Consulta: subjectFacets:"Activation"
Registros recuperados: 5
Data/hora: 29/05/2024 00:33:36

Brazilian natural fiber (jute) as raw material for activated carbon production
Provedor de dados: 42
Autores: ROMBALDO,CARLA F.S.; LISBOA,ANTONIO C.L.; MENDEZ,MANOEL O.A.; COUTINHO,APARECIDO R.
Jute fiber is the second most common natural cellulose fiber worldwide, especially in recent years, due to its excellent physical, chemical and structural properties. The objective of this paper was to investigate: the thermal degradation of in natura jute fiber, and the production and characterization of the generated activated carbon. The production consisted of carbonization of the jute fiber and activation with steam. During the activation step the amorphous carbon produced in the initial carbonization step reacted with oxidizing gas, forming new pores and opening closed pores, which enhanced the adsorptive capacity of the activated carbon. N2 gas adsorption at 77K was used in order to evaluate the effect of the carbonization and activation steps. The...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Activation; Adsorption; Carbonization; Jute fiber; Thermogravimetry.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652014000402137

Activation of bovine oocytes by strontium combined or not with an electric pulse
Provedor de dados: 45
Autores: Leal,C.L.V.; Méo,S.C.; Garcia,J.M.
O objetivo deste trabalho foi avaliar as taxas de ativação e de clivagem de oócitos bovinos tratados com estrôncio (10mm de SrCl2), após maturação in vitro por 27-28 horas. No experimento 1, os tratamentos foram: S4 - ativação pelo estrôncio por 4 horas; S12 - ativação pelo estrôncio por 12 horas; S30 - ativação pelo estrôncio por 30 horas; e P - ativação por pulso elétrico (3 pulsos de 1,0kv/cm). No experimento 2 os tratamentos foram: PS4 - ativação combinada pelo pulso elétrico e pelo estrôncio por 4 horas; S4P - ativação pelo estrôncio por 4 horas e pelo pulso elétrico; e PS30 - ativação pelo pulso elétrico e pelo estrôncio por 30 horas. No experimento 1, todos os tratamentos apresentaram taxas similares de ativação (83-90%; P&gt;0,05). Para clivagem, P...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: Cattle; Activation; Parthenogenesis; Oocyte; Strontium; Electric pulse.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0102-09352003000300020

Disintegrins: integrin selective ligands which activate integrin-coupled signaling and modulate leukocyte functions
Provedor de dados: 56
Autores: Barja-Fidalgo,C.; Coelho,A.L.J.; Saldanha-Gama,R.; Helal-Neto,E.; Mariano-Oliveira,A.; Freitas,M.S. de.
Extracellular matrix proteins and cell adhesion receptors (integrins) play essential roles in the regulation of cell adhesion and migration. Interactions of integrins with the extracellular matrix proteins lead to phosphorylation of several intracellular proteins such as focal adhesion kinase, activating different signaling pathways responsible for the regulation of a variety of cell functions, including cytoskeleton mobilization. Once leukocytes are guided to sites of infection, inflammation, or antigen presentation, integrins can participate in the initiation, maintenance, or termination of the immune and inflammatory responses. The modulation of neutrophil activation through integrin-mediated pathways is important in the homeostatic control of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Integrin; Disintegrin; Leukocytes; Activation; Proliferation; Signal transduction.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005001000008

Factors affecting the thermal activation of Neosartorya fischeri in pineapple and papaya nectars
Provedor de dados: 58
Autores: Slongo,Adriana Paula; Aragão,Gláucia Maria Falcão de.
In this research factors that influence the activation of Neosartorya fischeri ascospores (heating medium, temperature of production and age of the ascospores) were studied. The heating medium used was pineapple and papaya nectars at different ratios (ºBrix/acidity). Lower activation times were observed for the N. fischeri ascospores in pineapple and papaya nectars under the conditions of temperature and production age of 25ºC for 1 month and using ratios of the heating medium of 10 for pineapple nectar and 26 for papaya nectar. In these cases, the activation time was 5 minutes for the pineapple nectar and 10 minutes for the papaya nectar at 85ºC. For the ascospores produced at 35ºC over three months, heated in pineapple nectar at a ratio of 38 and in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Ascospores; Ratio; Neosartorya fischeri; Activation.
Ano: 2006
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822006000300021

New raw material for activated carbon: I. Methylene blue adsorption on activated carbon prepared from Khaya senegalensis fruits
Provedor de dados: 118
Autores: Gimba,Casmir E; Ocholi,Odike; Egwaikhide,Peter A; Muyiwa,Turoti; Akporhonor,Emmanuel E.
Activated carbons were prepared from Khaya senegalensis fruits. Carbonization and activation temperatures were 500°C and 800°C, respectively, at residence time of 5 min for each process. Activating agents were 1M each of NaCI, KCl, CaCl2, MgCl2.6H2O, Na2CO3 K2CO3 H2SO4, and ZnCl2. Particle size was 125 um and adsorption studies were carried out using methylene blue in aqueous solution as adsórbate through fixed beds in micro columns. Equilibrium data were analyzed using adsorption intensity and capacity parameters from the Freundlich isotherms as well as breakthrough curves. Results were compared with performances of commercial animal charcoal and granular activated carbon. The results suggest that K senegalensis fruits are suitable raw matenals for...
Tipo: Journal article
Palavras-chave: Activation; Adsorption; Carbonization; Isotherm Khaya senegalensis.
Ano: 2009
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-16202009000100010