862 research outputs found
Quantum Cosmology in Scalar-Tensor Theories With Non Minimal Coupling
Quantization in the minisuperspace of non minimal scalar-tensor theories
leads to a partial differential equation which is non separable. Through a
conformal transformation we can recast the Wheeler-DeWitt equation in an
integrable form, which corresponds to the minimal coupling case, whose general
solution is known. Performing the inverse conformal transformation in the
solution so found, we can construct the corresponding one in the original
frame. This procedure can also be employed with the bohmian trajectories. In
this way, we can study the classical limit of some solutions of this quantum
model. While the classical limit of these solutions occurs for small scale
factors in the Einstein's frame, it happens for small values of the scalar
field non minimally coupled to gravity in the Jordan's frame, which includes
large scale factors.Comment: latex, 18 page
Metodologia para tratamento de acetonitrila comercial para uso em laboratórios de cromatografia líquida.
bitstream/item/84236/1/pub-134.pd
Crescimento e produção de alcalóides totais de quebra-pedra em função da calagem e da adubação nitrogenada.
Characteristics of Convective Sources of Gravity Waves and Sprites Present in Satellite IR Images During the SpreadFEx 2005 Campaign
We developed a technique to identify and estimate the size, intensity, and Tropopause overshoot of thunderstorm convective cores expected to be significant sources of gravity waves. The work was based on GOES IR images of South America on the night of 30 September to 1 October and 25–26 October 2005, as part of the Spread F Experiment (SpreadFEx) in Brazil in 2005. We also characterized, for the first time, the convective activity of three small TLE producing thunderstorms that yielded 11 TLEs on 25–26 October 2005. The campaign occurred during the dry to wet season transition in central Brazil, marked by the presence of extra-tropical cyclogenesis over the Atlantic Ocean, and cold fronts penetrating inland. The Tropopause temperature was typically −76°C with a corresponding altitude of ~15 200 m. Vigorous convective cores capable of generating strong gravity waves were located in convective regions having areas with cloud top temperatures ≤−76°C. They had typical cloud-top temperature deficits of ΔT−2.0°C to −8.0°C from the average surroundings, implying overshoot heights of 200 to 3100 m, which are within the typical range. Fast vertical development and high horizontal growth rates were associated with a large number of simultaneously active vigorous convective cores, indicating that their dynamics may have determined the spatial-temporal development of the thunderstorms analyzed. Moderate convective cores were also present in areas with cloud top −76°C≤T≤−70°C. They had ΔT of −1.9°C to −5.3°C producing overshoots between 80–300 m. All convective cores had typical diameters of 5–20 km and their size tended to increase with ΔT, there was a 57% correlation between the two parameters. Analysis of the relationship of cloud top T with positive and negative cloud-to-ground lightning (+/−CG) occurrence rate and with peak current showed that lighting activity may provide an independent way to identify convective cores and measure their intensity, since they were characterized by a high incidence of low peak current −CGs that forms the bulk of the −CG population
Flexibility and uncertainty in agribusiness projects: investing in a cogeneration plant
[urinary Incontinence Among Climateric Brazilian Women: Household Survey].
To investigate the prevalence of stress urinary incontinence and its associated factors in perimenopause women using a population-based household survey. A descriptive, exploratory cross-sectional population-based study with secondary analysis of a population-based household survey on perimenopause and menopause was conducted among women living in the city of Campinas, Brazil. Through a sampling process, 456 women between 45 and 60 years old were selected. Complaints of urinary incontinence and related risk factors, such as age, socioeconomic status, education level, race, parity, smoking habits, body mass index, previous gynecological surgeries, menopausal status, and hormonal replacement therapy were explored. Data were collected through home interviews using an adapted version of the structured pre-tested questionnaire elaborated by the International Health Foundation, International Menopause Society and the American Menopause Society. Statistical analysis were performed using prevalence rates (CI 95%). Thirty-five percent of the interviewees referred stress urinary incontinence. None of the sociodemographic factors studied was associated to the risk of urinary incontinence. In addition, parity did not significantly change the risk of urinary incontinence. Other factors, such as previous gynecological surgeries, body mass index, and smoking habits, were not associated with the prevalence of stress urinary incontinence. Also, menopausal status and hormonal replacement therapy did not change the risk of stress urinary incontinence. Though there was a high prevalence of stress urinary incontinence among perimenopause women, there was not found any associations with sociodemographic and reproductive factors.35428-3
Variação sazonal de parâmetros relacionados à duração do fluxo de látex em seringueira (Hevea brasiliensis Muell. ARG.) no planalto paulista.
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