Estudio de las prestaciones energéticas de SigFox y NB-IoT

Internet of things (IoT) is having an increasing presence in our society and the industry is committed to its development and evolution. IoT represents a new form of communication between machines without requiring human interactions in order that different devices and sensors are able to transmit data to the network about the physical world, these can be analyzed and interpreted thus obtaining useful information to help take decisions, monitor or store data among other examples. In most cases, these devices or sensors are not connected to the power grid and require autonomous sources of energy to be powered. This circumstance is relevant when it comes to deploying networks that fits these devices. Therefore, new technologies have been developed recently in order to allow the correct development and deployment of these devices. This is how Low Power Wide Area Network came about. These technologies are designed to be able to offer long-range communications using a low use of energy resources. Within these technologies, two relevant examples are SigFox and Narrowband-IoT. The main objective of this project is to evaluate the energy consumption of these two technologies using different platforms available in the market, laboratory tools such as a power analyzer and different software to configure the devices and obtain the results. In this way, a realistic model of energy consumption can be generated with both technologies and, based on the results obtained, estimate the lifetime and the energy cost of data delivery of devices that use these technologies

Estimación de demanda de transporte de carga a partir de fuentes secundarias. Caso de estudio : Manhattan

RESUMEN: La formulación propuesta para sintetizar matrices Origen-Destino de carga se basa en un modelo gravitatorio que permite estimar los flujos de viajes de carga en Manhattan basado en conteos vehiculares. Estos flujos de viajes se asignan a la red para obtener una serie de volúmenes de tráfico de camiones en determinados arcos viales. Estos volúmenes estimados se comparan con el número de camiones observados, para luego calcular iterativamente los parámetros del modelo que permitan disminuir las diferencias entre volúmenes estimados y volúmenes calculados. El proceso termina cuando no se puede lograr mejores resultados por medio de ajustes en los parámetros del modelo.ABSTARCT: The proposed freight Origin-Destination Synthesis formulation uses a gravity model to estimate trip fl ows in Manhattan based on traffi c counts. The resulting total truck trips are assigned to the network to obtain a set of estimated truck traffi c volumes, which are compared to the observed truck traffi c. At this stage, the parameters of the model are then recomputed to improve the agreement between estimated and observed truck traffi c. The process ends once no further improvement is possible

Investigación empírica sobre los impactos de agregación espacial y temporal en los modelos de viajes vacíos

RESUMEN: Este artículo analiza los impactos de agregación espacial y temporal en los modelos de viajes vacíos. Los autores analizan 5 modelos de viajes vacíos (Noortman and van Es, y cuatro modelos de HolguÌn-Veras y Thorson) para diferentes niveles de agregación de seis matrices origen-destino. Las matrices fueron obtenidas por el Ministerio de Transporte de Colombia en los años 2000 a 2005. La investigación incluye una evaluación de la agregación espacial y la dependencia en el tiempo de los par·metros de los modelos. Adicionalmente, se examinaron tres niveles de agregación para estudiar el desempeño de las especificaciones en los diferentes modelos de viajes vacíos y la estabilidad temporal de sus par·metros.ABSTRACT: This paper analyzes the impacts of spatial and temporal aggregation of empty trips models. The authors analyze Æ ve models of empty trips (Noortman and van Es, and four Holguin-Veras and Thorson empty trips models) for different aggregation levels of six national freight origin-destination (OD) matrices. They were collected by Colombiaís Ministry of Transportation during the 2000 to 2005 time period. The research includes an assessment of the spatial aggregation and time-dependency of the parameters for the different models. Furthermore, three aggregation levels are examined to study the performance of the different empty trips models speciÆ cations and the spatial and temporal stability of the parameters for these models

Estabilidad de parámetros en modelos de generación y distribución de carga en Colombia

