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Search Results: 1 - 10 of 247914 matches for " José Carlos F.; "
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Volatile constituents of the oils from Povedadaphne Quadriporata (lauraceae) from "Alberto M. Brenes" biological preserve, Costa Rica
Cicció, José F.;Chaverri, Carlos;
Química Nova , 2008, DOI: 10.1590/S0100-40422008000300027
Abstract: the composition of the leaf, bark and wood oils of povedadaphne quadriporata w. burger from costa rica were analyzed by capillary gc/fid and gc/ms. one hundred and sixty-three compounds were identified. the major components from the leaf oil were a-pinene (21.2%), germacrene d (18.1%), b-pinene (14.8%), a-phellandrene (7.8%), a-copaene (6.6%), b-caryophyllene (6.1%) and d-cadinene (3.5%). from bark oil, the main constituents were a-pinene (27.7%), p-cymene (7.8%), b-pinene (7.4%), camphene (3.6%), a-copaene (3.5%) and limonene (3.3%). from wood oil, 1,10-di-epi-cubenol (8.0%), a-eudesmol (3.4%), cadalene (3.4%) and d-cadinene (3.0%) were the major compounds identified. this paper describes for the first time the composition of essential oils in this unique species and genus.
Essential oil of trees of the genus Ocotea (Lauraceae) in Costa Rica. I. Ocotea brenesii
Chaverri,Carlos; Cicció,José F;
Revista de Biología Tropical , 2005,
Abstract: the chemical composition of the essential oils from leaves and wood of ocotea brenesii standl. growing wild in costa rica was determined by capillary gc/fid and gc/ms. from the leaves, 4 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. the major constituents identified in the leaf oil were α -copaene (21.1%), δ -cadinene (9.2%), spathulenol (7.3%), globulol (5.6%) and β -caryophyllene (5.2%). the major constituents of the wood oil were α -copaene (6.6%), caryophyllene oxide (6.3%), β -caryophyllene (6.1%) and humulene epoxide (4.6%). rev. biol. trop. 53(3-4): 431-436. epub 2005 oct 3.
Reforming thought. Reformando el pensamiento. Reformando o pensamento.
Jos???? Carlos F. Diniz Gama
International Journal of High Dilution Research , 2007,
Abstract: This article discusses a proposal for a reform in thinking, grounded on Heisenberg’s principle of uncertanty, Chew’s bootstrap theory and Bohm’s principle of implicated order. By synthetizing all three grounds together, it is concluded that thought ought to be turned to the uncertainty of phenomena. Behind uncertainty lies an implicated order, which mantains the interactive pattern with onself, the others and the world.
Essential oil of trees of the genus Ocotea (Lauraceae) in Costa Rica. I. Ocotea brenesii
Carlos Chaverri,José F Cicció
Revista de Biología Tropical , 2005,
Abstract: The chemical composition of the essential oils from leaves and wood of Ocotea brenesii Standl. growing wild in Costa Rica was determined by capillary GC/FID and GC/MS. From the leaves, 4 compounds were identified, corresponding to 85.9% of the oil, and from the wood 57 compounds were identified corresponding to 69.0% of the oil. The major constituents identified in the leaf oil were α -copaene (21.1%), δ -cadinene (9.2%), spathulenol (7.3%), globulol (5.6%) and β -caryophyllene (5.2%). The major constituents of the wood oil were α -copaene (6.6%), caryophyllene oxide (6.3%), β -caryophyllene (6.1%) and humulene epoxide (4.6%). Rev. Biol. Trop. 53(3-4): 431-436. Epub 2005 Oct 3. Se determinó la composición química de los aceites esenciales obtenidos de las hojas y de la madera del árbol Ocotea brenesii Standl., perteneciente a la familia Lauraceae, que crece en forma silvestre en Costa Rica. Para el estudio se utilizaron técnicas de cromatografía de gases capilar con detector de ionización de flama (GC/FID) y cromatografía de gases capilar acoplada a un detector de espectrometría de masas (GC/MS). Del aceite volátil de las hojas fueron identificados 64 constituyentes, que correspondieron a un 85.9% del aceite. Del aceite de la madera se identificaron 57 compuestos que correspondieron a un 69.0% del aceite. Los constituyentes mayoritarios que se identificaron en el aceite de las hojas fueron α -copaeno (21.1%), δ -cadineno (9.2%), espatulenol (7.3%), globulol (5.6%) y β -cariofileno (5.2%). Los constituyentes mayoritarios del aceite de la madera fueron α -copaeno (6.6%), σxido de cariofileno (6.3%), β -cariofileno (6.1%) y el epσxido del humuleno (4.6%). La composiciσn de los aceites es de naturaleza terpιnica y no presentaron compuestos del tipo fenilpropanoide o bencenoide que son constituyentes característicos de la mayoría de los aceites de plantas del género Ocotea investigados anteriormente.
