294 research outputs found
Otimização da exploração de centrais hídricas utilizando algoritmos genéticos, em ambiente de mercado
Tese de mestrado integrado. Engenharia Electrotécnica e de Computadores. Área de Especialização de Energia. Faculdade de Engenharia. Universidade do Porto. 201
Análise aerodinâmica de asas usando o método VLM acoplado ao XFOIL
O objectivo do presente trabalho é desenvolver uma ferramenta numérica para a
análise aerodinâmica de asas subsónicas usando o método de análise VLM (Vortex
Lattice Method). A solução aerodinâmica é obtida em duas partes: o método VLM
fornece a sustentação e a resistência aerodinâmica induzida e as suas distribuições sobre a superfície média da asa; para se obter a resistência aerodinâmica parasita o código XFOIL, que usa um método dos painéis acoplado a uma formulação de camada limite, é
usado em cada um dos perfis aerodinâmicos definidos ao longo da envergadura da asa.
Os resultados obtidos da solução aerodinâmica irão ser analisados e comparados com o
método da linha sustentadora.The aim of this work is to develop a numerical tool for the aerodynamic analysis of
subsonic wings using the Vortex Lattice Method (VLM). The aerodynamic solution is
obtained in two parts: the VLM provides the lift and the induced drag and its
distribution over the wing mid surface; in order to get the parasite drag, the XFOIL code
that uses a panel method coupled to a boundary layer formulation is used at each
aerodynamic airfoil defined across the wing span. The results obtained by the
aerodynamic solution will be analyzed and compared with the Lifting Line method
The color dipole picture for prompt photon production in pp and pPb collisions at the CERN-LHC
A study on the prompt photon production within the QCD color dipole picture with emphasis in pp and pA collisions at the LHC energy regimes is performed. We present predictions for the differential cross section as a function of photon transverse momentum at different rapidity bins considering updated phenomenological color dipole models, which take into account the QCD gluon saturation physics. The results are directly compared to the recent experimental measurements provided by CMS and ATLAS Collaborations, showing a reasonable agreement in all rapidity bins with no free parameters. Special attention is given to the IPSAT model given its good description of the data in all rapidity bins from low- to high-pT ranges. As a result, a free-parameter approach has succeeded in describing the LHC data for prompt photon production, while new predictions for the 13-TeV data is presented in view of new data to confirm such prospect
Double charmed meson production in and collisions at the LHC within the dipole approach in momentum representation
A study of double charmed meson production in proton-proton and
proton-nucleus collisions at the LHC energies is performed. Based on the color
dipole formalism developed in the transverse momentum representation and the
double parton scattering mechanism, predictions are made for the transverse
momentum differential cross section for different pairs of -mesons. The
theoretical results consider the center-of-mass energy and forward rapidities
associated to the measurements by the LHCb Collaboration. The results
considering different unintegrated gluon distributions are presented and
compared to data and predictions for proton-nucleus collisions are provided.Comment: 20 pages, 4 figure
D-meson production in high energy pA collisions within the QCD color dipole transverse momentum representation
The D-meson production is investigated by considering the unintegrated gluon distribution within the dipole approach in the momentum representation. We analyze the D-meson spectrum accounting for the effects of nonlinear behavior of the QCD dynamics which can be accordingly addressed in the dipole framework. The unintegrated gluon distribution is obtained by using geometric scaling property and the results are compared to the Glauber–Gribov framework. The absolute transverse momentum spectra and the nuclear modification ratios are investigated. Predictions are compared with the experimental measurements by the ALICE and LHCb Collaborations in p A collisions for different rapidity bins
Prompt photon production in high-energy collisions at forward rapidity
Prompt photon production in hadronic collisions at the RHIC and the LHC
energies is investigated within the QCD color dipole approach. Predictions for
the nuclear modification factor in collisions are evaluated based on
parton saturation framework and the results are compared to the experimental
measurements as a function of the photon transverse momentum at different
rapidity bins. The reliability of the models is performed with the data from
PHENIX, ATLAS, and ALICE Collaborations. Moreover, we show that the observed
-scaling of prompt photon production in and collisions can
positively be addressed in the QCD color dipole formalism.Comment: 17 pages, 10 figure
