439 research outputs found

    Optimal Design and Synthesis of MEA Power System Architectures considering Reliability Specifications

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    IEEE Aircraft electrification requires novel designs to supply the growing demand for electric power on-board through efficient and reliable production and distribution of electrical energy. Moreover, the aircraft power system will be a key enabler for the integration of future technologies. Pledging to these intentions, we propose a formulation to synthesize a power system architecture that complies with safety specifications following a Platform Based Design methodology that optimizes the main aerospace drivers. Due to the non-linear nature of the design problem, this paper presents reliability based MILP network design formulations for topology synthesis. The novelty of this approach relies in the adoption of network design optimization for MEA power system construction that allows explicit design formulations as MILP problems. This approach will provide an effective way to include safety specifications by introducing reliability and resiliency constraints

    Síndrome de Lynch. Prevalencia, características clínicas y tratamiento

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    El cáncer colorrectal hereditario no polipósico (HNPCC) o síndrome de Lynch es de transmisión autosómica dominante con una penetrancia del 85% y representa alrededor del 5% de todos los cánceres colorrectales. El presente trabajo se realizó para establecer la prevalencia del síndrome de Lynch y comparar, sus características clínicas y tipos de tratamientos empleados, con los pacientes con cáncer colorrectal esporádico. Es un estudio observacional descriptivo con componente analítico donde se incluyeron todos los pacientes con cáncer colorrectal demostrado por estudio histopatológico que concurrieron entre junio del 1999 a abril del 2005 a los servicios de cirugía general del Hospital de Clínicas e Instituto de Previsión Social. Se contactó en forma personal con el paciente o familiar de primer grado para evaluar los antecedentes familiares de otras neoplasias y así reunir información para el diagnóstico del síndrome de Lynch utilizando los criterios de Amsterdam II. Fueron estudiados 324 pacientes con cáncer colorrectal y la prevalencia del síndrome de Lynch fue de 2,7% (IC 95% 0,9-4,5). La mediana de edad fue significativamente más baja, mientras que, la presencia de tumores sincrónicos y metacrónicos fueron significativamente más alta en los sujetos con síndrome de Lynch que en los pacientes con cáncer colorrectal esporádico. No se encontró diferencia significativa en el estadío evolutivo de los tumores y ninguna diferencia en el tipo de resecciones quirúrgicas en ambos grupos de pacientes. La prevalencia del síndrome de Lynch en pacientes con cáncer colorrectal fue baja, sus características clínicas fueron significativamente diferentes al de cáncer colorrectal esporádico, mientras que el tipo de resecciones quirúrgicas no difiere en ambos grupos de pacientes

    Heuristics‐enhanced geospatial machine learning (SaaS) of an ancient Mediterranean environment

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    Raw soil core physical data used in machine learning algorithms with corresponding spatial remotely sensed data is an emerging science. Using data derived from soil core samples previously collected in Universal Transverse Mercator zone 50 (Western Australia) and remotely sensed data, a model that predicted ground movement (GM) was developed specific to Australian Standards manual AS 1726–2017. This is the first approach for Australian soils and first in the world for soils older than 200 million yr. The model developed reliably predicted GM with 91.1% accuracy. The error obtained from the prediction is within acceptable limits currently used by engineers in calculations concerning soil classification for engineering purposes. Concerning the remotely sensed data analyzed, accuracy of the Atterberg limits method might be improved if additional information about soil structure (layering and horizon) or other variables (seasonal data) are built into this model. This model can be used to save on construction material costs, reduce the potential for human error associated with data collection and sample manipulation, but also fast-track (by up to 6 wk based on current wait times) building approvals while ensuring compliance to the relevant legislation. This platform also reduces the environmental effects of invasive drilling techniques. A requirement within principles of sustainable building practices, and associated with current standards commonly used by structural engineers who may seek better understanding of soil properties in Australia as a software service (with application potential in North America)

    Proyecto de producción y exportación de dulce de membrillo a inmigrantes ecuatorianos que residen en la ciudad de nueva york, estados unidos

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    Project Production and Export of Sweet Quince aims to reach the market for Ecuadorian migrants residing in the New York City. The market strategy is to appeal to the sentiment of the Ecuadorian immigrants, who yearn to enjoy its typical products of Ecuador. Through market research, it was determined that there is a high degree of acceptance of the product. About 90% of respondents, who have already tried sweet quince, are willing to buy the product. 16% of people who consume traditional sweets Ecuadorians in New York City, they qualify sweet quince as your preference. Regarding the Technical Study emphasizes that the project does not require a large investment in terms of investment in equipment and physical works, which becomes attractive relative to the project. In the Financial Study two scenarios were developed, one with a debt of 40% debt and 60% equity and the other method under 100% of equity. In both cash flows the NPV is a positive value and the IRR is higher than TMAR, making the project profitable

    Viabilidade econômica agrícola e responsabilidade ambiental em unidades rurais de produção orgânica e convencional em Mundo Novo, MS.

