7 research outputs found

    Analysis of the difficulties in reconstructing the infrastructure damaged by natural disasters in New Zealand and Puerto Rico

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    Once a natural disaster damages essential infrastructure services, such as roads, bridges, electric power and potable water, the priority is to restore these services as soon as possible. Under normal circumstances, the planning, design and construction of complex infrastructure projects requires an extended period of time that in many cases lasts for years. The reconstruction of essential services after a disaster is complex not only because the amount of time that can be devoted to planning is extremely limited, but also because government agencies and their officials are under public scrutiny. The press and political institutions frequently criticize the reaction time and decisions of public officials, which increases the complexity of the projects. This article uses a five-dimensional project management model (5DPM) to identify and manage the sources of complexity in emergency projects. The article describes the sources of complexity in reconstruction projects after natural disasters hit the islands of New Zealand and Puerto Rico causing great devastation. The natural disasters analyzed in this article are the earthquakes of 2010 and 2011 in New Zealand and the hurricanes Irma and Maria in 2017 in Puerto Rico. The islands, due to their geographical location, faced similar challenges in terms of the shortage of workers, and materials and equipment for reconstruction, which had to be imported. The shortage negatively impacted the response time to the emergency, the perception of the press, and public opinion about the proper handling of the emergencies. The article analyzes the sources of complexity in the reconstruction of the damaged infrastructure and concludes that the sociopolitical context is often the most complex dimension when reconstruction projects are carried out in an expeditious manner

    Review of Dynamic and Transient Modeling of Power Electronic Converters for Converter Dominated Power Systems

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    In response to national and international carbon reduction goals, renewable energy resources like photovoltaics (PV) and wind, and energy storage technologies like fuel-cells are being extensively integrated in electric grids. All these energy resources require power electronic converters (PECs) to interconnect to the electric grid. These PECs have different response characteristics to dynamic stability issues compared to conventional synchronous generators. As a result, the demand for validated models to study and control these stability issues of PECs has increased drastically. This paper provides a review of the existing PEC model types and their applicable uses. The paper provides a description of the suitable model types based on the relevant dynamic stability issues. Challenges and benefits of using the appropriate PEC model type for studying each type of stability issue are also presented

    Erythrina speciosa (Leguminosae-Papilionoideae) under soil water saturation: morphophysiological and growth responses

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Erythrina speciosa is a Neotropical tree that grows mainly in moist habitats. To characterize the physiological, morphological and growth responses to soil water saturation, young plants of E. speciosa were subjected experimentally to soil flooding. Flooding was imposed from 2 to 4 cm above the soil surface in water-filled tanks for 60 d. Non-flooded (control) plants were well watered, but never flooded. The net CO(2) exchange (A(CO2)), stomatal conductance (g(s)) and intercellular CO(2) concentration (C(i)) were assessed for 60 d. Soluble sugar and free amino acid concentrations and the proportion of free amino acids were determined at 0, 7, 10, 21, 28 and 45 d of treatments. After 28, 45 and 60 d, dry masses of leaves, stems and roots were determined. Stem and root cross-sections were viewed using light microscopy. The A(CO2) and g(s) were severely reduced by flooding treatment, but only for the first 10 d. The soluble sugars and free amino acids increased until the tenth day but decreased subsequently. The content of asparagine in the roots showed a drastic decrease while those of alanine and gamma-aminobutyric increased sharply throughout the first 10 d after flooding. From the 20th day on, the flooded plants reached A(CO2) and g(s) values similar to those observed for non-flooded plants. These events were coupled with the development of lenticels, adventitious roots and aerenchyma tissue of honeycomb type. Flooding reduced the growth rate and altered carbon allocation. The biomass allocated to the stem was higher and the root mass ratio was lower for flooded plants when compared with non-flooded plants. Erythrina speciosa showed 100 % survival until the 60th day of flooding and was able to recover its metabolism. The recovery during soil flooding seems to be associated with morphological alterations, such as development of hypertrophic lenticels, adventitious roots and aerenchyma tissue, and with the maintenance of neutral amino acids in roots under long-term exposure to root-zone O(2) deprivation.1044671680Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [03/12595-7]CNPq [520334/99-0

    Systematics of Spiny Predatory Katydids (Tettigoniidae: Listroscelidinae) from the Brazilian Atlantic Forest Based on Morphology and Molecular Data

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    <div><p>Listroscelidinae (Orthoptera: Tettigoniidae) are insectivorous Pantropical katydids whose taxonomy presents a long history of controversy, with several genera incertae sedis. This work focused on species occurring in the Brazilian Atlantic Forest, one of the world's most threatened biomes. We examined material deposited in scientific collections and visited 15 conservation units from Rio de Janeiro to southern Bahia between November 2011 and January 2012, catching 104 specimens from 10 conservation units. Based on morphological and molecular data we redefined Listroscelidini, adding a new tribe, new genus and eight new species to the subfamily. Using morphological analysis, we redescribed and added new geographic records for six species, synonymized two species and built a provisional identification key for the Atlantic Forest Listroscelidinae. Molecular results suggest two new species and a new genus to be described, possibly by the fission of the genus <i>Hamayulus</i>. We also proposed a 500 bp region in the final portion of the COI to be used as a molecular barcode. Our data suggest that the Atlantic Forest Listroscelidinae are seriously endangered, because they occur in highly preserved forest remnants, show high rates of endemism and have a narrow geographic distribution. Based on our results, we suggest future collection efforts must take into account the molecular barcode data to accelerate species recognition.</p></div

    Acid Suppression Therapy: Where Do We Go from Here?

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    Empowering Latina scientists

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