7,142 research outputs found
Spectangular: Disentangling variable spectra
Spectangular is a GUI based software package written in C++ designed for
spectral disentangling on the wavelength scale. The code disentangles spectra
of SB1 and SB2 systems and can now also be used also for spectra showing
variability. In this work, effects of variability caused by telluric lines,
line profile, and continuum flux are being investigated. Also shown is the
disentangling on spectra from an artificial eclipsing binary. It is now
possible to optimize on the flux ratios of each spectrum, making the
disentangling a technique for extracting photometric information from
spectroscopic observations usually provided by additional photometry.
Furthermore, we make some comments about changes to the code since it was first
published.Comment: accepted to A&
Sistemas Agroflorestais para a MesorregiĂŁo Sudoeste de Mato Grosso do Sul: um estudo propositivo.
bitstream/item/66228/1/31298.pdfOrganizado por: Alberto Feiden, Milton Parron Padovan, Adalgiza InĂȘs Campolim, AurĂ©lio VinĂcius Borsato, Ivo de SĂĄ Motta, JoĂŁo Batista Catto, TĂ©rcio Jacques Fehlauer
Simple implementation of complex functionals: scaled selfconsistency
We explore and compare three approximate schemes allowing simple
implementation of complex density functionals by making use of selfconsistent
implementation of simpler functionals: (i) post-LDA evaluation of complex
functionals at the LDA densities (or those of other simple functionals); (ii)
application of a global scaling factor to the potential of the simple
functional; and (iii) application of a local scaling factor to that potential.
Option (i) is a common choice in density-functional calculations. Option (ii)
was recently proposed by Cafiero and Gonzalez. We here put their proposal on a
more rigorous basis, by deriving it, and explaining why it works, directly from
the theorems of density-functional theory. Option (iii) is proposed here for
the first time. We provide detailed comparisons of the three approaches among
each other and with fully selfconsistent implementations for Hartree,
local-density, generalized-gradient, self-interaction corrected, and
meta-generalized-gradient approximations, for atoms, ions, quantum wells and
model Hamiltonians. Scaled approaches turn out to be, on average, better than
post-approaches, and unlike these also provide corrections to eigenvalues and
orbitals. Scaled selfconsistency thus opens the possibility of efficient and
reliable implementation of density functionals of hitherto unprecedented
complexity.Comment: 12 pages, 1 figur
Mesoscopic order and the dimentionality of long-range resonance energy transfer in supramolecular semiconductors
We present time-resolved photoluminescence measurements on two series of
oligo-p-phenylenevinylene materials that self-assemble into supramolecular
nanostructures with thermotropic reversibility in dodecane. One set of
derivatives form chiral, helical stacks while the second set form less
organised, frustrated stacks. Here we study the effects of supramolecular
organisation on the resonance energy transfer rates. We measure these rates in
nanoassemblies formed with mixed blends of oligomers and compare them with the
rates predicted by Foerster theory. Our results and analysis show that control
of supramolecular order in the nanometre lengthscale has a dominant effect on
the efficiency and dimentionality of resonance energy transfer.Comment: 17 Pages, 5 Figures, Submitted to J. Chem. Phy
Carbon 12C/13C isotope ratio of alpha Aurigae revised
Context. Capella ({\alpha} Aur) is one of the few binaries in the sky with
two cool giant stars. With spectral types of G8III and G0III, the two
components appear at different but distinct stages in their evolution. The G0
secondary star is a Hertzsprung-gap giant, and the G8 primary star is thought
to be a clump giant. Aims. We present a new measure of the carbon 12 C/ 13 C
isotope ratio of the primary component of Capella using high-resolution R
250 000 spectra obtained with the Potsdam Echelle Polarimetric and
Spectroscopic Instrument (PEPSI) with both the Vatican Advanced Technology
Telescope (VATT) and the Large Binocular Telescope (LBT). Methods.
