  displacement  was  measured  using  an  Acuity  AR600  triangulation  laser  displacement...this group. Magpol has higher actuation stress than  solenoids  and moving  coil  actuators  and work  capacity  is  164  kJ/m3,  better  than  the work...heal thermoplastic polymers can be derived  from the  fusion   bonding or welding processes  in  thermoplastic polymers, which essentially  follow

  20. Induction of mutations in citrus for the development of resistance to Xanthomonas citri (Hasse) Dowson

    International Nuclear Information System (INIS)

    Zubrzycki, H.M.; Diamante de Zubrzycki, A.

    1982-01-01

    With the aim of obtaining resistance to Xanthomonas citri in citrus, mutagenic treatment was carried out with X-rays and gamma rays on buds and seedlings. As a prerequisite, attempts were made to determine some physiological and structural differences in leaves in order to evaluate and analyse the reaction to the bacterium in qualitative and quantitative terms. Citrus were found to present 3-4 annual sproutings, each having a different intensity. Grapefruit showed a greater initial increase and final length than orange, but lemon growth was greater than all the others. According to their growth, leaves clustered in three groups. Those in the middle part of the sprout showed the greatest daily increase, followed in decreasing order by those of the base and those of the apex. In orange cultivars with different degrees of reaction to Xanthomonas citri a direct association between daily growth of leaves and susceptibility was found. In fully developed leaves the number of stomata per surface unit presented an inverse ratio with susceptibility. It was observed that in a given genotype the stomata frequency per surface unit was higher in young leaves than in developed ones. Also a direct association between the leaf area and the number of stomata per leaf was found. Natural field infections were measured in leaves of developed plants. Infection in each of the 3-4 annual sproutings depends on environmental factors during the growth period and the predisposition period of the leaves. The available variation for reaction to Xanthomonas citri was higher in oranges than in grapefruit. The abscission of each leaf depends on its degree of infection, but the cultivars classed as more resistant are those requiring a smaller affected area to provoke the leaf abscission. However, abscission of a leaf is independent of the fate of the neighbouring ones. The existence of a continuous grading of infection damage within the orange cultivars suggests a genetic component for resistance to Xanthomonas citri

  1. Hip and groin pain in sub-elite South African footballers | Dowson ...

    African Journals Online (AJOL)

    Background. Groin injuries are common in football. This can be attributed to the nature of the sport involving rapid accelerations, decelerations, abrupt directional changes and kicking. Groin injuries require lengthy rehabilitation times and predispose players to further injuries. Previous groin injury is a risk factor for future ...

  2. Interaction of the phage-xanthomonas campestris (Pammel) Dowson at the eletronic microscopy level, Virazole effect and radioautographic study of the phage action on the host

    International Nuclear Information System (INIS)

    Sittolin, I.M.

    1982-04-01

    A bacteriophage from the cabbage tissue infected with Xanthomonas campestris is described. The infection process is studied through a negative staining technique (PTA) and ultrathin section. The effect of Virazole, an antivirus agent, is tested. Radioautography showed that the phage presented a reasonable domain on the bacterial host genome since the beginning of the treatment. Sorological reactions indicated the induction of specific antibodies for the phage. (M.A.C.) [pt

  3. Genetic sequences derived from suppression subtractive ...

    African Journals Online (AJOL)

    Leaf scald disease (LSD) is caused by the Gram-negative bacterium, Xanthomonas albilineans. Genomic DNA from X. albilineans and Xanthomonas hyacinthi were analyzed by suppression subtractive hybridization (SSH) using X. albilineans as the tester from which unique sequences were sought and X. hyacinthi as the ...

  4. Genetic sequences derived from suppression subtractive ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-06-17

    Jun 17, 2008 ... Genomic DNA from X. albilineans and Xanthomonas hyacinthi were analyzed by suppression subtractive ... Clone X. albilineans 12 showed 92% homology to the acetate repressor proteins and clone. X. albilineans 18 .... stranded DNA will be enriched for tester-specific DNA, as DNA fragments that are not ...

  5. Identifikasi Dan Uji Antagonisme Jamur Endofit Tanaman Tebu (Saccharum Officinarum L.) Terhadap Perkembangan Xanthomonas Albilineans L. Dengan Metode Sterilisasi Autoklaf Dan Membran Filter

    OpenAIRE

    Wahyuni, Siti Hardianti

    2016-01-01

    This research was conducted in a Laboratory of Agricuture Faculty and greenhouse of Agricuture Faculty, North Sumatra University, Medan, from April until December 2014. The research used completely randomized design with three factors and three replications. The first factor were endophytic fungi 1, endophytic fungi 2, endophytic fungi 3, endophytic fungi 4, endophytic fungi 5, endophytic fungi 6, endophytic fungi 7, and endophytic fungi 8. The second factor were dilution 10-1, 10-2, 10-3 da...

  6. 7 CFR 319.19 - Notice of quarantine.

    Science.gov (United States)

    2010-01-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE FOREIGN QUARANTINE NOTICES Citrus Canker and Other Citrus Diseases... citrus canker disease (Xanthomonas citri (Hasse) Dowson) and other citrus diseases, the importation into the United States of plants or any plant part, except fruit and seeds, of all genera, species, and...

  7. extraction of high quality dna from polysaccharides-secreting ...

    African Journals Online (AJOL)

    cistvr

    They produce typical yellow pigments known as xanthomonadins which have been used as chemotaxonomic markers (Starr et al.,. 1977). Two major diseases of sugarcane are caused by members of the Xanthomonas genus, and they are Xanthomonas campestris pv. vasculorum and Xanthomonas albilineans (Ricaud et ...

  8. Computational Cognitive Neuroscience Modeling of Sequential Skill Learning

    Science.gov (United States)

    2016-09-21

    system for reflective exploratory behavior . Neurobiology of Learning and Memory. 5. Cantwell, G., Crossley, M. J., & Ashby, F. G. (2015). Multiple...stages of learning in DISTRIBUTION A: Distribution approved for public release. perceptual categorization: Evidence and neurocomputational theory ...M. J., & Ashby, F. G. (2015). Multiple stages of learning in perceptual categorization: Evidence and neurocomputational theory . Psychonomic Bulletin

  9. Compressibilities and viscosities of reference, vegetable, and synthetic gear lubricants

    DEFF Research Database (Denmark)

    Regueira Muñiz, Teresa; Lugo, Luis; Fernández, Josefa

    2014-01-01

    Nowadays, one of the primary choices of base oils for environmentally aware lubricants is vegetable oils. This is due to their good natural biodegradability and very low toxicity in combination with very good lubricity characteristics. The development of new vegetable-based lubricants requires...... values of six gear lubricants, two of them reference mineral oils and the other four developed biodegradable oils based in high oleic sunflower oil or in synthetic esters. It was found that all of the lubricants have both similar compressibilities and similar expansivities. Dowson and Higginson, Zhu.......06%. Dowson and Higginson and Zhu and Wen equations of state do not predict well the isothermal compressibilities, with AAD % being around 45% for both equations. Moreover, the viscosities were measured in the temperature range from 278.15 to 373.15 K at atmospheric pressure for these oils, and the viscosity...

  10. Genomes-based phylogeny of the genus Xanthomonas

    Directory of Open Access Journals (Sweden)

    Rodriguez-R Luis M

    2012-03-01

    Full Text Available Abstract Background The genus Xanthomonas comprises several plant pathogenic bacteria affecting a wide range of hosts. Despite the economic, industrial and biological importance of Xanthomonas, the classification and phylogenetic relationships within the genus are still under active debate. Some of the relationships between pathovars and species have not been thoroughly clarified, with old pathovars becoming new species. A change in the genus name has been recently suggested for Xanthomonas albilineans, an early branching species currently located in this genus, but a thorough phylogenomic reconstruction would aid in solving these and other discrepancies in this genus. Results Here we report the results of the genome-wide analysis of DNA sequences from 989 orthologous groups from 17 Xanthomonas spp. genomes available to date, representing all major lineages within the genus. The phylogenetic and computational analyses used in this study have been automated in a Perl package designated Unus, which provides a framework for phylogenomic analyses which can be applied to other datasets at the genomic level. Unus can also be easily incorporated into other phylogenomic pipelines. Conclusions Our phylogeny agrees with previous phylogenetic topologies on the genus, but revealed that the genomes of Xanthomonas citri and Xanthomonas fuscans belong to the same species, and that of Xanthomonas albilineans is basal to the joint clade of Xanthomonas and Xylella fastidiosa. Genome reduction was identified in the species Xanthomonas vasicola in addition to the previously identified reduction in Xanthomonas albilineans. Lateral gene transfer was also observed in two gene clusters.

  11. Untitled

    Indian Academy of Sciences (India)

    Total nitrogen in milligrams at the end of ten days in each fias. - - - - - -. ; Nitrogen after i0 day's : Nitrogen Average of gait as: to begin the three. --------|-- i. ss are : 0.67 0.66 ... Asiy Solution 66 0.66 ( 0.66 f. 2. Ashby solution and rice root le y extract . . 0.76 0.84 0-87 0.82 n : 3. Ashby solution and rice root grana & 8 . . 5.24 6.29 ...

  12. Approximate Analysis of Dynamic Characteristics of Short Journal Bearings in Turbulent Micropolar Lubrication

    Science.gov (United States)

    Rana, N. K.; Gautam, S. S.; Samanta, S.

    2014-10-01

    An approximate analysis has been carried out for short journal bearing to determine the dynamic behavior under micropolar turbulent flow condition. In this analysis, the Constantinescu's turbulent shear coefficient has been considered, which was later proposed by Taylor and Dowson. For the calculation of dynamic pressures, the classical Reynolds equation has been modified to incorporate turbulence and micropolar fluid parameters. The analysis has been further extended to determine the mass and whirl parameters to analyze the stability of the bearing. The bearing is found to be more stable with increase in eccentricity with high speed and large Reynolds number.

  13. Base-rate effects in multidimensional perceptual categorization.

    Science.gov (United States)

    Maddox, W T

    1995-03-01

    The optimality of human performance when category base rates differ was investigated in 2 multidimensional perceptual categorization tasks. All participants were sensitive to differences in base rate, even during their 1st experimental session. Nearly half of the participants learned the optimal decision bound by their final experimental session. Little evidence for conservative cutoff placement was found (i.e., an underestimation of category base-rate differences). In fact, participants who did not learn the optimal decision bound tended to use a decision bound that overestimated the base-rate difference. Across all conditions participants showed a clear shift toward the optimal decision bound with experience. These data suggest that experienced participants are highly sensitive to differences in category base rate. The model-based analyses suggest that the decision-bound model of categorization (Ashby, 1992a; Ashby & Maddox, 1993; Maddox & Ashby, 1993) provides a powerful tool for investigating the limits of human categorization performance.

  14. Perfectionism and Career Decision-Making Self-Efficacy

    Science.gov (United States)

    Ganske, Kathryn H.; Ashby, Jeffrey S.

    2007-01-01

    This study investigated the relationship between perfectionism and career decision-making self-efficacy. Participants completed the Almost Perfect Scale-Revised (R. B. Slaney, K. G. Rice, M. Mobley, J. Trippi, & J. S. Ashby, 2001) and the Career Decision-Making Self-Efficacy-Short Form (N. E. Betz, K. L. Klein, & K. M. Taylor, 1996). Adaptive…

  15. Gender Analysis of Sandwich Admissions: A Case Study of South-South Nigeria

    Science.gov (United States)

    Imakpokpomwan, Monday Imuetinyan; Adeyemi, J. K.

    2016-01-01

    Even though university institutions produce high level manpower for the various sectors of the economy Nigeria had none until 1948. In its desire to increase the spread of university education, Ashby Commission recommended a dual mode delivery especially to accommodate the workers quest for upgrade of their qualification. Sandwich is the part-time…

  16. Untitled

    Indian Academy of Sciences (India)

    Frost HJ, Ashby M F 1982 Deformation mechanism maps: the plasticity and creep of metals and ceramics (Oxford: Pergamon). Greenwood GW 1956 The growth of dispersed precipitates in solution Acta Metall. 4: 243-248. Iacocca RG, Woodford D A 1988 The growth of dispersed precipitates in nickel and its relevance.

  17. Comparative Service Quality Metrics in Regular and Nonregular Undergraduate Marketing Programs: Implications for Marketing Education and Professionalism

    Science.gov (United States)

    Okpara, Gazie S.; Agu, Agu G.

    2017-01-01

    Nonregular higher education in Nigeria became an integral part of the university manpower development since 1960, when the Ashby Commission recommended establishing evening degree programs. These ubiquitous programs have contributed to national capacity-building and remain relatively unmonitored by the National Universities Commission. This…

  18. Profiling application potential for alkali treated sisal fiber ...

    African Journals Online (AJOL)

    ATHARVA

    Keywords: Ashby plot, Weibull analysis, sisal-fiber composite, alkali treatment. DOI: http://dx.doi.org/10.4314/ijest.v9i3.4. 1. Introduction. Presently, there is an ever-increasing demand for .... identify potential causal to degradation of the fiber structural integrity, and subsequently assign market application potential of the.

  19. DIVERSITY AND DISTRIBUTION OF WHITEFLIES IN ...

    African Journals Online (AJOL)

    ACSS

    diverse in the rainforest zone than any other zone in the region. The cosmopolitan Aleurocanthus woglumi Ashby. (Aleyrodinae) infested plants in the family Rutaceae more than any other species of whiteflies in the region. Citrus species was observed to host larger population of whiteflies than any other crop in the study ...

  20. Individual and Family Perfectionism and Its Relationship to Depression, Anxiety, and Self-Esteem among Latino College Students

    Science.gov (United States)

    Ortega, Norma E.

    2010-01-01

    This study examined the relationship between individual and family perfectionism and mental health functioning among two hundred and seven Latino college students. One aim of this study was to test the factor structure of the Almost Perfect Scale-Revised (APS-R; Slaney, Rice, Mobley, Trippi, & Ashby, 2001) with Latino college students by…

  1. An Intelligence Collection Management Model.

    Science.gov (United States)

    1984-06-01

    classification of inteligence collection requirements in terms of. the a-.- metnodo"c, .ev--e in Chaster Five. 116 APPgENDIX A A METHOD OF RANKING...of Artificial Intelligence Tools and Technigues to!TN’X n~l is n rs aa~emfft-.3-ufnyva: ’A TZ Ashby W. Ecss. An Introduction to Cybernetics. New York

  2. Evaluating the performance of a retrofitted stormwater wet pond for treatment of urban runoff.

    Science.gov (United States)

    Schwartz, Daniel; Sample, David J; Grizzard, Thomas J

    2017-06-01

    This paper describes the performance of a retrofitted stormwater retention pond (Ashby Pond) in Northern Virginia, USA. Retrofitting is a common practice which involves modifying existing structures and/or urban landscapes to improve water quality treatment, often compromising standards to meet budgetary and site constraints. Ashby Pond is located in a highly developed headwater watershed of the Potomac River and the Chesapeake Bay. A total maximum daily load (TMDL) was imposed on the Bay watershed by the US Environmental Protection Agency in 2010 due to excessive sediment and nutrient loadings leading to eutrophication of the estuary. As a result of the TMDL, reducing nutrient and sediment discharged loads has become the key objective of many stormwater programs in the Bay watershed. The Ashby Pond retrofit project included dredging of accumulated sediment to increase storage, construction of an outlet structure to control flows, and repairs to the dam. Due to space limitations, pond volume was less than ideal. Despite this shortcoming, Ashby Pond provided statistically significant reductions of phosphorus, nitrogen, and suspended sediments. Compared to the treatment credited to retention ponds built to current state standards, the retrofitted pond provided less phosphorus but more nitrogen reduction. Retrofitting the existing stock of ponds in a watershed to at least partially meet current design standards could be a straightforward way for communities to attain downstream water quality goals, as these improvements represent reductions in baseline loads, whereas new ponds in new urban developments simply limit future load increases or maintain the status quo.

  3. Reviews | Feinauer | Lexikos

    African Journals Online (AJOL)

    Jonathan Crowther (Editor), Kathryn Kavanagh (Assistant Editor) and. Michael Ashby (Phonetics Editor). Oxford Advanced Learner's Dictionary of Current English, 5th edition· (New International Students' Edition) 1995, x + 1428 pp. ISBN 0-19-431423-5. Oxford: Oxford University Press. Price R54,95.

  4. Effects of artificial soil surface management on changes of ...

    African Journals Online (AJOL)

    user

    analise quimica, mineralogica e fisica de solos do Instituto. Agronomico de Campinas. Boletim Tecnico. No.106. EMBRAPA (1981). Mapa de solo do Brasil. Rio de Janeiro, Mapa scala. 1:5 000 000. FAO-UNESCO (1998). Soil map of the world. UNESCO Paris. Huettman CA, Preece JE, Ashby WC, Roth PL (1992). First year ...

  5. Profiling application potential for alkali treated sisal fiber ...

    African Journals Online (AJOL)

    Profiling application potential for alkali treated sisal fiber-polypropylene composite in Ashby material-property plots. ... International Journal of Engineering, Science and Technology ... The effect of alkali treatment on sisal fiber from the plant agave sisalana in appropriation for composite material application is presented.

  6. 78 FR 56710 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

    Science.gov (United States)

    2013-09-13

    .... Type of Information Collection Request: Reinstatement without change of a previously approved... Lori Ashby at 410-786-6322.) 2. Type of Information Collection Request: Reinstatement with change of a... provide coverage for carotid artery stenting (CAS) with embolic protection for patients at high risk for...

  7. Exploring the Role of Modality: L2-Heritage Learner Interactions in the Spanish Language Classroom

    Science.gov (United States)

    Bowles, Melissa A.

    2011-01-01

    In most post-secondary Spanish language programs in the U.S., heritage language (HL) learners and second-language (L2) learners are enrolled together, in the same courses (Ingold, Rivers, Tesser, & Ashby, 2002). Nevertheless, there is scant empirical research on what actually goes on in these classrooms and what the nature of learner-learner…

  8. Perfectionism, Depression, Loneliness, and Life Satisfaction: A Study of High School Students in Hong Kong

    Science.gov (United States)

    Wang, Kenneth T.; Yuen, Mantak; Slaney, Robert B.

    2009-01-01

    This study investigates the cross-cultural construct validity of perfectionism using the Chinese translation of the Almost Perfect Scale-Revised (APS-R; Slaney, Mobley, Trippi, Ashby, & Johnson, 1996) with 509 Chinese high school students from Hong Kong. The factor structure of the Chinese APS-R and correlations between the APS-R subscales and…

  9. Untitled

    Indian Academy of Sciences (India)

    Perry A J 1974.J. Mater. Sci. 9 1016. Petch NJ 1953 J. Iron Steel Inst. 17425. Petty G R 1974 Physical metallurgy of engineering materials (England: George Allen and Unwin. Limited) p. 103. Pickering FB 1978 Physical metallurgy and the design of steels (England: Appl. Sci. Publ., Barking). Raj R & Ashby M F 1971 Metall.

  10. abstract

    African Journals Online (AJOL)

    communication and institutions activities in removing constraints which impede the acceptance and continued usage .... With farmers' feedback, scientists cannot misinterpret a problem or attribute wrong causes to it. ..... Protection and Environmental Management, University of lbadan,. Ibadan. Ashby, J. (1990): Small-farmer ...

  11. A system-approach to the elastohydrodynamic lubrication point-contact problem

    Science.gov (United States)

    Lim, Sang Gyu; Brewe, David E.

    1991-01-01

    The classical EHL (elastohydrodynamic lubrication) point contact problem is solved using a new system-approach, similar to that introduced by Houpert and Hamrock for the line-contact problem. Introducing a body-fitted coordinate system, the troublesome free-boundary is transformed to a fixed domain. The Newton-Raphson method can then be used to determine the pressure distribution and the cavitation boundary subject to the Reynolds boundary condition. This method provides an efficient and rigorous way of solving the EHL point contact problem with the aid of a supercomputer and a promising method to deal with the transient EHL point contact problem. A typical pressure distribution and film thickness profile are presented and the minimum film thicknesses are compared with the solution of Hamrock and Dowson. The details of the cavitation boundaries for various operating parameters are discussed.

  12. Sintering diagrams of UO2

    International Nuclear Information System (INIS)

    Mohan, A.; Soni, N.C.; Moorthy, V.K.

    1979-01-01

    Ashby's method (see Acta Met., vol. 22, p. 275, 1974) of constructing sintering diagrams has been modified to obtain contribution diagrams directly from the computer. The interplay of sintering variables and mechanisms are studied and the factors that affect the participation of mechanisms in UO 2 are determined. By studying the physical properties, it emerges that the order of inaccuracies is small in most cases and do not affect the diagrams. On the other hand, even a 10% error in activation energies, which is quite plausible, would make a significant difference to the diagram. The main criticism of Ashby's approach is that the numerous properties and equations used, communicate their inaccuracies to the diagrams and make them unreliable. The present study has considerably reduced the number of factors that need to be refined to make the sintering diagrams more meaningful. (Auth.)

