725 resultados para long period


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Se presenta un estudio de detección y caracterización de eventos sísmicos del tipo volcano tectónicos y largo periodo de registros sísmicos generados por el volcán Cotopaxi. La estructura secuencial de detección propuesta permite en un registro sísmico maximizar la probabilidad de presencia de un evento y minimizar la ausencia de este. La detección se la realiza en el dominio del tiempo en cuasi tiempo real manteniendo una tasa constante de falsa alarma para posteriormente realizar un estudio del contenido espectral de los eventos mediante el uso de estimadores espectrales clásicos como el periodograma y paramétricos como el método de máxima entropía de Burg, logrando así, categorizar a los eventos detectados como volcano tectónicos, largo periodo y otros cuando no poseen características pertenecientes a los otros dos tipos como son los rayos.

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Dataloggerit ovat tärkeitä mittaustekniikassa käytettäviä mittalaitteita, joiden tarkoituksena on kerätä talteen mittausdataa pitkiltä aikaväleiltä. Dataloggereita voidaan käyttää esimerkiksi teollista prosessia osana olevien toimilaitteiden tai kotitalouden energiajärjestelmän seurannassa. Teollisen luokan dataloggerit ovat yleensä hinnaltaan satojen tai tuhansien eurojen luokkaa. Työssä pyrittiin löytämään teollisen luokan laitteille halpa ja helppokäyttöinen vaihtoehto, joka on kuitenkin riittävän tehokas ja toimiva. Työssä suunniteltiin ja toteutettiin dataloggeri Raspberry Pi-alustalle ja testattiin sitä oikeaa teollista ympäristöä vastaavissa olosuhteissa. Kirjallisuudesta ja internet artikkeleista etsittiin samankaltaisia laite- ja ohjelmistoratkaisuja ja niitä käytettiin dataloggausjärjestelmän pohjana. Raspberry Pi-alustalle koodattiin yksinkertainen Python-kielinen data-loggausohjelma, joka käyttää Modbus-tiedonsiirtoprotokollaa. Testien perusteella voidaan todeta, että toteutettu dataloggeri on toimiva ja kykenee kaupallisten dataloggereiden tasoiseen mittaukseen ainakin pienillä näytteistystaajuuksilla. Toteutettu dataloggeri on myös huomattavasti kaupallisia dataloggereita halvempi. Helppokäyttöisyyden näkökulmasta dataloggerissa havaittiin puutteita, joita käydään läpi jatkokehitysideoiden muodossa.

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Roots normally grow in darkness, but they may be exposed to light. After perceiving light, roots bend to escape from light (root light avoidance) and reduce their growth. How root light avoidance responses are regulated is not well understood. Here, we show that illumination induces the accumulation of flavonols in Arabidopsis thaliana roots. During root illumination, flavonols rapidly accumulate at the side closer to light in the transition zone. This accumulation promotes asymmetrical cell elongation and causes differential growth between the two sides, leading to root bending. Furthermore, roots illuminated for a long period of time accumulate high levels of flavonols. This high flavonol content decreases both auxin signaling and PLETHORA gradient as well as superoxide radical content, resulting in reduction of cell proliferation. In addition, cytokinin and hydrogen peroxide, which promote root differentiation, induce flavonol accumulation in the root transition zone. As an outcome of prolonged light exposure and flavonol accumulation, root growth is reduced and a different root developmental zonation is established. Finally, we observed that these differentiation-related pathways are required for root light avoidance. We propose that flavonols function as positional signals, integrating hormonal and ROS pathways to regulate root growth direction and rate in response to light.

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The coco de zambê is a dance of which origin is credited to old slaves who inhabited the coastalregion of Rio Grande do Norte. The zambê appears intensely in the narratives related to the past and present of Sibaúma, a quilombola community located in the southern coast of the state. It is conceived as a sign of ethnicity linked to a local black ancestry. The group is known as "remnant of Quilombo," and is demanding the process of territorial settlement, as guaranteed through the Brazilian federal constitution. The coco de zambê, presented as a kind of "certificate of ancestry to the group, besides, after a long period of abandonment, the dance is beeing "revitalized" and exploited by a part of the group alongside the demands for recognition. In this process there are several interlinked actors: NGOs, state agencies to promote the culture, representatives of public authorities and local leaders. Here, I'm interested in understanding how this process of revival occurs with the coco de zambê in Sibaúma: how a "brincadeira" (play) of the ancients comes to be a "cultural reference" and a means of political mobilization concerning their recognition