RESUMEN: Este artículo presenta una investigación empírica sobre la estabilidad de parámetros en los modelos de demanda de transporte de carga en periodos cortos de tiempo. El análisis es realizado con base en 7 encuestas origen-destino a vehículos de carga efectuadas por el Ministerio de Transporte durante los años 1999 al 2005. El artículo estudia la estabilidad en el tiempo de los parámetros en los modelos de generación y distribución de carga, calibrándolos con secciones transversales de datos correspondientes a cada año y haciendo regresiones a los parámetros resultantes como función del tiempo para identifi car el efecto de la dependencia del mismo en los modelos. Los resultados indican que todos los modelos de generación de carga son dependientes del tiempo así como los modelos de distribución de carga basados en camiones cargados. En contraste, se encontró que los parámetros de los modelos de distribución de carga basados en toneladas transportadas son estables en el tiempo.ABSTARCT: This paper conducts an empirical investigation on the temporal stability of parameters of freight demand models in the shortmedium term. The analyses are based on seven national freight origin-destination samples conducted by the Colombian government during the years 1999 to 2005. The paper studies the stability of the parameters of freight generation and freight distribution. Typical formulations of these models were calibrated using the cross-sectional data corresponding to each year. Then, to identify time-dependent effects, the resulting parameters were regressed as a function of a time index. The results indicate the presence of statistically signifi cant time-dependent effects on all freight generation models (production and attraction), as well as on the freight distribution model estimated with loaded vehicle trips. In contrast, the parameters of the freight distribution models based on commodity fl ows were found to be stable overtime

Sweat conductivity: An accurate diagnostic test for cystic fibrosis?

AbstractBackgroundSweat chloride test is the gold standard test for cystic fibrosis (CF) diagnosis. Sweat conductivity is widely used although still considered a screening test.MethodsThis was a prospective, cross-sectional, diagnostic research conducted at the laboratory of the Instituto da Criança of the Hospital das Clínicas, São Paulo, Brazil. Sweat chloride (quantitative pilocarpine iontophoresis) and sweat conductivity tests were simultaneously performed in patients referred for a sweat test between March 2007 and October 2008. Conductivity and chloride cut-off values used to rule out or diagnose CF were <75 and ≥90mmol/L and <60 and ≥60mmol/L, respectively. The ROC curve method was used to calculate the sensitivity, specificity, positive (PPV) and negative predictive value (NPV), as well as the respective 95% confidence intervals and to calculate the area under the curve for both tests. The kappa coefficient was used to evaluate agreement between the tests.ResultsBoth tests were performed in 738 children, and CF was ruled out in 714 subjects; the median sweat chloride and conductivity values were 11 and 25mmol/L in these populations, respectively. Twenty-four patients who had received a diagnosis of CF presented median sweat chloride and conductivity values of 87 and 103mmol/L, respectively. Conductivity values above 90mmol/L had 83.3% sensitivity, 99.7% specificity, 90.9% PPV and 99.4% NPV to diagnose CF. The best conductivity cut-off value to exclude CF was <75mmol/L. Good agreement was observed between the tests (kappa: 0.934).ConclusionsThe sweat conductivity test yielded a high degree of diagnostic accuracy and it showed good agreement with sweat chloride. We suggest that it should play a role as a diagnostic test for CF in the near future

The chemical percolation devolatilization model applied to the devolatilization of coal in high intensity acoustic fields

Neste trabalho, um modelo de percolação química (CPD), desenvolvido para o cálculo da evolução dos produtos de pirólise de partículas de carvão, foi estendido de forma a ser empregado em regimes de degradação térmica sobre a influência de campos acústicos de alta intensidade, típicos de combustores do tipo tubo de Rijke. As oscilações acústicas incrementam os processos de transferência de calor e massa no leito de combustível, bem como na região livre acima do mesmo. Os resultados obtidos em simulações com um combustor do tipo Rijke mostraram um aumento nas taxas de evaporação de água e de degradação térmica das partículas. O modelo de percolação química empregado, no regime pulsante, permitiu o cálculo da evolução dinâmica de CO, CO2, CH4, H2O, outros gases leves e alcatrão, importantes no processo de ignição e estabilização de chamas. O modelo também forneceu a quantidade e forma dos compostos nitrogenados liberados no processo de pirólise que são indispensáveis nas estratégias para abatimento da emissão de poluentes (NOx) em regimes de queima excitados por oscilações acústicas. O bioma Pantanal é caracterizado pela inundação sazonal que determina processos ecossistêmicos específicos, com a ocorrência de plantas e animais adaptados à mudança anual de encolhimento e expansão de hábitats em virtude do regime hidrológico sazonal. A biodiversidade do Pantanal é um componente fundamental dos serviços ecossistêmicos prestados à sociedade humana, que inclui reciclagem de nutrientes, produção pesqueira, ecoturismo, resgate de carbono, controle de enchentes, entre outros, que são importantes consequências ambientais em nível regional e global. O bioma tem sido afetado pelo impacto da conversão de sua vegetação natural em campos agrícolas e pasto para a pecuária, com alteração e perda de hábitats e biodiversidade. O impacto maior tem ocorrido nas terras altas do planalto do entorno da planície, com desmatamento do Cerrado nas áreas onde nascem os rios que alimentam o Pantanal. Este artigo discute as necessidades e prioridades futuras de pesquisa ecológica para melhor entender o ecossistema e, assim, atingir sua conservação e uso sustentável. _______________________________________________________________________________ ABSTRACTThe chemical percolation devolatilization model (CPD) was extended for the prediction of drying and devolatilization of coal particles in high intensity acoustic fields found in Rijke tube reactors. The acoustic oscillations enhance the heat and mass transfer processes in the fuel bed as well as in the freeboard, above the grate. The results from simulations in a Rijke tube combustor have shown an increase in the rate of water evaporation and thermal degradation of the particles. The devolatilization model, based on chemical percolation, applied in pulsating regime allowed the dynamic prediction on the yields of CO, CO2, CH4, H2O, other light gases as well as tar which are important on ignition and stabilization of flames. The model predicted the quantity and form of nitrogen containing species generated during devolatilization, for which knowledge is strategically indispensable for reducing pollutant emissions (NOx) in flames under acoustic excitation

