902 research outputs found
Bifurcations in the wake of a thick circular disk
Using DNS, we investigate the dynamics in the wake of a circular disk of aspect ratio χ = d/w = 3(where d is the diameter and w the thickness) embedded in a uniform flow of magnitude U0 perpendicular to its symmetry axis. As the Reynolds number Re = U0d/ν is increased, the flow is shown to experience an original series of bifurcations leading to chaos. The range Re ∈ [150, 218] is analysed in detail. In this range, five different non-axisymmetric regimes are successively encountered, including states similar to those previously identified in the flow past a sphere or an infinitely thin disk, as well as a new regime characterised by the presence of two distinct frequencies. A theoretical model based on the theory of mode interaction with symmetries, previously introduced to explain the bifurcations in the flow past a sphere or an infinitely thin disk (Fabre et al. in Phys Fluids 20:051702, 2008), is shown to explain correctly all these results. Higher values of the Reynolds number, up to 270, are also considered. Results indicate that the flow encounters at least four additional bifurcations before reaching a chaotic state
Ação do Agrostemin sobre a altura e o número de folhas de plantas de soja (Glycine max L. MERRILL cv. IAC-8)
A greenhouse experiment was conducted to evaluate the effects of Agrostemmin (plant stimulant) on height and number of leaves of soybean plants (Glycine max L Merril cv. IAC-8). Six treatments were studied: check (T1); 0,125g Agrostemmin/l00g seed (T2); 0,125g Agrostemmin/100 seed and foliar spraying 333 ppm (T3); 0,125g Agrostemmin/l00g seed and foliar spraying 500 ppm (T4); foliar spraying 333 ppm (T5) and foliar spraying 500 ppm (T6). Three samplings were made at 14 day intervals. The experimental layout was completely randomized, using two variance, testing regression effects. Agrostemmin applied to the seed (T2) or sprayed on the leaves at the rate of 500 ppm (T6) increased height and number of leaves of soybean, whereas the combination of Agrostemmin applied to the seeds and sprayed at 500 ppm (T4) decreased those values.O presente estudo teve por finalidade avaliar o efeito de um estimulante vegetal, o Agrostemin, sobre a altura e o número de folhas das plantas de soja (Glycine max L. MERRILL cv. IAC-8). O experimento foi conduzido em casa de vegetação. Foram estudados seis tratamentos, correspondentes as seguintes dosagens, épocas e formas de aplicação: testemunha (T1); 0,125g Agrostemin/l00g sementes (T2); 0,125g Agrostemin/100g semente e pulverização foliar à 333 ppm (T3); 0,125g Agrostemin/l00g sementes e pulverização foliar à 500 ppm (T4); pulverização foliar à 333 ppm (T5) e pulverização foliar à 500 ppm (T6). Realizaram-se três coletas de plantas, com intervalo de 14 dias. O experimento foi em delineamento inteiramente casualizado, utilizando-se duas análises de variância com desdobramento em efeitos de regressão. Através dos resultados obtidos concluiu-se que o Agrostemin quando aplicado via semente (T2) ou via foliar à 500 ppm (T6), aumentou a altura e o número de folhas. Ao aplicar o produto via semente mais via foliar à 500 ppm (T4), estas medidas diminuiram
Efeitos do agrostemin em plantas de soja (Glicine max (L.) Merrill cv. IAC-8), através dos parâmetros fisiológicos: razão de área foliar, taxa assimilatória líquida e taxa de crescimento relativo
The objetive of this work was to evaluate the effect of Agrostemmin on the development of soybean (Glycine max (L.) Merrill cv. IAC-8) plants through physiological parameters related to plant growth. The experiment was carried out in a greenhouse.Six treatments corresponding to the following dosages, time and application ways were studied: control (T1); 0,125g Agrostemmin/l00g seed (T2); 0,125g Agrostemmin/100g seed and foliar spraying at 333 ppm (T3); 0,125g Agrostemmin/100g seed and foliar spraying at 500 ppm (T4); foliar spraying at 333 ppm (T5) and foliar spaying at 500 ppm (T6). Three samplings were made at 14 day intervals. The experimental layout was completely randomized. The parameters studied were: foliar area ratio (FAR), net assimilation rate (NAR) and relative growth rate (RGR). It could be concluded that in proportion to increased rates there was a decrease in the parameters, in intervals 71-85.O presente estudo teve por finalidade avaliar o efeito de um estimulante vegetal, Agrostemin, no desenvolvimento de plantas de soja (Glycine max (L.) Merrill cv. IAC-8), através de alguns parâmetros que compõem a análise de crescimento. O experimento foi conduzido em casa de vegetação. Foram estudados seis tratamentos, correspondentes às seguintes dosagens, épocas e formas de aplicação: testemunha (T1); 0,125g de Agrostemin/100g sementes (T2); 0,125g de Agrostemin/l00g sementes e pulverização foliar à 333 ppm (T3); 0,125g de Agrostemin/100g sementes e pulverização foliar à 500 ppm (T4); pulverização foliar à 333 ppm (T5) e pulverização foliar à 500 ppm (T6). Realizaram-se três épocas de coleta, à intervalos de 14 dias. O experimento foi em delineamento inteiramente casualizado. Os parâmetros estudados foram: razão de área foliar (RAF), taxa assimilatória líquida (TAL) e taxa de crescimento relativo (TCR). Dentre os resultados obtidos, concluiu-se que à medida que aumentou-se a concentração, diminuiram-se os parâmetros estudados, no intervalo 71-85
The economic, environmental and public health impacts of new power plants: a sequential interindustry model integrated with GIS data
The electrical sector is responsible for a considerable amount of greenhouse gases emissions worldwide, but also the one in which modern society depends the most for maintenance of quality of life as well as the functioning of economic and social activities. Invariably, even CO2 emission-free power plants have some indirect environmental impacts due to the economic effects they produce during their life cycle (construction, O&M and decommissioning). Thus, sustainability issues should be always considered in energy planning, by evaluating the balance of positive/negative externalities on different areas of the country. This study aims to introduce a social-environmental economic model, based on a Regional Sequential Interindustry Model (SIM) integrated with geoprocessing data, in order to identify economic, pollution and public health impacts in state level for energy planning analysis. The model is based on the Impact Pathway Approach Methodology, using geoprocessing to locate social-environmental variables for dispersion and health evaluations. The final goal is to provide an auxiliary tool for policy makers to assess energy planning scenarios in Brazil