  13. Models, Analysis, and Recommendations Pertaining to the Retention of Naval Special Warfare s Mid-Level Officers

    Science.gov (United States)

    2013-12-01

    I would like to thank Sarah Ashby, an amazing human being and friend; you spent countless hours researching information that was absolutely critical...The Analytic Hierarch/Network Process,” in Rev. R. Acad. Cien. Serie A. Mat (RACSAM), submitted by Francisco Javier Giron (Real Academia de Ciencias ...Academia de Ciencias : Spain. Scott, Nathan. Naval Special Warfare Officer Retention Survey. Monterey, CA: NPS Press, September 2013. Whittenberger

  14. Maintenance Enterprise Resource Planning: Information Value Among Supply Chain Elements

    Science.gov (United States)

    2014-12-01

    3879. doi:10.1080/00207543.2012.752587 Ashby, W. R. (1947). Principles of the self-organizing dynamic system. The Journal of General Psychology , 37...Teaching of Psychology , 8(1), 35– 38. doi:10.1207/s15328023top0801_10 Bertalanffy, L. Von. (1969). General system theory: Foundations, development...Bertalanffy’s “general system theory: Foundations, development, applications.” Gestalt Theory, 26(1), 44–57. Halldorsson, A., Kotzab, H., Mikkola, J. H

  15. Primer registro de “la mosca negra de los cítricos” Aleurocanthus woglumi (Hemiptera: Aleyrodidae en la Argentina

    Directory of Open Access Journals (Sweden)

    Silvia N. LÓPEZ

    2011-01-01

    Full Text Available Aleurocanthus woglumi Ashby es una especie polífaga que ataca principalmente cultivos de Citrus spp. El objetivo de este trabajo es dar a conocer la primera detección de A. woglumi en Argentina. Los especímenes estudiados fueron recolectados en cultivos de pomelo en Tres Lagunas, departamento de Pilagá, Formosa, en febrero de 2011.

  16. Etude des propriétés acoustiques et mécaniques d'un matériau métallique poreux modèle à base de sphères creuses de nickel

    OpenAIRE

    Gasser, Stéphane

    2003-01-01

    Président du jury : Michael F. Ashby Rapporteurs : Andreas Mortensen, Yves Aurégan Autres membres : Jean-Louis Auriault, Hervé Batard; This thesis has focused on a model metallic cellular material, in order to provide a candidate material and design tools of an acoustic liner for turboengine exhausters. The acoustic absorption problem has lead to discuss an analytic, descriptive modelling that was available in the literature, and then to introduce a numerical technique allowing to predict the...

  17. Model Uncertainty and Test of a Segmented Mirror Telescope

    Science.gov (United States)

    2014-03-01

    the eigenanalysis of large systems. A NASTRAN compatible model was provided by NPS. The model consists of elements representing all the... NASTRAN compatible model was provided by NPS. First attempts at model validation are presented in Ref. 10. The model consists of the full telescope...Superelements in MSC Nastran , a Super Tool for Segmented Optics. MSC.Software VPD Conference. Huntington Beach, CA. Gibson, L., & Ashby, M. (1988). Cellular

  18. Ammonia in simulated Hanford double-shell tank wastes: Solubility and effects on surface tension

    International Nuclear Information System (INIS)

    Norton, J.D.; Pederson, L.R.

    1994-09-01

    Radioactive and wastes left from defense materials production activities are temporarily stored in large underground tanks at the Hanford Site in south central Washington State (Tank Waste Science Panel 1991). Some of these wastes are in the form of a thick slurry (''double-shell slurry'') containing sodium nitrate, sodium nitrite, sodium aluminate, sodium hydroxide, sodium carbonate, organic complexants and buffering agents, complexant fragments and other minor components (Herting et al. 1992a; Herting et al. 1992b; Campbell et al. 1994). As a result of thermal and radiolytic processes, a number of gases are known to be produced by some of these stored wastes, including ammonia, nitrous oxide, nitrogen, hydrogen, and methane (Babad et al. 1991; Ashby et al. 1992; Meisel et al. 1993; Ashby et al. 1993; Ashby et al. 1994; Bryan et al. 1993; US Department of Energy 1994). Before the emplacement of a mixer pump, these gases were retained in and periodically released from Tank 241-SY-101, a double-shell tank at the Hanford Site (Babad et al. 1992; US Department of Energy 1994). Gases are believed to be retained primarily in the form of bubbles attached to solid particles (Bryan, Pederson, and Scheele 1992), with very little actually dissolved in the liquid. Ammonia is an exception. The relation between the concentration of aqueous ammonia in such concentrated, caustic mixtures and the ammonia partial pressure is not well known, however

  19. Induction of resistance to bacterial leaf-blight (Xanthomonas oryzae) disease in the high-yielding variety, Vijaya (IR8 x T90)

    International Nuclear Information System (INIS)

    Padmanabhan, S.Y.; Kaur, S.; Rao, M.

    1977-01-01

    The high-yielding variety, Vijaya (IR8 x T90) susceptible to bacterial leaf-blight (Xanthomonas oryzae, Uyeda and Ishiyama, Dowson) was taken up for induction of resistance to bacterial leaf-blight disease through EMS treatments. The frequency distribution of bacterial leaf blight of Vijaya (untreated) was bimodal while the frequency curves of the EMS-treated population in M 2 was polymodal, showing the introduction of new peaks, thus indicating that a wider range of variability had been induced both towards resistance and susceptibility. The seeds of ''resistant'' (R), ''moderately resistant'' (MR) and ''susceptible'' (S) selections were carried forward up to the M 6 generation. The frequency curve of bacterial leaf-blight reaction in each generation (M 3 - M 6 ) was polymodal or had a normal distribution, thus indicating that the bacterial leaf-blight reaction of the variety, Vijaya, was probably controlled by a polygenic system. Resistant plants had a very low yield potential whereas the yield range of some MR selections was the same as that of the untreated parent, and in some S selections the yield was higher than that of the parent. (author)

  20. Some basic properties of environmentally adapted oils

    Energy Technology Data Exchange (ETDEWEB)

    Hoeglund, E. [Div. of Machine Elements, Luleaa University of Technology (Sweden)

    1998-11-01

    Environmental concern has led to a development of lubricants that are less harmful to the environmental than traditional mineral based oils. Biodegradability and non-toxicity are desired properties together with a competitive price and if possible they should also be derived from renewable raw materials. In order to have a major breakthrough for the new, environmentally adapted lubricating oils they must perform well in mechanical and hydraulic systems. They must reduce wear, increase efficiency and reduce maintenance costs equally well, or preferably better than mineral based oils. This paper presents primary results from an investigation where four environmentally adapted oils (rape seed, pine tree, diester and TMP-ester) are compared to a conventional naphthenic mineral oil. Viscosity and viscosity-pressure coefficients, limiting shear stress, friction properties and film forming ability have been evaluated under elastohydrodynamic conditions. It was found that the mineral oil had the highest values of pressure-viscosity coefficient, limiting shear stress and coefficient of friction. Rape seed oil had the second highest pressure-viscosity coefficient but the lowest limiting shear stress and coefficient of friction. Pine tree oil, diester and TMP-ester formed an intermediate group with rather similar results. The Hamrock-Dowson equation for central film thickness was found to overestimate film thickness by about 10-20 per cent with the least discrepancy for the mineral oil. (orig.) 8 refs.

  1. Bio-tribology.

    Science.gov (United States)

    Dowson, Duncan

    2012-01-01

    It is now forty six years since the separate topics of friction, lubrication, wear and bearing design were integrated under the title 'Tribology' [Department of Education and Science, Lubrication (Tribology) Education and Research. A Report on the Present Position and Industry's Needs, HMSO, London, 1966]. Significant developments have been reported in many established and new aspects of tribology during this period. The subject has contributed to improved performance of much familiar equipment, such as reciprocating engines, where there have been vast improvements in engine reliability and efficiency. Nano-tribology has been central to remarkable advances in information processing and digital equipment. Shortly after widespread introduction of the term tribology, integration with biology and medicine prompted rapid and extensive interest in the fascinating sub-field now known as Bio-tribology [D. Dowson and V. Wright, Bio-tribology, in The Rheology of Lubricants, ed. T. C. Davenport, Applied Science Publishers, Barking, 1973, pp. 81-88]. An outline will be given of some of the developments in the latter field.

  2. Diverse Antibacterial activity of Pectobacterium carotovorum subsp.carotovorum isolated in Korea.

    Science.gov (United States)

    Roh, Eunjung; Lee, Seungdon; Lee, Yonghoon; Ra, Dongsu; Choi, Jaehyuk; Moon, Eunpyo; Heu, Sunggi

    2009-01-01

    Fifty-four Pectobacterium carotovorum subsp. carotovorum strains isolated in Korea were characterized by a spectrum of antibacterial activities against 7 indicator strains chosen to represent various regions and host plants. All P. carotovorum subsp. carotovorum isolates tested could be grouped into 4 classes depending on the pattern of antibacterial substance production. All tested strains had DNA fragment(s) homologous to the genes encoding carotovoricin and 21 of them had genes homologous to DNA invertase. Sixteen strains had genes homologous to the genes encoding carocin S1. Several isolates produced antibacterial substances active against strains in Brenneria, Pantoea, and Pectobacterium genera that belonged formerly to the genus Erwinia. Strains in Pseudomonas or Xanthomonas sp. were not sensitive to the antibacterial substances produced by P. carotovorum subsp. carotovorum, except for X. albilineans that was sensitive to antibacterial substances produced by most strains in P. carotovorum subsp. carotovorum and P. betavasculorum KACC10056. These results demonstrated the diverse patterns of antibacterial substance production and the possibility of the existence of new antibacterial substance(s) produced by P. carotovorum subsp. carotovorum isolated in Korea.

  3. Mutabilidade e habitação de interesse social: precedentes e certificação

    OpenAIRE

    Marcio da Costa Pereira

    2012-01-01

    A pesquisa aborda o conceito de mutabilidade com vistas a contribuir para o processo e a análise de projetos de Habitação de Interesse Social e seu desempenho ambiental. A abordagem conceitual de mutabilidade e autonomia é desenvolvida sob a ótica da cibernética (ASHBY, 1957), cuja aplicação em projeto tem como referências o conceito de interdependências (YEANG, 1995) e o conceito de suportes ou support structure (HABRAKEN, 1999). A análise do Conjunto Habitacional Zezinho Magalhães Prado é i...

  4. Reply to ‘Comment on Relativistic theory of the falling cube gravimeter’

    Science.gov (United States)

    Ashby, Neil

    2018-04-01

    The comment (Křen and Pálinkás 2017 Metrologia 55 314-5) claims that the paper Relativistic theory of the falling cube gravimeter (Ashby 2017 Metrologia 55 1-10) is incorrect. The authors of this comment assert that optical paths in the two interferometer arms of an absolute gravimeter shift only the absolute phase difference between interferometer arms and therefore cannot affect the measured value of g, and that the only needed relativistic correction is the commonly applied ‘speed of light correction’. Neither claim stands up to scrutiny. Work of the U.S. government, not subject to copyright.

  5. Op. No A4495 Columbia, STS-93 Chandra - Breakfast, Suiting, and Walkout

    Science.gov (United States)

    1999-01-01

    The primary objective of the STS-93 mission was to deploy the Advanced X-ray Astrophysical Facility, which had been renamed the Chandra X-ray Observatory in honor of the late Indian-American Nobel Laureate Subrahmanyan Chandrasekhar. The mission was launched at 12:31 on July 23, 1999 onboard the space shuttle Columbia. The mission was led by Commander Eileen Collins. The crew was Pilot Jeff Ashby and Mission Specialists Cady Coleman, Steve Hawley and Michel Tognini from the Centre National d'Etudes Spatiales (CNES). This videotape shows the astronauts after breakfast getting into spacesuits, walking out to board the bus, and boarding the bus prior to launch.

  6. Sancho Panza es aqueste [Grabación sonora

    OpenAIRE

    La Grande Chapelle (Grupo musical); Recasens, Àngel; Lambea, Mariano; Josa, Lola; Recasens, Albert

    2005-01-01

    Duración: 3:30. Selección y adaptación (texto y música), Lola Josa (Universidad de Barcelona) y Mariano Lambea (Consejo Superior de Investigaciones Científicas). Intérpretes: La Grande Chapelle ; Cécile Kempenaers, soprano ; Kate Ashby, soprano ; Sytse Buwalda, contratenor ; Hervé Lamy, tenor. Director: Àngel Recasens. Fuente: Cancionero Musical de la Casa de Medinaceli (s.XVI). Productor ejecutivo, asesor musicológico y editor: Albert Recasens. Textos en español, inglés, francés y alemán....

  7. Modelo holónico de la ingeniería del producto

    OpenAIRE

    Aguayo-González, Francisco; Lama-Ruiz, Juan Ramón; Marcos Bárcena, Mariano; Sánchez Carrilero, Manuel; Soltero Sánchez Víctor; Pérez Gutiérrez,José Ramón

    2004-01-01

    En el presente trabajo se formula un modelo holónico de la Ingeniería del Producto,soportado por las siguientes entidades holónicas: Estrategia de Producto, Producto, Proceso, Entorno de Diseño y Desarrollo. Dicho modelo se fundamenta desde los principios holónicos propuestos por Koestler y la teoría de la variedad de Ashby. Esta formulación permite dar soporte a: los requerimientos de empresa y producto extendido y virtual, así como al diseño colaborativo y distribuido inteligente. The...

  8. La holónica como marco paradigmático para el diseño de interfaces

    OpenAIRE

    Aguayo-González, Francisco; Lama-Ruiz, Juan Ramón; Marcos Bárcena, Mariano; Sánchez Carrilero, Manuel; Soltero Sánchez Víctor

    2004-01-01

    Inicialmente proponemos los principios que constituyen los sistemas holónicos y cómo estos satisfacen la ley de variedad requerida propuesta por Ashby, para su proyección en la formalización de la ingeniería de la usabilidad, así como para el diseño y desarrollo de interfaces holónicas que satisfagan los principios de autonomía, autoasertividad y cooperación, desde la identificación de su dominio de colaboración y el establecimiento de la competencias que ha de integrar en sus dominios ...

  9. Cybernetic brain sketches of another future

    CERN Document Server

    Pickering, Andrew

    2014-01-01

    Cybernetics is often thought of as a grim military or industrial science of control. But as Andrew Pickering reveals in this beguiling book, a much more lively and experimental strain of cybernetics can be traced from the 1940s to the present.The Cybernetic Brain explores a largely forgotten group of British thinkers, including Grey Walter, Ross Ashby, Gregory Bateson, R. D. Laing, Stafford Beer, and Gordon Pask, and their singular work in a dazzling array of fields. Psychiatry, engineering, management, politics, music, architecture, education, tantric yoga, the Beats, and the sixties counterc

  10. STS-93 crew speak to media after arrival at SLF for launch

    Science.gov (United States)

    1999-01-01

    After arrival at KSC's Shuttle Landing Facility, the STS-93 crew speak to the media about their mission. From left are Mission Specialists Michel Tognini of France, who is with the Centre National d'Etudes Spatiales (CNES), Steven A. Hawley (Ph.D.), and Catherine G. 'Cady' Coleman (Ph.D.), Pilot Jeffrey S. Ashby, and Commander Eileen M. Collins. Hawley has the most Shuttle flights, this being his fifth. Collins is making her third flight (the first as a commander), Coleman is making her second flight, and Ashby and Tognini are making their first flights. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes.

  11. Influence of using nanoobjects as filler on functionality-based energy use of nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Roes, A. L., E-mail: a.l.roes@uu.nl; Tabak, L. B.; Shen, L.; Nieuwlaar, E.; Patel, M. K. [Utrecht University, Copernicus Institute, Department of Science, Technology and Society (Netherlands)

    2010-08-15

    The goal of our study was to investigate the potential benefits of reinforcing polymer matrices with nanoobjects for structural applications by looking at both the mechanical properties and environmental impacts. For determining the mechanical properties, we applied the material indices defined by Ashby for stiffness and strength. For the calculation of environmental impacts, we applied the life cycle assessment methodology, focusing on non-renewable energy use (NREU). NREU has shown to be a good indicator also for other environmental impacts. We then divided the NREU by the appropriate Ashby index to obtain the 'functionality-based NREU'. We studied 23 different nanocomposites, based on thermoplastic and thermosetting polymer matrices and organophilic montmorillonite, silica, carbon nanotubes (single-walled and multiwalled) and calcium carbonate as filler. For 17 of these, we saw a decrease of the functionality-based NREU with increasing filler content. We draw the conclusion that the use of nanoobjects as filler can have benefits from both an environmental point of view and with respect to mechanical properties.

  12. Knowledge based system and decision making methodologies in materials selection for aircraft cabin metallic structures

    Science.gov (United States)

    Adhikari, Pashupati Raj

    Materials selection processes have been the most important aspects in product design and development. Knowledge-based system (KBS) and some of the methodologies used in the materials selection for the design of aircraft cabin metallic structures are discussed. Overall aircraft weight reduction means substantially less fuel consumption. Part of the solution to this problem is to find a way to reduce overall weight of metallic structures inside the cabin. Among various methodologies of materials selection using Multi Criterion Decision Making (MCDM) techniques, a few of them are demonstrated with examples and the results are compared with those obtained using Ashby's approach in materials selection. Pre-defined constraint values, mainly mechanical properties, are employed as relevant attributes in the process. Aluminum alloys with high strength-to-weight ratio have been second-to-none in most of the aircraft parts manufacturing. Magnesium alloys that are much lighter in weight as alternatives to the Al-alloys currently in use in the structures are tested using the methodologies and ranked results are compared. Each material attribute considered in the design are categorized as benefit and non-benefit attribute. Using Ashby's approach, material indices that are required to be maximized for an optimum performance are determined, and materials are ranked based on the average of consolidated indices ranking. Ranking results are compared for any disparity among the methodologies.

  13. Efecto de la época de plantación en la dinámica de la emergencia de caña semilla de alta calidad (termotratada y micropropagada de las variedades CP 65-357 y LCP 85-384 Effect of planting date on emergence dynamics of high quality CP 65-357 and LCP 85-384 seed cane (hot-water treated and micropropagated

    Directory of Open Access Journals (Sweden)

    Patricia A. Digonzelli

    2005-12-01

    Full Text Available Se evalúa el efecto de la época de plantación en la dinámica de la emergencia de caña semilla de alta calidad (micropropagada y termotratada de las variedades CP 65-357 y LCP 85-384, en condiciones de disponibilidad hídrica adecuada. La caña semilla micropropagada y termotratada (50ºC, 2 hs se plantó, con una densidad de 15 yemas/m, en tres épocas contrastantes: otoño, invierno y primavera. El material empleado estaba libre de escaldadura de la hoja (Xanthomonas albilineans y achaparramiento (Leifsonia xyli subsp. xyli. La época de plantación afectó todas las variables de la dinámica de la emergencia en las dos variedades y en ambos orígenes de la semilla. El origen afectó significativamente el inicio y la duración de la emergencia (t e y t50, pero no tuvo efecto en el porcentaje final ni en la tasa media de emergencia. La emergencia (% fue mayor en la plantación de octubre, que en las de mayo y agosto (59%, 35% y 45%, respectivamente. El te y el t50 fueron mayores en mayo que en agosto y octubre. La semilla micropropagada presentó, en general, valores de t e y t50 menores que la termotratada. La época de plantación fue el principal factor que afectó la dinámica de la emergencia de caña semilla de alta calidad de CP 65-357 y LCP 85-384. La variedad y el origen de la semilla afectaron significativamente, aunque en menor magnitud que la época de plantación, el inicio y la duración de la fase de emergencia.Planting date influence on emergence dynamics of high quality CP 65-357 and LCP 85-384 seed cane (hot-water treated and micropropagated, without humidity constraints, was evaluated. Material used was free from leaf scald disease (Xanthomonas albilineans and ratoon stunting disease (Leifsonia xyli subsp. xyli. Seed cane, micropropagated and hot-water treated (50ºC, 2 hours, was planted with a 15 buds/m density in three contrasting dates: autumn, winter and spring. The material was irrigated during the trial. Planting

  14. Diagnóstico molecular de enfermedades sistémicas de la caña de azúcar en la Argentina: ajuste metodológico y aplicaciones Molecular diagnosis of sistemic sugarcane diseases in Argentina: methodology adjustment and applications

    Directory of Open Access Journals (Sweden)

    María P. Filippone

    Full Text Available Las enfermedades sistémicas representan uno de los principales factores que afectan la producción de caña de azúcar. El conocimiento del estado fitosanitario del cultivo y la identificación correcta de los fitopatógenos son claves para reducir las pérdidas por enfermedades. En este sentido, es fundamental contar con técnicas de diagnóstico sensibles, rápidas y fáciles de ejecutar, para realizar un diagnóstico preciso y precoz. A partir del año 2005, en la Estación Exper imental Agroindustrial Obispo Colombres se incorporó el diagnóstico molecular basado en la reacción en cadena de la polimerasa, para la detección específica de cuatro enfermedades sistémicas de la caña de azúcar: raquitismo de la caña soca (Leifsonia xyli sp. xyli, escaldadura de la hoja (Xanthomonas albilineans, mosaico de la caña de azúcar (Sugarcane mosaic virus, ScMV y síndrome de la hoja amarilla (Sugarcane yellow leaf virus, ScYLV. En este trabajo, se presenta la optimización metodológica del diagnóstico molecular y se compara su eficiencia con la de la técnica inmunoquímica ELISA. El método molecular mostró mayor sensibilidad para las enfermedades evaluadas, tanto bacterianas como virales. El establecimiento del diagnóstico molecular constituye un avance tecnológico de gran importancia para la industria azucarera regional, ya que no solo ayudará a disminuir la incidencia de dichas enfermedades, sino que también evitará el ingreso de otras nuevas al introducir germoplasma de caña de azúcar desde otras regiones.Systemic diseases represent one of the main factors affecting sugarcane production. The knowledge of crop sanitary conditions and the correct identification of phytopathogens are key factors to reduce losses caused by them. To diagnose diseases as early as possible is crucial, so techniques that are sensitive, fast, accurate and easy to use are essential. Since 2005, molecular diagnosis based on polymerase chain reaction has

  15. Dinámica de la brotación potencial de caña semilla micropropagada y termotratada de tres cultivares de caña de azúcar Potential germination dynamics of micropropagated and hot-water-treated seedcane of three sugarcane cultivars