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Las resinas compuestas y adhesivos dentales se utilizan ampliamente para la restauración de dientes con pulpas vitales. La preferencia en el uso de estas resinas compuestas podría estar atribuida a que son materiales con buenos resultados estéticos y se consideran materiales de restauración estables. Sin embargo se ha demostrado que son susceptibles a la degradación y liberación de la fracción de sus componentes y que cierta cantidad de los monómeros de su composición permanecen sin polimerizar por un largo periodo de tiempo, pudiendo estos filtrarse hacia el tejido pulpar y causar alteraciones de la actividad fisiológica de las células de la pulpa (DPCs) (1). Además, estudios in vitro han demostrado que los componentes de las resinas compuestas tienen potenciales tóxicos, generando respuestas inmediatas y a largo plazo luego de su aplicación. Identificar el potencial tóxico y deletéreo de los materiales de restauración sobre el tejido pulpar es de gran interés y relevancia clínica, por ello este estudio comprende en una revisión de la literatura acerca de la respuesta pulpar a los materiales de restauración tipo resina.

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Dissertação de mest. em Aquacultura, Unidade de Ciências e Tecnologias dos Recursos Aquáticos, Univ. do Algarve, 1997

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A wide range of non-destructive testing (NDT) methods for the monitoring the health of concrete structure has been studied for several years. The recent rapid evolution of wireless sensor network (WSN) technologies has resulted in the development of sensing elements that can be embedded in concrete, to monitor the health of infrastructure, collect and report valuable related data. The monitoring system can potentially decrease the high installation time and reduce maintenance cost associated with wired monitoring systems. The monitoring sensors need to operate for a long period of time, but sensors batteries have a finite life span. Hence, novel wireless powering methods must be devised. The optimization of wireless power transfer via Strongly Coupled Magnetic Resonance (SCMR) to sensors embedded in concrete is studied here. First, we analytically derive the optimal geometric parameters for transmission of power in the air. This specifically leads to the identification of the local and global optimization parameters and conditions, it was validated through electromagnetic simulations. Second, the optimum conditions were employed in the model for propagation of energy through plain and reinforced concrete at different humidity conditions, and frequencies with extended Debye's model. This analysis leads to the conclusion that SCMR can be used to efficiently power sensors in plain and reinforced concrete at different humidity levels and depth, also validated through electromagnetic simulations. The optimization of wireless power transmission via SMCR to Wearable and Implantable Medical Device (WIMD) are also explored. The optimum conditions from the analytics were used in the model for propagation of energy through different human tissues. This analysis shows that SCMR can be used to efficiently transfer power to sensors in human tissue without overheating through electromagnetic simulations, as excessive power might result in overheating of the tissue. Standard SCMR is sensitive to misalignment; both 2-loops and 3-loops SCMR with misalignment-insensitive performances are presented. The power transfer efficiencies above 50% was achieved over the complete misalignment range of 0°-90° and dramatically better than typical SCMR with efficiencies less than 10% in extreme misalignment topologies.

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Predicting the evolution of a coastal cell requires the identification of the key drivers of morphology. Soft coastlines are naturally dynamic but severe storm events and even human intervention can accelerate any changes that are occurring. However, when erosive events such as barrier breaching occur with no obvious contributory factors, a deeper understanding of the underlying coastal processes is required. Ideally conclusions on morphological drivers should be drawn from field data collection and remote sensing over a long period of time. Unfortunately, when the Rossbeigh barrier beach in Dingle Bay, County Kerry, began to erode rapidly in the early 2000’s, eventually leading to it breaching in 2008, no such baseline data existed. This thesis presents a study of the morphodynamic evolution of the Inner Dingle Bay coastal system. The study combines existing coastal zone analysis approaches with experimental field data collection techniques and a novel approach to long term morphodynamic modelling to predict the evolution of the barrier beach inlet system. A conceptual model describing the long term evolution of Inner Dingle Bay in 5 stages post breaching was developed. The dominant coastal processes driving the evolution of the coastal system were identified and quantified. A new methodology of long term process based numerical modelling approach to coastal evolution was developed. This method was used to predict over 20 years of coastal evolution in Inner Dingle Bay. On a broader context this thesis utilised several experimental coastal zone data collection and analysis methods such as ocean radar and grain size trend analysis. These were applied during the study and their suitability to a dynamic coastal system was assessed.