Signal-to-noise ratios of up to 2 700 were obtained by averaging nightly
spectra. These average spectra were used to disentangle the two binary
components. The isotope ratio was derived with the use of spectrum synthesis
from the CN lines at 8004 {\AA}. Results. We found that the 12 C/ 13 C ratio of
the primary component of Capella is 17.81.9. Our measurement precision is
now primarily limited by the spectral-line data and by the grid-step size of
the model atmospheres rather than the data. The separated spectrum of the
secondary component does not show distinguishable 12 CN and 13 CN lines because
of its v sin i and higher temperature. Conclusions. Our new 12 C/ 13 C value is
significantly lower than the previous value of 274 but now agrees better
with the recent model prediction of 18.8 - 20.7.Comment: accepted to A&A Letters to the Edito
Metadata analysis of systematic literature reviews on academic spin-offs: an overview of reviews
Besides assuming the role of teaching, research, and extension, the university, has expanded the boundaries of scientific knowledge to promote a business ecosystem. The business-related activities can be driven by the leadership of students with an entrepreneurial capacity, based on the technology transfer produced by the academic research and generated by companies that somehow have been idealized or had the active participation of the faculty members and the technology under their control. This model of companies, named in the literature as academic spin-off, has increased the attention of researchers at two main points: i. understanding the phenomenon itself and ii. contribute to identifying the lack of the process, whether related to the support structure or capacitation of faculty members to develop the entrepreneurial activities, as well as in understanding the commercialization of knowledge as technology transfer. In this context, the present work provided a metadata analysis of systematic literature reviews on the academic spin-off, mapping the knowledge on the subject and searching for reviews that cover the technology transfer models to study the viability of protecting the academic intellectual property as a product. Methodology: the data used in this study were retrieved from the database Web of Science and revised according to the protocol Extension for Scoping Reviews (PRISMA-ScR). The bibliometric analysis of metadata was conducted in RStudio software with the package Bibliometrix and its web interface Biblioshiny. Results: 40 review articles published in peer-reviewed journals from 2006 to 2021 were selected from the initial collection. Then, as result of the bibliometric analysis, it was obtained the data of production indices (main authors, sources, and most cited articles), the evolution of chronological discussion on the subject, and other complementary. Conclusion: it was found indications of studies that discuss technology transfer models and others that examined empiric models in the academic scenario. However, in the selected collection, was not identified any review papers on academic entrepreneurship that were related to the viability of intellectual property as products to be commercialized. Also, it was identified that the word academic entrepreneurship stands out as the main keyword word to represent the research
Obesity and COVID-19 in-hospital fatality in southern Brazil: impact by age and skin color
OBJECTIVES: To estimate the relative risk (RR) of death associated with obesity, the attributable fraction in the exposed/with obesity (AFo), and the hospitalized population attributable risk (hospitalized PAR) associated with obesity of death among all adults and among Black and non-Black adults hospitalized for severe COVID-19 in the state of Rio Grande do Sul, Brazil. METHODS: This retrospective cohort study of prognostic factors analyzed all cases of adults hospitalized for severe COVID-19 in the state of Rio Grande do Sul, Brazil. The occurrence of obesity by hospital teams was primarily measured observing individualsâ medical records. The outcome assessed was hospital deaths caused by severe COVID-19. Poisson regression was used to estimate RRs and 95% confidence intervals (95%CI). RESULTS: The study sample consisted of 100,099 patients hospitalized for severe COVID-19, most of whom were White (84.7%) and male (54.7%). The effect of obesity was strongly modified by age. For the 18â39-year-old age group, RR = 2.54 (95%CI: 2.33â2.77), and in individuals 70 years and above, RR = 1.09 (95%CI: 1.05â1.13). For the 18â39-year-old age range, AFo = 60.6% and AFo = 42.5% in individuals 40â59 years old. For all hospitalizations, the hospitalized population attributable risk (hospitalized PAR) measuring obesity for individuals 18â39 years old was 25.3%, while in the 40â59-year-old range, the hospitalized PAR = 11.2%. The hospitalized PAR was 31.7% in the Black population aged 18â39 years and 24.8% in non-Blacks. The hospitalized PAR was also larger in Blacks aged 40-59 years. CONCLUSIONS: Obesity largely impacted in-hospital case-fatality rates among young adults and Black people contaminated by COVID-19. These data highlight the extent of the risk concerning obesity, a highly prevalent chronic condition
First evidence for the annihilation decay mode B+ â D+sΊ
Evidence for the hadronic annihilation decay mode B+âD+sÏ is found with greater than 3Ï significance. The branching fraction and CP asymmetry are measured to be B(B+âD+sÏ)=(1.87+1.25â0.73(stat)±0.19(syst)±0.32(norm))Ă10â6,\hfillACP(B+âD+sÏ)=â0.01±0.41(stat)±0.03(syst).\hfill The last uncertainty on B(B+âD+sÏ) is from the branching fractions of the B+âD+sDââ0 normalization mode and intermediate resonance decays. Upper limits are also set for the branching fractions of the related decay modes B+(c)âD+(s)Kâ0,B+(c)âD+(s)Kâââ0 and B+câD+sÏ , including the result B(B+âD+Kâ0)<1.8Ă10â6 at the 90% credibility level
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