    Directory of Open Access Journals (Sweden)

    Patricia A. Digonzelli

    2006-12-01

    Full Text Available Se comparó la dinámica de la brotación potencial (brotación en condiciones óptimas de humedad y temperatura de estacas uninodales de caña semilla saneada, obtenida por micropropagación y por termoterapia (inmersión en agua caliente 50ºC durante 2 h de tres cultivares (LCP 85-384, CP 65-357 y CP 48-103 y en tres edades (7, 10 y 12 meses. La semilla micropropagada e hidrotermotratada se encontraba libre de achaparramiento de la caña soca (Ratoon Stunting Disease, RSD (Leifsonia xyli subsp. xyli y escaldadura de la hoja (Xanthomonas albilineans. Las estacas se colocaron en una cámara de cría, en bandejas con arena lavada y esterilizada, a temperatura de 26 ± 2ºC, luz continua y control de humedad. El diseño experimental utilizado fue un factorial completamente aleatorizado (3x3x2, con dos repeticiones. Los factores fueron: edad (tres niveles, cultivar (tres niveles y origen de la semilla (dos niveles. Diariamente se contaron las yemas brotadas (clavo visible hasta la estabilización de la brotación. La dinámica de la brotación potencial se ajustó al modelo exponencial simple, función sigmoide simétrica, con R2 ≥ 0,97 y a partir del modelo se derivaron las variables deducidas: t50 y t90 (días al 50% y 90% de la emergencia máxima, porcentaje máximo de brotación, tasa media y tasa máxima de brotación potencial. La brotación en la semilla micropropagada presentó una mayor velocidad y una menor duración que en la termotratada. El porcentaje final varió entre el 80% y el 100%, en independencia del origen de la semilla.The potential germination dynamics (germination under optimal humidity and temperature conditions of healthy seedcane of three cultivars (LCP 85-384, CP 65-357 and CP 48-103 at three different ages (7, 10 and 12 months were compared, by studying one-joint billets of seedcane obtained through micropropagation and hot water treatment (inmersion into water heated at 50ºC, for 2 h. This micropropagated and hot

  16. Comparación de la calidad de semilla de caña de azúcar en el segundo corte según el método de saneamiento Assessment of first ratoon seedcane quality obtained through different methods

    Directory of Open Access Journals (Sweden)

    Patricia A. Digonzelli

    Full Text Available En Semilleros Registrados de caña azúcar de tres cultivares, provenientes de diferentes orígenes de saneamiento, se compararon los componentes de producción de caña semilla para la edad de soca 1 (segundo corte del semillero. La semilla estaba libre de RSD (Leifsonia xyli subsp. xyli y escaldadura de la hoja (Xanthomonas albilineans. El diseño experimental fue completamente aleatorizado, con cuatro repeticiones. Los tratamientos evaluados fueron: dos orígenes de la semilla, micropropagada e hidrotermotratada (50ºC, 2 h, y tres variedades (LCP 85-384, CP 65-357 y CP 48-103. Cada parcela experimental constaba de cinco surcos de 3 m y se evaluó la caña de los tres surcos centrales. En la cosecha del semillero, se contaron todos los tallos por parcela y se midió su altura hasta hoja +1. En una muestra de 36 tallos por parcela se determinó el peso, el diámetro en la parte media y el número de yemas por tallo. A partir de los datos obtenidos, se calculó el número de yemas por surco de 100 metros de longitud y la producción de caña por parcela. La caña semilla micropropagada presentó mayor altura y peso por tallo y una mayor producción de caña que la semilla termotratada. En cuanto al número de tallos, diámetro y número de yemas por tallo y por surco, no hubo diferencias significativas relacionadas al origen de la semilla. La variedad afectó significativamente a todos los componentes de la producción de caña semilla, a excepción de la altura de tallos, que solo dependió del origen de la simiente.Seedcane production components were assessed in first ratoon (cane from second cut from Registered Nurseries obtained through micropropagation and hot water treatment (50ºC, 2 h of LCP 85-384, CP 65-357 and CP 48-103 cultivars. Micropropagated and hot-water-treated seedcane was free from ratoon stunting disease (RSD (Leifsonia xyli subsp. xyli and leaf scald (Xanthomonas albilineans. A completely randomized factorial design (3x3x2

  17. Producción de caña semilla en Semilleros Registrados provenientes de micropropagación y de hidrotermoterapia de tres cultivares de caña de azúcar Seedcane production in Registered Nurseries obtained through micropropagation and hot water treatment of three sugarcane cultivars

    Directory of Open Access Journals (Sweden)

    Patricia A. Digonzelli

    2006-12-01

    Full Text Available Se evaluaron los componentes de la producción de caña semilla en Semilleros Registrados de caña de azúcar provenientes de micropropagación e hidrotermoterapia (50ºC, 2 h, en tres variedades (LCP 85-384, CP 65-357 y CP 48-103 y tres épocas de plantación (mayo, agosto y octubre. La semilla micropropagada y la hidrotermotratada estaban libres de achaparramiento de la caña soca (Leifsonia xyli subsp. xyli o RSD, por sus siglas en inglés, y escaldadura de la hoja (Xanthomonas albilineans. El diseño experimental fue un factorial completamente aleatorizado 3x3x2, con tres repeticiones. Los factores fueron: época de plantación (tres niveles, variedad (tres niveles y origen de la semilla (dos niveles. Cada parcela constaba de cinco surcos de 3 metros, evaluando los tres surcos centrales. En la cosecha del semillero se contaron todos los tallos por parcela y se midió su altura hasta hoja TVD. En una muestra de 45 tallos por parcela se determinaron el peso y número de yemas por tallo. A partir de los datos obtenidos se calculó el número de yemas por surco de 100 metros de longitud y por hectárea. El origen de la caña semilla (micropropagada o hidrotermotratada afectó el número de tallos y la altura y número de yemas por tallo, por surco y por hectárea. La época de plantación y la variedad afectaron los componentes de la producción de caña semilla. La micropropagada presentó una mayor población, altura y número de yemas por tallo, permitiendo aumentar entre el 8% y 23% el área que es posible plantar a partir de una hectárea de Semillero Registrado. La magnitud de las diferencias entre la caña semilla micropropagada y termotratada varió según cultivares y época de plantación.Seedcane yield components in sugarcane Registered Nurseries obtained through micropropagation and hot water treatment (50ºC, 2 h were evaluated, considering three varieties (LCP 85-384, CP 65-357 and CP 48-103 and three plantation dates (May, August

  18. Epicoccum nigrum P16, a sugarcane endophyte, produces antifungal compounds and induces root growth.

    Directory of Open Access Journals (Sweden)

    Léia Cecilia de Lima Fávaro

    Full Text Available BACKGROUND: Sugarcane is one of the most important crops in Brazil, mainly because of its use in biofuel production. Recent studies have sought to determine the role of sugarcane endophytic microbial diversity in microorganism-plant interactions, and their biotechnological potential. Epicoccum nigrum is an important sugarcane endophytic fungus that has been associated with the biological control of phytopathogens, and the production of secondary metabolites. In spite of several studies carried out to define the better conditions to use E. nigrum in different crops, little is known about the establishment of an endophytic interaction, and its potential effects on plant physiology. METHODOLOGY/PRINCIPAL FINDINGS: We report an approach based on inoculation followed by re-isolation, molecular monitoring, microscopic analysis, plant growth responses to fungal colonization, and antimicrobial activity tests to study the basic aspects of the E. nigrum endophytic interaction with sugarcane, and the effects of colonization on plant physiology. The results indicate that E. nigrum was capable of increasing the root system biomass and producing compounds that inhibit the in vitro growth of sugarcane pathogens Fusarium verticillioides, Colletotrichum falcatum, Ceratocystis paradoxa, and Xanthomomas albilineans. In addition, E. nigrum preferentially colonizes the sugarcane surface and, occasionally, the endophytic environment. CONCLUSIONS/SIGNIFICANCE: Our work demonstrates that E. nigrum has great potential for sugarcane crop application because it is capable of increasing the root system biomass and controlling pathogens. The study of the basic aspects of the interaction of E. nigrum with sugarcane demonstrated the facultative endophytism of E. nigrum and its preference for the phylloplane environment, which should be considered in future studies of biocontrol using this species. In addition, this work contributes to the knowledge of the interaction of this

  19. Communication of Semantic Properties

    DEFF Research Database (Denmark)

    Lenau, Torben Anker; Boelskifte, Per

    2004-01-01

    The selection of materials and planning for production play a key role for the design of physical products. Product function, appearance and expression are influenced by the chosen materials and how they are shaped. However these properties are not carried by the material itself......, but by the specific way that the materials are used in the product. Selection of materials is therefore often done by looking at similar products. The product as well as its constitutive materials possesses a number of technical properties like strength, stiffness and hardness. Furthermore the product possesses...... a distinct character. For the technical properties there exists a well developed and commonly accepted terminology that can be utilised at product search and material selection (Ashby 1996). This is not the case for the semantic properties which are important for the outcome reflecting the product design...

  20. Comment on ‘Relativistic theory of the falling retroreflector gravimeter’

    Science.gov (United States)

    Křen, Petr; Pálinkáš, Vojtech

    2018-04-01

    In the paper by Ashby (2018 Metrologia 55 1-10) the correction due to the time delay of light propagated through the prism retroreflector of absolute gravimeters is discussed. Accordingly, the correction of about  -6.8 µGal should be applied for a typical gravimeter such as the most precise FG5(X) gravimeter declaring standard uncertainty at the level of 2 µGal. In consequence, the present gravimetric results related to the Kibble balance or the global absolute gravity reference system should be significantly changed. However, such a change needs a deeper scientific consensus. In our comment, we would like to show that the proposed correction should not be applied since the author’s consideration is incorrect.

  1. The Effect of Grain Size and Strain on the Tensile Flow Stress of Aluminium at Room Temperature

    DEFF Research Database (Denmark)

    Hansen, Niels

    1977-01-01

    Tensile-stress-strain data over a strain range from 0.2 to 30% were obtained at room temperature for 99.999 and 99.5% aluminium as a function of grain size. The yield stress-grain size relationship can be expressed by a Petch-Hall relation with approximately the same slope for the two materials....... The flow stress-grain size relationship can adequately be expressed by a modified Petch-Hall relation; for 99.999% aluminium material the slope increases with strain through a maximum around 15–20%, whereas for 99.5% aluminium the slope decreases with the strain to zero at strains about 10%. The flow...... stress-grain size relationship was analyzed in terms of matrix strengthening and grain boundary strengthening according to the dislocation concept of Ashby. At intermediate strains this approach gives a good description of the effect of strain, grain size and purity on the flow stress....

  2. STS-93 Commander Collins suits up for launch

    Science.gov (United States)

    1999-01-01

    During the third launch preparations in the Operations and Checkout Building, STS-93 Commander Eileen M. Collins waves while having her launch and entry suit checked. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  3. STS-93 Commander Eileen Collins waves to her family

    Science.gov (United States)

    1999-01-01

    STS-93 Commander Eileen M. Collins waves to her family nearby, a last meeting before launch of mission STS-93 on July 20. Liftoff is scheduled for 12:36 a.m. EDT. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  4. STS-93 Mission Specialist Cady Coleman suits up for launch

    Science.gov (United States)

    1999-01-01

    For the third time, during final launch preparations in the Operations and Checkout Building, STS-93 Mission Specialist Catherine G. Coleman (Ph.D.) dons her launch and entry suit. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Coleman, and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  5. STS-93 M.S. Michel Tognini suits up before launch

    Science.gov (United States)

    1999-01-01

    For the third time, in the Operations and Checkout Building, STS- 93 Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), waves after donning his launch and entry suit during final launch preparations. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Tognini. Collins is the first woman to serve as commander of a shuttle mission.

  6. Liftoff of Space Shuttle Columbia on mission STS-93

    Science.gov (United States)

    1999-01-01

    The fiery launch of Space Shuttle Columbia lights up the night sky on its successful liftoff from Launch Pad 39-B on mission STS-93. Liftoff occurred at 12:31 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a Shuttle mission. The target landing date is July 27, 1999, at 11:20 p.m. EDT.

  7. STS-93 Commander Eileen Collins suits up for launch

    Science.gov (United States)

    1999-01-01

    For the third time, in the Operations and Checkout Building, STS- 93 Commander Eileen M. Collins tries on her helmet with her launch and entry suit. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  8. STS-93 Mission Specialist Hawley suits up for launch

    Science.gov (United States)

    1999-01-01

    For the third time, during final launch preparations in the Operations and Checkout Building, STS-93 Mission Specialist Steven A. Hawley (Ph.D.) waves after donning his launch and entry suit. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Hawley, Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  9. Diagnostics of a stationary MPD-type plasma jet with a HCN laser interferometer

    International Nuclear Information System (INIS)

    Graser, W.; Hoffmann, P.

    1975-01-01

    A HCN laser interferometer of the Ashby-Jephcott type operating at a wavelength of 337 μm was used to measure spatially resolved electron densities in a stationary MPD-type plasma jet with non-LTE behavior. Experiments were performed with and without superimposed magnetic fields up to 0.1 T at the exit of the plasma accelerator. Electron densities were obtained within the limits of 5times10 12 and 10 15 cm -3 with an accuracy better than 10%. Within the axially symmetric expanding plasma of about 15-cm average diameter and 50-cm length the radial resolving power came to less than 1 cm. So this technique has proved to be suitable to fill a gap in the diagnostics of stationary magnetized plasmas in the mean range of electron densities. (auth)

  10. Characterization of 316L Steel Cellular Dodecahedron Structures Produced by Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Konda Gokuldoss Prashanth

    2016-10-01

    Full Text Available The compression behavior of different 316L steel cellular dodecahedron structures with different density values were studied. The 316L steel structures produced using the selective laser melting process has four different geometries: single unit cells with and without the addition of base plates beneath and on top, and sandwich structures with multiple unit cells with different unit cell sizes. The relation between the relative compressive strength and the relative density was compared using different Gibson-Ashby models and with other published reports. The different aspects of the deformation and the mechanical properties were evaluated and the deformation at distinct loading levels was recorded. Finite element method (FEM simulations were carried out with the defined structures and the mechanical testing results were compared. The calculated theory, simulation estimation, and the observed experimental results are in good agreement.

  11. Creep behaviour of porous metal supports for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Boccaccini, Dino; Frandsen, Henrik Lund; Sudireddy, Bhaskar Reddy

    2014-01-01

    The creep behaviour of porous ironechromium alloy used as solid oxide fuel cell support was investigated, and the creep parameters are compared with those of dense strips of similar composition under different testing conditions. The creep parameters were determined using a thermo-mechanical anal......The creep behaviour of porous ironechromium alloy used as solid oxide fuel cell support was investigated, and the creep parameters are compared with those of dense strips of similar composition under different testing conditions. The creep parameters were determined using a thermo......-mechanical analyser with applied stresses in the range from 1 to 15 MPa and temperatures between 650 and 800 _C. The GibsoneAshby and Mueller models developed for uniaxial creep of open-cell foams were used to analyse the results. The influence of scale formation on creep behaviour was assessed by comparing the creep...

  12. Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils.

    Science.gov (United States)

    Jiménez, Diego Javier; Montaña, José Salvador; Martínez, María Mercedes

    2011-07-01

    With the purpose of isolating and characterizing free nitrogen fixing bacteria (FNFB) of the genus Azotobacter, soil samples were collected randomly from different vegetable organic cultures with neutral pH in different zones of Boyacá-Colombia. Isolations were done in selective free nitrogen Ashby-Sucrose agar obtaining a recovery of 40%. Twenty four isolates were evaluated for colony and cellular morphology, pigment production and metabolic activities. Molecular characterization was carried out using amplified ribosomal DNA restriction analysis (ARDRA). After digestion of 16S rDNA Y1-Y3 PCR products (1487pb) with AluI, HpaII and RsaI endonucleases, a polymorphism of 16% was obtained. Cluster analysis showed three main groups based on DNA fingerprints. Comparison between ribotypes generated by isolates and in silico restriction of 16S rDNA partial sequences with same restriction enzymes was done with Gen Workbench v.2.2.4 software. Nevertheless, Y1-Y2 PCR products were analysed using BLASTn. Isolate C5T from tomato (Lycopersicon esculentum) grown soils presented the same in silico restriction patterns with A. chroococcum (AY353708) and 99% of similarity with the same sequence. Isolate C5CO from cauliflower (Brassica oleracea var. botrytis) grown soils showed black pigmentation in Ashby-Benzoate agar and high similarity (91%) with A. nigricans (AB175651) sequence. In this work we demonstrated the utility of molecular techniques and bioinformatics tools as a support to conventional techniques in characterization of the genus Azotobacter from vegetable-grown soils.

  13. Characterization of free nitrogen fixing bacteria of the genus Azotobacter in organic vegetable-grown Colombian soils

    Directory of Open Access Journals (Sweden)

    Diego Javier Jiménez

    2011-09-01

    Full Text Available With the purpose of isolating and characterizing free nitrogen fixing bacteria (FNFB of the genus Azotobacter, soil samples were collected randomly from different vegetable organic cultures with neutral pH in different zones of Boyacá-Colombia. Isolations were done in selective free nitrogen Ashby-Sucrose agar obtaining a recovery of 40%. Twenty four isolates were evaluated for colony and cellular morphology, pigment production and metabolic activities. Molecular characterization was carried out using amplified ribosomal DNA restriction analysis (ARDRA. After digestion of 16S rDNA Y1-Y3 PCR products (1487pb with AluI, HpaII and RsaI endonucleases, a polymorphism of 16% was obtained. Cluster analysis showed three main groups based on DNA fingerprints. Comparison between ribotypes generated by isolates and in silico restriction of 16S rDNA partial sequences with same restriction enzymes was done with Gen Workbench v.2.2.4 software. Nevertheless, Y1-Y2 PCR products were analysed using BLASTn. Isolate C5T from tomato (Lycopersicon esculentum grown soils presented the same in silico restriction patterns with A. chroococcum (AY353708 and 99% of similarity with the same sequence. Isolate C5CO from cauliflower (Brassica oleracea var. botrytis grown soils showed black pigmentation in Ashby-Benzoate agar and high similarity (91% with A. nigricans (AB175651 sequence. In this work we demonstrated the utility of molecular techniques and bioinformatics tools as a support to conventional techniques in characterization of the genus Azotobacter from vegetable-grown soils.

  14. Caracterización de cepas nativas de Azotobacter spp. y su efecto en el desarrollo de Lycopersicon esculentum Mill. “tomate” en Lambayeque

    Directory of Open Access Journals (Sweden)

    Cynthia Escobar

    2011-01-01

    Full Text Available El objetivo de la presente investigación fue caracterizar y determinar el efecto de cepas nativas de Azotobacter spp. en el desarrollo vegetativo de Lycopersicon esculentum Mill. “tomate”, como una alternativa al uso indiscriminado de fertilizantes químicos. Se tomaron muestras de raíces y suelo rizosférico de hortalizas con las que se realizaron diluciones (10-4 en caldo Ashby-Sacarosa y se incubaron a 30 ºC hasta observar un color amarillo, turbidez y película superficial. El género Azotobacter se identificó en agar mineral sin nitrógeno y Ashby-Benzoato, obteniéndose 96 cepas con una producción de 7.10 a 57.99 mgL-1 de ácido indolacético, 0.13 a 1.64 mgL-1 de nitrógeno fijado como amonio y hasta 1.61 % de eficiencia en la solubilización de roca fosfórica de Bayóvar. Se obtuvo una suspensión celular (108 de cada una de las cuatro cepas con los mayores valores y se inocularon independientemente y en consorcio, así como una combinación con 50 % de urea-100 % de roca fosfórica, en la rizósfera de tomate cv. Río Grande, en un diseño experimental completamente aleatorio. Todas las cepas nativas incrementaron la altura, volumen radicular, materia seca total, parte aérea y radicular frente al testigo absoluto.

  15. Enzymatic characterization and gene identification of aconitate isomerase, an enzyme involved in assimilation of trans-aconitic acid, from Pseudomonas sp. WU-0701.

    Science.gov (United States)

    Yuhara, Kahori; Yonehara, Hiromi; Hattori, Takasumi; Kobayashi, Keiichi; Kirimura, Kohtaro

    2015-11-01

    trans-Aconitic acid is an unsaturated organic acid that is present in some plants such as soybean and wheat; however, it remains unclear how trans-aconitic acid is degraded and/or assimilated by living cells in nature. From soil, we isolated Pseudomonas sp. WU-0701 assimilating trans-aconitic acid as a sole carbon source. In the cell-free extract of Pseudomonas sp. WU-0701, aconitate isomerase (AI; EC 5.3.3.7) activity was detected. Therefore, it seems likely that strain Pseudomonas sp. WU-0701 converts trans-aconitic acid to cis-aconitic acid with AI, and assimilates this via the tricarboxylic acid cycle. For the characterization of AI from Pseudomonas sp. WU-0701, we performed purification, determination of enzymatic properties and gene identification of AI. The molecular mass of AI purified from cell-free extract was estimated to be ~ 25 kDa by both SDS/PAGE and gel filtration analyses, indicating that AI is a monomeric enzyme. The optimal pH and temperature of purified AI for the reaction were 6.0 °C and 37 °C, respectively. The gene ais encoding AI was cloned on the basis of the N-terminal amino acid sequence of the protein, and Southern blot analysis revealed that only one copy of ais is located on the bacterial genome. The gene ais contains an ORF of 786 bp, encoding a polypeptide of 262 amino acids, including the N-terminal 22 amino acids as a putative periplasm-targeting signal peptide. It is noteworthy that the amino acid sequence of AI shows 90% and 74% identity with molybdenum ABC transporter substrate-binding proteins of Pseudomonas psychrotolerans and Xanthomonas albilineans, respectively. This is the first report on purification to homogeneity, characterization and gene identification of AI. The nucleotide sequence of ais described in this article is available in the DDBJ/EMBL/GenBank nucleotide sequence databases under the Accession No. LC010980. © 2015 FEBS.

