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 | Acesso ao texto completo restrito à biblioteca da Embrapa Amazônia Oriental. Para informações adicionais entre em contato com cpatu.biblioteca@embrapa.br. |
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Registro Completo |
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Biblioteca(s): |
Embrapa Amazônia Oriental. |
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Data corrente: |
06/12/2011 |
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Data da última atualização: |
11/11/2022 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Autoria: |
ALVES, T. V. G.; TAVARES, E. J. M.; AOUADA, F. A.; NEGRÃO, C. A. B.; OLIVEIRA, M. E. C.; DUARTE JÚNIOR, A. P.; COSTA, C. E. F. da; SILVA JÚNIOR, J. O. C.; COSTA, R. M. R. |
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Afiliação: |
TAÍS VANESSA AGBBAY ALVES, UFPA; ERALDO JOSE MADUREIRA TAVARES, CPATU; FAUZE AHMAD AOUADA, USP; CHALES ALBERTO BRITO NEGRÃO, UFPA; MARCOS ENE CHAVES OLIVEIRA, USP / CPATU; ANIVALDO PEREIRA DUARTE JÚNIOR, UFPA; CARLOS EMMERSON FERREIRA DA COSTA, UFPA; JOSÉ OTÁVIO CARRÉRA SILVA JUNIOR, UFPA; ROSEANE MARIA RIBEIRO COSTA, UFPA. |
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Título: |
Thermal analysis characterization of PAAm-co-MC hydrogels. |
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Ano de publicação: |
2011 |
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Fonte/Imprenta: |
Journal of Thermal Analysis and Calorimetry, v. 106, n. 3, p. 717-724, 2011. |
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DOI: |
10.1007/s10973-011-1572-z |
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Idioma: |
Inglês |
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Conteúdo: |
This paper reports the thermal characterization of polyacrylamide-co-methylcellulose hydrogels and the constituent monomers (acrylamide and methylcellulose). Polymeric materials can be used to produce hydrogels, which can be natural, synthetic, or a mixture. The hydrogels described here were obtained by free radical polymerization, in the presence of N,N0-methylene-bisacrylamide as a cross-linker agent. Four acrylamide concentrations were used for the synthesis of hydrogels: 3.6, 7.2, 14.7, and 21.7% (w/v). The materials so obtained were analyzed by TG, DTG, DSC, and FT-IR. The TG curves of acrylamide and methylcellulose showed three mass loss events. In DSC curves, the acrylamide exhibited one melting peak at 84.5 C, and methylcellulose indicated one exothermic event. Nevertheless, acrylamide was considered more stable than methylcellulose. The TG curves of the hydrogels exhibited three mass loss events, and on the DSC curves, three endothermic events were observed. It was verified that the different acrylamide proportions influenced the thermic behavior of hydrogels, and that the authors considered the 7.2% hydrogel a promising drug carrier system. The absorption bands were well defined, confirming the presence of the functional groups in the samples. |
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Palavras-Chave: |
Análise térmica; Hidrogel. |
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Categoria do assunto: |
W Química e Física |
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Marc: |
LEADER 02040naa a2200253 a 4500
001 1908634
005 2022-11-11
008 2011 bl uuuu u00u1 u #d
024 7 $a10.1007/s10973-011-1572-z$2DOI
100 1 $aALVES, T. V. G.
245 $aThermal analysis characterization of PAAm-co-MC hydrogels.$h[electronic resource]
260 $c2011
520 $aThis paper reports the thermal characterization of polyacrylamide-co-methylcellulose hydrogels and the constituent monomers (acrylamide and methylcellulose). Polymeric materials can be used to produce hydrogels, which can be natural, synthetic, or a mixture. The hydrogels described here were obtained by free radical polymerization, in the presence of N,N0-methylene-bisacrylamide as a cross-linker agent. Four acrylamide concentrations were used for the synthesis of hydrogels: 3.6, 7.2, 14.7, and 21.7% (w/v). The materials so obtained were analyzed by TG, DTG, DSC, and FT-IR. The TG curves of acrylamide and methylcellulose showed three mass loss events. In DSC curves, the acrylamide exhibited one melting peak at 84.5 C, and methylcellulose indicated one exothermic event. Nevertheless, acrylamide was considered more stable than methylcellulose. The TG curves of the hydrogels exhibited three mass loss events, and on the DSC curves, three endothermic events were observed. It was verified that the different acrylamide proportions influenced the thermic behavior of hydrogels, and that the authors considered the 7.2% hydrogel a promising drug carrier system. The absorption bands were well defined, confirming the presence of the functional groups in the samples.
653 $aAnálise térmica
653 $aHidrogel
700 1 $aTAVARES, E. J. M.
700 1 $aAOUADA, F. A.
700 1 $aNEGRÃO, C. A. B.
700 1 $aOLIVEIRA, M. E. C.
700 1 $aDUARTE JÚNIOR, A. P.
700 1 $aCOSTA, C. E. F. da
700 1 $aSILVA JÚNIOR, J. O. C.
700 1 $aCOSTA, R. M. R.
