2,682 research outputs found

    Greenhouse screening for Fusarium wilt resistance in lupine

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    Fusarium wilt can cause total crop failure. Evaluation of Ffusarium resistance in heavily infected soil were performed in a grenhouse where the dominant fusarium species in the soil in descending order was F. oxysporum then F. avenaceum, F. culmorum, F. solani, F. gibbosum. Large fusarium wilt presure was observed and fully susceptible lines were completely destroyed by Fusarium wilt caused by F. oxisporum. Segregation in F2 and F3 in L. angustifolius showed that resistant genotypes have two dominant non-allelic resistance genes to wilt. We call this gene Relation to fusarium oxisporum (Rfo1,Rfo2). Susceptible genotypes have either two wild genes (++ ++) or one wild and one dominant resistant gene (++ Rfo2 Rfo2, or Rfo1Rfo1 ++). Crossing ‘++ Rfo2Rfo2’ to ‘Rfo1Rfo1 ++’ segregates in 9:7 resistant to susceptible in F2, respectively. The same segregation was observed by crossing ‘Rfo1Rfo1 Rfo2Rfo2’ to ‘++ ++’. We recommend the use of these resistant genes in breeding in areas with potential Fusarium wilt problems

    Nonlocal study of ultimate plasmon hybridization

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    Within our recently proposed generalized nonlocal optical response (GNOR) model, we revisit the fundamental problem of an optically excited plasmonic dimer. The dimer consists of two identical cylinders separated by a nanometre-sized gap. We consider the transition from separated dimers via touching dimers to finally overlapping dimers. In particular, we focus on the touching case, showing a fundamental limit on the hybridization of the bonding plasmon modes due to nonlocality. Using transformation optics we determine a simple analytical equation for the resonance energies of the bonding plasmon modes of the touching dimer

    Nonlocal optical response in metallic nanostructures

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    This review provides a broad overview of the studies and effects of nonlocal response in metallic nanostructures. In particular, we thoroughly present the nonlocal hydrodynamic model and the recently introduced generalized nonlocal optical response (GNOR) model. The influence of nonlocal response on plasmonic excitations is studied in key metallic geometries, such as spheres and dimers, and we derive new consequences due to the GNOR model. Finally, we propose several trajectories for future work on nonlocal response, including experimental setups that may unveil further effects of nonlocal response

    Generalized nonlocal optical response in nanoplasmonics

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    Metallic nanostructures exhibit a multitude of optical resonances associated with localized surface plasmon excitations. Recent observations of plasmonic phenomena at the sub-nanometer to atomic scale have stimulated the development of various sophisticated theoretical approaches for their description. Here instead we present a comparatively simple semiclassical generalized nonlocal optical response (GNOR) theory that unifies quantum-pressure convection effects and induced-charge diffusion kinetics, with a concomitant complex-valued GNOR parameter. Our theory explains surprisingly well both the frequency shifts and size-dependent damping in individual metallic nanoparticles (MNPs) as well as the observed broadening of the cross-over regime from bonding-dipole plasmons to charge-transfer plasmons in MNP dimers, thus unraveling a classical broadening mechanism that even dominates the widely anticipated short-circuiting by quantum tunneling. We anticipate that the GNOR theory can be successfully applied in plasmonics to a wide class of conducting media, including doped semiconductors and low-dimensional materials such as graphene.Comment: 7 pages, including 3 figures. Supplementary information is available upon request to author

    Delay and reliability analysis of p-persistent carrier sense multiple access for multi-event industrial wireless sensor networks

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    In industrial environments various events can concurrently occur and may require different quality of service (QoS) provision based on different priority levels. To reduce the chances of collision and to improve efficiency in multi-event occurrence, Carrier Sense Multiple Access (CSMA) is a preferable choice for Medium Access Control (MAC) protocols. However, it also increases the overall delay. In this paper, a Priority MAC protocol for Multi-Event industrial wireless sensor networks (PMME) is proposed. In PMME, use of different p values/sequences is proposed to enable multi-priority operation, which can be optimized to suit different operational classes within industrial applications including emergency, regulatory control, supervisory control, open-loop control, alerting and monitoring systems. In this work, novel mathematical model as well as simulations are presented to validate the accuracy and performance of the proposed protocol. Mathematical analysis shows that the proposed PMME can prioritize data packets effectively while ensuring ultra-reliable and low latency communications for high priority nodes. Simulations in Castalia verify that PMME with different p values/sequences notably reduces packet delay for all four priority classes. The PMME also returns a high packet success rate compared to other two well-known priority enabled MAC protocols, QoS aware energy-efficient (QAEE) and multi-priority based QoS (MPQ), in multi-event industrial wireless sensor networks

    Nanoplasmonics beyond Ohm's law

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    In tiny metallic nanostructures, quantum confinement and nonlocal response change the collective plasmonic behavior with important consequences for e.g. field-enhancement and extinction cross sections. We report on our most recent developments of a real-space formulation of an equation-of-motion that goes beyond the common local-response approximation and use of Ohm's law as the central constitutive equation. The electron gas is treated within a semi-classical hydrodynamic model with the emergence of a new intrinsic length scale. We briefly review the new governing wave equations and give examples of applying the nonlocal framework to calculation of extinction cross sections and field enhancement in isolated particles, dimers, and corrugated surfaces.Comment: Invited paper for TaCoNa-Photonics 2012 (www.tacona-photonics.org), to appear in AIP Conf. Pro
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