  16. Comportamiento productivo y fitosanitario de la nueva variedad de caña de azúcar (Saccharum spp. TUC 95-37 en Tucumán, R. Argentina Productivity and disease tolerance of TUC 95-37, a new sugarcane (Saccharum spp. variety in Tucumán, Argentina

    Directory of Open Access Journals (Sweden)

    Ernesto R. Chavanne

    2012-06-01

    Full Text Available En este trabajo se presenta el comportamiento productivo y fitosanitario del nuevo cultivar de caña de azúcar (Saccharum spp. TUC 95-37, obtenido y seleccionado por el Programa de Mejoramiento Genético de la Caña de Azúcar de la Estación Experimental Agroindustrial Obispo Colombres (Tucumán, R. Argentina. La información que se presenta proviene de 24 cosechas realizadas en ensayos con 18 genotipos, implantados de acuerdo a un diseño experimental de bloques completamente aleatorizados con tres repeticiones. Los ensayos se replicaron en seis localidades de Tucumán y fueron evaluados en cuatro edades de corte (caña planta, soca 1, soca 2 y soca 3 entre los años 2002 y 2005. Las variables toneladas de caña/ha y de azúcar/ha y rendimiento fabril porciento se evaluaron en mayo. Para cada variable, edad y localidad se realizaron análisis de la varianza y pruebas de comparación de medias. También se aplicó la metodología de GGE biplot como herramienta gráfica, para identificar genotipos superiores y estables frente a distintos ambientes de expresión. Se evaluó además el comportamiento fitosanitario de TUC 95-37. Los resultados indicaron que la nueva variedad evidenció un comportamiento productivo similar al de LCP 85-384 en la mayoría de las edades de corte y localidades evaluadas. En caña planta, el nuevo cultivar fue el genotipo más productivo, presentando además una amplia adaptación a diferentes ambientes. En soca 1 y 2, TUC 95-37 resultó segunda en orden de mérito, siendo estable en las diferentes localidades. En soca 3, la nueva variedad evidenció una menor estabilidad frente al ambiente. Con respecto al comportamiento fitosanitario, TUC 95-37 se comportó como moderadasmente resistente a roya marrón (Puccinia melanocephala, a escaldadura de la hoja (Xanthomonas albilineans y a carbón (Sporisorium scitamineum. Se mostró moderadamente susceptible al mosaico (Sugarcane mosaic virus y a estría roja (Acidovorax

  17. Resiliencia, tamaño de grano y microestructura generada en la ZAC de los aceros HSLA 450 EMZ soldados bajo un proceso SMAW

    Directory of Open Access Journals (Sweden)

    González, R.

    2001-12-01

    Full Text Available In this paper several features of the HAZ between the weld metal and the parent metal, after the heat cycle produced by a SMAW process in 450 N/mm2 HSLA steels are analysed, taking into consideration the temperatures reached in the HAZ as from Rosenthal's equation. The aspects under examination are: grain morphology by means of micrographs obtained with the Scannig Electron Microscopy to check the bands that control the grain size due to the microalloyings of the designed steel, taking into account the temperatures reached and the cooling rate in each of the HAZ regions; fracture toughness, checked by means of CTOD testing; hardness grain size determined by the Ashby and Esterling procedure[1] and based on the values obtained with the Heyn method[2] , ratio between stable growth and heat input; CTOD values which are found to be satisfactory under the welding conditions with a heat input of 1.6 Kj/mm.

    Tras el ciclo térmico producido por un proceso de soldadura manual con electrodo revestido (SMAW, en los aceros HSLA de 450 N/ mm2 y, considerando las temperaturas alcanzadas en la ZAC según la ecuación de Rosenthal, se analizan los siguientes aspectos en esta zona (ZAC, entre el metal de soldadura y el metal base: la morfología del grano mediante micrografías obtenidas en el microscopio electrónico de barrido, comprobando las barreras que pinzan el grano debido a los microaleantes de este acero de diseño, teniendo en cuenta las temperaturas alcanzadas y la velocidad de enfriamiento en cada una de las regiones de la ZAC; la tenacidad a la fractura mediante los ensayos de CTOD; la dureza; el tamaño de grano, mediante el procedimiento de Ashby y Esterling[1] y basado en los valores obtenidos por el método de Heyn[2]; la proporcionalidad entre el crecimiento estable y la energía calorífica aportada; los valores de CTOD, satisfactorios en las condiciones de soldeo con

  18. Perfeccionismo positivo / negativo y calidad de vida percibida en estudiantes de Psicología, Medicina e Ingeniería de la Ciudad de Buenos Aires Positive / negative perfectionism and perceived quality of life in Psychology, Medicine and Engineering students of the city of Buenos Aires

    Directory of Open Access Journals (Sweden)

    Fernán Guido Arana

    2010-12-01

    Full Text Available El objetivo del presente estudio es dar cuenta de la relación entre el perfeccionismo en sus tres dimensiones (Altos Estándares -AE-, Orden -O- y Discrepancia-D- y la calidad de vida percibida (CV en tres muestras de estudiantes universitarios de las carreras de Psicología, Medicina e Ingeniería de la Ciudad de Buenos Aires. La muestra estuvo conformada por 476 estudiantes que completaron los siguientes instrumentos: cuestionario sociodemográfico, la almost Perfect Scale-revised (APS-R, Slaney, Rice, Mobley, Trippi, & Ashby, 2001; adaptación: Arana, Keegan, & Rutsztein, 2009 y el Inventario de Calidad de Vida Percibida (ICV, Mikulic, 2006. Los resultados sugieren una asociación signiicativa para un aspecto del perfeccionismo positivo (O y una alta CV percibida, y para el perfeccionismo negativo (D en relación a una baja CV percibida. Diferencias halladas en las diversas carreras para estas dimensiones indican la necesidad de atender a las variables contextuales especíicas para el análisis de este constructo.The aim of this study is to account for the relationship between perfectionism in its three dimensions (High Standards -HS-, Order -O-, and Discrepancy -D- and the perceived quality of life (QL in three samples of university students of Psychology, Medicine and Engineering of the City of Buenos Aires. The sample consisted of 476 students who completed the following in struments: Socio-demographic questionnaire, the Almost Perfect Scale-revised (APS-R, Slaney, Rice, Mobley, Trippi, & Ashby, 2001; adaptation: Arana, Keegan, & Rutsztein, 2009 and the Inventario de Calidad de Vida Percibida (ICV, Mikulic, 2006. Results suggest a signiicant association for one aspect of positive perfectionism (O and a perceived high QL, and for negative perfectionism (D and a perceived low QL. Differences found for these dimensions in the students of each career indicate the need to pay attention to specific contextual variables for the analysis of this

  19. Conductas y actitudes alimentarias, imagen corporal y perfeccionismo en estudiantes universitarias mujeres Eating behaviors and attitudes, body image and perfectionism in female college students

    Directory of Open Access Journals (Sweden)

    Guido Salvador Cruz

    2011-12-01

    Full Text Available Objetivo: comparar estudiantes universitarias mujeres con y sin riesgo de trastorno alimentario, en función de características asociadas a dichas patologías. Muestra: 83 mujeres de 19 a 31 años, estudiantes de una universidad pública de la Ciudad Autónoma de Buenos Aires. Procedimiento: las participantes completaron un Cuestionario de datos, Contour Drawing Rating Scale (Thompson & Gray, 1995, Eating Disorder Inventory-2 (Garner, 1991; adaptación Rutsztein et al., 2006 y la Almost Perfect Scale Revised (Slaney, Rice, Mobley, Trippi & Ashby, 2001; adaptación Arana, Keegan & Rutsztein, 2009. Resultados: las mujeres con riesgo de trastorno alimentario presentan mayor porcentaje de insatisfacción con la imagen corporal y vómitos autoinducidos, además de puntajes superiores en la mayoría de las subescalas del EDI-2 y en la subescala Discrepancia de la APS-R. Conclusiones: las mujeres con riesgo de trastorno alimentario presentan un mayor nivel de perfeccionismo desadaptativo. Estos hallazgos son relevantes para el desarrollo de tratamientos para sintomatología específica de trastorno alimentario.Objective: to compare female university students with and without risk of eating disorders, based on characteristics associated with these disorders. Sample: 83 women aged 19 to 31 years old, students from a public university in the City of Buenos Aires. Procedure: Participants completed a Data questionnaire, Contour Drawing Rating Scale (Thompson & Gray, 1995, Eating Disorder Inventory-2 (Garner, 1991; adaptation Rutsztein et al., 2006 and the Almost Perfect Scale-Revised (Slaney, Rice, Mobley, Trippi & Ashby, 2001; adaptation Arana, Keegan & Rutsztein, 2009. Results: Women presenting risk of eating disorders have a higher percentage of body image dissatisfaction and self-induced vomiting, as well as higher scores in most of the subscales of the EDI-2 and the Discrepancy subscale of the APS-R. Conclusions: Women presenting risk of eating

  20. Homeostatic Agent for General Environment

    Science.gov (United States)

    Yoshida, Naoto

    2018-03-01

    One of the essential aspect in biological agents is dynamic stability. This aspect, called homeostasis, is widely discussed in ethology, neuroscience and during the early stages of artificial intelligence. Ashby's homeostats are general-purpose learning machines for stabilizing essential variables of the agent in the face of general environments. However, despite their generality, the original homeostats couldn't be scaled because they searched their parameters randomly. In this paper, first we re-define the objective of homeostats as the maximization of a multi-step survival probability from the view point of sequential decision theory and probabilistic theory. Then we show that this optimization problem can be treated by using reinforcement learning algorithms with special agent architectures and theoretically-derived intrinsic reward functions. Finally we empirically demonstrate that agents with our architecture automatically learn to survive in a given environment, including environments with visual stimuli. Our survival agents can learn to eat food, avoid poison and stabilize essential variables through theoretically-derived single intrinsic reward formulations.

  1. Archaeologies of Hair: an introduction

    Directory of Open Access Journals (Sweden)

    Steven P. Ashby

    2016-11-01

    Full Text Available This collection of short articles represents an original attempt to bring together scholarship that is usually divided along lines of specialism in time, place, method, or discipline. The shared focus of its contributions is on hair: more than an infrequently preserved element of human remains, but a widespread (and arguably cross-cultural symbol of power, of fertility, of identity and the self. Moreover, its care and treatment using various forms of material culture, and its artistic representation in diverse media, offer a unique opportunity to examine the interface between the body and material culture. Where exceptional taphonomic conditions facilitate the preservation of hair and associated organic material, the result is some of the richest assemblages of human remains and associated material culture in the archaeological record (e.g. Wilson et al. 2007; Fletcher 1998. In contrast, 'everyday' objects associated with haircare are among the most taphonomically robust, frequently encountered and recognisable personal items known to archaeologists (e.g. Stephens 2008; Ashby 2011, and provide us with insight into the making of personal and bodily identities, even in the absence of human remains themselves. When studied in an interdisciplinary framework, the interpretative potential of this material is clear, but such work has been rare. This collection aims to set a new agenda for cross-disciplinary research focused on the nexus of human and artefactual remains, by highlighting the rich and diverse potential of this material when studied through archaeological, biochemical, artistic, historical, sociological and anthropological lenses.

  2. Perfectionism, shame, and self-concept in dancers: a mediation analysis.

    Science.gov (United States)

    Eusanio, Jacqueline; Thomson, Paula; Jaque, S Victoria

    2014-01-01

    Perfectionism has been linked to various forms of physiological and psychological maladjustment. This study examined the inter-relationships between multi-dimensional aspects of perfectionism (self-oriented, other-oriented, and socially prescribed), internalized shame, and total self-concept in elite dancers (N = 24) as compared to a control group of healthy, active non-dancers (N = 23). All participants completed psychometric self-report measures targeting the variables of interest. Multivariate analysis of covariance (gender as covariate) indicated that the dancers had higher levels of self-oriented perfectionism than the control group. Building on the findings of Ashby, Rice, and Martin, we examined a model in which dancers' shame mediates the relationship between maladaptive aspects of perfectionism and self-concept. Analysis revealed internalized shame to fully mediate the relationship between dancers' socially prescribed perfectionism and total self-concept; however, shame did not mediate self-concept in the control group. We conclude that dancers would benefit from programs that enhance self-esteem and reduce the negative effects of internalized shame and self-oriented and socially prescribed perfectionism.

  3. Mechanical properties: wood lumber versus plastic lumber and thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Bernardo Zandomenico Dias

    Full Text Available Abstract Plastic lumber and thermoplastic composites are sold as alternatives to wood products. However, many technical standards and scientific studies state that the two materials cannot be considered to have the same structural behaviour and strength. Moreover, there are many compositions of thermoplastic-based products and plenty of wood species. How different are their mechanical properties? This study compares the modulus of elasticity and the flexural, compressive, tensile and shear strengths of such materials, as well as the materials' specific mechanical properties. It analyses the properties of wood from the coniferae and dicotyledon species and those of commercialized and experimental thermoplastic-based product formulations. The data were collected from books, scientific papers and manufacturers' websites and technical data sheets, and subsequently compiled and presented in Ashby plots and bar graphs. The high values of the compressive strength and specific compressive and tensile strengths perpendicular to the grain (width direction shown by the experimental thermoplastic composites compared to wood reveal their great potential for use in compressed elements and in functions where components are compressed or tensioned perpendicularly to the grain. However, the low specific flexural modulus and high density of thermoplastic materials limit their usage in certain civil engineering and building applications.

  4. [Screening and identification of an endophytic bacterium with 1-aminocyclopropane-1-carboxylate deaminase activity from Panax ginseng and its effect on host growth].

    Science.gov (United States)

    Tian, Lei; Jiang, Yun; Chen, Changqing; Zhang, Guanjun; Li, Tong; Tong, Bin; Xu, Peng

    2014-07-04

    This study aimed to screen endophytic bacteria with 1-aminocyclopropane-1-carboxylate deaminase activity from Panax ginseng and test the capability of growth promotion to its host. In total 120 endophytic bacterial strains isolated from Panax ginseng were screened for 1-aminocyclopropane-1-carboxylate deaminase activity using the qualitative and quantitative methods. The obtained strain was also tested for its ability of nitrogen fixation using the Ashby agar plates and the gene of nifH, for its ability of phosphate solubilization using the Pikovaskaia's plates and quantitative analysis of Mo-Sb-Ascrobiology acid colorimetry, for its ability of producing siderophores using the method of Chrome azurol S detecting, and its effect on promoting growth of Panax ginseng by laboratory and field experiments. The bacterial strain with ACC deaminase was identified based on morphology, physiological and biochemical traits, and 16S rRNA sequence analysis. The bacterial stain JJ8-3 with the ability of producing ACC deaminase activity was obtained through screening, which its ACC deaminase activity was alpha-ketobutyric acid 6.7 micromol/(mg x h). Strain JJ8-3 had other traits of phosphate solubilizing, nitrogen fixation, producing siderophores, and the ability of promoting growth of Panax ginseng. Strain JJ8-3 was identified as Pseudomonas fluorescens. Strain JJ8-3 of endophytic bacterium with ACC deaminase activity from Panax ginseng was obtained and would lay the foundation for its further study and application on plant growth promotion.

  5. Materials selection for a transport packaging of Mo-99

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Debora H.S.; Lucchesi, Raquel F.; Mancini, Victor A.; Rossi, Jesualdo L., E-mail: debora_hara@yahoo.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Fiore, Marina [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais. Escola Politecnica

    2015-07-01

    The radiopharmaceuticals are radioactive isotopes used in nuclear medicine for more accurate diagnosis and treatment of diseases or dysfunctions. Currently, the most important radionuclide for the preparation of radiopharmaceuticals for diagnostic purposes is technetium-99m ({sup 99m}Tc), a product of the radioactive decay of molybdenum-99 (Mo-99). The aim of this work was the materials selection that can enable the manufacture of a package for Mo-99 transport with the aid of CES EduPack program and the methodology developed by Ashby. The ESTAR program was used to check the occurrence of Bremsstrahlung and the XCOM program was used to calculate the attenuation coefficient of gamma radiation from some of the selected materials for the shield; after, the thickness required for radiation shielding was calculated. From the results, the materials selected as potential candidates for the manufacture of the shielding were the tungsten alloys. Related to the thermal insulation and the impact protection, woods, plywoods and particle boards stand out. With regard to internal and external coatings, the selected materials focus on groups of steels and nickel alloys. (author)

  6. An experimental search for gamma radiation associated with thunderstorm activity

    Energy Technology Data Exchange (ETDEWEB)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and [gt] 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source.

  7. An experimental search for gamma radiation associated with thunderstorm activity

    Energy Technology Data Exchange (ETDEWEB)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and {gt} 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source.

  8. Competing Grain Boundary and Interior Deformation Mechanisms with Varying Sizes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [University of Tennessee (UT); Gao, Yanfei [ORNL; Nieh, T. G. [University of Tennessee, Knoxville (UTK)

    2018-01-01

    In typical coarse-grained alloys, the dominant plastic deformations are dislocation gliding or climbing, and material strengths can be tuned by dislocation interactions with grain boundaries, precipitates, solid solutions, and other defects. With the reduction of grain size, the increase of material strengths follows the classic Hall-Petch relationship up to nano-grained materials. Even at room temperatures, nano-grained materials exhibit strength softening, or called the inverse Hall-Petch effect, as grain boundary processes take over as the dominant deformation mechanisms. On the other hand, at elevated temperatures, grain boundary processes compete with grain interior deformation mechanisms over a wide range of the applied stress and grain sizes. This book chapter reviews and compares the rate equation model and the microstructure-based finite element simulations. The latter explicitly accounts for the grain boundary sliding, grain boundary diffusion and migration, as well as the grain interior dislocation creep. Therefore the explicit finite element method has clear advantages in problems where microstructural heterogeneities play a critical role, such as in the gradient microstructure in shot peening or weldment. Furthermore, combined with the Hall-Petch effect and its breakdown, the above competing processes help construct deformation mechanism maps by extending from the classic Frost-Ashby type to the ones with the dependence of grain size.

  9. Study of the compression and wear-resistance properties of freeze-cast Ti and Ti‒5W alloy foams for biomedical applications.

    Science.gov (United States)

    Choi, Hyelim; Shil'ko, Serge; Gubicza, Jenő; Choe, Heeman

    2017-08-01

    Ti and Ti‒5wt% W alloy foams were produced by freeze-casting process and their mechanical behaviors were compared. The Ti‒5W alloy foam showed a typical acicular Widmanstätten α/β structure with most of the W dissolved in the β phase. An electron-probe microanalysis revealed that approximately 2wt% W was uniformly dissolved in the Ti matrix of Ti‒5W alloy foam with few partially dissolved W particles. The compressive-yield strength of Ti‒5W alloy foam (~323MPa) was approximately 20% higher than that of the Ti foam (~256MPa) owing to the solid-solution-strengthening effect of W in the Ti matrix, which also resulted in a dramatic improvement in the wear resistance of Ti‒5W alloy foam. The compressive behaviors of the Ti and Ti‒5W alloy foams were predicted by analytical models and compared with the experimental values. Compared with the Gibson-Ashby and cellular-lattice-structure-in-square-orientation models of porous materials, the orientation-averaging method provided prediction results that are much more accurate in terms of both the Young's modulus and the yield strength of the Ti and Ti‒5W alloy foams. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Not Just Horsing Around: The Impact of Equine-Assisted Learning on Levels of Hope and Depression in At-Risk Adolescents.

    Science.gov (United States)

    Frederick, Karen E; Ivey Hatz, Julie; Lanning, Beth

    2015-10-01

    Equine-assisted learning (EAL) is an experiential modality which utilizes horses to provide a unique learning experience for personal growth. Research by Damon et al. (Appl Dev Sci 7:119-128, 2003) suggests a positive relationship between hope and positive developmental trajectories. Hagen et al. (Am J Orthopsychiatr 75:211-219, 2005) showed hope to be a protective factor associated with adaptive functioning in at-risk youth. Ashby et al. (J Couns Dev 89:131-139, 2011) found a significant inverse relationship between hope and depression: as hope increases, depression decreases. The current study investigates the impact of a non-riding EAL curriculum entitled L.A.S.S.O. (Leading Adolescents to Successful School Outcomes) on levels of hope and depression in at-risk youth. The study uses an experimental design with longitudinal, repeated measures. Participants were randomly assigned to treatment and control groups. Participants in the treatment received 5 weeks of EAL, while participants in the control group received treatment as usual. Repeated measures ANOVA of participants' levels of hope and depression showed statistically significant improvements in the treatment group as compared with the control group. Even a brief (5-week) intervention of EAL had a positive impact on the lives and attitudes of at-risk adolescents, with increased levels of hope and decreased levels of depression.

  11. Estimation of transfused red cell survival using an enzyme-linked antiglobulin test

    International Nuclear Information System (INIS)

    Kickler, T.S.; Smith, B.; Bell, W.; Drew, H.; Baldwin, M.; Ness, P.M.