Explorando el papel de las Relaciones Públicas y la Comunicación en los Museos. Un análisis de la cartografía científica en Web of Science y Scopus

Museums are born from the need to preserve historical heritage in a space where they can research and disseminate knowledge. The evolution of museum communication, together with the use of new technologies or new forms of communication, has been an unprecedented milestone between museums and their public, as it allows them to establish interactions, contributing to the development of a greater knowledge of the cultural demands of museum visitors. Social media, blogs or mobile social media fall within this new way of communicating, being used by museums to expand their dissemination and publicize their activities. The use of these networks has created wider spaces and more open museums. Therefore, social media are already being used by museums to expand their dissemination and publicize their activities, this being a clear use of what is known as "museum 2.0". This research work carries out a bibliometric study since 1976, the first year in which publications in this field were detected. Sixty-four publications have been identified in the databases, Web of Science Core Collection and Scopus, showing a mapping of authorship networks, citation and co-occurrence of keywords or scientific interrelation between organizations and countries

Effects of wet CO oxidation on the operation of engines and power generators

A simplified method is used to determine the optimum water content in the flue gases of charcoal gasifiers to be utilized as alternative fuels in the operation of engines and gas turbines for power generation. Computational models of plug flow reactors and well stirred reactors are employed to simulate the reaction and post-flame zones, adopting different chemical mechanisms. In the simulations reactants enter the reactors at 1000 K, 1 atm and equivalence ratio 0.25. It was observed that mixtures about 3% to 4% in volume of water vapor allow to obtain optimal operation characteristics, including high blowout limit, low ignition delay, maximum reaction zone temperature, high CO2 prodution and low thermal NO formation. It was observed that increasing water contents reduce significantly ignition times up to 3% in volume, while blowout mass flow rates increase continuously up to 6 % in volume, the maximum value considered. Formation of NO decreases continuously with humidity after the flame zone, while there are peaks of NO formation within the flame zone below 1% in volume. Higher water vapor content decreases the final temperatures below 1700 K, leading to a lower thermal efficiency. The method can be used to estimate optimum operational conditions with other input parameters

INFÂNCIA E SOFRIMENTO PSÍQUICO: MEDICALIZAÇÃO, MERCANTILIZAÇÃO E JUDICIALIZAÇÃO

Quais discursos vêm sendo produzidos sobre a(as) infância(as) na contemporaneidade? Realizar esse questionamento, à luz da psicanálise, é o objetivo principal deste artigo que também incita reflexões a respeito dos processos de judicialização, medicalização e mercantilização dos primeiros estágios da vida. Compreende-se que os momentos iniciais do desenvolvimento repercutem no modo de funcionamento do sujeito. De modo que as maneiras com as quais os grupos sociais lidam com suas diferentes crianças exercerão influências no projeto de futuro de cada sociedade. Assim, confirma-se a relevância de pensar sobre o tema “sofrimento psíquico na infância e seus desdobramentos”

Evaluation of marginal sealing quality of restorations with low shrinkage composite resins

This study compared the quality of marginal sealing in the gingival wall of class II preparations of two low-shirinkage resins of the bulk fill type with a conventional resin isolated or associated with a glass ionomer cement (GIC). 40 human molars wer