209 research outputs found

    Quadro Nacional de Atribuição de Frequências

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    O Quadro Nacional de Atribuição de Frequências – QNAF é um documento que apresenta de forma detalhada as subdivisões do espectro radioeléctrico, discriminando para cada faixa de frequências os serviços de radiocomunicações de acordo com as atribuições do Artigo 5º do Regulamento das Radiocomunicações – RR aplicáveis em Cabo Verde

    Field Tuning of Linear Resonant Actuators Using Motion Sensor Feedback

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    Linear resonant actuators (LRAs) create tactile feedback in consumer devices by generating vibrations. LRA characteristics can change with time due to environmental conditions, thereby degrading the performance of the LRA. Variations in LRA performance can be compensated during operation by using techniques of parameter detection, measurement, and correction, which themselves rely on accurate back EMF measurement. A back EMF test is accurate so long as the LRA is stationary, the device is lying on a flat, vibration-free surface, and is free of external movement. This disclosure describes techniques that ensure accurate measurement of LRA parameters by performing back EMF measurements when onboard motion sensors indicate zero or low device motion

    Vistorias de aeronaves: centralização do planejamento e controle

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    A ideia da centralização surgiu objetivando que os usuários da aviação civil em todo o país tivessem um tempo de espera igual para a realização de vistorias. A partir do dia 4 de janeiro de 2010, foi instituída a forma centralizada do controle das vistorias de aeronaves visando à melhoria e agilidade do processo. Trata- se de uma centralização virtual, pois cada inspetor permaneceu sediado em seu próprio local de origem, porém cumprindo as missões definidas pela coordenação central, a fim de atender a vistoria em qualquer ponto do território nacionalNúmero de páginas: 07 p.Fiscalização. RegulaçãoInovaçãoIniciativa premiada no 16º Concurso Inovação na Gestão Pública Federal sob responsabilidade de Mário Igawa, gerente geral de Aeronavegabilidade Continuada.Ações premiadas no 16º Concurso Inovação na Gestão Pública Federal – 2011Áreas temáticas: Melhoria dos processos de trabalho; Implementação de melhoria contínua; Simplificação e agilização de procedimento

    Vegetation structure and effects of human use of Dambos ecosystem in northern Mozambique

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    Original research articleThe Niassa National Reserve (NNR) is the most extensive conservation area in Mozambique and the third largest in Africa, encompassing 42,000 km2 of endemic miombo vegetation. Dambos wetlands occur within the wooded grassland and grassland vegetation of NNR and provide a wide range of Ecosystem Services (ES), including life support for animal species, regulation of water flow and prevention of soil erosion. It also generates income for the livelihoods of local communities by providing land for agriculture and harvesting of non-timber products. The dynamics of these ecosystems is poorly understood despite the contribution of the dambos to global biodiversity and ES. This research is the first preliminary assessment of the vegetation structure and composition of six dambos within NNR, selected using Google Earth, MODIS satellite images and an exploratory field visit. Field data collection was performed using a two-stage systematic sampling approach, along transect lines of 100 10m (0.1 ha), perpendicular to the dambos' flow. Square plots of 0.25m2 were established for grass survey within the transects where grass vegetation was measured, counted and identified. Data were analyzed with R software. The sociological position of each species was analyzed with regard to the vertical structure while for horizontal structure, the abundance, dominance, frequency and Importance Value Index (IVI) were determined. In order to understand the differences between dambos, evenness (H) and reciprocal of Simpson's heterogeneity index (Hill's N2) were calculated. Principal Coordinates Analysis (PCoA) and Cluster Analysis were also used to characterize the surveyed species communities. A total of 58 transects (5.8 ha) and 336 subplots were assessed, recording 110 woody and 73 grass species, respectively. The most common tree species were Vitex doniana, Burkea africana, Syzygium cordatum and Annona senegalensis, while for grass vegetation the most abundant species were Andropogon eucomus and Helictotrichon turgidulum. According to the IVI, the most dominant tree and shrub species were V. doniana, Pseudolachnostylis maprouneifolia, A. senegalensis and S. cordatum. Homogeneity (Hill's N2 ¼18.92) and evenness (H¼ 4.27) were, on average, low in all dambos. Dambo 2 was the most heterogeneous (Hill's N2 ¼18.21) while dambo 1 was the least heterogeneous (Hill's N2 ¼ 5.71). Dambo 6 was most equitable (H¼ 1.35) whereas dambo 2 the least equitable (H¼ 3.72). Using species abundance and based on PCoA and cluster analysis, four main groups of dambos were identified based mainly on the water gradient, with data variation captured by the first three axes reaching almost 83%. The p-value (0.42), suggested no significant differences between species communities in the dambos, and thus, human disturbances appear not to be enough to modify dambos microenvironment. Accordingly, the results suggest that human activities, at this level, do not necessarily affect the structure and diversity of dambos in the NNR. The results also suggest that the species A. senegalensis, Combretum psidioides, Crossopteryx febrifuga, Protea nitida, P. maprouneifolia and S. cordatum can be used as indicator dambo species in NNR, with high likelihood of occurrenceinfo:eu-repo/semantics/publishedVersio