    1985-01-01

    An enzyme-linked antiglobulin test (ELAT) method was developed to estimate survival of transfused red cells. This procedure is based on a principle analogous to that of the Ashby technique were antigenically distinct red cells are transfused and their survival studied. The authors compared the ELAT survival to the 51 Chromium method ( 51 Cr) in four patients. Three patients with hypoproliferative anemias showed T 1/2 by ELAT of 17.5, 18, and 17 days versus 18.5, 20, and 19 days by the 51 Cr method. A fourth patient with traumatic cardiac hemolysis had two studies performed. In this case, the ELAT showed a T 1/2 of 10 and 8.1 days while 51 Cr T 1/2 values were 11 and 10.5 days. The ELAT method for measuring red cell survival yielded data which agreed closely with the results of the 51 Cr method. Although 51 Cr is the accepted method for red cell survival, the ELAT method can be used to estimate transfused red cell survival

  12. Analytic processing of distance.

    Science.gov (United States)

    Dopkins, Stephen; Galyer, Darin

    2018-01-01

    How does a human observer extract from the distance between two frontal points the component corresponding to an axis of a rectangular reference frame? To find out we had participants classify pairs of small circles, varying on the horizontal and vertical axes of a computer screen, in terms of the horizontal distance between them. A response signal controlled response time. The error rate depended on the irrelevant vertical as well as the relevant horizontal distance between the test circles with the relevant distance effect being larger than the irrelevant distance effect. The results implied that the horizontal distance between the test circles was imperfectly extracted from the overall distance between them. The results supported an account, derived from the Exemplar Based Random Walk model (Nosofsky & Palmieri, 1997), under which distance classification is based on the overall distance between the test circles, with relevant distance being extracted from overall distance to the extent that the relevant and irrelevant axes are differentially weighted so as to reduce the contribution of irrelevant distance to overall distance. The results did not support an account, derived from the General Recognition Theory (Ashby & Maddox, 1994), under which distance classification is based on the relevant distance between the test circles, with the irrelevant distance effect arising because a test circle's perceived location on the relevant axis depends on its location on the irrelevant axis, and with relevant distance being extracted from overall distance to the extent that this dependency is absent. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Investigation of Macroscopic Brittle Creep Failure Caused by Microcrack Growth Under Step Loading and Unloading in Rocks

    Science.gov (United States)

    Li, Xiaozhao; Shao, Zhushan

    2016-07-01

    The growth of subcritical cracks plays an important role in the creep of brittle rock. The stress path has a great influence on creep properties. A micromechanics-based model is presented to study the effect of the stress path on creep properties. The microcrack model of Ashby and Sammis, Charles' Law, and a new micro-macro relation are employed in our model. This new micro-macro relation is proposed by using the correlation between the micromechanical and macroscopic definition of damage. A stress path function is also introduced by the relationship between stress and time. Theoretical expressions of the stress-strain relationship and creep behavior are derived. The effects of confining pressure on the stress-strain relationship are studied. Crack initiation stress and peak stress are achieved under different confining pressures. The applied constant stress that could cause creep behavior is predicted. Creep properties are studied under the step loading of axial stress or the unloading of confining pressure. Rationality of the micromechanics-based model is verified by the experimental results of Jinping marble. Furthermore, the effects of model parameters and the unloading rate of confining pressure on creep behavior are analyzed. The coupling effect of step axial stress and confining pressure on creep failure is also discussed. The results provide implications on the deformation behavior and time-delayed rockburst mechanism caused by microcrack growth on surrounding rocks during deep underground excavations.

  14. Environmental health impacts: occurrence, exposure and significance, Lancaster University, UK, 9-10 September 2003.

    Science.gov (United States)

    Martin, Francis L; Semple, Kirk T

    2004-09-01

    Speakers: John Ashby (Syngenta CTL, UK), Peter A. Behnisch (Eurofins GfA, Germany), Paul L. Carmichael (Unilever Colworth, UK), Curtis C.Harris (National Cancer Institute, USA), Kevin C. Jones (Lancaster University, UK), Andreas Kortenkamp (School of Pharmacy, London, UK), Caroline J. Langdon (Reading University, UK), Anthony M. Lynch (GlaxoSmithKline, UK), Francis L. Martin (Lancaster University, UK), Trevor J. McMillan (Lancaster University, UK), David H. Phillips (Institute of Cancer Research, UK), Huw J. Ricketts (University of Cardiff, UK), Michael N. Routledge (University of Leeds, UK), J. Thomas Sanderson (Utrecht University, The Netherlands) and Kirk T. Semple (Lancaster University, UK) The effects of many environmental exposures to either single contaminants or to mixtures still remain to be properly assessed in ecotoxicological and human toxicological settings. Such assessments need to be carried out using relevant biological assays. On a mechanistic basis, future studies need to be able to extrapolate exposure to disease risk. It is envisaged that such an approach would lead to the development of appropriate strategies to either reduce exposures or to initiate preventative measures in susceptible individuals or populations. To mark the opening of a new Institute, the Lancaster Environmental Centre, an environmental health workshop was held over 2 days (9-10 September 2003) at Lancaster University, UK. The fate, behaviour and movement of chemicals in the environment, together with environmental exposures and human health, biomarkers of such exposures, hormone-like compounds and appropriate genetic toxicology methodologies, were discussed.

  15. STS-93 Commander Collins suits up before launch

    Science.gov (United States)

    1999-01-01

    In the Operations and Checkout Building, STS-93 Commander Eileen M. Collins gets help donning her launch and entry suit. After Space Shuttle Columbia's July 20 launch attempt was scrubbed at the T-7 second mark in the countdown, the launch was rescheduled for Thursday, July 22, at 12:28 a.m. EDT. The target landing date is July 26, 1999, at 11:24 p.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  16. STS-93 crew cheers as they near the van for ride to launch pad

    Science.gov (United States)

    1999-01-01

    The STS-93 crew wave and cheer as they head for the 'Astrovan' a third time to take them to Launch Pad 39-B and liftoff of Space Shuttle Columbia. In their orange launch and entry suits, they are (starting at rear, left to right) Mission Specialists Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), Catherine G. Coleman (Ph.D.), and Stephen A. Hawley (Ph.D.); Pilot Jeffrey S. Ashby; and Commander Eileen M. Collins. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. The target landing date is July 27 at 11:20 p.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. Collins is the first woman to serve as commander of a Shuttle mission.

  17. STS-93 crew heads out of O&C for ride to launch pad

    Science.gov (United States)

    1999-01-01

    The STS-93 crew wave and smile at onlookers as they walk out of the Operations and Checkout Building for the third time enroute to Launch Pad 39-B and liftoff of Space Shuttle Columbia. After Space Shuttle Columbia's July 20 and 22 launch attempts were scrubbed, the launch was again rescheduled for Friday, July 23, at 12:24 a.m. EDT. The target landing date is July 27, 1999, at 11:20 p.m. EDT. In their orange launch and entry suits, they are (starting at rear, left to right) Mission Specialists Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), and Catherine G. Coleman (Ph.D.); Pilot Jeffrey S. Ashby; Mission Specialist Stephen A. Hawley (Ph.D.); and Commander Eileen M. Collins. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. Collins is the first woman to serve as commander of a Shuttle mission.

  18. The STS-93 crew pose in front of Columbia

    Science.gov (United States)

    1999-01-01

    The STS-93 crew pose in front of the Space Shuttle orbiter Columbia following their landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. From left to right, they are Mission Specialists Catherine G. Coleman (Ph.D.) and Stephen A. Hawley (Ph.D.), Pilot Jeffrey S. Ashby, Commander Eileen Collins, and Mission Specialist Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history. On this mission, Collins became the first woman to serve as a Shuttle commander.

  19. Columbia makes a nighttime landing at KSC following STS-93

    Science.gov (United States)

    1999-01-01

    The Space Shuttle orbiter Columbia swoops out of the darkness onto runway 33 at the Shuttle Landing Facility after a successful mission of nearly five days and 1.8 million miles. Main gear touchdown was at 11:20:35 p.m. EDT on July 27. Aboard are the STS-93 crew members: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history.

  20. STS-93 M.S. Hawley suits up for launch

    Science.gov (United States)

    1999-01-01

    During final launch preparations in the Operations and Checkout Building, STS-93 Mission Specialist Steven A. Hawley (Ph.D.)gets help donning his launch and entry suit from a suit tech. After Space Shuttle Columbia's July 20 launch attempt was scrubbed at the T-7 second mark in the countdown, the launch was rescheduled for Thursday, July 22, at 12:28 a.m. EDT. The target landing date is July 26, 1999, at 11:24 p.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X- ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Hawley, Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  1. STS-93 crew have breakfast before launch in O&C Building

    Science.gov (United States)

    1999-01-01

    The STS-93 crew gathers a third time for a pre-launch breakfast in the Operations and Checkout Building before suiting up for launch. After Space Shuttle Columbia's July 22 launch attempt was scrubbed due to the weather, the launch was rescheduled for Friday, July 23, at 12:24 a.m. EDT. Seated from left are Mission Specialists Catherine G. Coleman (Ph.D.) and Steven A. Hawley (Ph.D.); Commander Eileen M. Collins; Mission Specialist Michel Tognini, of France, who represents the Centre National d'Etudes Spatiales (CNES); and Pilot Jeffrey S. Ashby. STS-93 is a five- day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. Collins is the first woman to serve as commander of a Shuttle mission. The target landing date is July 27, 1999, at 11:20 p.m. EDT.

  2. STS-93 crew gathers for pre-launch breakfast in O&C Building

    Science.gov (United States)

    1999-01-01

    The STS-93 crew gathers a second time for a pre-launch breakfast in the Operations and Checkout Building before suiting up for launch. After Space Shuttle Columbia's July 20 launch attempt was scrubbed at the T-7 second mark in the countdown, the launch was rescheduled for Thursday, July 22, at 12:28 a.m. EDT. Seated from left are Mission Specialists Michel Tognini, of France, who represents the Centre National d'Etudes Spatiales (CNES), and Steven A. Hawley (Ph.D.), Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialist Catherine G. Coleman (Ph.D.). STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. Collins is the first woman to serve as commander of a Shuttle mission. The target landing date is July 26, 1999, at 11:24 p.m. EDT.

  3. STS-93 Commander Collins poses in front of Columbia

    Science.gov (United States)

    1999-01-01

    STS-93 Commander Eileen Collins poses in front of the Space Shuttle orbiter Columbia following her textbook landing on runway 33 at the Shuttle Landing Facility. Main gear touchdown occurred at 11:20:35 p.m. EDT on July 27. On this mission, Collins became the first woman to serve as a Shuttle commander. Also on board were her fellow STS-93 crew members: Pilot Jeffrey S. Ashby and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). The mission's primary objective was to deploy the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. This was the 95th flight in the Space Shuttle program and the 26th for Columbia. The landing was the 19th consecutive Shuttle landing in Florida and the 12th night landing in Shuttle program history.

  4. STS-93 Commander Collins waves after suiting up before launch

    Science.gov (United States)

    1999-01-01

    During final launch preparations in the Operations and Checkout Building, STS-93 Commander Eileen M. Collins waves after donning her launch and entry suit. After Space Shuttle Columbia's July 20 launch attempt was scrubbed at the T-7 second mark in the countdown, the launch was rescheduled for Thursday, July 22, at 12:28 a.m. EDT. The target landing date is July 26, 1999, at 11:24 p.m. EDT. STS-93 is a five-day mission primarily to release the Chandra X-ray Observatory, which will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected unlock the secrets of supernovae, quasars and black holes. The STS-93 crew numbers five: Commander Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Stephen A. Hawley (Ph.D.), Catherine G. Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES). Collins is the first woman to serve as commander of a shuttle mission.

  5. Comparing the effects of positive and negative feedback in information-integration category learning.

    Science.gov (United States)

    Freedberg, Michael; Glass, Brian; Filoteo, J Vincent; Hazeltine, Eliot; Maddox, W Todd

    2017-01-01

    Categorical learning is dependent on feedback. Here, we compare how positive and negative feedback affect information-integration (II) category learning. Ashby and O'Brien (2007) demonstrated that both positive and negative feedback are required to solve II category problems when feedback was not guaranteed on each trial, and reported no differences between positive-only and negative-only feedback in terms of their effectiveness. We followed up on these findings and conducted 3 experiments in which participants completed 2,400 II categorization trials across three days under 1 of 3 conditions: positive feedback only (PFB), negative feedback only (NFB), or both types of feedback (CP; control partial). An adaptive algorithm controlled the amount of feedback given to each group so that feedback was nearly equated. Using different feedback control procedures, Experiments 1 and 2 demonstrated that participants in the NFB and CP group were able to engage II learning strategies, whereas the PFB group was not. Additionally, the NFB group was able to achieve significantly higher accuracy than the PFB group by Day 3. Experiment 3 revealed that these differences remained even when we equated the information received on feedback trials. Thus, negative feedback appears significantly more effective for learning II category structures. This suggests that the human implicit learning system may be capable of learning in the absence of positive feedback.

  6. Microstructure and properties of LZSA glass-ceramic foams

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, E. de [Graduate Program on Materials Science and Engineering-PGMAT, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Rambo, C.R. [Graduate Program on Materials Science and Engineering-PGMAT, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Department of Chemical Engineering-EQA, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil)], E-mail: Rambo@enq.ufsc.br; Hotza, D. [Graduate Program on Materials Science and Engineering-PGMAT, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Department of Chemical Engineering-EQA, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Oliveira, A.P. Novaes de [Graduate Program on Materials Science and Engineering-PGMAT, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Department of Mechanical Engineering-EMC, Federal University of Santa Catarina-UFSC, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil); Fey, T.; Greil, P. [Department of Materials Science, Glass and Ceramics, University of Erlangen-Nuremberg, Martensstrasse 5, D-91058 Erlangen (Germany)

    2008-03-15

    Commercial polyurethane foams with a monomodal pore size distribution were used to produce LZSA glass-ceramic foams by the polymeric sponge method. A suspension containing LZSA glass powder, bentonite and sodium silicate was prepared in isopropanol to impregnate the polymeric foams by dip coating. The sintering conditions were varied in the range of 700-850 deg. C for 30-180 min. The cellular microstructure of glass-ceramic foams was characterized by scanning electron microscopy (SEM) and micro-computer X-ray tomography ({mu}CT). Optimum physical, mechanical and fluidynamic properties of the LZSA glass-ceramic foams were obtained at 750 deg. C for 60 min. Main crystalline phases detected were {beta}-spodumene and zirconium silicate. The compressive strength of the foams (0.1-10 MPa) is strongly dependent on their overall porosity and their behaviour could be explained using the Gibson-Ashby model. The Darcyan permeability of LZSA foams was found to be in the range of 0.1-4 x 10{sup -9} m{sup 2}, which is in the order of magnitude of cellular supports for aerosol filters, and, therefore, suitable for several other technological applications.

  7. OCORRÊNCIA DA MOSCA-NEGRA-DOS-CITROS Aleurocanthus woglumi ASHY NA PRODUÇÃO DE MUDAS NO MUNICÍPIO DE DONA EUZÉBIA - MG

    Directory of Open Access Journals (Sweden)

    Scarlet Santos Monteiro

    2017-02-01

    Full Text Available O município de Dona Euzébia - MG se destaca na produção de mudas ornamentais, florestais, exóticas e frutíferas, sendo as espécies cítricas mais afetadas por Aleurocanthus woglumi Ashby popularmente conhecida como mosca-negra-dos-citros. Nesse sentido, objetivou-se realizar um levantamento bibliográfico e estatístico sobre o grau de incidência de A. woglumi, bem como analisar a capacidade de reconhecimento e as práticas de manejo adotadas por trabalhadores rurais e proprietários de estabelecimentos agrícolas do município. Para tal, foram aplicados questionários semiestruturados de forma aleatória. Constatou-se a incidência de A. woglumi na produção de mudas do município, sendo que 49% dos entrevistados julgam que, atualmente, A. woglumi seja um problema em vários estabelecimentos de Dona Euzébia - MG. Além disso, todos os entrevistados afirmaram ser capazes de reconhecer o aparecimento de A. woglumi em suas plantas e 60% adotam agroquímicos como mecanismo de controle da praga agrícola. Os resultados apontam a necessidade de se estabelecer um efetivo programa de manejo de A. woglumi, sob condições mais sustentáveis.

  8. Assessing historical empathy through simulation – How do Finnish teacher students achieve contextual historical empathy?

    Directory of Open Access Journals (Sweden)

    Jukka Rantala

    2011-05-01

    Full Text Available There has been a great deal of international debate about introducing historical empathy as the focus in teaching history. However, as it is, the contents of the concept have been included in the curricula in many countries. Nevertheless, practising stepping into the shoes of a person from a previous era is still in its infancy in schools in many locations – Finland included. This article discusses Finnish class teacher students' understanding of historical empathy. The article is based on a study where 360 class teacher students played a game simulating the Cuban Missile Crisis. Their task was to assume the roles of the superpower leaders and make decisions on the basis of these roles. The simulation showed that a majority of the student teachers are able to attain a level of contextual historical empathy. They were able to empathize with the historical context in question and make such decisions that would have been possible for the historical actors. Some of the playing groups on the other hand, referred to their current knowledge and attitudes, which, according to Ashby and Lee's empathy classification, shows lower-level empathy. The study corroborates previous research results concerning great discrepancies in the understanding of empathy prevalent within one age group. Moreover, the study raises the question of how historical empathy should be handled in teaching if many future teachers have difficulties in understanding it.

  9. Porous Nb-Ti-Ta alloy scaffolds for bone tissue engineering: Fabrication, mechanical properties and in vitro/vivo biocompatibility.

    Science.gov (United States)

    Liu, Jue; Ruan, Jianming; Chang, Lin; Yang, Hailin; Ruan, Wei

    2017-09-01

    Porous Nb-Ti-Ta (at.%) alloys with the pore size of 100-600μm and the porosity of 50%-80% were fabricated by the combination of the sponge impregnation technique and sintering method. The results revealed that the pores were well connected with three-dimensional (3D) network structure, which showed morphological similarity to the anisotropic porous structure of human bones. The results also showed that the alloys could provide the compressive Young's modulus of 0.11±0.01GPa to 2.08±0.09GPa and the strength of 17.45±2.76MPa to 121.67±1.76MPa at different level of porosity, indicating that the mechanical properties of the alloys are similar to those of human bones. Pore structure on the compressive properties was also discussed on the basis of the deformation mode. The relationship between compressive properties and porosity was well consistent with the Gibson-Ashby model. The mechanical properties could be tailored to match different requirements of the human bones. Moreover, the alloys had good biocompatibility due to the porous structure with higher surface, which were suitable for apatite formation and cell adhesion. In conclusion, the porous Nb-Ti-Ta alloy is potentially useful in the hard tissue implants for the appropriate mechanical properties as well as the good biocompatible properties. Copyright © 2017. Published by Elsevier B.V.

  10. Trial-by-trial identification of categorization strategy using iterative decision-bound modeling.

    Science.gov (United States)

    Hélie, Sébastien; Turner, Benjamin O; Crossley, Matthew J; Ell, Shawn W; Ashby, F Gregory

    2017-06-01

    Identifying the strategy that participants use in laboratory experiments is crucial in interpreting the results of behavioral experiments. This article introduces a new modeling procedure called iterative decision-bound modeling (iDBM), which iteratively fits decision-bound models to the trial-by-trial responses generated from single participants in perceptual categorization experiments. The goals of iDBM are to identify: (1) all response strategies used by a participant, (2) changes in response strategy, and (3) the trial number at which each change occurs. The new method is validated by testing its ability to identify the response strategies used in noisy simulated data. The benchmark simulation results show that iDBM is able to detect and identify strategy switches during an experiment and accurately estimate the trial number at which the strategy change occurs in low to moderate noise conditions. The new method is then used to reanalyze data from Ell and Ashby (2006). Applying iDBM revealed that increasing category overlap in an information-integration category learning task increased the proportion of participants who abandoned explicit rules, and reduced the number of training trials needed to abandon rules in favor of a procedural strategy. Finally, we discuss new research questions made possible through iDBM.

  11. STS-93 Post Flight Presentation

    Science.gov (United States)

    1999-01-01

    An overview of Flight STS-93 is presented. The primary objective of the STS-93 mission was to deploy the Advanced X-Ray Astrophysics Facility (AXAF), also known as the Chandra X-ray Observatory. The mission flew on the Columbia Shuttle, on July 22, 1999. This facility is the most sophisticated X-ray observatory ever built. Other payloads on STS-93 were: (1) the Midcourse Space Experiment (MSX), (2) Shuttle Ionospheric Modification with Pulsed Local Exhaust (SIMPLEX), (3) Southwest Ultraviolet Imaging System (SWUIS), (4) Gelation of Sols: Applied Microgravity Research (GOSAMR), Space Tissue Loss-B (STL-B), (5) Light Weight Flexible Solar Array Hinge (LFSAH), (6) Cell Culture Module (CCM), and (7) the Shuttle Amateur Radio Experiment-II (SAREX-II), (8) EarthKam, (9) Plant Growth Investigations in Microgravity (PGIM), (10) Commercial Generic Bioprocessing Apparatus (CGBA), (11) Micro-Electrical Mechanical System (MEMS), and (12) the Biological Research in Canisters (BRIC). The crew was: Eileen M. Collins, Mission Commander, the first female shuttle commander; Jeffrey S. Ashby, Pilot; Steven A. Hawley , Mission Specialist; Catherine G. Coleman, Mission Specialist; Michel Tognini (CNES), Mission Specialist. The video contains views of life aboard the space shuttle. This mission featured both a night launching and a night landing at the Kennedy Space Center.

