9,045 research outputs found
On the triplet state of poly(N-vinylcarbazole)
Triplet state properties including transient triplet absorption spectrum, intersystem crossing yields in solution at room temperature and phosphorescence spectra, quantum yields and lifetimes at low temperature as well as singlet oxygen yields were obtained for poly(N-vinylcarbazole) (PVK) in 2-methyl-tetrahydrofuran (2-MeTHF), cyclohexane or benzene. The results allow the determination of the energy value for the lowest lying triplet state and also show that triplet formation and deactivation is a minor route for relaxation of the lowest excited singlet state of PVK. In addition, they show the triplet state is at higher energy than reported heavy metal dopants used for electrophosphorescent devices, such that if this is used as a host it will not quench their luminescence.http://www.sciencedirect.com/science/article/B6TFN-4DTTJJC-7/1/b605edb9859b607f1a9b1c1348af029
Factorial Moments in a Generalized Lattice Gas Model
We construct a simple multicomponent lattice gas model in one dimension in
which each site can either be empty or occupied by at most one particle of any
one of species. Particles interact with a nearest neighbor interaction
which depends on the species involved. This model is capable of reproducing the
relations between factorial moments observed in high--energy scattering
experiments for moderate values of . The factorial moments of the negative
binomial distribution can be obtained exactly in the limit as becomes
large, and two suitable prescriptions involving randomly drawn nearest neighbor
interactions are given. These results indicate the need for considerable care
in any attempt to extract information regarding possible critical phenomena
from empirical factorial moments.Comment: 15 pages + 1 figure (appended as postscript file), REVTEX 3.0,
NORDITA preprint 93/4
Intramolecular excimer formation and sensing behavior of new fluorimetric probes and their interactions with metal cations and barbituric acids
A new family of compounds able to promote host-guest interactions with specific molecules (e.g., cyanuric and parabanic acids) and to coordinate metal ions, namely Zn(II) and Cu(II), has been synthesized and fully characterized. The new probes derive from the attachment of two methylaminopyrene units to the carbonyl precursor 2,6-bis(2-formylphenoxymethyl)pyridine.http://www.sciencedirect.com/science/article/B6THH-4HF5KD3-1/1/ef66847d1e019d05e2068bef93cfbd9
Ferramentas computacionais de apoio às boas práticas de manejo de tilápia.
A piscicultura brasileira cresce cerca de 30% ao ano, por tratar-se de fonte de proteína de alta qualidade e pela lucratividade. De origem africana, a tilapicultura está presente hoje em grande parte do território nacional, mas ainda sofrendo as pressões para a maior qualidade do produto e adoção de práticas menos impactantes ao ambiente. Entre alguns desses impactos citam-se as poluição e interferências em níveis de biodiversidade e de qualidade da água. Assim, o produtor carece de informação e ferramentas que favoreçam a rápida transferência de práticas já identificadas pela pesquisa, que aumentem seu conhecimento e agilidade na incorporação destas às atividades da propriedade. O projeto "Manejo e Gestão Ambiental da Aqüicultura" da Embrapa Meio Ambiente, componente do projeto em rede Aquabrasil, vem identificando Boas Práticas de Manejo (BPM) de tilápia passíveis de uso imediato pelo produtor a partir de sua rápida observação da propriedade. Nele, o sistema informatizado Aquisys está em desenvolvimento para vialibizar o acesso dinâmico, via web, às avaliações e indicadores de produção, manejo e qualidade de água em atenção às BPM. Este trabalho apresenta duas de suas ferramentas computacionais desenvolvidas para tilápia: a) um sistema especialista de rápida avaliação de BPM na propriedade (em linguagem CLIPS); e b) um programa para determinar a %ração e %proteína bruta a ser oferecida, considerando os pesos dos peixes e temperatura local (em linguagens PHP e HTML)
Identification of stillbirths in NSW linked population health datasets
This manuscript has not been submitted for publication. It compares stillbirth reporting from four different population data sources, and develops an algorithm for maximum identification of definite and probable stillbirths in linked population data while avoiding false positive and duplicate reports. By placing the results on this repository we are hoping to inform future use of population data for research on stillbirths in NSW.This work was supported by the Stillbirth Foundation Australia. Christine Roberts is supported by a NHMRC Senior Research Fellowship (APP1021025). We thank the NSW Ministry of Health for access to the population health data and the Centre for Health Record Linkage (CHeReL) for linking the data sets
First results from the NA60 experiment at CERN
Since 1986, several heavy ion experiments have studied some signatures of the
formation of the quark-gluon plasma and a few exciting results have been found.
However, some important questions are still unanswered and require new
measurements. The NA60 experiment, with a new detector concept that vastly
improves dimuon detection in proton-nucleus and heavy-ion collisions, studies
several of those open questions, including the production of open charm. This
paper presents the experiment and some first results from data collected in
2002.Comment: Paper presented at the XXXVIII Rencontres de Moriond, QCD and High
Energy Hadronic Interactions, Les Arcs, March 22-29, 2003. 4 pages, 6 figure
Fluorescence Enhancement of the Water- Soluble Poly{1,4-phenylene-[9,9-bis- (4-phenoxybutylsulfonate)]fluorene-2,7-diyl} Copolymer in n-Dodecylpentaoxyethylene Glycol Ether Micelles
http://dx.doi.org/10.1021/ma048780
Study of dimuon production in Indium-Indium collisions with the NA60 experiment
The NA60 experiment at the CERN-SPS is devoted to the study of dimuon
production in heavy-ion and proton-nucleus collisions. We present preliminary
results from the analysis of Indium-Indium collisions at 158 GeV per nucleon.
The topics covered are low mass vector meson production, J/psi production and
suppression, and the feasibility of the open charm measurement from the dimuon
continuum in the mass range below the J/psi peak.Comment: Contribution at XXXXth Rencontres de Moriond, "QCD and High Energy
Hadronic Interactions
Sistema computacional para apoyar las buenas prácticas de gestión de la acuicultura en Brasil (AQUISYS) - énfasis en la tilapicultura.
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