| Author (s): |
Lavinel G. Ionescu and Luis Alcides Brandini De Boni
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| Title: |
THEODORO AUGUSTO RAMOS - A BRAZILIAN CONTRIBUTION TO THE MODEL OF THE ATOM |
| Abstract: |
The present article discusses the contribution of Theodoro Augusto Ramos, A Brazilian mathematician, to the model of the atom. In a paper entitled "The Theory of Relativity and the Spectral Lines of Hydrogen", presented to the Brazilian Academy of Sciences in November 1923, Theodoro Ramos analyzed the fine spectra of the hydrogen atom using the principles of the general theory of relativity. His results represent an improvement of the Bohr-Sommerfeld model.
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| Keywords: |
Hydrogen Atom, Atomic Models, Fine Spectra, Theory of Relativity.
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| Year: |
2005
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| Initial page: |
1
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| Final page: |
12
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.4_2005.pdf |
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| Author (s): |
Ana Tereza Jordao Pigozzo; Jorge De Lucas Jr; Ervim Lenzi; Carlos Alberto Scapim; Antonio Carlos Saraiva da Costa
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| Title: |
EXTRACTION OF HEAVY METALS IN A SEWAGE SLUDGE-TREATED LATOSOL |
| Abstract: |
The presence of heavy metals is one of the main hazards against the use of sewage sludge in agronomy. In a field experiment applications of sewage sludge in medium-textured Dark Red Latisol (DRL) were evaluated by the extraction of essential or non-essential metals with a DTPA extractor. The experimental design consisted of randomized blocks subdivided into sections of 6 treatments of sewage sludge (0, 6, 20, 40, 60 and 80 t ha-1) during the first year and (0, 6, 20, 40, 60 and 80 t ha-1) during the second year. The experiment had 4 replications and 5 soil collection periods (0, 30, 60, 90, and 120 days of sludge incorporation). Sewage sludge was applied at a mean depth of 0-20 cm. Soil sampling was undertaken during the periods of sludge incorporation so that the elements available in the soil in different doses could be evaluated Soil samples were analyzed as to fertility level. Concentrations of the metals Cu, Zn, Cd, Ni, Co, Pb, and Cr were determined by atomic absorption in DTPA extractor solution. Concentrations of Cd, Ni, Co, Pb, and Cr were not detected since values were lower than the detection limit of each. Application of sewage sludge increased Cation Exchange Capacity (CEC) and there was an initial pH variation, albeit the latter returned concentration to its original level. Owing to the repetition of applied sludge, Cu and Zn rates in soil samples gradually increased during the two agricultural years caused by an increase in the doses of applied sewage sludge.
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| Keywords: |
heavy metals; biosolid; DTPA; availability of nutrients.
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| Year: |
2005
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| Initial page: |
13
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| Final page: |
25
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.17_2005.pdf |
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| Author (s): |
Tania R. Prochnow, Bernardo Liberman, Nadia T. S. Pfeifer, Marilene G.Porawski, Norma Marroni, Emerson A. Prochnow, Masurquerde Coimbra.
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| Title: |
POLLUTION EFFECTS ON THE ENVIRONMENT, MACROPHYTES AND FISHES IN THE SAPUCAIA STREAM, GUAiBA HYDROGRAPHIC BASIN, RS, BRAZIL |
| Abstract: |
This paper shows the results of air, water and sediment quality of Sapucaia stream, which belongs to Guafba Hydrographic Basin, in the State of Rio Grande do Sul, Southern Brazil. The correlations among the concentrations of Al, Cu, Fe, Mn, and Zn, present in the atmosphere, water and sediments, and their bioaccumulation in macrophytes are determined. Different degrees of pollution is characterized through the study of oxidative damage in fishes. The results indicate metal accumulation in macrophytes and fishes.
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| Keywords: |
environmental survey, fishes, macrophytes, micro and macro elements, pollution.
