Predicting the Potential Worldwide Distribution of the Red Palm Weevil Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) using Ecological Niche Modeling

This is the publisher's version, also available electronically from http://www.bioone.org/doi/abs/10.1653/024.095.0317.The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae), ranks among the most important pests of various palm species. The pest originates from South and Southeast Asia, but has expanded its range dramatically since the 1980s. We used ecological niche modeling (ENM) approaches to explore its likely geographic potential. Two techniques, the Genetic Algorithm for Rule-set Prediction (GARP) and a maximum entropy approach (MaxEnt), were used. However, MaxEnt provided more significant results, with all 5 random replicate subsamples having P < 0.002 while GARP models failed to achieve statistical significance in 3 of 5 cases, in which predictions achieved probabilities of 0.07 < P < 0.10. The MaxEnt models predicted successfully the known distribution, including the single North American occurrence point of Laguna Beach, California, and various areas where the pest has been reported in North Africa, southern Europe, Middle East and South and Southeastern Asia. In addition, areas where the pest has not been yet reported were found to be suitable for invasion by RPW in sub-Saharan Africa, southern, central and northern America, Asia, Europe, and Oceania. Highly suitable areas in the United States of America were limited mostly to coastal California and southern Florida, while all Caribbean islands were found highly suitable for establishment and spread of the pest

Использование принципа клиентоориентированности при формировании стратегии развития предприятий

Материалы межвуз. науч. конф. студентов, магистрантов и аспирантов, Гомель, 15 мая 2008 г

Carbon vacancy control in p+-n silicon carbide diodes for high voltage bipolar applications

Publisher Copyright: © 2021 IOP Publishing Ltd.Controlling the carbon vacancy (V-C) in silicon carbide (SiC) is one of the major remaining bottleneck in manufacturing of high voltage SiC bipolar devices, because V-C provokes recombination levels in the bandgap, offensively reducing the charge carrier lifetime. In literature, prominent V-C evolutions have been measured by capacitance spectroscopy employing Schottky diodes, however the trade-offs occurring in the p(+)-n diodes received much less attention. In the present work, applying similar methodology, we showed that V-C is re-generated to its unacceptably high equilibrium level at similar to 2 x10(13) V-C cm(-3) by 1800 degrees C anneals required for the implanted acceptor activation in the p(+)-n components. Nevertheless, we have also demonstrated that the V-C eliminating by thermodynamic equilibrium anneals at 1500 degrees C employing carbon-cap can be readily integrated into the p(+)-n components fabrication resulting inPeer reviewe

Anisotropic and plane-selective migration of the carbon vacancy in SiC: Theory and experiment

We investigate the migration mechanism of the carbon vacancy (V-C) in silicon carbide (SiC) using a combination of theoretical and experimental methodologies. The V-C, commonly present even in state-of-the-art epitaxial SiC material, is known to be a carrier lifetime killer and therefore strongly detrimental to device performance. The desire for V-C removal has prompted extensive investigations involving its stability and reactivity. Despite suggestions from theory that V(C )migrates exclusively on the C sublattice via vacancy-atom exchange, experimental support for such a picture is still unavailable. Moreover, the existence of two inequivalent locations for the vacancy in 4H-SiC [hexagonal, V-C(h), and pseudocubic, V-C(k)] and their consequences for V-C migration have not been considered so far. The first part of the paper presents a theoretical study of V(C )migration in 3C- and 4H-SiC. We employ a combination of nudged elastic band (NEB) and dimer methods to identify the migration mechanisms, transition state geometries, and respective energy barriers for V(C )migration. In 3C-SiC, V-C is found to migrate with an activation energy of E-A = 4.0 eV. In 4H-SiC, on the other hand, we anticipate that V-C migration is both anisotropic and basal-plane selective. The consequence of these effects is a slower diffusivity along the axial direction, with a predicted activation energy of E-A = 4.2 eV, and a striking preference for basal migration within the h plane with a barrier of E-A = 3.7 eV, to the detriment of the k-basal plane. Both effects are rationalized in terms of coordination and bond angle changes near the transition state. In the second part, we provide experimental data that corroborates the above theoretical picture. Anisotropic migration of V-C in 4H-SiC is demonstrated by deep level transient spectroscopy (DLTS) depth profiling of the Z(1/2) electron trap in annealed samples that were subject to ion implantation. Activation energies of E-A = (4.4 +/- 0.3) eV and E-A = (3.6 +/- 0.3) eV were found for V-C migration along the c and a directions, respectively, in excellent agreement with the analogous theoretical values. The corresponding prefactors of D-0 = 0.54 cm(2)/s and 0.017 cm(2)/s are in line with a simple jump process, as expected for a primary vacancy point defect.Funding Agencies|Research Council of Norway; University of Oslo through the frontier research project FUNDAMeNT [251131]; University of Oslo through the Norwegian Micro- and Nanofabrication Facility [NorFAB 245963]; Fundacao para a Ciencia e a Tecnologia (FCT) [UID/CTM/50025/2019]; FEDER funds through the COMPETE 2020 Program; NATO SPS programme [985215]; Swedish Energy Agency Energimyndigheten project [43611-1]; Swedish Government Strategic Research Area in Materials Science (AFM)</p

Biotechnology contributing to integrated pest management: The example of two major coconut pests, oryctes rhinoceros and brontispa longissima

Pests and diseases are major limiting factors in coconut (Cocos nucifera L.) production. Pests ranging from insects to mites and diseases from fungi to phytoplasma all negatively affect the palm, from the seedling to the field production stage. By presenting examples of two major pests, the coconut rhinoceros beetle (Oryctes rhinoceros L.) and the coconut hispid beetle (Brontispa longissima Gestro), this chapter illustrates how various biotechnologies have helped in the development of an efficient integrated pest management program, in which the available control approaches are combined to provide an effective management system. Biotechnological tools to help control these major production constraints of coconut are already available, but not always efficacious in reducing damage economically. Hence, further innovations in pest and disease management are required to better suppress the build-up of pest and disease populations in the field