Scattering of scalar, electromagnetic and gravitational waves from binary systems

The direct detection of gravitational waves crowns decades of efforts in the modelling of sources and of increasing detectors' sensitivity. With future third-generation Earth-based detectors or space-based observatories, gravitational-wave astronomy will be at its full bloom. Previously brushed-aside questions on environmental or other systematic effects in the generation and propagation of gravitational waves are now begging for a systematic treatment. Here, we study how electromagnetic and gravitational radiation is scattered by a binary system. Scattering cross-sections, resonances and the effect of an impinging wave on a gravitational-bound binary are worked out for the first time. The ratio between the scattered-wave amplitude and the incident wave can be of order $10^{-5}$ for known pulsars, bringing this into the realm of future gravitational-wave observatories. For currently realistic distribution of compact-object binaries, the interaction cross-section is too small to be of relevance.Comment: 19 pages, 3 figures, to appear in PR

Estimation of parameters and state variables in an alcoholic fermentation process in a fed-batch bioreactor

Energy consumption in the world is based on two types of sources: fossil fuels and renewable energy. In this case, bioethanol presents itself as an alternative resource to fossil fuels, whose production can occur through specific processes called alcoholic fermentation. In parallel, the growing demand for energy has motivated scientists to develop even more efficient systems and technologies. In this work, mathematical modeling and simulation was performed to represent the kinetics of alcoholic fermentation in a fed-batch bioreactor. The modeling was developed taking into account the microbial inhibition caused by the presence of excess substrate and product through the Tosetto and Hoppe-Hansford models. In the simulation, Bayesian statistics was used as a tool to estimate the kinetic parameters and the state variables of the bioprocess. The estimates were obtained through the use of a particle filter proposed by Liu and West, with 500 particles and experimental measurements from the literature, whose approach presented 99% accuracy and proved to be effective for describing alcoholic fermentation

Occupational Risk Prevention in the Management of Companies in the Electricity Sector. The case of Galicia (Spain)

30-34The present work aims at analysing the awareness and prevention in the management system of companies in the electricity sector, in order to detect the main shortcomings, seeking to improve in terms of occupational risk prevention. After collecting and analyzing a sample of 180 surveys, numerous shortcomings have been detected in the sector of electrical and telecommunications installations in Galicia (Spain), including the lack of established goals and objectives in preventive matters or the absence of the use of preventive modalities

Bin coring: a simple practice for improving aeration performance and saving energy: Presentation

The coring operation consists of removing the center portion of the grain mass, or core of the silosilo, to improve airflow distribution. Additional benefit of this practice is the elimination of a significant portion of the fine material, which is a source of fungal inoculum and feed for insects. The effect of coring on airflow distribution through a grain mass has been previously addressed, but the effect on energy savings was not fully quantified. Thus, the goals of this reseach were: 1) to quantify the airflow increase due to the coring operation of a silosilo full of wheat; and 2) to quantify the reduction on fan runtime and energy consumtion due to improvement in airflow distribution and airflow increase after coring. The effect of coring on airflow was quantified using the AireAr software, and the effect on aeration efficiency was studied through simulation using a specialized software (PHAST-FDM). For levels of coring (0%, 3%, 5% and 8% of total grain mass) and four levels of nonuniformity of airflow (center side difference) (30, 20, 10 and 0) were considered. Results indicated that the coring operation reduced the total time to achieve cooling, number of fan run hours, and fan power consumption. The main effect of the coring operation was the increase in specific airflow (up to 45% increase). Energy savings increased with coring, obtaining savings of 11%, 28% and 30% for 3%, 5% and 8% of coring, respectively. It was concluded that coring the silosilo by unloading from 3 to 8% of the stored grain mass is a recommendable practice, because it increases the specific airflow rate and airflow uniformity, reduces fan run hours and generates energy (and cost) savings.The coring operation consists of removing the center portion of the grain mass, or core of the silosilo, to improve airflow distribution. Additional benefit of this practice is the elimination of a significant portion of the fine material, which is a source of fungal inoculum and feed for insects. The effect of coring on airflow distribution through a grain mass has been previously addressed, but the effect on energy savings was not fully quantified. Thus, the goals of this reseach were: 1) to quantify the airflow increase due to the coring operation of a silosilo full of wheat; and 2) to quantify the reduction on fan runtime and energy consumtion due to improvement in airflow distribution and airflow increase after coring. The effect of coring on airflow was quantified using the AireAr software, and the effect on aeration efficiency was studied through simulation using a specialized software (PHAST-FDM). For levels of coring (0%, 3%, 5% and 8% of total grain mass) and four levels of nonuniformity of airflow (center side difference) (30, 20, 10 and 0) were considered. Results indicated that the coring operation reduced the total time to achieve cooling, number of fan run hours, and fan power consumption. The main effect of the coring operation was the increase in specific airflow (up to 45% increase). Energy savings increased with coring, obtaining savings of 11%, 28% and 30% for 3%, 5% and 8% of coring, respectively. It was concluded that coring the silosilo by unloading from 3 to 8% of the stored grain mass is a recommendable practice, because it increases the specific airflow rate and airflow uniformity, reduces fan run hours and generates energy (and cost) savings

Faecal bacteria in Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia) for biomonitoring coastal waters and seafood quality

Urban development in coastal areas is intense and leads to the increase of sewage outfall and other negative impacts as consequences. Thus, stringent regulations establishing limits to the microbiological contamination of water and seafood are needed. The objective of this study is to evaluate the usefulness of Enterococci and Thermotolerant Coliform densities in the flesh of mussels Perna perna as an alternative tool for monitoring the microbiological quality of coastal waters. The study also considers allometric relations applied to clearance rates to understand rates of bacterial concentration. Bacterial loads obtained in mussels' flesh were from 50 to 4,300 times greater than in the water sampled in the vicinity of the mussels and some were considered inappropriate for consumption even when the water presented no restrictions. The mean clearance rate obtained for Enterococci retention was 317.7 ml h-1 and this rate (CR) is related to the mussels' size (L) by the equation CR = 28.3229L1.6421. The results showed that bacterial densities in the mussels' tissues may reflect chronic contamination of the environment and that clearance rates are important for taking the best decision in situations where, for example, it is desired to introduce mussels for aquaculture and the evaluation of the water concerned is required.O desenvolvimento urbano em áreas costeiras é intenso e o aumento das descargas de esgoto é uma das conseqüências. Assim, leis específicas que regulem limites para a contaminação microbiológica das águas e de alimentos de origem marinha são necessárias. O objetivo deste estudo é avaliar a utilização de Enterococos e coliformes termotolerantes na carne de mexilhões Perna perna como alternativa para o monitoramento da qualidade microbiológica de águas costeiras. O estudo também considera relações alométricas aplicadas às taxas de "clearance" para entender a concentração de bactérias pelo molusco. As densidades bacterianas obtidas no molusco foram de 50 a 4300 vezes maiores do que nas amostras de água coletadas próximas dos moluscos e alguns foram considerados impróprios para consumo, mesmo quando as águas não mostraram restrições. A taxa de "clearance" média obtida para retenção de Enterococos foi 317.7 ml h-1 e essas taxas (CR) puderam ser relacionadas com o tamanho dos mexilhões (L) pela equação CR = 28.3229L1.6421. Os resultados mostram que as densidades bacterianas nos tecidos dos mexilhões podem refletir a contaminação crônica do ambiente e que as taxas de "clearance" devem ser consideradas para a tomada de decisão em situações onde, por exemplo, se deseja implantar mexilhões para cultivo

Markovian Approach to Time Transition Inference on Bayesian Networks

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