    Switching Transport through Nanopores with pH-Responsive Polymer Brushes for Controlled Ion Permeability

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    Several nanoporous platforms were functionalized with pH-responsive poly(methacrylic acid) (PMAA) brushes using surface-initiated atom transfer radical polymerization (SI-ATRP). The growth of the PMAA brush and its pH-responsive behavior from the nanoporous platforms were confirmed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The swelling behavior of the pH-responsive PMAA brushes grafted only from the nanopore walls was investigated by AFM in aqueous liquid environment with pH values of 4 and 8. AFM images displayed open nanopores at pH 4 and closed ones at pH 8, which rationalizes their use as gating platforms. Ion conductivity across the nanopores was investigated with current–voltage measurements at various pH values. Enhanced higher resistance across the nanopores was observed in a neutral polymer brush state (lower pH values) and lower resistance when the brush was charged (higher pH values). By adding a fluorescent dye in an environment of pH 4 or pH 8 at one side of the PMAA-brush functionalized nanopore array chips, diffusion across the nanopores was followed. These experiments displayed faster diffusion rates of the fluorescent molecules at pH 4 (PMAA neutral state, open pores) and slower diffusion at pH 8 (PMAA charged state, closed pores) showing the potential of this technology toward nanoscale valve applications

    Corruption in Public projects and Megaprojects: There is an elephant in the room!

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    Despite the relevance of corruption in project selection, planning and delivery, the project management literature pays little attention to this crucial phenomenon. This paper sets the background to foster the discussion concerning how to select, plan and deliver infrastructure in corrupt project contexts. It presents the different types of corruptions and the characteristics of projects that are more likely to suffer from it. Corruption is particularly relevant for large and uncommon projects where the public sector acts as client/owner or even as the main contractor. Megaprojects are “large unique projects” where public actors play a key role and are very likely to be affected by corruption. Corruption worsens both cost and time performance, and the benefits delivered. This paper leverages the institutional theory to introduce the concept of “corrupt project context” and, using the case study of the Italian high-speed railways, shows the impact of a corrupt context on megaprojects

    Urban waste disposal explains the distribution of Black Vultures (Coragyps atratus) in an Amazonian metropolis: management implications for birdstrikes and urban planning

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    Collision rates between aircraft and birds have been rising worldwide. The increases in both air traffic and population sizes of large-bodied birds in cities lacking urban planning result in human-wildlife conflicts, economic loss and even lethal casualties. Black Vultures (Coragyps atratus) represent the most hazardous bird to Brazilian civil and military aviation on the basis of their flight behavior, body mass and consequently physical damage to aircraft following collisions. This study investigated how storage apparatus and type of organic residue discarded in public street markets modulate the spatial distribution and abundance of urban Black Vultures in the largest city in the Amazon (Manaus, Brazil). We estimated Black Vulture abundance in relation to the type of solid human waste (animal or plant), the type of waste storage containers and market sizes in terms of the number of vendor stalls at 20 public markets. We also visually quantified the abundance of Black Vultures in urban markets in relation to air traffic. Our results suggest that urban solid waste storage procedures currently used (or the lack thereof) are related to the occurrence and abundance of Black Vultures. Moreover, storage type and the proportion of animal protein (red meat and fish) within rubbish bins directly affects foraging aggregations in vultures. We recommend that policymakers should invest more efforts in building larger and more resistant closable waste containers to avoid organic solid waste exposure. We also identified five outdoor markets as urgent priorities to improve waste disposal. Finally, our waste management guidelines would not only reduce aviation collision risks but also benefit human health and well-being in most cities

    Relatório de consulta publica OPMS

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    Relatório da consulta publica realizada a proposito da definição de mercados relevantes de Comunicações Electrónicas e definição de Operadores com Poder de mercado significativo

    Metodologia de Calculo de custo de capital da CVTelecom 2011 2013

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    Apresenta a consulta publica sobre a revisão do calculo do WACC visando fixar uma Metodologia de Cálculo do Custo de Capital e Determinar o valor da taxa do custo de capital da CVTelecom para o triénio de 2011 a 2013 aplicado na definição das tarifas do serviço de telefonia fixa.ANA
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