  12. Self-critical perfectionism, daily stress, and disclosure of daily emotional events.

    Science.gov (United States)

    Richardson, Clarissa M E; Rice, Kenneth G

    2015-10-01

    Although disclosure of stressful events can alleviate distress, self-critical perfectionism may pose an especially strong impediment to disclosure during stress, likely contributing to poorer psychological well-being. In the current study, after completing a measure of self-critical perfectionism (the Discrepancy subscale of the Almost Perfect Scale--Revised; Slaney, Rice, Mobley, Trippi, & Ashby, 2001), 396 undergraduates completed measures of stress and disclosure at the end of each day for 1 week. Consistent with hypotheses and previous research, multilevel modeling results indicated significant intraindividual coupling of daily stress and daily disclosure where disclosure was more likely when experiencing high stress than low stress. As hypothesized, Discrepancy moderated the relationship between daily stress and daily disclosure. Individuals higher in self-critical perfectionism (Discrepancy) were less likely to engage in disclosure under high stress, when disclosure is often most beneficial, than those with lower Discrepancy scores. These results have implications for understanding the role of stress and coping in the daily lives of self-critical perfectionists. (c) 2015 APA, all rights reserved).

  13. Plant growth promotion properties of bacterial strains isolated from the rhizosphere of the Jerusalem artichoke (Helianthus tuberosus L.) adapted to saline-alkaline soils and their effect on wheat growth.

    Science.gov (United States)

    Liu, Xiaolin; Li, Xiangyue; Li, Yan; Li, Runzhi; Xie, Zhihong

    2017-03-01

    The Jerusalem artichoke (JA; Helianthus tuberosus), known to be tolerant to saline-alkaline soil conditions, has been cultivated for many years in the Yellow River delta, Shandong Province coastal zone, in China. The aim of our study was to isolate nitrogen-fixing bacteria colonizing the rhizosphere of JA and to characterize other plant growth promotion properties. The ultimate goal was to identify isolates that could be used as inoculants benefiting an economic crop, in particular for improving wheat growth production in the Yellow River delta. Bacterial strains were isolated from the rhizosphere soil of JA on the basis of growth on nitrogen-free Ashby medium. Identification and phylogenetic analysis was performed after nucleotide sequencing of 16S rRNA gene. Plant-growth-promoting traits, such as nitrogen fixation activity, phosphate solubilization activity, indole-3-acetic acid production, were determined using conventional methods. Eleven strains were isolated and 6 of them were further examined for their level of salt tolerance and their effect on plant growth promotion. Inoculation of Enterobacter sp. strain N10 on JA and wheat led to significant increases in both root and shoot dry mass and shoot height. Enterobacter sp. strain N10 appeared to be the best plant-growth-promoting rhizobacteria to increase wheat productivity in future field applications.

  14. Study on Topology Optimization Design, Manufacturability, and Performance Evaluation of Ti-6Al-4V Porous Structures Fabricated by Selective Laser Melting (SLM).

    Science.gov (United States)

    Xu, Yangli; Zhang, Dongyun; Zhou, Yan; Wang, Weidong; Cao, Xuanyang

    2017-09-07

    The combination of topology optimization (TOP) and selective laser melting (SLM) provides the possibility of fabricating the complex, lightweight and high performance geometries overcoming the traditional manufacturing "bottleneck". This paper evaluates the biomechanical properties of porous structures with porosity from 40% to 80% and unit cell size from 2 to 8 mm, which are designed by TOP and manufactured by SLM. During manufacturability exploration, three typical structures including spiral structure, arched bridge structure and structures with thin walls and small holes are abstracted and investigated, analyzing their manufacturing limits and forming reason. The property tests show that dynamic elastic modulus and compressive strength of porous structures decreases with increases of porosity (constant unit cell size) or unit cell size (constant porosity). Based on the Gibson-Ashby model, three failure models are proposed to describe their compressive behavior, and the structural parameter λ is used to evaluate the stability of the porous structure. Finally, a numerical model for the correlation between porous structural parameters (unit cell size and porosity) and elastic modulus is established, which provides a theoretical reference for matching the elastic modulus of human bones from different age, gender and skeletal sites during innovative medical implant design and manufacturing.

  15. Study on iron metabolism in children using double labelling of 51Cr and 59Fe

    International Nuclear Information System (INIS)

    Kobayashi, Masatsura

    1974-01-01

    In the children before and after treatment for iron deficiency anemia and those on ingesting a long-term low caloric and iron diet, life span of Ashby Technique 1/2(AST) red cells, circulatory blood volume (CBV), plasma iron disappearance(PID), red cell-iron utility(RCIU), plasma-iron turnover rate(PITR), and red cell-ironturnover rate(RCITR) were respectively determined using double labeling of 51 Cr and 59 Fe, and the following results and conclusions were obtained: In the patients with iron deficiency anemia, the rate of RCIU was highly increased, and simultaneously the shortening in AST was observed. Among the children with the iron deficiency anemia, five patients were examined immediately after the improvement on the anemia by iron drugs; the serum iron (SFe) averaged 74μg/ml. So the erthropiesis appeared to recover to normal, yet AST has hardly changed, still more has it shortened. In five children with celebral palsy associated with disturbance of physical development, who had ingested a long-term liquid low iron diet no evident increase of RCIU was found except for high calues of RCITR. The shortening in AST was not entirely seen in contrast with that of the simple alimentary iron deficiency anemia. Besides the CBV measured par kg of weight showed the remarkable increase. (Oyama, S.)

  16. Materials selection for a transport packaging of Mo-99

    International Nuclear Information System (INIS)

    Hara, Debora H.S.; Lucchesi, Raquel F.; Mancini, Victor A.; Rossi, Jesualdo L.; Fiore, Marina

    2015-01-01

    The radiopharmaceuticals are radioactive isotopes used in nuclear medicine for more accurate diagnosis and treatment of diseases or dysfunctions. Currently, the most important radionuclide for the preparation of radiopharmaceuticals for diagnostic purposes is technetium-99m ( 99m Tc), a product of the radioactive decay of molybdenum-99 (Mo-99). The aim of this work was the materials selection that can enable the manufacture of a package for Mo-99 transport with the aid of CES EduPack program and the methodology developed by Ashby. The ESTAR program was used to check the occurrence of Bremsstrahlung and the XCOM program was used to calculate the attenuation coefficient of gamma radiation from some of the selected materials for the shield; after, the thickness required for radiation shielding was calculated. From the results, the materials selected as potential candidates for the manufacture of the shielding were the tungsten alloys. Related to the thermal insulation and the impact protection, woods, plywoods and particle boards stand out. With regard to internal and external coatings, the selected materials focus on groups of steels and nickel alloys. (author)

  17. Efecto del uso del suelo sobre rizobacterias fosfatosolubizadoras y diazotroficas en el distrito de riego del río zulia,norte de santander (colombia

    Directory of Open Access Journals (Sweden)

    Ronal Fernando-Cañon

    2009-07-01

    Full Text Available It was quantified the population of diazotrophic and phosphate solubilizer bacteria with the aim of determine the effect of the use of soils during different periods of intervention with culture of rice in three agro-ecological zones of the District of Irrigation of the Zulia river. The results showed that the management of the culture of rice in the different studied zones significantly influenced the population of microorganisms in all the studied culture media, excepting the semi-solid culture media JMV. The populations of the genera Azospirillum spp., Azotobacter spp., Beijerinckia spp., were influenced by the fertility of the soils in the zones of Buena Esperanza and Restauración compared with Limoncito, where the quantities of organic matter and nutritional escential elements were lower. It were obtained 28 isolations of entophytic, associative, free-living diazotrophic and phosphate solubilizer rhizobacteria according with their macroscopic characteristics in the culture media Batata, JMV, Ashby and nutritive, from the analysis of the population in the zones of Buena Esperanza, Restauración and Limoncito. These isolations were purified and preserved in sterilized saline solution (0.85% NaCl at 4°C in the Laboratory of Microbiology of the Colombian Agricultural Institute, ICA, with the purpose to be used in subsequent studies about their potential as biofertilizers in rice cultured soils of the department.

  18. Understanding the application of knowledge management to the safety critical facilities

    International Nuclear Information System (INIS)

    Ilina, Elena

    2010-01-01

    Challenges to the operating nuclear power plants and transport infrastructures are outlined. It is concluded that most aggravating factors are related to knowledge. Thus, of necessity, effective knowledge management is required. Knowledge management theories are reviewed in their historical perspective as a natural extension and unification of information theories and theories about learning. The first line is identified with names as Wiener, Ashby, Shannon, Jaynes, Dretske, Harkevich. The second line - with Vygotsky, Engestroem, Carayannis. The recent developments of knowledge management theorists as Davenport, Prusak, Drew, Wiig, Zack are considered stressing learning, retaining of knowledge, approaching the state awareness of awareness, and alignment of knowledge management with the strategy of the concerned organizations. Further, some of the details and results are presented of what is achieved so far. More specifically, knowledge management tools are applied to the practical work activities as event reporting, data collection, condition assessment, verification of safety functions and incident investigation. Obstacles are identified and improvements are proposed. Finally, it is advised to continue to implement and further develop knowledge management tools in the organizations involved in various aspects of safety critical facilities

  19. Nickel–carbon nanocomposites: Synthesis, structural changes and strengthening mechanisms

    International Nuclear Information System (INIS)

    Nunes, D.; Vilarigues, M.; Correia, J.B.; Carvalho, P.A.

    2012-01-01

    The present work investigates Ni–nanodiamond and Ni–graphite composites produced by mechanical synthesis and subsequent heat treatments. Processing of nickel–carbon nanocomposites by this powder metallurgy route poses specific challenges, as carbon phases are prone to carbide conversion and amorphization. The processing window for carbide prevention has been established through X-ray diffraction by a systematic variation of the milling parameters. Transmission electron microscopy confirmed the absence of carbide and showed homogeneous particle distributions, as well as intimate bonding between the metallic matrix and the carbon phases. Ring diffraction patterns of chemically extracted carbon phases demonstrated that milled nanodiamond preserved crystallinity, while an essentially amorphous nature could be inferred for milled graphite. Raman spectra confirmed that nanodiamond particles remained largely unaffected by mechanical synthesis, whereas the bands of milled graphite were significantly changed into the typical amorphous carbon fingerprint. The results on the annealed nanocomposites showed that milling with Ni accelerated graphitization of the carbon phases during heat treatments at 973 and 1073 K in both composites. At the finer scales, the nanocomposites exhibited a remarkable microhardness enhancement (∼70%) compared with pure nanostructured nickel. The Hall–Petch relation and the Orowan–Ashby equation are used to discuss strengthening mechanisms and the load transfer ability to the reinforcing particles.

  20. An experimental search for gamma radiation associated with thunderstorm activity

    International Nuclear Information System (INIS)

    Fryberger, D.

    1992-11-01

    This experiment is a repeat of an earlier experiment, but with more sensitive apparatus and in a location with a higher incidence of thunderstorm activity. The earlier experiment was undertaken by Ashby and Whitehead to investigate the theory that ball lightning might be associated with the annihilation of small amounts of antimatter, and it yielded some very interesting but inconclusive results. In the course of about 12 months of data taking, four high rate bursts of gamma radiation were detected. These events lasted a few seconds and had many thousands of counts (16500, 5000, 3700, and > 7700. Unfortunately, the association of these gamma ray bursts with thunderstorms or ball lightning was not clearly established, although one of the bursts did occur during a local thunderstorm in rough coincidence with a lightning bolt striking a flagpole about 100 yards from the gamma ray detection crystals. A pulse height spectrum taken for this burst (no spectrum was taken for the other three) exhibited a significant peak, well above background, the energy of which appeared to be compatible with the 511 keV positron annihilation line. While the peak could not be unambiguously attributed to positron annihilation, this certainly appeared to be the most likely source

  1. Unravelling the materials genome: Symmetry relationships in alloy properties

    Energy Technology Data Exchange (ETDEWEB)

    Toda-Caraballo, Isaac [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Galindo-Nava, Enrique I. [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Delft University of Technology, Mekelweg 2, Delft 2628 CD (Netherlands); Rivera-Díaz-del-Castillo, Pedro E.J., E-mail: pejr2@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge New Museums Site, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom)

    2013-07-25

    Highlights: ► Research strategy for Accelerated Metallurgy project is outlined. ► Surprising symmetry among atomic, nanoscale and mechanical properties. ► Generalisation of Ashby diagrams via principal component analysis. ► Atomic-related properties can be described with linear regression. ► Mechanical properties modelled via Kocks–Mecking-type physical method. -- Abstract: Metals and alloys have been indispensable for technological progress, but only a fraction of the possible ternary systems (combinations of three elements) is known. Statistical inference methods combined with physical models are presented to discover new systems of enhanced properties. It is demonstrated that properties originating from atomic-level interactions can be described employing a linear regression analysis, but properties incorporating microstructural and thermal history effects require a balance between physical and statistical modelling. In spite of this, there is a remarkable degree of symmetry among all properties, and by employing a principal components analysis it is shown that ten properties essential to engineering can be described well in a three dimensional space. This will aid in the discovery of novel alloying systems.

  2. Multigrid Methods for EHL Problems

    Science.gov (United States)

    Nurgat, Elyas; Berzins, Martin

    1996-01-01

    the application of such methods is the recent Effective Influence Method of Dowson and Wang. Multigrid methods have also been used with great success by Venner and Venner and Lubrecht with a good summary being given by Venner. As both these finite difference discretization based approaches appear to provide an efficient way of solving EHL problems, it is important to understand their relative merits. This paper is a first attempt at providing such an understanding in the context of EHL point contact problem, (contact of two spheres), in which the contact zone is a point and an ellipse or circle for unloaded and loaded dry contacts respectively. Since the film thickness and the contact width are generally small compared to the local radius of curvature of the two surfaces, the reduced geometry of the surfaces in the contact area can be accurately approximated to the contact between a paraboloid and a flat surface. The layout of the remainder of this paper is as follows. In section 2 we introduce the form of the equations to be solved. The Effective Influence Newton Method is described in Section 3 while Section 4 describes the Multigrid method to be used. Sections 5 and 6 describe the test problems to be used in the comparison between the two methods and compare the performance of the two methods. Section 7 concludes the paper with an argument of the two methods and suggests some future research directions.

  3. Adaptive and Rational Anticipations in Risk Management Systems and Economy

    Science.gov (United States)

    Dubois, Daniel M.; Holmberg, Stig C.

    2010-11-01

    The global financial crisis of year 2009 is explained as a result of uncoordinated risk management decisions in business firms and economic organisations. The underlying reason for this can be found in the current financial system. As the financial market has lost much of its direct coupling to the concrete economy it provides misleading information to economic decision makers at all levels. Hence, the financial system has moved from a state of moderate and slow cyclical fluctuations into a state of fast and chaotic ones. Those misleading decisions can further be described, but not explained, by help of adaptive and rational expectations from macroeconomic theory. In this context, AE, the Adaptive Expectations are related to weak passive Exo-anticipation, and RE, the Rational expectations can be related to a strong, active and design oriented anticipation. The shortcomings of conventional cures, which builds on a reactive paradigm, have already been demonstrated in economic literature and are here further underlined by help of Ashby's "Law of Requisite Variety", Weaver's distinction between systems of "Disorganized Complexity" and those of "Organized Complexity", and Klir's "Reconstructability Analysis". Anticipatory decision-making is hence here proposed as a replacement to current expectation based and passive risk management. An anticipatory model of the business cycle is presented for supporting that proposition. The model, which is an extension of the Kaldor-Kalecki model, includes both retardation and anticipation. While cybernetics with the feedback process in control system deals with an explicit goal or purpose given to a system, the anticipatory system discussed here deals with a behaviour for which the future state of the system is built by the system itself, without explicit goal. A system with weak anticipation is based on a predictive model of the system, while a system with strong anticipation builds its own future by itself. Numerical simulations on

  4. Questions and answers on the Belgian model of integral end-of-life care: experiment? Prototype? : "Eu-euthanasia": the close historical, and evidently synergistic, relationship between palliative care and euthanasia in Belgium: an interview with a doctor involved in the early development of both and two of his successors.

    Science.gov (United States)

    Bernheim, Jan L; Distelmans, Wim; Mullie, Arsène; Ashby, Michael A

    2014-12-01

    This article analyses domestic and foreign reactions to a 2008 report in the British Medical Journal on the complementary and, as argued, synergistic relationship between palliative care and euthanasia in Belgium. The earliest initiators of palliative care in Belgium in the late 1970s held the view that access to proper palliative care was a precondition for euthanasia to be acceptable and that euthanasia and palliative care could, and should, develop together. Advocates of euthanasia including author Jan Bernheim, independent from but together with British expatriates, were among the founders of what was probably the first palliative care service in Europe outside of the United Kingdom. In what has become known as the Belgian model of integral end-of-life care, euthanasia is an available option, also at the end of a palliative care pathway. This approach became the majority view among the wider Belgian public, palliative care workers, other health professionals, and legislators. The legal regulation of euthanasia in 2002 was preceded and followed by a considerable expansion of palliative care services. It is argued that this synergistic development was made possible by public confidence in the health care system and widespread progressive social attitudes that gave rise to a high level of community support for both palliative care and euthanasia. The Belgian model of so-called integral end-of-life care is continuing to evolve, with constant scrutiny of practice and improvements to procedures. It still exhibits several imperfections, for which some solutions are being developed. This article analyses this model by way of answers to a series of questions posed by Journal of Bioethical Inquiry consulting editor Michael Ashby to the Belgian authors.

  5. Reward and punishment effects on error processing and conflict control

    Directory of Open Access Journals (Sweden)

    Birgit eStürmer

    2011-11-01

    Full Text Available Recently, positive mood has been shown to reduce cognitive conflicts and adaptation related to conflict control. Van Steenbergen et al. (2009 proposed that short-term adaptation after conflict is driven by the aversive quality of the conflict. They reasoned that monetary gain and its positive emotional consequences might counteract the aversive quality of the preceding conflict and hence reduce subsequent conflict-driven adaptation processes. According to Ashby et al. (1999, however, positive affect increases cognitive flexibility and might, therefore, support cognitive conflict control.In two experiments, we combined Simon-type conflicts with monetary gains and losses in between trials and analyzed event-related brain potentials (ERPs. In Experiment 1 gains and losses were applied randomly as a lottery in between two Simon trials whereas in the second experiment gains and losses were related to behavioral performance. Either the 25 % fastest responses were rewarded or the 25 % slowest responses were penalized. In Experiment 1 conflict adaptation was not at all modulated by gains and losses and in Experiment 2 conflict adaptation increased after a gain. In addition we analyzed the error-related negativity (ERN in Experiment 2 – a brain signal proposed to be related to the reward prediction error and response conflicts. The ERN and post-error slowing were enlarged in the context of reward. We conclude that a context of reward increases the subjective value of an error, thus, enhancing error adaptation. However, modulatory effects of affective states on cognitive conflict control are much more limited as previously asserted.

  6. Biological control of fruit flies (Diptera: Tephritidae) through parasitoid augmentative releases: Current status

    International Nuclear Information System (INIS)

    Montoya, Pablo; Liedo, Pablo

    2000-01-01

    Fruit flies are among the main pests affecting the world fruit industry (Aluja 1993). Bait sprays have traditionally been used successfully to control them; however, the side effects on the environment and health hazards commonly associated with pesticides, have resulted in strong public opposition to the use of bait sprays. This is particularly so when sprays are applied in urban areas or in coffee plantations where, although Medflies are present, they do not pose a danger to crops. Alternative methods that are effective and environmental friendly to suppress fruit fly populations are highly desirable. Biological control, the use of natural enemies to suppress pest populations, represents such an alternative. Some of the most successful cases of biological control are the control of Iceria purchasi Maskell (Homoptera: Margarodidae) by Rodolia cardinalis Mulsant (Coleoptera: Coccinellidae) in California (De Bach 1968, van den Bosch et al. 1982), and the control of Aleurocanthus woglumi Ashby (Homoptera: Aleyrodidae) mainly by Encarsia (=Prospaltella) opulenta Silv. (Hymenoptera: Aphelinidae) in Mexico (Jimenez 1961, 1971), both using the classical approach. However, this approach has been limited to certain conditions of environmental stability and biodiversity which are only found in a few ecosystems. Other factors, such as types of pests, the economic threshold and product quality requirements represent additional limitations. The best option in many cases could be augmentative biological control, which could overcome some of the deficiencies of the classical approach (Sivinski 1996). According to Knipling (1992) and Barclay (1987), augmentative biological control can be considered as a formal alternative for suppressing pest populations and even for use in eradication programmes, after integration with the sterile insect technique (SIT). In this approach, mass production of natural enemies is required and this production has to be cost effective

  7. STS-93 Mission Specialist Tognini drives an M-113 during training

    Science.gov (United States)

    1999-01-01

    Under the watchful eyes of KSC Fire Department trainer Capt. George Hoggard (seated on the front), STS-93 Mission Specialist Michel Tognini of France (right) drives the M-113 armored personnel carrier during emergency egress training at the launch pad. Tognini represents the Centre National d'Etudes Spatiales (CNES). At the far left is Roland Nedelkovich, with the Vehicle Integration Test Team, JSC. In preparation for their mission, the STS-93 crew are participating in Terminal Countdown Demonstration Test activities that also include a launch-day dress rehearsal culminating with a simulated main engine cut-off. Others in the crew participating are Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.) and Catherine G. Coleman (Ph.D.) Collins is the first woman to serve as a Shuttle commander. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which will allow scientists from around the world to obtain unprecedented X-ray images of exotic environments in space to help understand the structure and evolution of the universe. Chandra is expected to provide unique and crucial information on the nature of objects ranging from comets in our solar system to quasars at the edge of the observable universe. Since X-rays are absorbed by the Earth's atmosphere, space-based observatories are necessary to study these phenomena and allow scientists to analyze some of the greatest mysteries of the universe. The targeted launch date for STS-93 is no earlier than July 20 at 12:36 a.m. EDT from Launch Pad 39B.

  8. Flow curves of hcp-iron up to 19 GPa and 600 K using a combination of synchrotron radiation and the DDIA

    Science.gov (United States)

    Nishiyama, N.; Wang, Y.; Rivers, M. L.; Sutton, S. R.; Cookson, D.

