762 research outputs found
Influência da temperatura sobre a duração das fases de expansão e enchimento da semente de mamona (ricinus communis l.).
Variabilidade no tempo de enchimento de sementes entre diferentes genótipos de mamona (ricinus communis).
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A deterministic, gigabit serial timing, synchronization and data link for the RHIC LLRF
A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To provide synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally
Non-Adiabatic Electronic and Vibrational Ring-Opening Dynamics resolved with Attosecond Core-Level Spectroscopy
Non-adiabatic dynamics and conical intersections play a central role in the
chemistry of most polyatomic molecules, ranging from isomerization to
heterocyclic ring opening and avoided photo-damage of DNA. Studying the
underpinning correlated dynamics of electronic and nuclear wave packets is a
major challenge in real-time and, many times involves optically dark transient
states. We show that attosecond core-level spectroscopy reveals the pathway
dynamics of neutral furan across its conical intersections and dark states. Our
method measures electronic-nuclear correlations to detect the dephasing of
electronic coherence due to nuclear motion and identifies the ring-opened
isomer as the dominant product. These results demonstrate the efficacy of
attosecond core level spectroscopy as a potent method to investigate the
real-time dynamics of photochemical reaction pathways in complex molecular
systems
Two-Dimensional Helioseismic Power, Phase, and Coherence Spectra of {\it Solar Dynamics Observatory} Photospheric and Chromospheric Observables
While the {\it Helioseismic and Magnetic Imager} (HMI) onboard the {\it Solar
Dynamics Observatory} (SDO) provides Doppler velocity [], continuum
intensity [], and line-depth [] observations, each of which is
sensitive to the five-minute acoustic spectrum, the {\it Atmospheric Imaging
Array} (AIA) also observes at wavelengths -- specifically the 1600 and 1700
Angstrom bands -- that are partly formed in the upper photosphere and have good
sensitivity to acoustic modes. In this article we consider the characteristics
of the spatio--temporal Fourier spectra in AIA and HMI observables for a
15-degree region around NOAA Active Region 11072. We map the
spatio--temporal-power distribution for the different observables and the HMI
Line Core [], or Continuum minus Line Depth, and the phase and coherence
functions for selected observable pairs, as a function of position and
frequency. Five-minute oscillation power in all observables is suppressed in
the sunspot and also in plage areas. Above the acoustic cut-off frequency, the
behaviour is more complicated: power in HMI is still suppressed in the
presence of surface magnetic fields, while power in HMI and the AIA bands
is suppressed in areas of surface field but enhanced in an extended area around
the active region, and power in HMI is enhanced in a narrow zone around
strong-field concentrations and suppressed in a wider surrounding area. The
relative phase of the observables, and their cross-coherence functions, are
also altered around the active region. These effects may help us to understand
the interaction of waves and magnetic fields in the different layers of the
photosphere, and will need to be taken into account in multi-wavelength local
helioseismic analysis of active regions.Comment: 18 pages, 15 figures, to be published in Solar Physic
Stellar Iron Abundances: non-LTE Effects
We report new statistical equilibrium calculations for Fe I and Fe II in the
atmosphere of Late-Type stars. We used atomic models for Fe I and Fe II having
respectively 256 and 190 levels, as well as 2117 and 3443 radiative
transitions. Photoionization cross-sections are from the Iron Project. These
atomic models were used to investigate non-LTE effects in iron abundances of
Late-Type stars with different atmospheric parameters.
We found that most Fe I lines in metal-poor stars are formed in conditions
far from LTE. We derived metallicity corrections of about 0.3 dex with respect
to LTE values, for the case of stars with [Fe/H] ~ -3.0. Fe II is found not to
be affected by significant non-LTE effects. The main non-LTE effect invoked in
the case of Fe I is overionization by ultraviolet radiation, thus classical
ionization equilibrium is far to be satisfied. An important consequence is that
surface gravities derived by LTE analysis are in error and should be corrected
before final abundances corrections.
This apparently solves the observed discrepancy between spectroscopic surface
gravities derived by LTE analyses and those derived from Hipparcos parallaxes.
A table of non-LTE [Fe/H] and log g values for a sample of metal-poor late-type
stars is given.Comment: 22 pages, 9 figures, 1 table, ApJ style, accepte
O conhecimento local e o potencial de coleta de lianas produtoras de fibras nos municípios de Pedra Branca do Amapari e Porto Grande/AP, com ênfase ao cipó-tititca (Heteropsis spp - Araceae).
O cipó é a matéria prima mais utilizada pelos artesãos na fabricação de móveis e artesanato, tanto no Amapá, como em outros estados brasileiros. O Objetivo foi verificar a freqüência de planta da família Araceae com potencial de produção de fibras e entrevistas com artesãos, agroextratores, extratores, comunitários e estudante sobre o nível de conhecimento da comunidade envolvida sobre o manejo de cipós naquela região. Verificou-se que existem 7 espécies que os coletores denominam popularmente de cipó-titica, a saber: Heteropsis steyermarkii, H. salicifolia, H. tenuispadix, spruceana, H. mellinonii, H. linearis e H. flexuosa, sendo esta, a espécie com o maior índice de ocorrência no levantamento. Das 984 plantas da família Araceae inventariadas, 32.24% eram de plantas produtoras de fibras denominadas de cipó-titica. Em relação à quantidade de cipó coletado, 71.42% dos entrevistados afirmaram que chegam a coletar mais de 50 kg/dia, e 222% afirmaram que essa coleta, feita durante todo ano. É necessário observar a época de corte da liana, para se pensar na viabilidade do manejo. para a manutenção de indivíduos jovens, garantindo assim, a recuperação das espécies no período em que ocorre o déficit hídrico
Encapsulation of active pharmaceutical ingredients in lipid micro/nanoparticles for oral administration by spray-cooling
Nanoencapsulation via spray cooling (also known as spray chilling and spray congealing) has been used with the aim to improve the functionality, solubility, and protection of drugs; as well as to reduce hygroscopicity; to modify taste and odor to enable oral administration; and many times to achieve a controlled release profile. It is a relatively simple technology, it does not require the use of low-cost solvents (mostly associated to toxicological risk), and it can be applied for lipid raw materials as excipients of oral pharmaceutical formulations. The objective of this work was to revise and discuss the advances of spray cooling technology, with a greater emphasis on the development of lipid micro/nanoparticles to the load of active pharmaceutical ingredients for oral administration.This research was funded by the Portuguese Science and Technology Foundation (FCT/MCT)
and European Funds (PRODER/COMPETE), under the project reference UIDB/04469/2020 (strategic
fund), co-financed by FEDER, under the Partnership Agreement PT2020, granted to Eliana B. Souto.
This work was also supported by the National Science Centre within the MINIATURA 4 for a single
research activity carried out by Aleksandra Zieli ´nska (grant no: 2020/04/X/ST5/00789), and by the
Institute of Human Genetics, Polish Academy of Sciences by the internal grant for the implementation
of a single scientific activity.info:eu-repo/semantics/publishedVersio
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