| Author (s): |
Lavinel G. Ionescu, Luis Alcides Brandini De Boni and Eduardo Goldani
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| Title: |
A TRIBUTE TO PROF. DR. FARUK JOSÉ NOME AGUILERA ON HIS 60th BIRTHDAY |
| Abstract: |
Prof. Faruk José Nome Aguilera was born in Linares, Chile on May 29, 1947. He graduated in biochemistry from the University of Chile in 1971, obtained a Ph.D. Degree in Chemistry from Texas A& M University in 1976 and has been a faculty member at the Universidade Federal de Santa Catarina, Florianópolis, Brazil since 1977. His main research interests deal with catalysis and mechanisms of organic reactions in solution. He has trained approximately eighty research scientists including more than forty master and twenty doctoral students and has published about three hundred scientific articles. Prof. Faruk is a member of the Brazilian Academy of Science.
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| Keywords: |
History of chemistry. Organic Reactions Mechanism, Science in Brazil .
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| Year: |
2007
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| Initial page: |
1
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| Final page: |
14
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.7_revistadec2007partial.pdf |
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| Author (s): |
Ana Cristina Franzoi, Gledir T. Stein Martins, Sérgio Duvoisin Jr., Bruno Szpoganicz.
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| Title: |
HYDROLYSIS AND DEUTERATION OF GLYCYLGLYCINE CATALYZED BY DINUCLEAR [BMXDCu 2]4+ COMPLEX |
| Abstract: |
Kinetic studies of hydrolysis and deuteration of glycylglycine by dinuclear [BMXDCu 2]4+ complexes were following by NMR1H. Two parallel reactions were observed for the ternary system BMXD-Cu 2-Glycylglycine: peptide bond hydrolysis and NCH2 deuteration reactions. The reaction rates show the first-order behavior to the concentration of the ternary [BMXDCu2Glycylglycine] complex. The specific rate constants for the hydrolysis reaction are: KLCu2HGG4+ (L = BMXD and GG = glycylglycine) = 1,8 x 10-6 s-1; KLCu 2GG3+ = 2,3 x 10-6 s-1; KLCu2H-1GG2+, KLCu 2(OH)H-1GG+ and KLCu 2(OH) 2H-1GG = 0, and the specific deuteration rate constants for individual species are: KLCu 2HGG4+ = 3,9 x 10-6 s-1; KLCu 2GG3+ = 4,3 x 10-6 s-1; KLCu2H-1GG2+, KLCu2(OH)H-1GG+ and KLCu2(OH)2H-1GG = 0. The results show that the most active species toward hydrolysis and deuteration reactions are the protonated and non-protonated species, the former being the most reactive species. Semi-empirical calculations for energy minimization showed that the binuclear [BMXDCu 2]4+) complexes adopt the boat-type conformation, in order to accommodate the dipeptide glycylglycine.
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| Keywords: |
hydrolysis; deuteration; dinuclear [BMXDCu 2]4+ complexes, glycylglycine. .
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| Year: |
2007
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| Initial page: |
15
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| Final page: |
27
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.21_revistadec2007partial.pdf |
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| Author (s): |
Lavinel G. Ionescu, Paulo César Pereira das Neves, Flávia Schenato & Flávio Antônio Bachi
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| Title: |
THE PERIODIC TABLE OF THE ELEMENTS AND THE ASSOCIATED MINERALS: GOLD |
| Abstract: |
Gold is a natural solid with a crystalline stable structure and exhibits an abundance of 0.04 ppm (mg/Kg) in the Earth crust. Gold, like silver, is one of the chemical elements less abundant in nature. Only palladium, tellurium, platinum, ruthenium, rhodium, osmium, rhenium, and iridium, present a smaller geochemical distribution. Because of its low chemical reactivity, the metal has very few minerals. This review presents a synopsis of the twenty nine (29) gold minerals known at the present time.
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| Keywords: |
gold, mineralogy of gold, uses of gold..
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| Year: |
2007
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| Initial page: |
29
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| Final page: |
41
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.34_revistadec2007partial.pdf |
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| Author (s): |
Liana Simona Sbîrna, Vasilica Muresan, Sebastian Sbîrna, Nicolae Muresana, Florina Ciolan
|
| Title: |
[Au-S 4]Z AND [Au-O2S2] Z – TYPE COMPLEX COMPOUNDS RELATED BY ELECTRON-TRANSFER REACTIONS |
| Abstract: |
The synthesis and the properties of square-planar [Au-S 4]Z and [Au-O2S2] Z – type complex compounds, involved in electron-transfer reactions, are presented. The complexes obtained are characterized by elemental analysis, IR, visible, UV, ESR spectroscopy, conductivity, and polarographic data.
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| Keywords: |
Gold (III), complex compounds, electron-transfer reactions.
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| Year: |
2007
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| Initial page: |
43
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| Final page: |
48
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.47_revistadec2007partial.pdf |
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| Author (s): |
George Bratulescu and Ion Ganescu
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| Title: |
CHROMIUM (III) COMPLEXES ANIONS IN THE CHEMICAL ANALYSIS ANAFRANILE DETERMINATION |
| Abstract: |
Some new gravimetric, oxidimetric, and spectrophotometric methods for the determination of anafranile as anafranile H[Cr(NCS)4(amine) 2] have been described. Statis1ical treatment of the experimental data shows that the methods employed are sufficiently accurate and are not affected by systematic errors
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| Keywords: |
Cr(III), anafranile determination, complex salts.
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| Year: |
2007
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| Initial page: |
49
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| Final page: |
57
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.53_revistadec2007partial.pdf |
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| Author (s): |
Adriana Samide, Ion Bibicu, Mircea Preda, Olimpia Rusu, Paul Chirita
|
| Title: |
INVESTIGATION OF CARBON STEEL CORROSION IN DILUTED AMMONIACAL MEDIA |
| Abstract: |
Electrochemical measurements (steady-state current-voltage curves) were coupled with Mossbauer spectroscopy techniques to investigate the corrosion of carbon steel in diluted ammoniacal media. The corrosion current for carbon steel in diluted ammoniacal media was determined from galvanostatic measurements, through extrapolation of the Tafel segments at the corrosion potential. Mossbauer measurements were performed at room temperature in the transmission (TMS) and conversion electron spectroscopy (CEMS) using a conventional constant-accelerating spectrometer with a 57Co-Rh source. The result of the corrosion is the layer appearance (nonstoichiometric iron oxide) on the sample surface.
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| Keywords: |
ammoniacal media; carbon steel, corrosion, Mossbauer spectroscopy.
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| Year: |
2007
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| Initial page: |
59
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| Final page: |
69
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.62_revistadec2007partial.pdf |
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| Author (s): |
Paul Atyim; I.Bolocan-Viasu O. Croitoru; C. Tigae AI. Popescu; G. Ardelean
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| Title: |
A NEW METHOD OF COAL SEPARA TION IN GRANULOMETRIC CLASSES AND THE STUDY OF SOME ANAL YTICAL PROPERTIES |
| Abstract: |
Coal is a complex heterogeneous material and for its knowledge a homogeneous fractionation is necessary. Coal presents variations in the same grains depending on density, so a more adequate fractionation is obtained by its separation according to density. The density was determined with a pycnometer and the separation of coal in different fractions according to density. The organic and inorganic solutions were replaced with distilled water.
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| Keywords: |
coal, density, ash, biphasic model of coal.
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| Year: |
2007
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| Initial page: |
71
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| Final page: |
80
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v15.n15.2007.73_revistadec2007partial.pdf |
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