| Author (s): |
loan Burnea; Lucia Burnea, Ion Gãnescu, George Bratulescu and Anca Gãnescu
|
| Title: |
CONTRIBUTION TO CO(III) NITROCOMPLEXES CHEMISTRY. NEW ANALAGUES OF NH4[CO(NO2)4(NH3)2] COMPLEX WITH HEXAMETHYLENETETRAMINE |
| Abstract: |
The work presents experimental data about new analogs of ammonium tetranitro-diamine Co (III) complex (Erdmann complex) with hexamethylenetetramine (hta). The base complex obtained, NH4[CO(NO2)4(hta)]2, as well as the Erdmann complex, present practical importance for agriculture. They contain nitrogen under cationic, anionic, and molecular form and Co (III) as a micronutrient and serve as a source of other micronutrients through replacement of NH4+ with other complex cations. Some of these complexes are soluble in water, others are hardly soluble and nonhygroscopic. Their efficiency in fertilizing was demonstrated by us experimentally.
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| Keywords: |
Co(III), nitrocomplexes, Hexamethyllenetetramine, Micronutrients.
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| Year: |
2004
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| Initial page: |
1
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| Final page: |
9
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v12.n12.2004.30_2003_2004.pdf |
|
|
| Author (s): |
Brvim Lenzi; Silvia Naves de Souza
|
| Title: |
FINAL DESTINATION OF CADMIUM FOUND IN CONTAMINATED SEWAGE SLUDGE IN MAIZE-CULTIVATED RED NITOSOIL |
| Abstract: |
Remains of human activity, such as sewage sludge, caused by population growth, ate a challenge to the environment and need urgent solutions. Cadmium from contaminated biosolid (sewage sludge) in Red Nitosoil, in PVC tubes (10 cm diameter and 80 cm height) located in the greenhouse, has been analyzed. Natural biosolid in one treatment (control), cadmium-and-lead contaminated biosolid in other two treatments (2,500 and 5,000 μg.g-1); cadmium-and-lead contaminated biosolid in other two treatments (2,500 Cd+ 2,500 Pb and 5,000 Pb μg.g-1, respectively) were added to the 0- 20 cm soil surface layer. Maize was the test plant in the triple replication experiment. The aerial part of maize plants, samples of surface soil (0 - 20 cm), and that within the tubes, divided into internal and external samples of each tube, were harvested seventy-five days after sowing. After the preparation and nitro perchloric digestion of samples, Cd concentrations were measured by atomic absorption spectrometry. Cd concentrations in maize were within phytotoxic tolerance. There was no significant difference among treatments in the production of plant dry matter. The highest Cd concentration was found in the 0-20 cm soil layer and differed significantly from the rest.
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| Keywords: |
heavy metal; percolation, organic residues; pollution; cadmium..
|
| Year: |
2003
|
| Initial page: |
1
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| Final page: |
11
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v11.n12.2003.6_2003_2004.pdf |
|
|
| Author (s): |
Ervim Lenzi, Luzia Otilia Bortotti Favero, Vitor de Cinque Almeida, Elen Juciléia Romão Sartori.
|
| Title: |
THE HEAVY METAL COPPER IN THE SEWAGE SLUDGE OF MARINGÁ, PR, BRAZIL |
| Abstract: |
Human wastes are a permanent challenge to the environment. Current research has evaluated the amount of copper metal in the sewerage and in the sludge of the Sewerage Treatment Stations (STSs) of Maringa PR Brazil. Sample collection was undertaken at the STSs and samples were digested with nitric acid at a reduced volume. Biosolid samples, previously dried and ground, at constant weights, were digested by aqua regia. Determination of metal concentrations was made by atomic absorption spectrometry. The pH, nitrogen, carbon, and organic matter (OM) values were determined by the respective classical methods. Total average were: a) Cu in affluent sewerage 0.077 and effluent sewerage 0.058 .μg.ml-1. b) biosolid; Cu = 0.74 mg.g-1; pH= 3.38; N = 3.24 %; C = 24.5 % e OM= 42.1 %. Variance analysis of the experimental values, and taking into consideration the variation sources of STSs and collection time showed that no significant difference between the values of copper concentration, N (%), C (%), and organic matter (%) respectively existed in both variation sources. The total average rate of copper concentration of STSs is higher than the international world average value found in the relating literature. Amounts of organic matter and the C: N (carbon: nitrogen) proportions of sewage sludge are appropriate for soil application;
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| Keywords: |
sewerage, biosolid, heavy metals, nutrients, environmental pollution, organic matter.