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| Year: |
2005
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| Initial page: |
27
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| Final page: |
43
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.30_2005.pdf |
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| Author (s): |
Ion Gănescu, Aurora Reiss, Alin Barbu and Anca Gănescu
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| Title: |
CHROMIUM (III) COMPLEX ANIONS IN THE CHEMICAL ANALYSIS. ATROPINE DETERMINATION |
| Abstract: |
Complex anions or Cr(III) analogues of Reinecke s salt, [Cr(NCS)2(amine)2]- are good analytical reagents with high sensibility and selectivity for N-organic bases of pharmaceutical importance. We have observed that the atropine with Cr(III) complex anions. Some new oxidative methods for the determination of atropine are described. The results were evaluated statistically.
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| Keywords: |
chromium (III), atropine, drugs, oxidimetric and spectrometric methods.
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| Year: |
2005
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| Initial page: |
45
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| Final page: |
51
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.47_2005.pdf |
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| Author (s): |
J.C. Toniolo, R. Bonadiman, L. L. Oliveira, J.M. Hohemberger, C. P. Bergmann
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| Title: |
SYNTHESIS OF NANOCRYSTALLINE NICKEL OXIDE POWDERS VIA GLYCINE-NITRATE COMBUSTION |
| Abstract: |
NiO is a candidate material for a variety of potential applications, for example, active optical filters, antiferromagnetic layers, coloring agents for enamel, pigments, catalysts, cathode materials for alkaline batteries and temperature sensors. Nanocrystalline nickel oxide powders have been synthesized by the combustion technique using glycine as a fuel and nitrate as an oxidizer. The precursor solution was heated to evaporate water, yielding a viscous liquid. It ignited and underwent self-sustaining combustion, producing an ash composed of the oxide product. The as-synthesized particles have been characterized by Xray diffraction (XRD), and scanning electron microscopy (SEM). Nanocrystalline nickel oxide was possible to be obtained from fuel-lean ratios. The smallest crystallite size was obtained under fuel-lean (0.09) formulation. The size of the NiO nanoparticles varied from 4 to 18 nm.
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| Keywords: |
Ceramics; Nanoparticle chemical synthesis; X-ray diffraction; Thermodynamic properties..
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| Year: |
2005
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| Initial page: |
53
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| Final page: |
63
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.54_2005.pdf |
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| Author (s): |
Paulo Cesar Pereira das Neves; Flavia Schenato
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| Title: |
THE CHEMICAL ELEMENTS OF THE PERIODIC TABLE AND THE ASSOCIATED MINERALS - THE SILVER |
| Abstract: |
Silver is a natural solid with a crystalline stable structure and exhibits an abundance of 0.04 ppm (mg/kg) in the earth crust. Silver thus, like gold, is one of the chemical elements less abundant in nature. Only palladium, tellurium, platinum, ruthenium, rhodium, osmium, rhenium and iridium, present smaller geochemical distribution. However, because of its lower chemical reactivity, the metal presents a low representative in the mineral constitution. This review presents a synopsis of silver minerals (129 substances) as a contribution to the scientific knowledge of these substances.
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| Keywords: |
silver, mineralogy of silver; use of silver minerals.
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| Year: |
2005
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| Initial page: |
63
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| Final page: |
79
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.63_2005.pdf |
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| Author (s): |
Lavinel G. Ionescu, Joao Marcos Hohemberger, Juliane Vicenzi and Carlos Perez Bergmann
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| Title: |
ELIMINATION AND CONTROL OF AQUATIC PESTS IN THE ENVIRONMENT |
| Abstract: |
The present paper is a brief review of possible methods that can be used to control or eliminate aquatic pests from the environment, with particular emphasis on the golden mussel, Limnoperna fortunei (Dunker 1856). This bivalve mollusk, a native of Southeast Asia, has infested most of the rivers in Northern Argentina, Uruguay, Paraguay, and Southern Brazil and is causing serious environmental difficulties and biofouling. In addition, it causes serious problems to water treatment stations and hydroelectric power plants.
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| Keywords: |
Aquatic Pests, Golden Mussel, Biofouling, Hydroeletric Power Plants, Water Treatment.
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| Year: |
2005
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| Initial page: |
81
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| Final page: |
91
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v13.n13.2005.80_2005.pdf |
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