The color dipole picture for prompt photon production in and collisions at the CERN-LHC
A study on the prompt photon production within the QCD color dipole picture
with emphasis in and collisions at the LHC energy regimes is
performed. We present predictions for the differential cross section as a
function of photon transverse momentum at different rapidity bins considering
updated phenomenological color dipole models, which take into account the QCD
gluon saturation physics. The results are directly compared to the recent
experimental measurements provided by CMS and ATLAS Collaborations, showing a
reasonable agreement in all rapidity bins with no free parameters. Special
attention is given to the IPSAT model given its good description of the data in
all rapidity bins from low- to high- ranges. As a result, a
free-parameter approach has succeeded in describing the LHC data for prompt
photon production, while new predictions for the 13-TeV data is presented in
view of new data to confirm such prospect.Comment: 12 pages, 18 figure
A study on the isolated photon production in nuclear collisions at the CERN-LHC energies
An analysis of prompt photon production in high energy nuclear collisions at
the LHC energy regime is performed within the parton saturation picture taking
into account the updated phenomenological color dipole models. The results are
confronted with the measurements made by the ALICE, ATLAS, and CMS experiments
in terms of photon transverse momentum at different rapidity bins. As a result,
we show that the prompt photon production exhibits distinct scalings in
events associated to geometrical properties of the collision and can be
properly addressed in the color dipole formalism.Comment: 17 pages, 5 figure
Prompt photon production in high-energy pA collisions at forward rapidity
Prompt photon production in hadronic collisions at energies available at RHIC and at the LHC is investigated within the QCD color dipole approach. Predictions for the nuclear modification factor in pA collisions are evaluated based on the parton saturation framework, and the results are compared with the experimental measurements as a function of the photon transverse momentum at different rapidity bins. The reliability of the models is performed with the data from the PHENIX, ATLAS, and ALICE Collaborations. Moreover, we show that the observed xT scaling of prompt photon production in pp and pA collisions can positively be addressed in the QCD color dipole formalism
Questioning the proverb ‘more haste, less speed’: classic versus metabarcoding approaches for the diet study of a remote island endemic gecko
Dietary studies can reveal valuable information on how species exploit their habitats and
are of particular importance for insular endemics conservation as these species present
higher risk of extinction. Reptiles are often neglected in island systems, principally the
ones inhabiting remote areas, therefore little is known on their ecological networks.
The Selvagens gecko Tarentola (boettgeri) bischoffi, endemic to the remote and integral
reserve of Selvagens Archipelago, is classified as Vulnerable by the Portuguese Red
Data Book. Little is known about this gecko’s ecology and dietary habits, but it is
assumed to be exclusively insectivorous. The diet of the continental Tarentola species
was already studied using classical methods. Only two studies have used next-generation
sequencing (NGS) techniques for this genus thus far, and very few NGS studies have
been employed for reptiles in general. Considering the lack of information on its diet
and the conservation interest of the Selvagens gecko, we used morphological and
DNA metabarcoding approaches to characterize its diet. The traditional method of
morphological identification of prey remains in faecal pellets collected over a longer
period was compared with metabarcoding of samples collected during rapid surveys.
Molecular results revealed that this species is a generalist, feeding on invertebrate, plant
and vertebrate items, whereas the morphological approaches were unable to detect the
latter two. These results opened up new questions on the ecological role of the Selvagens
gecko that deserves to be further explored, such as the possible predation on seabirds,
plant services or trophic competition with the sympatric Madeira lizard Teira dugesii.
Metabarcoding identified a greater diversity of dietary items at higher taxonomic
resolution, but morphological identification enabled calculation of relative abundances
and biomasses of ingested arthropods, and detected a dietary shift on invertebrate
preys between seasons. Results of this study highlight the global applicability of rapid
metabarcoding surveys for understudied taxa on remote islands that are difficult to
access. We recommend using the metabarcoding approach, even if ‘speedy’ sampling
only is possible, but we must highlight that disregarding long-term ecological data may
lead to ‘hasty’ conclusion.info:eu-repo/semantics/publishedVersio
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