The economic, environmental and public health impacts of new power plants: a sequential interindustry model integrated with GIS data
The electrical sector is responsible for a considerable amount of greenhouse gases emissions worldwide, but also the one in which modern society depends the most for maintenance of quality of life as well as the functioning of economic and social activities. Invariably, even CO2 emission-free power plants have some indirect environmental impacts due to the economic effects they produce during their life cycle (construction, O&M and decommissioning). Thus, sustainability issues should be always considered in energy planning, by evaluating the balance of positive/negative externalities on different areas of the country. This study aims to introduce a social-environmental economic model, based on a Regional Sequential Interindustry Model (SIM) integrated with geoprocessing data, in order to identify economic, pollution and public health impacts in state level for energy planning analysis. The model is based on the Impact Pathway Approach Methodology, using geoprocessing to locate social-environmental variables for dispersion and health evaluations. The final goal is to provide an auxiliary tool for policy makers to assess energy planning scenarios in Brazil
The effect of a 24-hour photoperiod on the survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae
The effects of two different continuous photoperiod regimes on survival, growth and swim bladder inflation of pre-flexion yellowfin tuna (Thunnus albacares) larvae were investigated. Each photoperiod regime was tested twice with a different larval cohort to confirm the observed results. Trials 1 and 2 tested the effect of a reduced night-time light intensity (10-molesm-2s-1=30% of the daytime intensity) and found that those larvae reared for 8days under the 24h lighting (24-L) photoperiod exhibited a slight improvement in survival compared to those reared under the control photoperiod of 12h light (12-L), however these improvements were not significant. In addition, those larvae reared under this photoperiod regime were equal in length to those in the control. Trials 3 and 4 compared the same variables in larvae reared under a continuous photoperiod (24-L) with a constant light intensity of 30-molesm-2s-1, against those reared under the aforementioned 12-L photoperiod. Survival of larvae under the continuous photoperiods were 9±1% (n=2) and 10±2% (n=3) for Trials 3 and 4, respectively, compared to less than 1% in both control treatments; differences that in both cases were highly significant. In addition, in both trials larvae cultured under the 24-L photoperiod were significantly larger and exhibited more advanced development than those reared under the 12-L photoperiod, however swim bladder inflation was significantly lower. We suggest that the improved survival and growth achieved under a continuous photoperiod is due to the extended foraging time combined with the prevention of mortality caused by night-time sinking
Processo de formação da(o) enfermeira(o) na contemporaneidade: desafios e perspectivas
Pressure Studies on a High- Superconductor Pseudogap and Critical Temperatures
We report simultaneous hydrostatic pressure studies on the critical
temperature and on the pseudogap temperature performed through
resistivity measurements on an optimally doped high- oxide
. The resistivity is measured as
function of the temperature for several different applied pressure below 1GPa.
We find that both and increases linearly with the pressure. This
result demonstrate that the well known intrinsic pressure effect on is
also present at and both temperatures are originated by the same
superconducting mechanism.Comment: 4 pages and 2 figures in eps, final versio
Permanência do familiar no centro de terapia intensiva (CTI) : nível de satisfação profissional
Theoretical description of phase coexistence in model C60
We have investigated the phase diagram of the Girifalco model of C60
fullerene in the framework provided by the MHNC and the SCOZA liquid state
theories, and by a Perturbation Theory (PT), for the free energy of the solid
phase. We present an extended assessment of such theories as set against a
recent Monte Carlo study of the same model [D. Costa et al, J. Chem. Phys.
118:304 (2003)]. We have compared the theoretical predictions with the
corresponding simulation results for several thermodynamic properties. Then we
have determined the phase diagram of the model, by using either the SCOZA, or
the MHNC, or the PT predictions for one of the coexisting phases, and the
simulation data for the other phase, in order to separately ascertain the
accuracy of each theory. It turns out that the overall appearance of the phase
portrait is reproduced fairly well by all theories, with remarkable accuracy as
for the melting line and the solid-vapor equilibrium. The MHNC and SCOZA
results for the liquid-vapor coexistence, as well as for the corresponding
critical points, are quite accurate. All results are discussed in terms of the
basic assumptions underlying each theory. We have selected the MHNC for the
fluid and the first-order PT for the solid phase, as the most accurate tools to
investigate the phase behavior of the model in terms of purely theoretical
approaches. The overall results appear as a robust benchmark for further
theoretical investigations on higher order C(n>60) fullerenes, as well as on
other fullerene-related materials, whose description can be based on a
modelization similar to that adopted in this work.Comment: RevTeX4, 15 pages, 7 figures; submitted to Phys. Rev.
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