578 research outputs found
A Simplified Method to Select Combined Energy Systems
The European Union aims to ensure that investment in energy efficiency measures is cost- effective. Thus, the minimum energy performance requirements of buildings must follow the so-called cost-optimal levels. It is known that the impact of a specific measure on the energy performance is affected by others measures when implemented simultaneously, influencing its profitability. For this reason, the profitability of a given package of measures cannot result from the simple sum of potential benefits of each measure. Consequently, to define a cost-optimal solution it is needed to run a great amount of combinations, implying an expensive computational effort. In order to help with the selection of the energy systems, this work proposes a simplified method for selecting heating and domestic hot water systems as a function of the following variables: initial investment, maintenance cost, energy needs and cost, and efficiency of energy systems. The proposed method is user-friendly and can assist various stakeholders: policy makers, energy experts, suppliers of products and services and building owners.Sérgio Tadeu is grateful for the financial support provided by the Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP, through grant PIPE - 2016/00880-9 (Brazil). Márcio Gonçalves is grateful for the support by the doctoral FCT grant PD/BD/135194/2017. This work was framed within the project Expert A+ (POCI-01-0246-FEDER-026751) funded by Portugal 2020 through the COMPETE 2020 programme
Formation and evolution of the two 4/3 resonant giants planets in HD 200946
It has been suggested that HD 200964 is the first exoplanetary system with
two Jovian planets evolving in the 4/3 mean- motion resonance. Previous
scenarios to simulate the formation of two giant planets in the stable 4/3
resonance configuration have failed. Moreover, the orbital parameters available
in the literature point out an unstable configuration of the planetary pair.
The purpose of this paper is i) to determine the orbits of the planets from
the RV measurements and update the value of the stellar mass (1.57 M), ii) to
analyse the stability of the planetary evolution in the vicinity and inside the
4/3 MMR, and iii) to elaborate a possible scenario for the formation of systems
in the 4/3 MMR.
The results of the formation simulations are able to very closely reproduce
the 4/3 resonant dynamics of the best-fit config- uration obtained in this
paper. Moreover, the confidence interval of the fit matches well with the very
narrow stable region of the 4/3 mean-motion resonance. The formation process of
the HD 200964 system is very sensitive to the planetary masses and
protoplanetary disk parameters. Only a thin, flat disk allows the embryo-sized
planets to reach the 4/3 resonant configuration. The stable evolution of the
resonant planets is also sensitive to the mass of the central star, because of
overlapping high-order resonances inside the 4/3 resonance. Regardless of the
very narrow domain of stable motion, the confidence interval of our fit closely
matches the stability area
A IMPORTÂNCIA DA METODOLOGIA DA PESQUISA PARA A PRODUÇÃO DE CONHECIMENTO CIENTÍFICO NOS CURSOS DE PÓS-GRADUAÇÃO: A singularidade textual dos trabalhos científicos jurídicos
O presente trabalho contém uma análise crítica da construção do conhecimento científico com obediência a uma metodologia científica reconhecida e cristalizada. Desenvolve uma análise da importância da metodologia para a pesquisa de pós-graduação em direito e das dificuldades dos discentes na elaboração de Projetos de Pesquisa e Dissertações, sobretudo em relação aos problemas metodológicos e textuais. Apresenta igualmente uma análise da singularidade textual dos trabalhos acadêmicos jurídicos, abordando e demonstrando as causas deste processo. Portanto, evidencia a necessidade de mudança deste paradigma para garantir maior acessibilidade do conhecimento produzido e garantir o caráter científico das pesquisas jurídicas
On planetary mass determination in the case of super-Earths orbiting active stars. The case of the CoRoT-7 system
This investigation uses the excellent HARPS radial velocity measurements of
CoRoT-7 to re-determine the planet masses and to explore techniques able to
determine mass and elements of planets discovered around active stars when the
relative variation of the radial velocity due to the star activity cannot be
considered as just noise and can exceed the variation due to the planets. The
main technique used here is a self-consistent version of the high-pass filter
used by Queloz et al. (2009) in the first mass determination of CoRoT-7b and
CoRoT-7c. The results are compared to those given by two alternative
techniques: (1) The approach proposed by Hatzes et al. (2010) using only those
nights in which 2 or 3 observations were done; (2) A pure Fourier analysis. In
all cases, the eccentricities are taken equal to zero as indicated by the study
of the tidal evolution of the system; the periods are also kept fixed at the
values given by Queloz et al. Only the observations done in the time interval
BJD 2,454,847 - 873 are used because they include many nights with multiple
observations; otherwise it is not possible to separate the effects of the
rotation fourth harmonic (5.91d = Prot/4) from the alias of the orbital period
of CoRoT-7b (0.853585 d). The results of the various approaches are combined to
give for the planet masses the values 8.0 \pm 1.2 MEarth for CoRoT-7b and 13.6
\pm 1.4 MEarth for CoRoT 7c. An estimation of the variation of the radial
velocity of the star due to its activity is also given.The results obtained
with 3 different approaches agree to give masses larger than those in previous
determinations. From the existing internal structure models they indicate that
CoRoT-7b is a much denser super-Earth. The bulk density is 11 \pm 3.5 g.cm-3 .
