9,300 research outputs found
Charm and bottom production in inclusive double Pomeron exchange in heavy ion collisions at the LHC
The inclusive double Pomeron exchange cross section for heavy quark pair
production is calculated for nucleus-nucleus collisions at the LHC. The present
estimate is based on hard diffractive factorization, corrected by absorptive
corrections and nuclear effects. The theoretical uncertainties for nuclear
collisions are investigated and a comparison to other approaches is presented.
The production channels producing a similar final state configuration are
discussed as well.Comment: 7 pages, 3 tables. Final version to be published in Physical Review
On the renormalization of the electroweak chiral Lagrangian with a Higgs
We consider the scalar sector of the effective non-linear electroweak
Lagrangian with a light "Higgs" particle, up to four derivatives in the chiral
expansion. The complete off-shell renormalization procedure is implemented,
including one loop corrections stemming from the leading two-derivative terms,
for finite Higgs mass. This determines the complete set of independent chiral
invariant scalar counterterms required for consistency; these include bosonic
operators often disregarded. Furthermore, new counterterms involving the Higgs
particle which are apparently chiral non-invariant are identified in the
perturbative analysis. A novel general parametrization of the pseudoescalar
field redefinitions is proposed, which reduces to the various usual ones for
specific values of its parameter; the non-local field redefinitions reabsorbing
all chiral non-invariant counterterms are then explicitly determined. The
physical results translate into renormalization group equations which may be
useful when comparing future Higgs data at different energies
Trends in the fishery and catch patterns of kitefin shark, Dalatias licha (Bonaterre, 1788), from off Azores, through a GIS spatial analysis.
During the last two decades the Azorean fishing community has profited from the kitefin shark fishery which in the year 2000 generated an estimated revenue of approximately €12,500. This resource has been targeted mainly by small fishing vessels operating in the Azores archipelago since the late 1970s. The vulnerability of this species to exploitation has
raised the concern about the impact of the fishery on the resource. The monthly landings of three artisanal fishing vessels were monitored and possible changes to kitefin shark abundance and catch pattern, for the period between 1986 and 1998, were geographically analysed. A vector-based GIS (Geographic Information System) was constructed to evaluate the changes in the number of individuals captured and squalene oil barrels obtained through a spatio-temporal perspective. In order to investigate which were the most
profitable fishing areas. An optimum fishing pathway was generated for one of the vessels
in 1997 based on a raster GIS. The results indicated a decrease of kitefin shark catches in several areas around Azores archipelago and over the time period analysed. The analysis of the data in a GIS environment yield a dynamic and integrated view of the species catches off Azores in a temporal and spatial perspective
Influence of biological activity on 65Zn and 109Cd removal from tidal water by chronically-polluted mangrove sediments
The biological activity influence on the mangrove sediment capacity to remove 65Zn and 109Cd from tidal water was evaluated in a site chronically polluted. Benthic Activity Indexes (BAI), corresponding to relative estimates of biological impact on radiotracer accumulation, were higher for 109Cd (~ 38%) than for 65Zn (~ 10%) in the top centimetre of sediment. However, BAI exceeded 96% for deeper sediment layers. This apparent decrease in radiotracer diffusion into deep sediments through biological activity inhibition is stronger than reported for much less polluted mangrove nearby, suggesting that benthic organisms tolerant of chronic metal pollution may affect metal sorption mechanisms.info:eu-repo/semantics/publishedVersio
Collection of relevant results obtained with the Skylab images by the Institute for Space Research, INPE
There are no author-identified significant results in this report
Calagem no desenvolvimento inicial do guanandi em condições de vaso.
O interesse pelo plantio comercial de espécies nativas madeireiras no Brasil é crescente nos últimos anos. Para as espécies nativas brasileiras não existe um protocolo para o manejo da fertilidade do solo. O objetivo deste trabalho foi avaliar, em casa-de-vegetação, os efeitos de doses de calcário no desenvolvimento de mudas de guanandi (Calophyllum brasiliense Cambess.). Foram avaliados cinco níveis de saturação por bases em delineamento experimental inteiramente ao acaso com quatro repetições sendo cada parcela constituída por uma planta. O solo utilizado foi um Latossolo Vermelho distrófico textura argilosa coletado na camada 0 a 20 cm no campo experimental da Embrapa em Ponta Grossa, PR. As doses de calcário foram calculadas para elevar a saturação por bases (V%) a 25, 50, 75 e 100%, além do valor original do solo. Aos 8 meses após a implantação do ensaio, foram avaliados: altura e matéria seca das partes aérea e radicular das mudas. A resposta do guanandi à calagem varia conforme a característica biométrica considerada. O guanandi não tolera níveis elevados de saturação por bases.Resumo expandido
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