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    bitstream/item/69064/1/099-recalde-viabilidade.pdfPublicado também no Cadernos de Agroecologia, v. 7, n.2, 2012

    Solid-State Transformer for Energy Efficiency Enhancement

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    The rapid evolution of power electronic solutions in all around the globe brings a common problem, which is the adoption of nonlinear loads. This fact carries out a strong impact over the quality of power systems and consequently on energy efficiency, since nonlinear loads act as sources of harmonic currents that flow to other loads or even sources, causing non-optimal performance in their operation. Nowadays, conventional transformers are limited to just manage (increase or decrease) voltage level, but they are not able to deal with power quality events, such as harmonics, sag, swell, among others. Hence, there is a need to incorporate a versatile smart device to deal with the challenges previously described for a smart grid environment. This chapter introduces a solid-state transformer (SST) with topology of multilevel cascade H bridge converter as a solution. SST is an emerging technology that has the advantages of low volume, low weight, fault isolation, and other management features. Within its fundamental operation, this chapter presents a detailed description of a SST system comprising communication and control, highlighting their main advantages in comparison with conventional transformer such as mitigation of waveform harmonic distortion, allowance of integration of distributed generation, and bi-directional power flow

    Geothermal heating in the Panama Basin. Part II: abyssal water mass transformation

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    Diabatic upwelling of abyssal waters is investigated in the Panama Basin employing the water mass transformation framework of Walin [1982]. We find that, in large areas of the basin, the bottom boundary layer is very weakly stratified and extends hundreds of meters above the sea floor. Within the weakly stratified bottom boundary layer (wsBBL) neutral density layers intercept the bottom of the basin. The area of these density layer incrops increases gradually as the abyssal waters become lighter. Large incrop areas are associated with strong diabatic upwelling of abyssal water, geothermal heating being the largest buoyancy source. While a significant amount of water mass transformation is due to extreme turbulence downstream of the Ecuador Trench, the only abyssal water inflow passage, water mass transformation across the upper boundary of abyssal water layer is accomplished almost entirely by geothermal heating

    Geothermal heating in the Panama Basin. Part I: hydrography of the basin

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    The Panama Basin serves as a laboratory to investigate abyssal water upwelling. The basin has only a single abyssal water inflow pathway through the narrow Ecuador Trench. The estimated critical inflow through the Trench reaches 0.34 ± 0.07 m s−1, resulting in an abyssal water volume inflow of 0.29 ± 0.07 Sv. The same trench carries the return flow of basin waters that starts just 200 m above the bottom and is approximately 400 m deeper than the depth of the next possible deep water exchange pathway at the Carnegie Ridge Saddle. The curvature of temperature‐salinity diagrams is used to differentiate the effect of geothermal heating on the deep Panama Basin waters that was found to reach as high as 2200 m depth, which is about 500 m above the upper boundary of the abyssal water layer

    Passive acoustic monitoring of baleen whales in Geographe Bay, Western Australia

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    Baleen whales were monitored in Geographe Bay, Western Australia between 2008 and 2011 using passive acoustics. We aimed to monitor migratory timing through Geographe Bay, characterise whale vocalizations, and estimate detection ranges of vocalising whales in different background noise conditions. The results indicated that humpback and blue whales migrated through Geographe Bay every year, however the frequency and timing of their vocalisations varied among years. Humpback whale songs changed in composition among years, but most energy was consistently between 200-500 Hz. Blue whale calls were those of the eastern Indian Ocean pygmy blue whale with low quasi-tonal sounds with harmonics ranging from 20-100 Hz and variable down-sweep impulses with frequencies decreasing from ~100 Hz to ~20 Hz. No significant changes in calls were observed among years. Based on a range independent propagation model, the detection range for vocalising pygmy blue whales was estimated to be between 6-8 km, and for humpback whales ~20-30 km. The prevalence of high levels of noise from vessel traffic affected the detection range significantly for passive acoustic monitoring, and would have also affected the capacity for whales to communicate and perceive important cues in their environment

    A Randomized Study of Nutritional Supplementation in Patients with Unilateral Wet Age-Related Macular Degeneration

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    Carotenoides; Marcadors inflamatoris; Àcids grassos poliinsaturatsCarotenoides; Marcadores inflamatorios; Ácidos grasos poliinsaturadosCarotenoids; Inflammatory markers; Polyunsaturated fatty acidsThe purpose of this study is evaluate the efficacy and safety of medicinal products containing the original Age-Related Eye Disease group (AREDS) formulation at doses approved in Europe (EU, control group; n = 59) with a product that adds DHA, lutein, zeaxanthin, resveratrol and hydroxytyrosol to the formula (intervention group; n = 50). This was a multicenter, randomized, observer-blinded trial conducted in patients aged 50 years or older diagnosed with unilateral exudative Age related Macular Degeneration AMD. At month 12, the intervention did not have a significant differential effect on visual acuity compared with the control group, with an estimated treatment difference in Early Treatment Diabetic Retinopathy Study (ETDRS) of −1.63 (95% CI −0.83 to 4.09; p = 0.192). The intervention exhibited a significant and, in most cases, relevant effect in terms of a reduction in some inflammatory cytokines and a greater improvement in the fatty acid profile and serum lutein and zeaxantin concentration. In patients with unilateral wet AMD, the addition of lutein, zeaxanthin, resveratrol, hydroxytyrosol and DHA to the AREDS EU recommended doses in the short-term did not have a differential effect on visual acuity compared to a standard AREDS EU formula but, in addition to improving the fatty acid profile and increasing carotenoid serum levels, may provide a beneficial effect in improving the proinflammatory and proangiogenic profile of patients with AMD.The research was funded by Laboratorios Théa (Barcelona, Spain) and by research grants from the “Instituto de Salud Carlos III/European Regional Development Fund (ERDF)” and RD16/0008/0011, OFTARED: Enfermedades oculares: “Prevención, detección precoz, tratamiento y rehabilitación de las patologías oculares”
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