CoRoT-7b may be rocky with a large iron core.Comment: 12 pages, 11 figure
A new analysis of the GJ581 extrasolar planetary system
We have done a new analysis of the available observations for the GJ581
exoplanetary system. Today this system is controversial due to choices that can
be done in the orbital determination. The main ones are the ocurrence of
aliases and the additional bodies - the planets f and g - announced in Vogt et
al. 2010. Any dynamical study of exoplanets requires the good knowledge of the
orbital elements and the investigations involving the planet g are particularly
interesting, since this body would lie in the Habitable Zone (HZ) of the star
GJ581. This region,for this system, is very attractive of the dynamical point
of view due to several resonances of two and three bodies present there. In
this work, we investigate the conditions under which the planet g may exist. We
stress the fact that the planet g is intimately related with the orbital
elements of the planet d; more precisely, we conclude that it is not possible
to disconnect its existence from the determination of the eccentricity of the
planet d. Concerning the planet f, we have found one solution with period
days, but we are judicious about any affirmation concernig this
body because its signal is in the threshold of detection and the high period is
in a spectral region where the ocorruence of aliases is very common. Besides,
we outline some dynamical features of the habitable zone with the dynamical map
and point out the role played by some resonances laying there.Comment: 12 pages, 9 figure
The MHM Method for Elasticity on Polytopal Meshes
The multiscale hybrid-mixed (MHM) method consists of a multi-level strategy to approximate the solution of boundary value problems with heterogeneous coefficients. In this context, we propose a new family of finite elements for the linear elasticity equation defined on coarse polytopal partitions of the domain. The finite elements rely on face degrees of freedom associated with multiscale bases obtained from local Neumann problems with polynomial interpolations on faces. We establish sufficient conditions on the fine-scale interpolations such that the MHM method is well-posed. Also, discrete traction stays in local equilibrium with external forces. We show by means of a multi-level analysis that the MHM method achieves optimal convergence under local regularity conditions without refining the coarse partition. The upshot is that the Poincar\'e and Korn's inequalities do not degenerate, and then convergence arises on general meshes. We employ two- and three-dimensional numerical tests to assess theoretical results and to verify the robustness of the method through a multi-layer media case. Also, we address computational aspects of the underlying parallel algorithm associated with different configurations of the MHM method; our aim is to find the best compromise between execution time and memory allocation to achieve a given error threshold
Synthesis, antimalarial activity in vitro, and docking studies of novel neolignan derivatives
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESThe absence of effective vaccines against malaria and the difficulties associated with controlling mosquito vectors have left chemotherapy as the primary control measure against malaria. However, the emergence and spread of parasite resistance to conventi903464472CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESSEM INFORMAÇÃOSEM INFORMAÇÃOSEM INFORMAÇÃOThe authors thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) and COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES (CAPES) for financial suppor
Desenvolvimento de dispositivo caseiro para dessalinização de água salobra a partir de sementes de umbu (Spondias tuberosa Arruda Câmara)
The goal of this work was to develop a homemade device to desalinate brackish water, using biological material like seeds from different plant species of the semi arid regions. Umbu seeds (Spondias tuberosa Arruda Câmara) were found to be the most appropriate material, removing a higher quantity of salt from the water compared to the other tested materials. The salt content in 1 L of brackish water typical of the region can be removed with only 1 g of the material, if the water is heated to 50 °C and it may also lower the water hardness, achieving drinking water standards
Nicotinic acid induces antinociceptive and anti-inflammatory effects in different experimental models
AbstractAlthough in vitro studies have shown that nicotinic acid inhibits some aspects of the inflammatory response, a reduced number of in vivo studies have investigated this activity. To the best of our knowledge, the effects induced by nicotinic acid in models of nociceptive and inflammatory pain are not known. Per os (p.o.) administration of nicotinic acid (250, 500 or 1000mg/kg, −1h) inhibited the first and the second phases of the nociceptive response induced by formalin in mice. Nicotinic acid (250 or 500mg/kg, −1 and 3h) also inhibited the mechanical allodynia induced by carrageenan in rats, a model of inflammatory pain. However, in a model of nociceptive pain, exposure of mice to a hot-plate, nicotinic acid was devoid of activity. In addition to inhibiting the nociceptive response in models of inflammatory pain, nicotinic acid (250 or 500mg/kg, p.o., −1 and 3h) inhibited paw edema induced by carrageenan in mice and rats. Picolinic acid (62.5 or 125mg/kg, p.o., −1h), a nicotinic acid isomer, inhibited both phases of the nociceptive response induced by formalin, but not paw edema induced by carrageenan in mice. The other nicotinic acid isomer, isonicotinic acid, was devoid of activity in these two models. In conclusion, our results represent the first demonstration of the activity of nicotinic acid in experimental models of nociceptive and inflammatory pain and also provide further support to its anti-inflammatory activity. It is unlikely that conversion to nicotinamide represents an important mechanism to explain the antinociceptive and anti-inflammatory activities of nicotinic acid. The demonstration of new activities of nicotinic acid, a drug that has already been approved for clinical use and presents a positive safety record, may contribute to raise the interest in conducting clinical trials to investigate its usefulness in the treatment of painful and inflammatory diseases
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