    2006-12-01

    We performed in-situ X-ray diffraction and radiography experiments of hcp-iron up to 19 GPa and 600 K. Deformation experiments were performed at the GSECARS 13-BM-D beamline (APS) using a DDIA with a monochromatic X-ray diffraction and a radiographic imaging system. We used four tungsten carbide and two sintered diamond anvils with truncated edge length of 2 mm. Pressure medium was a mixture of boron and epoxy and a cylindrical graphite furnace was used. The starting material was a fragment of pure bcc-iron wire and two deformation pistons made of alumina were situated above and below the sample. First, the cell assembly was compressed uniformly at room temperature up to about 14 GPa. Then the sample was heated to about 700 K to convert bcc to hcp-iron. After the transformation, several deformation cycles were carried out, yielding five independent stress-strain curves with sample shortening at pressures up to 19 GPa and three different temperatures (600, 400, and 300 K). In all the curves, differential stresses reached saturation at about 3 percent strain, suggesting that deformation reached steady state. The differential stresses at steady state flow were 1.8-2.5 GPa, decreasing with increasing temperature and decreasing strain rate. Using isothermal mechanical data, we determined stress exponents (n) at 600 and 400 K, yielding 7 and 31, respectively. The mechanical data of hcp-iron are consistent with the deformation mechanism map of zinc (Ashby and Frost, 1981), which suggests that, at about 18 GPa, hcp-iron deforms in the Peierls plasticity (low-temperature plasticity) regime at 400 K whereas it deforms in the low-temperature power-law creep regime at 600 K. Thus, deformation mechanisms map of hcp-iron may be similar to those of other hexagonal metals, such as zinc.

  9. THE MACHINERY OF TIME MOVED TO IMAGINATION: RPG AND EMPATHY IN HISTORIC HISTORY OF EDUCATION

    Directory of Open Access Journals (Sweden)

    Juliano Pereira da Silva

    2014-12-01

    Full Text Available This Project arises from a desire to continue the monograph work done in 2010 in the course of Specialization in Teaching History and Social History at the State University of Londrina whose title was "The use RPG as a pedagogical tool in teaching history." The RPG proved to be a good teaching tool in that it aroused in students a love of history and his ability to put yourself in someone else's past, in other words, to establish an empathetic relationship with the past. It is the in-depth study of this relationship we wish to discuss. The historical empathy for Ashby & Lee serve as "a venture where students show the ability to reconstruct the goals, feelings, values and beliefs of others, accepting that they maybe different from your", thus becoming na important element in the teaching-learning process. The objective of this new phase was to verify the occurrence of historical empathic experience among students ofthe 6th year of the elementar school Professor Dr. Heber Soares Vargas of the content of history from a RPG game, watching their relationship in the seizure of historical concepts by students. This empathic experience occurred, helping many students to understand the concepts related to substantive matters studied from a historical perspective created in an RPG game. The project consisted of literature in order to define some concepts like game and the concept of historical empathy and its use in the teaching of history; creation of educational material, analysis of students' ideas and reflection on the experiment performed. Was conducted among the students of the sixth grade of elementary school in State College Professor. Dr. Heber Smith Vargas.

  10. Population increases and educational policies in Nigeria.

    Science.gov (United States)

    Fapohunda, O J

    1976-09-01

    Most governments today accept in principle that provision of education is a basic human right as embodied in article 26 of the Declaration of Human Rights. Through education, peace, good international relations, better prospects for economic developments, and improvement of human resources are possible. Despite this awareness, most governments cannot fulfill this requirement of education due to large population sizes, rapid growth and competition for scarce natural resources. An historical survey of the development of educational policies in Nigeria reveals that the Machiavellian policy of the colonial period largely created the present imbalance in the educational development of the Moslem north (where slow development was encouraged) compared to the Christian south. The 1st government participation in education by 1877 was minimal. The colonial government relied heavily on missionary educational activities. Political motives and religious conflicts between the northern and southern regions retarded missionary activities. Not until 1926 did active cooperation begin between the government and local states, reinforced by Elliot's Commission Report, the Phillipson Commission Report and the memorandum on Educational Policy in Nigeria. These reports laid out guidelines for government's aid and participation in provision of educational facilities. Post independence requirements for skilled manpower led to the adoption of the Ashby Commission Report as a basis for higher education. 1980 was set as the desired date for free compulsory education by a conference of African states. Nigeria, persuing this ideal goal, aimed at making education free at all levels and for every citizen. The burden and implications of these policies are examined in the context of projections of primary and secondary school enrollments, costs, and manpower needs. The cost of education is seen to rise with demand. By 1990, Nigeria will have about 24 million children to educate. With global

  11. Contribution of vortex structures and flow separation to local and overall pressure and heat transfer characteristics in an ultralightweight lattice material

    Energy Technology Data Exchange (ETDEWEB)

    Kim, T. [Seoul National Univ. (Korea). School of Mechanical and Aerospace Engineering; Hodson, H.P. [Cambridge Univ. (United Kingdom). Dept. of Engineering; Lu, T.J. [Cambridge Univ. (United Kingdom). Dept. of Engineering; Xian Jiaotong Univ., Xian (China). School of Aerospace

    2005-09-01

    Ultra lightweight lattice-frame materials (LFMs) with open, periodic microstructures are attractive multifunctional systems that can perform structural, thermal, actuation, power storage and other functions [A.G. Evans, J.W. Hutchinson, M.F. Ashby, Multifunctionality of cellular metal systems, Prog. Mater. Sci. 43 (1999) 171-221]. This paper presents experimental and numerical studies of local fluid flow behaviour and its contribution to local and overall pressure and heat transfer characteristics of such a lattice material with tetrahedral unit cells. A single layer of the LFM with porosity of 0.938 is sandwiched between impermeable endwalls that receive uniform heat flux and the heat transfer is subjected to forced air convection. Experimental measurements with particle image velocity (PIV) and thermochromic liquid crystal (TLC), backed by computational fluid mechanics (CFD) simulations, revealed two dominant local flow features in the LFM. Distinctive vortex structures near the vertices where the LFM meets the endwalls and flow separation on the surface of LFM struts were observed. The vortex structures formed around the vertices include horseshoe vortices and arch-shaped vortices. The horseshoe vortex increases local heat transfer on the endwall region up to 180% more than that in regions where the least influence of the horseshoe vortex is present. The arch-shaped vortex behind the vertices creates regions of flow recirculation and reattachment, leading to relatively high heat transfer. The location of flow separation along the struts varies with the spanwise position due to the presence of vertices (or endwalls). The regions on the strut surface before flow separation contribute approximately 40% of the total heat transfer in the LFM. The delay of the flow separation leads to an increase in the overall heat transfer. Comparisons with foams and other heat dissipation media such as packed beds, louvered fins and microtruss materials suggest that the LFMs

  12. "Self-critical perfectionism, daily stress, and disclosure of daily emotional events": Correction to Richardson and Rice (2015).

    Science.gov (United States)

    2016-01-01

    Reports an error in "Self-critical perfectionism, daily stress, and disclosure of daily emotional events" by Clarissa M. E. Richardson and Kenneth G. Rice (Journal of Counseling Psychology, 2015[Oct], Vol 62[4], 694-702). In the article, the labels of the two lines in Figure 1 were inadvertently transposed. The dotted line should be labeled High SCP and the solid line should be labeled Low SCP. The correct version is present in the erratum. (The following abstract of the original article appeared in record 2015-30890-001.) Although disclosure of stressful events can alleviate distress, self-critical perfectionism may pose an especially strong impediment to disclosure during stress, likely contributing to poorer psychological well-being. In the current study, after completing a measure of self-critical perfectionism (the Discrepancy subscale of the Almost Perfect Scale-Revised; Slaney, Rice, Mobley, Trippi, & Ashby, 2001), 396 undergraduates completed measures of stress and disclosure at the end of each day for 1 week. Consistent with hypotheses and previous research, multilevel modeling results indicated significant intraindividual coupling of daily stress and daily disclosure where disclosure was more likely when experiencing high stress than low stress. As hypothesized, Discrepancy moderated the relationship between daily stress and daily disclosure. Individuals higher in self-critical perfectionism (Discrepancy) were less likely to engage in disclosure under high stress, when disclosure is often most beneficial, than those with lower Discrepancy scores. These results have implications for understanding the role of stress and coping in the daily lives of self-critical perfectionists. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  13. Continuous functionally graded porous titanium scaffolds manufactured by selective laser melting for bone implants.

    Science.gov (United States)

    Han, Changjun; Li, Yan; Wang, Qian; Wen, Shifeng; Wei, Qingsong; Yan, Chunze; Hao, Liang; Liu, Jie; Shi, Yusheng

    2018-04-01

    A significant requirement for a bone implant is to replicate the functional gradient across the bone to mimic the localization change in stiffness. In this work, continuous functionally graded porous scaffolds (FGPSs) based on the Schwartz diamond unit cell with a wide range of graded volume fraction were manufactured by selective laser melting (SLM). The micro-topology, strut dimension characterization and effect of graded volume fraction on the mechanical properties of SLM-processed FGPSs were systematically investigated. The micro-topology observations indicate that diamond FGPSs with a wide range of graded volume fraction from 7.97% to 19.99% were fabricated without any defects, showing a good geometric reproduction of the original designs. The dimensional characterization demonstrates the capability of SLM in manufacturing titanium diamond FGPSs with the strut size of 483-905µm. The elastic modulus and yield strength of the titanium diamond FGPSs can be tailored in the range of 0.28-0.59GPa and 3.79-17.75MPa respectively by adjusting the graded volume fraction, which are comparable to those of the cancellous bone. The mathematical relationship between the graded porosity and compression properties of a FGPS was revealed. Furthermore, two equations based on the Gibson and Ashby model have been established to predict the modulus and yield strength of SLM-processed diamond FGPSs. Compared to homogeneous diamond porous scaffolds, FGPSs provide a wide range of mutative pore size and porosity, which are potential to be tailored to optimize the pore space for bone tissue growth. The findings provide a basis of new methodologies to design and manufacture superior graded scaffolds for bone implant applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. VizieR Online Data Catalog: Follow-up study of gal. & AGNs in z>1 clusters (Alberts+, 2016)

    Science.gov (United States)

    Alberts, S.; Pope, A.; Brodwin, M.; Chung, S. M.; Cybulski, R.; Dey, A.; Eisenhardt, P. R. M.; Galametz, A.; Gonzalez, A. H.; Jannuzi, B. T.; Stanford, S. A.; Snyder, G. F.; Stern, D.; Zeimann, G. R.

    2016-08-01

    In this work, we concentrate our analysis on 11 spectroscopically confirmed clusters from the IRAC Shallow/Distant Cluster Survey (ISCS/IDCS) that we observed with Herschel/PACS at 100 and 160um, obtained during Open Time 2 observing (PID: OT2apope3) (summary of imaging in table 6 spanning from June 2012 to January 2013). Given the resolution of PACS (FWHM~6.7" at 100um and 11" at 160um), we expect the majority of sources and all cluster galaxies in our maps to be point sources. See sections 2.1 and 2.3 for further details. The IRAC Shallow Survey (ISS) was followed up with three more observations as part of SDWFS (Ashby et al. 2009, see J/ApJ/716/530), providing a factor of 2 deeper IRAC catalog with an aperture-corrected 5σ limit of 5.2uJy at 4.5um ([4.5]=18.83mag). Spitzer/MIPS observations are available from the MIPS AGM and Galaxy Evolution Survey (MAGES; Jannuzi et al. 2010AAS...21547001J). See section 2.4 for further details. Targeted follow up campaigns by our group have obtained spectroscopic redshifts for galaxies and AGNs in z>1 clusters using multi-object Keck optical spectroscopy and Wide Field Camera 3 (WFC3) slitless NIR grism spectroscopy from the Hubble Space Telescope (HST). The reader is directed to Brodwin et al. (2013ApJ...779..138B), Zeimann et al. (2013, J/ApJ/779/137), and references therein for a detailed description of the targeted spectroscopy. Some spectroscopic redshifts are additionally provided by the AGN and Galaxy Evolution Survey (AGES; Kochanek et al. 2012, J/ApJS/200/8). See section 2.2. (3 data files).

  15. Burdale: An Anglian Settlement in the Yorkshire Wolds (Data Paper

    Directory of Open Access Journals (Sweden)

    Julian D. Richards

    2013-11-01

    Full Text Available The Burdale digital archive (Richards and Roskams 2013 comprises a broad range of primary and secondary data derived from fieldwork and post-excavation analysis. It complements the summary report published as Richards and Roskams (2012. Full stratigraphic reports are downloadable for each season of excavation and can be related to the sequence of CAD plans also available. These can, in turn, be set within the wider site map derived from aerial photography and geophysical survey. Final reports are available for the pottery, spindlewhorls, and worked bone and antler (Ashby 2013. Other finds are simply listed in the finds databases, split by excavation year, with some preliminary notes on the ironwork included in the investigative conservation reports. The non-ferrous finds assemblage was largely missing, apart from a small number of topsoil finds recovered during metal detector surveys. Given the alleged wealth of the site, and the interest in it from 'nighthawks' we have to assume that unfortunately, most of the coinage and copper alloy metalwork has been collected from the ploughsoil over many years and is in private hands or has been sold for profit. In common with other Yorkshire sites Burdale produced very little early medieval pottery but this is likely to be a real absence rather than a product of recovery bias. The animal bone assemblage (Richardson 2010 is one of the most important elements of the archive. Over 300 images are also presented, split by year of excavation. The file downloads are organised in 3 groups: those relating to the whole project and those specifically related to excavations in 2006 (BUR06 or 2007 (BUR07. Referee statement by Gabor Thomas

  16. Working with "rookies": A case study of science teachers mentors

    Science.gov (United States)

    Meagher, Thomas Francis

    To gain insight into the world of mentoring new science teachers it is imperative to examine how a veteran science teacher is influenced through his or her work mentoring a new teacher. The impacts of mentoring new teachers have been extensively researched within the literature, documenting many of the factors that may enhance the teaching abilities of new teachers (Hobson, Ashby, Malderez & Tomlinson, 2008; Ingersoll & Kralik, 2004; Wang & Odell, 2002). A thorough search of the literature reveals an unbalanced representation of research focusing on the many influences mentoring may bring to a new teacher while ignoring the impact on the mentor. It is when the activity of mentoring a new teacher is examined within the theoretical frame work of social cognitive learning, it is apparent that not only are two individuals participating in working together, but also that research needs to investigate both sides of the relationship. Also, since the mentoring relationship is situated within a community of practice, it becomes important to utilize a situated learning theoretical framework in tandem with social cognitive learning to provide the clearest picture of this dynamic social relationship. This case study seeks to share the impacts experienced by mentors through their work with new teachers and provide balance to the other side of research into the social partnership of mentoring. Five science teachers mentoring new teachers online, through the University of Minnesota's Science Engineering, Math Mentoring Program (STEMMP) and Science Teacher Induction Network (TIN), participated in this study that explores their experiences through a phenomenographic lens and follows an interpretive research approach. Four main themes emerged that identified how science teacher mentors were impacted from mentoring which included: (1) impacts to their teaching practice, (2) perceptions influenced from feedback, (3) enhanced reflection, and (4) enhancement of self-efficacy. The

  17. Distribución de bacterias potencialmente fijadoras de nitrógeno y su relación con parámetros fisicoquímicos en suelos con tres coberturas vegetales en el sur de la Amazonia colombiana

    Directory of Open Access Journals (Sweden)

    Andrea J Mantilla-Paredes

    2009-12-01

    Full Text Available Se evaluó la abundancia y distribución de bacterias microaerófilas y aerobias potencialmente fijadoras de nitrógeno aisladas a partir de suelos bajo coberturas de bosque, pastizal y chagra en dos paisajes, terraza y llanura inundable, en el sur de trapecio amazónico. Se relacionó el recuento en placa en el medio Ashby de estas bacterias aerobias con las características físicas y químicas del suelo. Se encontró mayor abundancia de bacterias aerobias y microaerofilas en suelos bajo cobertura de pastizal. Se observó influencia directa del paisaje sobre la abundancia de bacterias microaerófilas registrando mayores recuentos los suelos bajo terraza en las coberturas de bosque y pastizal. Los aislamientos aerobios obtenidos (51 se agruparon en 19 morfologías, de las cuales se obtuvo mayor número en suelos bajo bosque y en el paisaje de llanura inundable. A través del análisis multidimensional no métrico (NMDS y análisis de similaridades (ANOSIM (pDistribution of potentially nitrogen-fixing bacteria and its relationship with physicochemical parameters in soils with three vegetation types in the southern Colombian Amazon region. Potentially nitrogen-fixing microaerobic and aerobic bacteria were isolated from several Colombian Amazon soils (forest, pastures and chagras and two landscapes (floodable and non floodable areas. The abundance and distribution of bacteria were evaluated, as well as their relationship with soil physical and chemical characteristics. Landscape had a direct influence on the abundance of the microaerobic bacteria, with higher numbers in forest and pasture soils in non- floodable zones. The aerobic isolates (N=51 were grouped into 19 morphologies, with the highest numbers found in forest soil in floodable zones. A higher number of aerobic morphologies was shared among forest sites (Nonmetric Multidimensional Scaling and Analysis of Similarity p<0.05, and 40% of the distribution was explained by lime percentage and

  18. Carbon Sequestration on Surface Mine Lands

    Energy Technology Data Exchange (ETDEWEB)

    Donald Graves; Christopher Barton; Richard Sweigard; Richard Warner; Carmen Agouridis

    2006-03-31

    Since the implementation of the federal Surface Mining Control and Reclamation Act of 1977 (SMCRA) in May of 1978, many opportunities have been lost for the reforestation of surface mines in the eastern United States. Research has shown that excessive compaction of spoil material in the backfilling and grading process is the biggest impediment to the establishment of productive forests as a post-mining land use (Ashby, 1998, Burger et al., 1994, Graves et al., 2000). Stability of mine sites was a prominent concern among regulators and mine operators in the years immediately following the implementation of SMCRA. These concerns resulted in the highly compacted, flatly graded, and consequently unproductive spoils of the early post-SMCRA era. However, there is nothing in the regulations that requires mine sites to be overly compacted as long as stability is achieved. It has been cultural barriers and not regulatory barriers that have contributed to the failure of reforestation efforts under the federal law over the past 27 years. Efforts to change the perception that the federal law and regulations impede effective reforestation techniques and interfere with bond release must be implemented. Demonstration of techniques that lead to the successful reforestation of surface mines is one such method that can be used to change perceptions and protect the forest ecosystems that were indigenous to these areas prior to mining. The University of Kentucky initiated a large-scale reforestation effort to address regulatory and cultural impediments to forest reclamation in 2003. During the three years of this project 383,000 trees were planted on over 556 acres in different physiographic areas of Kentucky (Table 1, Figure 1). Species used for the project were similar to those that existed on the sites before mining was initiated (Table 2). A monitoring program was undertaken to evaluate growth and survival of the planted species as a function of spoil characteristics and

  19. Carbon nanotube-copper exhibiting metal-like thermal conductivity and silicon-like thermal expansion for efficient cooling of electronics.

