178 research outputs found
Miocene sediments from Foz da Fonte and Penedo sections (Lower Tagus basin): clay minerals and isotopic data
Eight depositional sequences (DS) delimited by regional disconformities had been recognized in the Miocene of Lisbon and
Setúbal Peninsula areas. In the case of the western coast of the Setúbal Peninsula, outcrops consisting of Lower Burdigalian to
Lower Tortonian sediments were studied. The stratigraphic zonography and the environmental considerations are mainly supported on data concerning to foraminifera, ostracoda, vertebrates and palynomorphs.
The first mineralogical and geochemical data determined for Foz da Fonte, Penedo Sul and Penedo Norte sedimentary sequences
are presented. These analytical data mainly correspond to the sediments' fine fractions. Mineralogical data are based on X-ray
diffraction (XRD), carried out on both the less than 38 nm and 2 nm fractions. Qualitative and semi-quantitative determinations of clay and non-clay minerals were obtained for both fractions. The clay minerals assemblages complete the lithostratigraphic and paleoenvironmental data obtained by stratigraphic and palaeontological studies. Some palaeomagnetic and isotopic data are discussed and correlated with the mineralogical data. Multivariate data analysis (Principal Components Analysis) of the mineralogical data was carried out using both R-mode and Q-mode factor analysis
Quantification of endogenous auxin levels and polyphenoloxidase enzymatic activity in olive (Olea europaea L.)
A actividade enzimática de polifenoloxidases foi avaliada em folhas e na zona apical, média e basal de ramos de duas cultivares de oliveira (Olea europaea L.), comuns no Alentejo ( Galega vulgar e Cobrançosa ), mostrando que a actividade enzimática nas folhas foi muito superior à encontrada em tecidos de ramos do ano. Maior actividade enzimática foi também detectada na variedade Cobrançosa versus Galega vulgar . As condições óptimas para a determinação da actividade enzimática foram: pH= 5.5 e T= 40 ºC, com 20 mM de 4-metilcatecol em tampão acetato. Nestas condições o KM determinado foi: 2,60 e 3,48 mM com o método de Michaelis-Menten e Lineweaver-Burk, respectivamente.
A melhor recuperação das auxinas AIA (ácido indol-3-acético) e AIB (ácido indolbutírico) em material vegetal foi conseguida através da extracção das amostras com acetona. A separação, identificação e quantificação do AIA e AIB em padrões, material vegetal dopado (tecidos de oliveira dopados com uma concentração conhecida de padrão) e não dopado, foi efectuada por técnicas cromatográficas (HPLC-DAD e LCMS), mostrando os resultados taxas de recuperação superiores a 40% para o AIA e 60% para o AIB
OLIVESIM: Gestão dos serviços de ecossistema no olival utilizando modelos espaciais avançados
Poster apresentado no Congresso Politécnico Setúbal - 40 anos a construir o futuro, 3-4 outubro 2019, Setúbal, PortugalN/
Performance of the LHCb muon system with cosmic rays
The LHCb Muon system performance is presented using cosmic ray events
collected in 2009. These events allowed to test and optimize the detector
configuration before the LHC start. The space and time alignment and the
measurement of chamber efficiency, time resolution and cluster size are
described in detail. The results are in agreement with the expected detector
performance.Comment: Submitted to JINST and accepte
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
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