773 $tJournal of Thermal Analysis and Calorimetry$gv. 106, n. 3, p. 717-724, 2011.
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Registro original: |
Embrapa Amazônia Oriental (CPATU) |
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Biblioteca |
ID |
Origem |
Tipo/Formato |
Classificação |
Cutter |
Registro |
Volume |
Status |
URL |
Voltar
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| Acesso ao texto completo restrito à biblioteca da Embrapa Meio Ambiente. Para informações adicionais entre em contato com cnpma.biblioteca@embrapa.br. |
Registro Completo
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Biblioteca(s): |
Embrapa Meio Ambiente. |
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Data corrente: |
22/12/2008 |
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Data da última atualização: |
24/08/2023 |
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Tipo da produção científica: |
Artigo em Periódico Indexado |
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Circulação/Nível: |
Internacional - A |
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Autoria: |
MARTINEZ, C. O.; SILVA, C. M. M. de S.; FAY, E. F.; ABAKERLI, R. B.; MAIA, A. de H. N.; DURRANT, L. R. |
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Afiliação: |
Camila Ortiz Martinez; Célia Maria Maganhotto de Souza Silva, Embrapa Meio Ambiente; ELISABETH FRANCISCONI FAY, CNPMA; Rosângela Blotta Abakerli, Embrapa Meio Ambiente; ALINE DE HOLANDA NUNES MAIA, CNPMA; Lucia Regina Durrant, FEA/UNICAMP. |
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Título: |
The effects of moisture and temperature on the degradation of sulfentrazone. |
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Ano de publicação: |
2008 |
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Fonte/Imprenta: |
Geoderma, v. 147, n. 1, p. 56-62, 2008. |
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Idioma: |
Inglês |
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Conteúdo: |
This study examined the degradation of sulfentrazone in Arenic Hapludult soil, such soil being representative of regions where sulfentrazone is used in Brazil. Soil samples were supplemented with the herbicide [0.7 ?g active ingredient (a.i.) g-1 soil] and maintained at 27 °C. The soil moisture content was corrected to 30, 70 or 100% of water holding capacity (WHC). Herbicide-free soil samples were used as controls. Aliquots were taken after 14, 30, 60, 120, 180 and 255 days of incubation for the quantitative analysis of sulfentrazone residues by gas chromatography. Another experiment was conducted using soil samples with and without herbicide, submitted to different temperatures of 15, 30 and 40 °C, and kept at a constant value for WHC of 70% . The sulfentrazone residues were quantified by gas chromatography after 14, 30, 60 and 120 days of incubation. The potential degrader microorganisms were isolated and identified. A half-life of 172.4 days was estimated at 27 °C and 70% WHC. The microorganisms identified as potential degraders of the herbicide were Acinetobacter calcoaceticus, Chrysosporium sp., Eupenicillium sp., Metarhizium sp. and Paecilomyces sp. After 120 days, temperature had no further effect (Pb0.16) on sulfentrazone degradation, and the soil moisture content had no effect on degradation at any time. |
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Palavras-Chave: |
Degradação. |
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Thesagro: |
Herbicida. |
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Categoria do assunto: |
W Química e Física |
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Marc: |
LEADER 01919naa a2200205 a 4500
001 1015603
005 2023-08-24
008 2008 bl uuuu u00u1 u #d
100 1 $aMARTINEZ, C. O.
245 $aThe effects of moisture and temperature on the degradation of sulfentrazone.$h[electronic resource]
260 $c2008
520 $aThis study examined the degradation of sulfentrazone in Arenic Hapludult soil, such soil being representative of regions where sulfentrazone is used in Brazil. Soil samples were supplemented with the herbicide [0.7 ?g active ingredient (a.i.) g-1 soil] and maintained at 27 °C. The soil moisture content was corrected to 30, 70 or 100% of water holding capacity (WHC). Herbicide-free soil samples were used as controls. Aliquots were taken after 14, 30, 60, 120, 180 and 255 days of incubation for the quantitative analysis of sulfentrazone residues by gas chromatography. Another experiment was conducted using soil samples with and without herbicide, submitted to different temperatures of 15, 30 and 40 °C, and kept at a constant value for WHC of 70% . The sulfentrazone residues were quantified by gas chromatography after 14, 30, 60 and 120 days of incubation. The potential degrader microorganisms were isolated and identified. A half-life of 172.4 days was estimated at 27 °C and 70% WHC. The microorganisms identified as potential degraders of the herbicide were Acinetobacter calcoaceticus, Chrysosporium sp., Eupenicillium sp., Metarhizium sp. and Paecilomyces sp. After 120 days, temperature had no further effect (Pb0.16) on sulfentrazone degradation, and the soil moisture content had no effect on degradation at any time.
650 $aHerbicida
653 $aDegradação
700 1 $aSILVA, C. M. M. de S.
700 1 $aFAY, E. F.
700 1 $aABAKERLI, R. B.
700 1 $aMAIA, A. de H. N.
700 1 $aDURRANT, L. R.
773 $tGeoderma$gv. 147, n. 1, p. 56-62, 2008.
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Embrapa Meio Ambiente (CNPMA) |
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