|
| Year: |
2004
|
| Initial page: |
11
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| Final page: |
25
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v12.n12.2004.39_2003_2004.pdf |
|
|
| Author (s): |
Mircea Preda, Adriana Samide, Olimpia Rusu, Paul Chirita, Nicoleta Cioatera
|
| Title: |
A STUDY OF THE CORROSION INHIBITION OF CARBON STEEL IN AMMONIACAL MEDIA DILUTED BY N-CYCLOHEXYL BENZOTHIAZOLE SULPHEN AMIDE |
| Abstract: |
The inhibition effect of N-cyclohexyl benzothiazole sulphen amide (NCBSA) was studied on the corrosion of carbon steel in diluted ammoniacal solution at temperatures of 25°C and 30°C. The effects of the inhibitor on the corrosion were investigated and determined by using electrochemical measurements (curves of intensity - voltage). The efficiency of NCBSA increased with an increase in concentration but decreased with an increase in temperature. The free energy of activation was determined from the Arrhenius type equation. Experimental data fitted on adsorption isotherm of Langmuir type, while the results Were correlated to the chemical structure of the inhibitor.
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| Keywords: |
carbon steel; annnoniacal media, inhibitor, N-cyclohexyl benzothiazole sulphen amide.
|
| Year: |
2003
|
| Initial page: |
13
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| Final page: |
20
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v11.n12.2003.17_2003_2004.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu and André A. Souto
|
| Title: |
DETERMINATION OF trans-RESVERATROL IN SOME ROMANIAN WINES AND SPIRITS |
| Abstract: |
Resveratrol, a phytoalexin of the hydroxystilbene group, is widely beneficial to health. It has been shown to possess anti-oxidative, anti-carcinogenic, anti-tumor, and anti-viral properties. The concentration of transresveratrol is some Romanian wines and spirits has been measured using a direct injection isocratic UV-HPLC (Ultra Violet - High Liquid Pressure Chromatography) method. The experimental values obtained ranged from 0,10 mg/L for Cognac Murfatlar to 2,32 mg/L for Carbent Sauvignon from the Dealu Mare region.
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| Keywords: |
trans-resveratrol, Romanian wines.
|
| Year: |
2004
|
| Initial page: |
27
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| Final page: |
34
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v12.n12.2004.54_2003_2004.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu, Luis Alcides Brandini De Boni, Eduardo Goldani
|
| Title: |
ANILDO BRISTOTI, A PIONEER IN SCIENCE IN RIO GRANDE DO SUL, BRAZIL |
| Abstract: |
Anildo Bristoti was born in São Francisco de Paula, Rio Grande do Sul, Brazil in 1936 and passed away in 2004. He studied chemistry physics and mathematics and obtained a Doctor of Engineering Degree from UCLA in 1970. His main research interests were renewable energy sources and he was instrumental in the establishment of graduate programs in science and engineering at various universities in Southern Brazil. He trained more than one hundred research scientists presently working in chemistry; physics, engineering, and materials science.
|
| Keywords: |
History of science and engineering, science in Brazil.
|
| Year: |
2004
|
| Initial page: |
35
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| Final page: |
43
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v12.n12.2004.62_2003_2004.pdf |
|
|
| Author (s): |
Lavinel G. Ionescu and B. K. Sumner
|
| Title: |
CATARINA, SOUTH AMERICA S FIRST HURRICANE. A SIGNAL OF GLOBAL CLIMATIC CHANGES |
| Abstract: |
On March 27, 2004, a strong storm (tropical cyclone) hit the coast of Southern Brazil and caused death and widespread devastation in part of the States of Santa Catarina and the Rio Grande do Sul. In spite of what some Brazilian meteorologists initially had to say, Catarina was South America s first hurricane. Many Brazilian meteorologists, for various reasons, did not want to recognize that it was a real hurricane and classified the phenomenon as an extratropical cyclone, a polar low, or even a hybrid occurrence. Catarina initiated about 1.OOOkm off the Brazilian coast (Santa Catarina) around March 20, 2004, as an extratropical cyclone (EC), underwent tropical transition (TT), and subsequently became a category I hurricane. It was really South America s first hurricane and it may be a possible indication of global climatechanges.
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| Keywords: |
tropical cyclone, hurricane, climate changes, Southern Brazil.
|
| Year: |
2004
|
| Initial page: |
45
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| Final page: |
51
|
| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v12.n12.2004.71_2003_2004.pdf |
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