10,747 research outputs found

    Studying agile organizational design to sustain innovation.

    Get PDF
    Innovation is a core part of software development companies, frequently determined by organizational design variables including structure, capacity for learning, for change and adaptation. Agile software methods have evolved as approaches to promote agility and innovativeness in software development organizations. However, little research has examined organizational innovativeness and its relationship with organizational design and adoption of agile methods. In this work, we propose a conceptual framework to characterize innovation?s prone and averse patterns on organizational design in agile companies by measuring diffusion and integration of technologies and practices within individual, team, organizational, and environmental levels

    Search for Associations Containing Young stars (SACY): Chemical tagging IC 2391 & the Argus association

    Full text link
    We explore the possible connection between the open cluster IC 2391 and the unbound Argus association identified by the SACY survey. In addition to common kinematics and ages between these two systems, here we explore their chemical abundance patterns to confirm if the two substructures shared a common origin. We carry out a homogenous high-resolution elemental abundance study of eight confirmed members of IC 2391 as well as six members of the Argus association using UVES spectra. We derive spectroscopic stellar parameters and abundances for Fe, Na, Mg, Al, Si, Ca, Ti, Cr, Ni and Ba. All stars in the open cluster and Argus association were found to share similar abundances with the scatter well within the uncertainties, where [Fe/H] = -0.04 +/-0.03 for cluster stars and [Fe/H] = -0.06 +/-0.05 for Argus stars. Effects of over-ionisation/excitation were seen for stars cooler than roughly 5200K as previously noted in the literature. Also, enhanced Ba abundances of around 0.6 dex were observed in both systems. The common ages, kinematics and chemical abundances strongly support that the Argus association stars originated from the open cluster IC 2391. Simple modeling of this system find this dissolution to be consistent with two-body interactions.Comment: 17 pages, 7 figs, accepted for publication in MNRA

    Search for associations containing young stars (SACY). V. Is multiplicity universal? Tight multiple systems

    Full text link
    Context: Dynamically undisrupted, young populations of stars are crucial to study the role of multiplicity in relation to star formation. Loose nearby associations provide us with a great sample of close (<<150 pc) Pre-Main Sequence (PMS) stars across the very important age range (\approx5-70 Myr) to conduct such research. Aims: We characterize the short period multiplicity fraction of the SACY (Search for Associations Containing Young stars) accounting for any identifiable bias in our techniques and present the role of multiplicity fractions of the SACY sample in the context of star formation. Methods: Using the cross-correlation technique we identified double-lined spectroscopic systems (SB2), in addition to this we computed Radial Velocity (RV) values for our subsample of SACY targets using several epochs of FEROS and UVES data. These values were used to revise the membership of each association then combined with archival data to determine significant RV variations across different data epochs characteristic of multiplicity; single-lined multiple systems (SB1). Results: We identified 7 new multiple systems (SB1s: 5, SB2s: 2). We find no significant difference between the short period multiplicity fraction (FmF_\mathrm{m}) of the SACY sample and that of nearby star forming regions (\approx1-2 Myr) and the field (FmF_\mathrm{m}\leq10%) both as a function of age and as a function of primary mass, M1M_1, in the ranges PP [1:200 day] and M2M_2 [0.08 MM_{\odot}-M1 M_1]. Conclusions: Our results are consistent with the picture of universal star formation, when compared to the field and nearby star forming regions (SFRs). We comment on the implications of the relationship between increasing multiplicity fraction with primary mass, within the close companion range, in relation to star formation.Comment: 14 pages, 18 figures, published, A&A http://dx.doi.org/10.1051/0004-6361/20142385

    Search for associations containing young stars (SACY) VII. New stellar and substellar candidate members in the young associations

    Get PDF
    The young associations offer us one of the best opportunities to study the properties of young stellar and substellar objects and to directly image planets thanks to their proximity (<<200 pc) and age (\approx5-150 Myr). However, many previous works have been limited to identifying the brighter, more active members (\approx1 M_\odot) owing to photometric survey sensitivities limiting the detections of lower mass objects. We search the field of view of 542 previously identified members of the young associations to identify wide or extremely wide (1000-100,000 au in physical separation) companions. We combined 2MASS near-infrared photometry (JJ, HH, KK) with proper motion values (from UCAC4, PPMXL, NOMAD) to identify companions in the field of view of known members. We collated further photometry and spectroscopy from the literature and conducted our own high-resolution spectroscopic observations for a subsample of candidate members. This complementary information allowed us to assess the efficiency of our method. We identified 84 targets (45: 0.2-1.3 M_\odot, 17: 0.08-0.2 M_\odot, 22: <<0.08 M_\odot) in our analysis, ten of which have been identified from spectroscopic analysis in previous young association works. For 33 of these 84, we were able to further assess their membership using a variety of properties (X-ray emission, UV excess, Hα_\alpha, lithium and K I equivalent widths, radial velocities, and CaH indices). We derive a success rate of 76-88% for this technique based on the consistency of these properties. Once confirmed, the targets identified in this work would significantly improve our knowledge of the lower mass end of the young associations. Additionally, these targets would make an ideal new sample for the identification and study of planets around nearby young stars.Comment: 28 pages, 24 figures, accepted in A&

    Polpas branqueadas de misturas de madeiras da Amazônia.

    Get PDF
    bitstream/item/31959/1/CPATU-BP82.pd

    Caracterização do sistema radicular e dos componentes da produtividade em quatro genótipos de milho cultivados sob déficit hídrico.

    Get PDF
    Nesse trabalho foram combinadas avaliações de parâmetros agronômicos com morfometria de raízes usando o programa WinRhizo, a fim de detectar características no sistema radicular que permitam a manutenção da produtividade em quatro materiais genéticos de milho (BRS1010, 2B710, DKB390 e BRS1055), cultivados em dois níveis de água no solo (CC- capacidade de campo, e DH- déficit hídrico). Plantas oriundas dos genótipos DKB390 e BRS1055 sob DH mantiveram valores de produção de grão similares aos de seus respectivos controles, sob CC. Por sua vez, plantas oriundas dos genótipos 2B710 e BRS1010 apresentaram perdas substanciais na produção de grãos com a imposição do DH. Cabe ressaltar que plantas oriundas do genótipo BRS 1055 apresentaram estratégia abaixo do solo de evitação à seca, por aumentarem a área superficial de raízes finas e muito finas, sendo esse um ponto de divergência em relação ao também tolerante genótipo DKB 390.bitstream/item/122152/1/bol-111.pd
    corecore