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Abstract: Professional brotherhoods were a fundamental structure of social organization during the Ancien Regime in Portugal. The traditional guild of musicians - Brotherhood of St. Cecilia - was a case of particular relevance to the musical context over a long period of time and was confirmed as a dominant institution, especially in Lisbon. This study establishes a confrontation across the Statutes of the Brotherhood under the Documents (Compromissos) known since 1749, in order to know (a) changes made by the end of the eighteenth century; (b) local specificities in Évora (1780) and Oporto (1784) according to the model of Lisbon (1749 and 1766); (c) connections to specific musical contexts. Resumo: As irmandades profissionais constituiram-se como uma estrutura fundamental de organização social durante o Antigo Regime em Portugal. No caso dos músicos a Irmandade de Santa Cecília afirmou-se como um caso de particular relevância para o estudo do sistema de organização e valorização de atividade confirmando-se como uma instituição dominante, sobretudo em Lisboa. Neste estudo estabelece-se um confronto entre os Estatutos da Irmandade segundo os Compromissos conhecidos desde 1749, no sentido de conhecer (a) alterações introduzidas até finais do século XVIII; (b) especificidades locais em Évora (1780) e Porto (1784) de acordo com o modelo de Lisboa (1749 e 1766); (c) relação com contextos musicais específicos.

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A developed and sustainable agriculture requires a permanent and reliable monitoring of climatic/ meteorological elements in (agro) meteorological stations which should be located close to agricultural, silvicultural or pastoral activities. An adequate network of meteorological stations is then a necessary condition to support innovation and development in any country. Developing countries, mainly those with a history of frequent conflicts, presents deficient number of weather stations, often poorly composed and improperly distributed within their territories, and without a regular operation that allows continuity of records for a sufficiently long period of time. The objective of this work was to build a network of meteorological and agro-meteorological stations in East Timor. To achieve this goal, the number and location of pre-existing stations, their structure and composition (number and type of sensors, communication system,… ), the administrative division of the country and the available agro-ecological zoning, the agricultural and forestry practices in the country, the existing centres for the agricultural research and the history of the weathers records were taken into account. Several troubles were found (some of the automatic stations were assembled incorrectly, others stations duplicated information regarding the same agricultural area, vast areas with relevant agro-ecological representativeness were not monitored …). It was proposed the elimination of 11 existing stations, the relocation of 7 new stations in places not covered until then, the automation of 3 manual meteorological stations. Two networks were then purposed, a major with 15 agro-meteorological stations (all automatized) and one other secondary composed by 32 weather stations (only two were manual). The set of the 47 stations corresponded to a density of 329 km2/station. The flexibility in the composition of each of the networks was safeguarded and intends to respond effectively to any substantive change in the conditions in a country in constant change. It was also discussed the national coverage by these networks under a “management concept for weather stations”.

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The purpose of the current undertaking was to study the electrophysiological properties of the sleep onset period (SOP) in order to gain understanding into the persistent sleep difficulties of those who complain of insomnia following mild traumatic brain injury (MTBI). While many believe that symptoms of post concussion syndrome (PCS) following MTBI resolve within 6 to 12 months, there are a number of people who complain of persistent sleep difficulty. Two models were proposed which hypothesize alternate electrophysiological presentations of the insomnia complaints of those sustaining a MTBI: 1) Analyses of standard polysomnography (PSG) sleep parameters were conducted in order to determine if the sleep difficulties of the MTBI population were similar to that of idiopathic insomniacs (i.e. greater proportion ofREM sleep, reduced delta sleep); 2) Power spectral analysis was conducted over the SOP to determine if the sleep onset signature of those with MTBI would be similar to psychophysiological insomniacs (characterized by increased cortical arousal). Finally, exploratory analyses examined whether the sleep difficulties associated with MTBI could be explained by increases in variability of the power spectral data. Data were collected from 9 individuals who had sustained a MTBI 6 months to 5 years earlier and reported sleep difficulties that had arisen within the month subsequent to injury and persisted to the present. The control group consisted of 9 individuals who had experienced neither sleep difficulties, nor MTBI. Previous to spending 3 consecutive uninterrupted nights in the sleep lab, subjects completed questionnaires regarding sleep difficulties, adaptive functioning, and personality.