999 resultados para permanent wilting point


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ABSTRACT The ecological restoration of degraded areas using seeds collected in forest remnants has shown significant results. This study was developed to verify the potential of seed rain to regenerate forest fragments of a Permanent Preservation Area (PPA) in the Apa River Basin which is located in the southwestern portion of the Mato Grosso do Sul state, Brazil. To develop the study, we installed 25 collectors measuring 1 m2 each, which were systematically distributed on an area of 1.5ha. Seed gathering was conducted in a monthly basis throughout the year of 2013. A total of 26.411 propagules were identified and distributed among 50 species, 45 genera and 32 families. In terms of the propagules distribution, 70.51% were identified as trees, 22.8% as lianas, 6.5% as shrubs, 0.1 as herbaceous, 0.05% as palm and 0.05% could not be classified. The value for the Shannon Diversity Index was (H') = 1.67 and the Pielou Evenness index was (J) = 0.42. These results indicate that the seeds rain has low species diversity with the abundance of a few species. The overall results suggest that seed rain can be a potential technique for restoration of the PPAs and other forested areas. However, it is necessary to enhance the diversity of tree species.

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ABSTRACT Permanent Preservation Areas (PPAs) along watercourses have been the focus of numerous studies, not only because of the fragility and ecological relevance of riverine vegetation, but also because of the inefficiency demonstrated in conforming to the legislation protecting it. One of the major difficulties encountered in terms of guaranteeing the effective conservation of these riverside areas is the absence of methodologies that can be used to define them rapidly and accurately without manually determining the widths of the rivers or assigning only uniform linear values for the entire watercourse. The present work sought to develop a spatial analysis methodology capable of automatically defining permanent preservation areas along watercourses using geographic information system (GIS) software. The present study was undertaken in the Sergipe River basin, "considering the river itself and its principal affluents. We used the database of the Digital Atlas of Hydrological Resources (SEMARH/SE), and the delimitations of the PPAs were performed using ArcGIS 10.1 and the XToolPro 9.0 extension. A total of 5,003.82 hectares of Permanent Preservation Areas were delimited along the margins of the rivers analyzed, with a margin of error of <1% in delimiting the widths of the rivers within the entire area considered. The methodology described here can be used to define PPAs efficiently, relatively rapidly, and with very small margins of error, thus representing a technological advance in terms of using GIS for land management.

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This master’s thesis mainly focuses on the design requirements of an Electric drive for Hybrid car application and its control strategy to achieve a wide speed range. It also emphasises how the control and performance requirements are transformed into its design variables. A parallel hybrid topology is considered where an IC engine and an electric drive share a common crank shaft. A permanent magnet synchronous machine (PMSM) is used as an electric drive machine. Performance requirements are converted into Machine design variables using the vector model of PMSM. Main dimensions of the machine are arrived using analytical approach and Finite Element Analysis (FEA) is used to verify the design and performance. Vector control algorithm was used to control the machine. The control algorithm was tested in a low power PMSM using an embedded controller. A prototype of 10 kW PMSM was built according to the design values. The prototype was tested in the laboratory using a high power converter. Tests were carried out to verify different operating modes. The results were in agreement with the calculations.

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This doctoral thesis presents a study on the development of a liquid-cooled frame salient pole permanent-magnet-exited traction machine for a four-wheel-driven electric car. The emphasis of the thesis is put on a radial flux machine design in order to achieve a light-weight machine structure for traction applications. The design features combine electromagnetic and thermal design methods, because traction machine operation does not have a strict operating point. Arbitrary load cycles and the flexible supply require special attention in the design process. It is shown that accurate modelling of the machine magnetic state is essential for high-performance operation. The saturation effect related to the cross-saturation has to be taken carefully into account in order to achieve the desired operation. Two prototype machines have been designed and built for testing: one totally enclosed machine with a special magnet module pole arrangement and another through-ventilated machine with a more traditional embedded magnet structure. Both structures are built with magnetically salient structures in order to increase the torque production capability with the reluctance torque component. Both machine structures show potential for traction usage. However, the traditional embedded magnet design turns out to be mechanically the more secure one of these two machine options.

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Tutkimuksessa selvitetään miten työvälineiden valmistajat käyttävät arvo-perusteista hinnoittelua teknologiaosaamisen palvelutuotteissa ja mikä vaikuttaa siihen, että sitä käytetään tai ei käytetä. Kirjallisuuskatsauksessa perehdytään markkinoinnin ja laskentatoimen kirjallisuuteen palveluliiketoiminnan, asiakasarvon ja arvoperusteisen hinnoittelun osalta. Palveluliiketoimintaa avataan nimenomaan teollisuuden palveluliiketoiminnan näkökulmasta. Asiakasarvoa puolestaan käsitellään näkökulmina missä asiakasarvo muodostuu ja ketkä sitä luovat. Arvoperusteista hinnoittelua tarkastellaan lähtökohtana sen erityispiirteet asiakkaan ja myynnin suhteen sekä esitetään arvoperusteisen hinnoittelumallin käytön esteitä ja hyötyjä. Empiirisessä osiossa tutkitaan miten Työvälineiden valmistajien toimiala-ryhmän jäsenet käyttävät omissa palvelutuotteissaan arvoperusteista hin-noittelua. Aineisto kerättiin web-kyselyn avulla. Tutkimuksessa nousi esiin, että kyseistä hinnoittelumallia on alettu käyttää joissakin palveluissa. Koetut hyödyt ja esteet osoittautuvat olevan paljolti samat kuin aikaisemmassa tutkimuskirjallisuudessa on havaittu. Suurimpina hyötyinä nähtiin pysyvämmät asiakassuhteet, suurempi voittomarginaali ja positiivinen pakko perehtyä asiakkaan ansaintalogiikkaan. Suurimpina esteinä koettiin palvelusta syntyvän arvon määrittämisen vaikeus ja sen viestiminen asiakkaalle sekä asiakkaan haluttomuus sitoutua pitkiin sopimuksiin.