Forecasting cosmological constraints from age of high-z galaxies

We perform Monte Carlo simulations based on current age estimates of high-z objects to forecast constraints on the equation of state (EoS) of the dark energy. In our analysis, we use two different EoS parameterizations, namely, the so-called CPL and its uncorrelated form and calculate the improvements on the figure of merit for both cases. Although there is a clear dependence of the FoM with the size and accuracy of the synthetic age samples, we find that the most substantial gain in FoM comes from a joint analysis involving age and baryon acoustic oscillation data.Comment: 4 pages, 13 figures, late

Cosmic homogeneity: a spectroscopic and model-independent measurement

Cosmology relies on the Cosmological Principle, i.e., the hypothesis that the Universe is homogeneous and isotropic on large scales. This implies in particular that the counts of galaxies should approach a homogeneous scaling with volume at sufficiently large scales. Testing homogeneity is crucial to obtain a correct interpretation of the physical assumptions underlying the current cosmic acceleration and structure formation of the Universe. In this Letter, we use the Baryon Oscillation Spectroscopic Survey to make the first spectroscopic and model-independent measurements of the angular homogeneity scale $\theta_{\rm h}$. Applying four statistical estimators, we show that the angular distribution of galaxies in the range 0.46 < z < 0.62 is consistent with homogeneity at large scales, and that $\theta_{\rm h}$ varies with redshift, indicating a smoother Universe in the past. These results are in agreement with the foundations of the standard cosmological paradigm.Comment: 5 pages, 2 figures, Version accepted by MNRA

The use of hydrazine as an alternate source of energy

The potentials of using hydrazine as an alternative source of energy was studied. Three chemical reactions are considered: oxidation with air, oxidation with hydrogen peroxide, and thermocatalytic decomposition. Performance data of gasoline, ethylic alcohol, and propane are compared. An item about the NO(x) emissions by the various investigated reactions is included. Promising results are shown, mainly those regarding the available energy per unit volume of unburned gases (vaporized fuel and oxidizer)

Remote and Safe Monitoring of Magnetic Fields Produced by Transmission Lines in Areas of High Concentration of Lightning Strokes

Monitoring of magnetic and electric fields in high voltage transmission lines (HVTL) of power plants and substations (SEs) is contemplated by Brazilian Regulatory Standard 616/2014. The measurement procedures of the magnetic and electric fields in SEs must follow a methodology in case of continuous field monitoring of the power equipment where it is common lightning stroke incidences. These monitoring procedures must be carried out in such a way that the recording of electromagnetic fields is done without necessity of exposuring the technical team to irradiation from the equipment and machines generating electrical power. This paper describes a prototype which is able to produce data at a specified safe distance from the irradiating area. The experimental recorded data was acquired, processed, compared and analyzed in areas of more intense radiation levels, acceptable levels and safe levels. This work aimed to establish basis of a technological innovation for the continuous recording of electromagnetic data, trying to cover the surroundings of transmission lines in urban environments, close to the generating units and substation installations wherever the highest levels of magnetic field could be found

Salmonella Typhimurium CARRIAGE at slaughter AFTER an enterocolitis outbreak in a swine herd

The aim of this study was to estimate the prevalence of slaughter pigs carrying Salmonella Typhimurium after a entericolitis outbreak in a commercial pig farm. A cross-sectional study was done during the slaughter of a batch of 86 animals. Mesenteric lymph nodes from 43 pigs were collected and pre-enriched in buffered peptone water (1:10) overnight at 37∞C Afterwards, aliquots of 1mL and 0.1mL were transferred to selenite-cystine and Rappaport-Vassiliadis broth, respectively. A loopful of each sample was streaked onto XLT4 and brilliant green agar plates, which were incubated at 37∞C for 24 hours. Salmonella was cultured in 23 out of 43 collected samples (53.48%). Salmonella Typhimurim (13 strains) and Salmonella enterica subs. enterica 1,4,5,12:i:- (10 strains) were isolated. These results indicated that the slaughter of pigs from batches previously affected by enteric salmonellosis may represent a high risk for pork contamination, since there is an positive association between infected pigs before slaughter and carcass contamination

Gauging N=2 Supersymmetric Non-Linear σ\sigma-Models in the Atiyah-Ward Space-Time

We build up a class of N=2 supersymmetric non-linear $\sigma$-models in an N=1 superspace based on the Atiyah-Ward space-time of (2+2)-signature metric. We also discuss the gauging of isometries of the associated hyper-K\"ahlerian target spaces and present the resulting gauge-covariant supersymmetric action functional.Comment: 12 pages, latex, no figure

REVIEW OF CFD SIMULATION OF OXY-COAL COMBUSTION FOR ELETRICAL POWER GENERATION: OPPORTUNITIES AND CHALLENGES

The oxy-combustion has generated significant interested for reduction of CO2 emission when the fossil fuel is coal, due to simplification on the separation process of CO2 from the flue gas, it can be more easily stored in reservoir. The CFD numerical simulation techniques in oxy-coal combustion has the potential to contribute to designers in cost savings and reduced computational time; Furthermore, such techniques also provide a robust tool for better understanding and description of the aerothermodynamics processes involved, as well as, aiding the design of most efficient furnaces. However, to obtain representative results of the physical phenomena, the numerical models employed by CFD needs to be suitable for oxy-coal combustion. So, the aim of the paper is to carry out a review of the recent models that are being used for turbulence, combustion and pollutant emissions. Moreover, it is shown a comparison of different results obtained in the numerical simulation of oxy-coal combustion among new models, existing models and experiments. The analysis of the models and experiments shows that the challenges that are still being faced to obtain better accuracy of numerical simulation results. Improvements in the models for oxy-coal combustion can be seen like potential opportunities to investigate and optimize the process that occur in the combustion

Optical studies of the correlation between interface disorder and the photoluminescence line shape in GaAs/InGaP quantum wells

Photoluminescence (PL) and excitation PL measurements have been performed at different temperatures in a number of lattice-matched GaAs/In0.49Ga0.51P quantum wells, where the uctuations of the potential energy are comparable with the thermal energy of the photocreated carriers. Two samples with different well widths allow to observe a series of anomalous e ects in their optical response. The observed effects are related to the disorder in the interface, characterizing uctuations in the confinement potential energy. It is proposed that the carrier relaxation processes occur either at the local minima or at the absolute minimum of the confinement potential, depending on the ratio of the thermal energy and the magnitude of the potential fluctuations.314317Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES