933 research outputs found
Two and Three Nucleon Forces
Chiral symmetry allows two and three nucleon forces to be treated in a single
theoretical framework. We discuss two new features of this research programme
at \cO(q^4) and the consistency of the overall chiral picture.Comment: Talk at the 18th International IUPAP Conference on Few-Body Problems
in Physics, Santos, Brazi
Inventariação e propagação de Thymus mastichina na Beira Interior
Integrado no Programa Agro, Medida 8.1, Projecto nº 800, foram elaborados
estudos de distribuição e propagação da espécie Thymus mastichina L., existentes
espontaneamente na Beira Interior. Foram avaliadas seis zonas ecológicas distintas
denominadas Vale do Tejo, Beira Interior Sul, Cova da Beira, Beira Interior Norte,
Serra da Estrela e Serra da Gardunha.
Durante dois anos fez-se prospecção no campo em cada zona ecológica e
recolheu-se material vegetal. Realizaram-se ensaios de germinação em laboratório em
condições de temperatura alterna 10º/20ºC (dia) e temperatura constante 23ºC (dia),
com fotoperíodo de 8 e 16 horas/dia, respectivamente. Testou-se ainda a capacidade
germinativa em estufa, na Primavera e efectuaram-se ensaios de enraizamento, com
estacas terminais, em condições de Outono/Inverno e Primavera/Verão.
Na Beira Interior foram encontrados 36 locais onde se verificou a ocorrência de
Thymus mastichina. Em cada zona ecológica onde foram encontrados indivíduos da
espécie em estudo, foi seleccionado um local para recolha de 20 plantas-mãe, que foram
posteriormente instaladas no campo de caracterização/demonstração da ESACB.
Nos ensaios de germinação verificaram-se taxas entre os 80% e 94% em
laboratório e entre os 76% e 84%, em viveiro. Nos ensaios de propagação vegetativa de
estacas terminais obtiveram-se taxas de enraizamento entre os 20% e 100%
Analysis of three-nucleon forces effects in the system
Using modern nucleon-nucleon interactions in the description of the
nuclear systems the per datum results to be much bigger than one. In
particular it is not possible to reproduce the three- and four-nucleon binding
energies and the scattering length simultaneously. This is one
manifestation of the necessity of including a three-nucleon force in the
nuclear Hamiltonian. In this paper we perform an analysis of some, widely used,
three-nucleon force models. We analyze their capability to describe the
aforementioned quantities and, to improve their description, we propose
modifications in the parametrization of the models. The effects of these new
parametrization are studied in some polarization observables at low energies.Comment: 10 pages, to be published in Few-Body Systems. Presented at the
workshop on "Relativistic Description of Two- and Three-body Systems in
Nuclear Physics" ECT* Trento, 19 - 23 October 200
phase shifts and CP Violation in Decay
In the study of CP violation signals in {\O}\to\pi\Xi nonleptonic decays,
the strong =3/2 and phase shifts for the final-state
interactions are needed. These phases are calculated using an effective
Lagrangian model, including , (1530), and the -term,
in the intermediate states. The -term is calculated in terms of the
scalar form factor of the baryon.Comment: 6 pages, 2 figure
MINIMIZATION OF PHENOL AND AMMONIACAL NITROGEN IN REFINERY WASTEWATER EMPLOYING BIOLOGICAL TREATMENT
Wastewater from refineries is usually characterized by presence of phenol and
ammoniacal nitrogen. The aim of this work was to search for a refinery wastewater
minimization employing a biological technology to reduce these pollutants.
Experimental data was obtained by treating a synthetic wastewater in a sequencing
batch reactor (SBR) operating on different operational schemes for batch scheduling.
COD, nitrate, ammonia, phosphate and phenol were monitored as well as dissolved
oxygen, pH, level and redox potential through a supervisory control software.