    Science.gov (United States)

    Subramaniam, Chandramouli; Yasuda, Yuzuri; Takeya, Satoshi; Ata, Seisuke; Nishizawa, Ayumi; Futaba, Don; Yamada, Takeo; Hata, Kenji

    2014-03-07

    Increasing functional complexity and dimensional compactness of electronic devices have led to progressively higher power dissipation, mainly in the form of heat. Overheating of semiconductor-based electronics has been the primary reason for their failure. Such failures originate at the interface of the heat sink (commonly Cu and Al) and the substrate (silicon) due to the large mismatch in thermal expansion coefficients (∼300%) of metals and silicon. Therefore, the effective cooling of such electronics demands a material with both high thermal conductivity and a similar coefficient of thermal expansion (CTE) to silicon. Addressing this demand, we have developed a carbon nanotube-copper (CNT-Cu) composite with high metallic thermal conductivity (395 W m(-1) K(-1)) and a low, silicon-like CTE (5.0 ppm K(-1)). The thermal conductivity was identical to that of Cu (400 W m(-1) K(-1)) and higher than those of most metals (Ti, Al, Au). Importantly, the CTE mismatch between CNT-Cu and silicon was only ∼10%, meaning an excellent compatibility. The seamless integration of CNTs and Cu was achieved through a unique two-stage electrodeposition approach to create an extensive and continuous interface between the Cu and CNTs. This allowed for thermal contributions from both Cu and CNTs, resulting in high thermal conductivity. Simultaneously, the high volume fraction of CNTs balanced the thermal expansion of Cu, accounting for the low CTE of the CNT-Cu composite. The experimental observations were in good quantitative concurrence with the theoretically described 'matrix-bubble' model. Further, we demonstrated identical in-situ thermal strain behaviour of the CNT-Cu composite to Si-based dielectrics, thereby generating the least interfacial thermal strain. This unique combination of properties places CNT-Cu as an isolated spot in an Ashby map of thermal conductivity and CTE. Finally, the CNT-Cu composite exhibited the greatest stability to temperature as indicated by its low

  20. A comparative study of bio-inspired protective scales using 3D printing and mechanical testing.

    Science.gov (United States)

    Martini, Roberto; Balit, Yanis; Barthelat, Francois

    2017-06-01

    Flexible natural armors from fish, alligators or armadillo are attracting an increasing amount of attention for their unique combinations of hardness, flexibility and light weight. The extreme contrast of stiffness between hard scales and surrounding soft tissues gives rise to unusual and attractive mechanisms, which now serve as models for the design of bio-inspired armors. Despite this growing interest, there is little guideline for the choice of materials, optimum thickness, size, shape and arrangement for the protective scales. In this work, we explore how the geometry and arrangement of hard scales can be tailored to promote scale-scale interactions. We use 3D printing to fabricate arrays of scales with increasingly complex geometries and arrangements, from simple squares with no overlap to complex ganoid-scales with overlaps and interlocking features. We performed puncture tests and flexural tests on each of the 3D printed materials, and we report the puncture resistance - compliance characteristics of each design on an Ashby chart. The interactions between the scales can significantly increase the resistance to puncture, and these interactions can be maximized by tuning the geometry and arrangement of the scales. Interestingly, the designs that offer the best combinations of puncture resistance and flexural compliance are similar to the geometry and arrangement of natural teleost and ganoid scales, which suggests that natural evolution has shaped these systems to maximize flexible protection. This study yields new insights into the mechanisms of natural dermal armor, and also suggests new designs for personal protective systems. Flexible natural armors from fishes, alligators or armadillos are attracting an increasing amount of attention for their unique and attractive combinations of hardness, flexibility and low weight. Despite a growing interest in bio-inspired flexible protection, there is still little guideline for the choice of materials, optimum

  1. NASA Managers Set July 20 As Launch Date for Chandra Telescope

    Science.gov (United States)

    1999-07-01

    NASA managers set Tuesday, July 20, 1999, as the official launch date for NASA's second Space Shuttle Mission of the year that will mark the launch of the first female Shuttle Commander and the Chandra X-Ray Observatory. Columbia is scheduled to liftoff from Launch Pad 39-B at the Kennedy Space Center on July 20 at the opening of a 46-minute launch window at 12:36 a.m. EDT. Columbia's planned five-day mission is scheduled to end with a night landing at the Kennedy Space Center just after 11:30 p.m. EDT on July 24. Following its deployment from the Shuttle, Chandra will join the Hubble Space Telescope and the Compton Gamma Ray Observatory as the next in NASA's series of "Great Observatories." Chandra will spend at least five years in a highly elliptical orbit which will carry it one-third of the way to the moon to observe invisible and often violent realms of the cosmos containing some of the most intriguing mysteries in astronomy ranging from comets in our solar system to quasars at the edge of the universe. Columbia's 26th flight is led by Air Force Col. Eileen Collins, who will command a Space Shuttle mission following two previous flights as a pilot. The STS-93 Pilot is Navy Captain Jeff Ashby who will be making his first flight into space. The three mission specialists for the flight are: Air Force Lt. Col. Catherine "Cady" Coleman, who will be making her second flight into space; Steven A. Hawley, Ph.D, making his fifth flight; and French Air Force Col. Michel Tognini of the French Space Agency (CNES), who is making his first Space Shuttle flight and second trip into space after spending two weeks on the Mir Space Station as a visiting cosmonaut in 1992. NASA press releases and other information are available automatically by sending an Internet electronic mail message to domo@hq.nasa.gov. In the body of the message (not the subject line) users should type the words "subscribe press-release" (no quotes). The system will reply with a confirmation via E-mail of

  2. Refractory metal superalloys: Design of yttrium aluminum garnet passivating niobium alloys

    Science.gov (United States)

    Bryan, David

    A systems-based approach, integrating computational modeling with experimental techniques to approach engineering problems in a time and cost efficient manner, was employed to design a Nb-based refractory superalloy for use at 1300°C. Ashby-type selection criteria for both thermodynamic and kinetic parameters were employed to identify a suitable protective oxide for Nb alloys. Yttrium aluminum garnet (YAG) was selected as the most promising candidate for its excellent combination of desirable properties. The alloy microstructural concept was based upon the gamma - gamma' nickel-based superalloys in which the multifunctional gamma' phase serves as both a creep strengthening dispersion and a source of reactive elements for oxide passivation. Candidate ternary Pd-Y-Al and Pt-Y-Al compounds were fabricated and characterized by XRD and DTA. Of the intermetallics studied, only PtYAl had a high enough melting point (1580°C) for use in an alloy operating at 1300°C. The alloy matrix design was based upon Wahl's extension of Wagner's criterion for protective oxidation, requiring a reduction of the product N ODO/DAl by 5 orders of magnitude relative to binary Nb-Al. A thermodynamic and kinetic analysis identified elements with large oxygen affinities as the most beneficial for reducing the magnitude of the quantity NOD O. Construction of a combined thermodynamic and mobility database identified increased Al solubility as the best approach for increasing D Al. Utilizing the thermodynamic and mobility databases, obtained from a combination of model alloys, oxidation experiments, and first principles calculations, theoretical designs predicted the large changes in solubility and transport parameters were achievable. Several prototype alloys were then fabricated and evaluated via oxidation tests at both 1300°C and 1100°C. YAG formation was demonstrated as part of multicomponent oxide scales in the alloys that exhibited the greatest reduction in oxidation rates. The oxidation

  3. Hierarchies of description of energy systems ИЕРАРХИИ ПРЕДСТАВЛЕНИЯ ЭНЕРГЕТИЧЕСКИХ СИСТЕМ

    Directory of Open Access Journals (Sweden)

    Volkov Andrey Anatol'evich

    2013-01-01

    Full Text Available The author considers one of the most important tasks to be tackled in the course of modeling of processes or phenomena, that is, identification of the degree of detail of a description. It is also applicable to energy systems and their efficiency. This task has a particular significance as any researcher needs to attribute names to the system elements and their states. This discussion originates from the basic provisions of the Ashby principles and fundamentals of the modeling of information systems in the realm of generalized states, or situations. A model should take a proper account of the fact that some information is lost whenever more detailed level of description is replaced by the less detailed one. Thus, the task consists in the hierarchical description of functioning systems. We introduce the hyper-system model to solve this task.The mathematical theory set forth in the paper proves that any losses of information about some object are inevitable whenever the level of description is changed. One may see new logical and mathematical problems arising in this field. For example, there is still no answer to the question how “deep” we can advance in our studies of hierarchical systems.Затронут вопрос, касающийся моделирования энергетических систем и их эффективности. Описан подход к решению задачи об иерархическом представлении функционирующих систем, базирующийся на модели гиперсистемы.

  4. The Time Is Now: Bioethics and LGBT Issues.

    Science.gov (United States)

    Powell, Tia; Foglia, Mary Beth

    2014-09-01

    disparities. Stephan Davis and Nancy Berlinger assess the challenges of access to care and health policy for transgender persons. Edward J. Callahan et al. tackle the ways in which diverse aspects of medicine should change to better incorporate the needs of LGBT patients, including through use of the electronic medical record, education of health professionals, and recruitment efforts for LGBT health professionals. Virginia Ashby Sharpe and Uchenna S. Uchendu describe multifaceted efforts within Veterans Administration facilities to create change for LGBT veterans across the largest integrated health care network in the United States. Lance Wahlert and Autumn Fiester find a mixed record in the use of case studies in teaching about LGBT issues. © 2014 by The Hastings Center.

  5. METASYSTEMIC TECHNOLOGY OF INSTRUCTION, STUDENT RESEARCH AND INNOVATION

    Directory of Open Access Journals (Sweden)

    Dumitru BALANEL

    2017-07-01

    Full Text Available Metasystemic technology of training, student research and innovation (D.Balanel – MTTRI is the development of educational technology J.F. Herbart by cybernetic, metasystem approach, feedbacks, diffusion of knowledges, com­petences in real time, intuition and with application in high education. “Metasystemic technology training, student research and innovation (D.Balanel” is introducing in science by author. Technology is based on metasystem, including pedagogy, psychology, management, cybernetics, mathematics.The paper discusses training, student-centered and competence-centered, the equation of training, equation of training with notes early, appropriate to Bologna Process, ways to educate interest and research capabilities, innovation of students; studying the factors that determine the student make transition to self-knowledge accumulation, learn with satisfaction the research and innovation, transition from apperception to intuition. The author relies on metasystemic training technology, skills to work in real time, using student thesaurus from computer science, informatics and history of cybernetics; learn experience and performance of the most eminent personalities in the development of computer science and cybernetics, Norbert Wiener and Alain Turing, William Ross Ashby and John von Neumann, others personalities, holding the Turing and Neumann and other Awards in cybernetics and informatics . Scientific education of students includes identifying scientific issues, enrollment of students in research. Identifying the scientific problems inherited as millennial problems in mathematics and computer science, current issues and future of science; incentives in applying forces young people to solve them. The enrollment of students in scientific work is done by conducting research with students on issues of university research in the scientific teams, scientific laboratories and simulators, training. The result of "IRI–triangle activity

  6. Multilevel stake holder consensus building in radioactive waste management

    International Nuclear Information System (INIS)

    Dreimanis, Andrejs

    2008-01-01

    Full text: The increased demand of our society to its quality of life, global security and environmental safety as well as to observing a basic ethical principle of equity have advanced our attitude towards the recent proposals to develop shared multinational projects in the use of nuclear energy technologies, in particular, to: a) Siting of shared deep repositories for high-level radioactive waste (RW) and spent nuclear fuel safe disposal. In turn, arrangement of multinational facilities requires to gain more complex consensus between all involved parties. Method: We propose an interdisciplinary synergetic approach to multilevel consensus building for siting and construction of shared multinational repositories for RW deep disposal, based on self-organization (SO) of various stake holders, chaos and fuzziness concepts as well as Ashby principle of requisite variety. In the siting of a multi-national repository there appears an essential novel component of stake holder consensus building, namely: to reach consent - political, social, economic, ecological - among international partners, in addition to solving the whole set of intra-national consensus building items. An entire partnering country is considered as a national stake holder, represented by the national government, being faced to simultaneous seeking an upward (international) and a downward (intra-national) consensus in a psychologically stressed environment, having possibly diverse political, economic and social interests. Main Results: Following inferences about building of multilevel consensus are developed: 1) The basis of synergetic approach to stake holder interaction - informational SO, by forming a knowledge-creating stake holder community via cooperation and competition among individuals, public bodies/groups, companies, institutions; 2) Building of international stake holder consensus could be promoted by activating and diversifying multilateral interactions between intra- and international stake

  7. Creep Deformation and Fracture Processes in OF and OFP Copper

    International Nuclear Information System (INIS)

    Bowyer, William H.

    2004-10-01

    The literature on creep processes in many materials, including copper, has been thoroughly reviewed and complemented by Ashby and co-workers. They have provided physical models which describe the deformation and fracture processes with good qualitative and quantitative agreement with experimental data for many cases. A description of the deformation and fracture models is provided and the relevant equations are included in the appendices. Published data from the canister development programme has been compared with the predictions from the models. The purpose was to improve our understanding of (1) a reported benefit to creep performance which arises from additions of 50 ppm phosphorus to oxygen free (OF) copper, and (2) an observed transition from brittle to ductile failure in OF copper. The models adequately describe the general variations in the observed creep behaviour of the experimental materials. Steady state creep rates for OF copper are observed to be up to one order of magnitude higher than the model predicts for pure copper across a wide range of temperatures and stresses in the power law and power law breakdown regimes. For OF copper with 50ppm of phosphorus added (OFP copper), observed steady state creep rates in the power law breakdown regime are up to one order of magnitude lower than the model predicts for pure copper. Creep lives in the experimental OFP material are also higher than creep lives for OF material under similar conditions. The lower creep deformation rates and the longer creep lives of OFP material are attributed the known effects of phosphorus on recovery in copper. The model predicts that the same mechanism will improve creep lives under repository conditions. It is suggested that the factor of improvement under repository conditions will be less than the factor which is observed in the power law breakdown regime. Predicted creep lives, based on measured steady state creep rates and stress exponents ('n' values) are in good agreement

  8. Inoculación de Cilantro (Coriandrum sativum L. con Rizobacterias en Villa del Rosario, Norte de Santander / Inoculation of Cilantro (Coriandrum sativum L. with Rhizobacterias in Villa del Rosario, Norte de Santander

    Directory of Open Access Journals (Sweden)

    Katherine Carrillo Becerra

    2014-12-01

    Full Text Available Resumen. Las rizobacterias promotoras de crecimiento vegetalrepresentan una alternativa de biofertilización. En este estudiose evaluó el efecto de su inoculación en plantas de cilantro y lautilización de la práctica de quema de cascarilla de arroz en lapreparación del suelo para el establecimiento del cultivo. Seempleó un diseño experimental en parcelas divididas donde, lasparcelas principales correspondieron a la preparación del suelo conquema de cascarilla de arroz y sin quema con la inoculación previade Trichoderma sp. Las subparcelas eran los tratamientos con lainoculación simple y en co-inoculación de Azospirillum RzH132y Azotobacter RzH120 y los testigos absoluto y químico. Unavez se comprobaron los supuestos en los residuales del modelo,normalidad, homogeneidad de varianzas y aleatoriedad, se realizóel análisis de varianza y pruebas de comparación múltiple porel test de Tukey y un análisis de componentes principales comotécnica de reducción de dimensiones. Los resultados mostraronun efecto positivo en el crecimiento de las plantas inoculadas conlas rizobacterias en las dos parcelas con quema y sin quema decascarilla de arroz; sin embargo, en la variable rendimiento nose obtuvieron diferencias significativas (P≤0,05. Así mismo, seencontró que la población de bacterias rizosféricas en los mediosde cultivo NFb semisólido, Ashby y King B, se vio favorecida por lano quema de cascarilla de arroz en el suelo. Es importante resaltarque los resultados se obtuvieron con la disminución al 30% de lafertilización química, con lo cual se puede reducir el uso de estosproductos químicos. /  Abstract. Plant growth promoting rhizobacteria (PGPR representan alternative biofertilization form. In this study, was evaluatedPGPR inoculation in cilantro plants. Likewise, was evaluatedthe practice of burning rice husk in soil preparation for cropestablishment. An experimental design was used in a split plotwhere the main plots were

  9. Time and Temperature Dependence of Viscoelastic Stress Relaxation in Gold and Gold Alloy Thin Films

    Science.gov (United States)

    Mongkolsuttirat, Kittisun

    modulus relaxation of Au films also proves that the films exhibit linear viscoelastic behavior. From this, a linear viscoelastic model is shown to fit very well to experimental steady state stress relaxation data and can predict time dependent stress for complex loading histories including the ability to predict stress-time behavior at other strain rates during loading. Two specific factors that are expected to influence the viscoelastic behavior-degree of alloying and grain size are investigated to explore the influence of V concentration in solid solution and grain size of pure Au. It is found that the normalized modulus of Au films is dependent on both concentration (C) and grain size (D) with proportionalities of C1/3 and D 2, respectively. A quantitative model of the rate-equation for dislocation glide plasticity based on Frost and Ashby is proposed and fitted well with steady state anelastic stress relaxation experimental data. The activation volume and the density of mobile dislocations is determined using repeated stress relaxation tests in order to further understand the viscoelastic relaxation mechanism. A rapid decrease of mobile dislocation density is found at the beginning of relaxation, which correlates well with a large reduction of viscoelastic modulus at the early stage of relaxation. The extracted activation volume and dislocation mobility can be ascribed to mobile dislocation loops with double kinks generated at grain boundaries, consistent with the dislocation mechanism proposed for the low activation energy measured in this study.

  10. High-Temperature Cast Aluminum for Efficient Engines

    Science.gov (United States)

    Bobel, Andrew C.

    Accurate thermodynamic databases are the foundation of predictive microstructure and property models. An initial assessment of the commercially available Thermo-Calc TCAL2 database and the proprietary aluminum database of QuesTek demonstrated a large degree of deviation with respect to equilibrium precipitate phase prediction in the compositional region of interest when compared to 3-D atom probe tomography (3DAPT) and transmission electron microscopy (TEM) experimental results. New compositional measurements of the Q-phase (Al-Cu-Mg-Si phase) led to a remodeling of the Q-phase thermodynamic description in the CALPHAD databases which has produced significant improvements in the phase prediction capabilities of the thermodynamic model. Due to the unique morphologies of strengthening precipitate phases commonly utilized in high-strength cast aluminum alloys, the development of new microstructural evolution models to describe both rod and plate particle growth was critical for accurate mechanistic strength models which rely heavily on precipitate size and shape. Particle size measurements through both 3DAPT and TEM experiments were used in conjunction with literature results of many alloy compositions to develop a physical growth model for the independent prediction of rod radii and rod length evolution. In addition a machine learning (ML) model was developed for the independent prediction of plate thickness and plate diameter evolution as a function of alloy composition, aging temperature, and aging time. The developed models are then compared with physical growth laws developed for spheres and modified for ellipsoidal morphology effects. Analysis of the effect of particle morphology on strength enhancement has been undertaken by modification of the Orowan-Ashby equation for 〈110〉 alpha-Al oriented finite rods in addition to an appropriate version for similarly oriented plates. A mechanistic strengthening model was developed for cast aluminum alloys containing

  11. Microstructural analysis of the thermal annealing of ice-Ih using EBSD

    Science.gov (United States)

    Hidas, Károly; Tommasi, Andréa; Mainprice, David; Chauve, Thomas; Barou, Fabrice; Montagnat, Maurine

    2017-04-01

    . Decrease in average intragranular misorientation at the sample scale and modification of the misorientation across subgrain boundaries provide evidence for recovery from the earliest stages of annealing. This evolution is similar for all studied samples irrespective of their initial strain or annealing temperature. After an incubation period up to 2 hours, recovery is accompanied by recrystallization (nucleation and grain boundary migration). Grain growth proceeds at the expense of domains with high intra-granular misorientations and its kinetics fits the parabolic growth law. Deformation-induced microstructures (tilt boundaries and kink bands) are stable features during early stages of static recrystallization and locally slow down grain boundary migration, pinning grain growth. REFERENCES 1. Duval, P., Ashby, M.F., Anderman, I., 1983. Rate-controlling processes in the creep of polycrystalline ice. Journal of Physical Chemistry 87, 4066-4074. 2. Grennerat, F., Montagnat, M., Castelnau, O., Vacher, P., Moulinec, H., Suquet, P., Duval, P., 2012. Experimental characterization of the intragranular strain field in columnar ice during transient creep. Acta Materialia 60, 3655-3666. 3. Chauve, T., Montagnat, M., Vacher, P., 2015. Strain field evolution during dynamic recrystallization nucleation: A case study on ice. Acta Materialia 101, 116-124. Funding: Research leading to these results was funded by the EU-FP7 Marie Curie postdoctoral grant PIEF-GA-2012-327226 to K.H.

  12. Foreword: In situ gas surface interactions: approaching realistic conditions

    Science.gov (United States)

    Lundgren, Edvin; Over, Herbert

    2008-03-01

    Weilach C 2008 Spectroscopic studies of surface-gas interactions and catalyst restructuring at ambient pressure: mind the gap! J. Phys.: Condens. Matter 20 184019 [14] Evans M and Tromp M 2008 Interaction of small gas phase molecules with alumina supportedrhodium nanoparticles: an in situ spectroscopic study J. Phys.: Condens. Matter 20 184020 [15] Stampfl C, Soon A, Piccinin S, Shi H and Zhang H 2008 Bridging the temperature and pressure gaps: close-packed transition metal surfaces in an oxygen environment J. Phys.: Condens. Matter 21 184021 [16] Li W-X 2008 Oxidation of platinum surfaces and reaction with carbon monoxide J. Phys.: Condens. Matter 20 184022 [17] Seriani N and Mittendorfer F 2008 Platinum-group and noble metals under oxidizing conditions J. Phys.: Condens. Matter 20 184023 [18] Ketteler G, Ashby P, Mun B S, Ratera I, Bluhm H, Kasemo B and Salmeron M 2008 In situ photoelectron spectroscopy study of water absorption on model biomaterial surfaces J. Phys.: Condens. Matter 20 184024 [19] Yamamoto S, Bluhm H, Andersson K, Ketteler G, Ogasawara H, Salmeron M and Nilsson A 2008 In situ x-ray photoelectron spectroscopy studies of water on metals and oxides at ambient conditions J. Phys.: Condens. Matter 20 184025

  13. EDITORIAL: Special issue on applied neurodynamics: from neural dynamics to neural engineering Special issue on applied neurodynamics: from neural dynamics to neural engineering

    Science.gov (United States)

    Chiel, Hillel J.; Thomas, Peter J.

    2011-12-01

    Tracing technologies back in time to their scientific and mathematical origins reveals surprising connections between the pure pursuit of knowledge and the opportunities afforded by that pursuit for new and unexpected applications. For example, Einstein's desire to eliminate the disparity between electricity and magnetism in Maxwell's equations impelled him to develop the special theory of relativity (Einstein 1922)Einstein 1922 p 41 'The advance in method arises from the fact that the electric and magnetic fields lose their separate existences through the relativity of motion. A field which appears to be purely an electric field, judged from one system, has also magnetic field components when judged from another inertial system.'. His conviction that there should be no privileged inertial frame of reference Einstein 1922 p 58 'The possibility of explaining the numerical equality of inertia and gravitation by the unity of their nature gives to the general theory of relativity, according to my conviction, such a superiority over the conceptions of classical mechanics, that all the difficulties encountered must be considered as small in comparison with this progress.' further impelled him to utilize the non-Euclidean geometry originally developed by Riemann and others as a purely hypothetical alternative to classical geometry as the foundation for the general theory of relativity. Nowadays, anyone who depends on a global positioning system—which now includes many people who own smart phones—uses a system that would not work effectively without incorporating corrections from both special and general relativity (Ashby 2003). As another example, G H Hardy famously proclaimed his conviction that his work on number theory, which he pursued for the sheer love of exploring the beauty of mathematical structures, was unlikely to find any practical applications (Hardy 1940)Hardy 1940 pp 135-6 'The general conclusion, surely, stands out plainly enough. If useful knowledge