On the complements of 3-dimensional convex polyhedra as polynomial images of ${\mathbb R}^3$
José F. Fernando,Carlos Ueno
Mathematics , 2012,
Abstract: We prove that the complement ${\mathcal S}:={\mathbb R}^3\setminus{\mathcal K}$ of a 3-dimensional convex polyhedron ${\mathcal K}\subset{\mathbb R}^3$ and its closure $\overline{{\mathcal S}}$ are polynomial images of ${\mathbb R}^3$. The former techniques cannot be extended in general to represent such semialgebraic sets ${\mathcal S}$ and $\overline{{\mathcal S}}$ as polynomial images of ${\mathbb R}^n$ if $n\geq4$.
On the set of points at infinity of a polynomial image of ${\mathbb R}^n$
José F. Fernando,Carlos Ueno
Mathematics , 2012,
Abstract: In this work we prove that the set of points at infinity $S_\infty:={\rm Cl}_{{\mathbb R}{\mathbb P}^m}(S)\cap\mathsf{H}_\infty$ of a semialgebraic set $S\subset{\mathbb R}^m$ which is the image of a polynomial map $f:{\mathbb R}^n\to{\mathbb R}^m$ is connected. This result is no further true in general if $f$ is a regular map, although it still works for a large family of regular maps that we call quasi-polynomial maps.
On complements of convex polyhedra as polynomial and regular images of $\R^n$
José F. Fernando,Carlos Ueno
Mathematics , 2012, DOI: 10.1093/imrn/rnt112
Abstract: In this work we prove constructively that the complement $\R^n\setminus\pol$ of a convex polyhedron $\pol\subset\R^n$ and the complement $\R^n\setminus\Int(\pol)$ of its interior are regular images of $\R^n$. If $\pol$ is moreover bounded, we can assure that $\R^n\setminus\pol$ and $\R^n\setminus\Int(\pol)$ are also polynomial images of $\R^n$. The construction of such regular and polynomial maps is done by double induction on the number of \em facets \em (faces of maximal dimension) and the dimension of $\pol$; the careful placing (\em first \em and \em second trimming positions\em) of the involved convex polyhedra which appear in each inductive step has interest by its own and it is the crucial part of our technique.
On complements of convex polyhedra as polynomial images of ${\mathbb R}^n$
José F. Fernando,Carlos Ueno
Mathematics , 2014,
Abstract: In this work we prove constructively that the complement ${\mathbb R}^n\setminus{\mathcal K}$ of an $n$-dimensional unbounded convex polyhedron ${\mathcal K}\subset{\mathbb R}^n$ and the complement ${\mathbb R}^n\setminus{\rm Int}({\mathcal K})$ of its interior are polynomial images of ${\mathbb R}^n$ whenever ${\mathcal K}$ does not disconnect ${\mathbb R}^n$. The compact case and the case of convex polyhedra of small dimension were approached by the authors in previous works. Consequently, the results of this article provide a full answer to the representation as polynomial images of Euclidean spaces of complements of convex polyhedra and its interiors. The techniques here are more sophisticated than those corresponding to the compact case and require a rational separation result for certain type of (non-compact) semialgebraic sets, that has interest by its own.
Epidemiologia do uso de álcool no Brasil
Galduróz, José Carlos F;Caetano, Raul;
Revista Brasileira de Psiquiatria , 2004, DOI: 10.1590/S1516-44462004000500002
Abstract: the authors describe the most recent and significant epidemiological studies on alcohol conducted in brazil in the last years. the aim was to outline the pattern of alcohol consumption in the country through the analysis of population surveys (household surveys, drug abuse among students, homeless children) and statistical indicators (hospital admissions for addictions, data from the institute of forensic medicine, related traffic accidents and information on sales of alcoholic beverages). the analysis of the data presented in this article suggests two basic points: greater emphasis should be laid on epidemiological studies in brazil, through increasing the scope of research, as well as its systematic updating. alcohol certainly has a strong influence in the etiology and maintenance of several social, economic and health problems faced in our country.
Risco de taxas de juros: inova??es na gest?o de ativos e passivos de institui??es financeiras
Alves, Mauro F. Halfeld;Moreira, José Carlos;
Revista de Administra??o de Empresas , 1996, DOI: 10.1590/S0034-75901996000300007
Abstract: this paper attempts to broaden the analysis of interest risk management in brazilian financial institutions. it first discusses the impact of the volatility of interest rates on the profitability of banks, introducing the concepts of duration and convexity.
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