Reductions of 95 % were achieved for different concentrations of NH4
+ and phenol,
providing an effluent acceptable by Brazilian environmental legislation
Numerical convergence of the block-maxima approach to the Generalized Extreme Value distribution
In this paper we perform an analytical and numerical study of Extreme Value
distributions in discrete dynamical systems. In this setting, recent works have
shown how to get a statistics of extremes in agreement with the classical
Extreme Value Theory. We pursue these investigations by giving analytical
expressions of Extreme Value distribution parameters for maps that have an
absolutely continuous invariant measure. We compare these analytical results
with numerical experiments in which we study the convergence to limiting
distributions using the so called block-maxima approach, pointing out in which
cases we obtain robust estimation of parameters. In regular maps for which
mixing properties do not hold, we show that the fitting procedure to the
classical Extreme Value Distribution fails, as expected. However, we obtain an
empirical distribution that can be explained starting from a different
observable function for which Nicolis et al. [2006] have found analytical
results.Comment: 34 pages, 7 figures; Journal of Statistical Physics 201
Fitting the integrated Spectral Energy Distributions of Galaxies
Fitting the spectral energy distributions (SEDs) of galaxies is an almost
universally used technique that has matured significantly in the last decade.
Model predictions and fitting procedures have improved significantly over this
time, attempting to keep up with the vastly increased volume and quality of
available data. We review here the field of SED fitting, describing the
modelling of ultraviolet to infrared galaxy SEDs, the creation of
multiwavelength data sets, and the methods used to fit model SEDs to observed
galaxy data sets. We touch upon the achievements and challenges in the major
ingredients of SED fitting, with a special emphasis on describing the interplay
between the quality of the available data, the quality of the available models,
and the best fitting technique to use in order to obtain a realistic
measurement as well as realistic uncertainties. We conclude that SED fitting
can be used effectively to derive a range of physical properties of galaxies,
such as redshift, stellar masses, star formation rates, dust masses, and
metallicities, with care taken not to over-interpret the available data. Yet
there still exist many issues such as estimating the age of the oldest stars in
a galaxy, finer details ofdust properties and dust-star geometry, and the
influences of poorly understood, luminous stellar types and phases. The
challenge for the coming years will be to improve both the models and the
observational data sets to resolve these uncertainties. The present review will
be made available on an interactive, moderated web page (sedfitting.org), where
the community can access and change the text. The intention is to expand the
text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics &
Space Scienc
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
Honey Bee (Apis mellifera L.) Broods: Composition, Technology and Gastronomic Applicability
Honey bee broods (larvae and pupae) can be consumed as human food, offering a rich nutritional value. Therefore, the objective of this work was to present an overview of the nutritional value of the honey bee brood and its gastronomic potential. The results indicated that honey bee broods are rich in protein (including essential amino acids), fat (essentially saturated and monounsaturated fatty acids), carbohydrates, vitamin C and those of the B complex, and minerals such as potassium, magnesium, calcium, and phosphorous. The results further highlight some variability according to the stage of development, with increasing content of fat and protein and decreasing carbohydrates from the larval to the pupal stages. The production of the honey bee brood in the hive, as well as its removal, can impact the wellbeing of the hive. This limits the production potential of the brood aimed at application for gastronomic purposes. The consumption and purchase of honey bee broods as food may be accessible in specialised markets where, for example, ethnic communities consume this type of food. However, in some markets, insects or products produced from insects are not readily accepted because of neophobia and disgust. The role of culinary chefs allied to traditional ways of preparing culinary dishes that include honey bee broods are relevant to motivate more people in western societies to consume of these types of food products.info:eu-repo/semantics/publishedVersio
Honey bee (Apis mellifera L.) broods: composition, technology and gastronomic applicability
Honey bee broods (larvae and pupae) can be consumed as human food, offering a rich
nutritional value. Therefore, the objective of this work was to present an overview of the nutritional value of the honey bee brood and its gastronomic potential. The results indicated that honey bee broods are rich in protein (including essential amino acids), fat (essentially saturated and monounsaturated fatty acids), carbohydrates, vitamin C and those of the B complex, and minerals such as potassium, magnesium, calcium, and phosphorous. The results further highlight some variability
according to the stage of development, with increasing content of fat and protein and decreasing carbohydrates from the larval to the pupal stages. The production of the honey bee brood in the hive, as well as its removal, can impact the wellbeing of the hive. This limits the production potential of the brood aimed at application for gastronomic purposes. The consumption and purchase of honey bee broods as food may be accessible in specialised markets where, for example, ethnic communities consume this type of food. However, in some markets, insects or products produced from insects are not readily accepted because of neophobia and disgust. The role of culinary chefs allied
to traditional ways of preparing culinary dishes that include honey bee broods are relevant to motivate more people in western societies to consume of these types of food products.info:eu-repo/semantics/publishedVersio
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