Ageing behavior in the Cu-10 wt.%Al and Cu-10 wt.%Al-4 wt.%Ag alloys

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal behavior of ara double dagger a oil (Psidium cattleianum Sabine)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Thermal behavior of jeriva oil (Syagrus romanzoffiana)

The jeriva is a well-known fruit, which belongs to the Arecaceae family, Syagrus romanzoffiana species frequently found in Brazil. Extraction of the jeriva oil was carried out, and the fatty acid profile of this oil indicates the linoleic and oleic acid presence, around 29.35 and 28.89%, respectively. Thermogravimetry (TG), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC) were used to characterize this oil. Additionally, this oil was evaluated by DSC from 25 to -80 A degrees C, and the crystallization behavior was verified. Details concerning the thermal behavior as well as data of kinetic parameters of these stages have been described here. The obtained data were evaluated, and the values were plotted in activation energy (E (a)/kJ mol(-1)) in function of the conversion degree (alpha).

Thermal Behavior of Sr(II) and Ba(II)-Diclofenac Complexes in Solid State: Study of the Dehydration and Thermal Decomposition

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Thermal behavior of residues (sludge) originated from Araraquara water and sewage treatment station

The number of the cities with canalized water and sewage treatment stations has increased lately and consequently having in mind the great concern on environment preservation and the quality of the water used by society. However, these stations are nowadays causing another kind of problem: a huge quantity of sludge as residue. Due to the implication of the residue on the environment and, consequently, to human life quality, performing of an accurate investigation about the components of such sludge, as well as the thermal stability of this residue in the environment become necessary. This paper presents a study on sludge from water and sewage treatment station, as well as the thermal characterization of residue. Such study was performed through FTIR, atomic absorption, thermoanalytical (TG/DTG, DTA) techniques, that made it possible to observe that the main components of the sludge are clay, carbonates and organic substance, presenting a low rate of metals and a unique thermal behavior since the sludge from the treatment station has a higher thermal stability.

Study of the thermal behavior of Al(III) and In(III)-diclofenac complexes in solid state

The Al and In-diclofenac compounds were prepared. Thermogravimetry (TG) and X-ray diffraction powder patterns were used to characterize these compounds. Details concerning the dehydration and thermal decomposition as well as data of kinetic parameters have been described here. The kinetic studies of these stages were evaluated from several heating rates with mass sample of 2 and 5 mg in open crucibles under nitrogen atmosphere. The results of the present study improve the knowledge on these compounds including their dehydration and thermal stability. The obtained data leads to a dependence on the sample mass, which results in two kinetic behavior patterns.

Characterization and thermal behavior of residues from industrial sugarcane processing

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Study of the thermal behavior of the transition phase of Co(II)-diclofenac compound by non-isothermal method

The Co(II)-diclofenac complex was evaluated by simultaneous thermogravimetry-differential thermal analysis (TG-DTA) and differential scanning calorimetry (DSC). The DTA curve profile shows one exothermic peak because of the transition phase of the compound between 170 and 180 A degrees C, which was confirmed by X-ray powder diffractometry. The transition phase behavior was studied by DSC curves at several heating rates of a sample mass between 1 and 10 mg in nitrogen atmosphere and in a crucible with and without a lid. Thus, the kinetic parameters were evaluated using an isoconversional non-linear fitting proposed by Capela and Ribeiro. The results show that the activation energy and pre-exponential factor for the transition phase is dependant on the different experimental conditions. Nevertheless, these results indicate that the kinetic compensation effect shows a relationship between them.

Synthesis, characterization, and thermal behavior of palladium(II) coordination compounds containing isonicotinamide

Palladium(II) coordination compounds of general formula trans-[PdX(2)(isn)(2)], X = Cl(-) (1), N(3) (-) (2), SCN(-) (3), NCO(-) (4), isn = isonicotinamide; were synthesized and characterized in solid state by elemental analysis, infrared spectroscopy, and simultaneous TG-DTA. TG experiments reveal that the compounds 1-4 undergo thermal decomposition in three or four stages, yielding Pd(0) as final residue, according to calculus and identification by X-ray powder diffraction.

Synthesis, characterization, and investigation of the thermal behavior of Cu(II) pyrazolyl complexes

This work reports the synthesis, characterization, and thermal behavior of three complexes of copper (II): [CuCl(2)(HPz)(4)] (1), [CuCl(2)(HdmPz)(4)] (2), and [CuCl(2)(HIPz)(4)] (3) (HPz = pyrazole; HdmPz = 3,5-dimethylpyrazole; HIPz = 4-iodopyrazole). The compounds were characterized by elemental analysis, infrared spectroscopy, and UV-Vis measurements. The thermal study of the compounds showed that the ligands are eliminated in 2-4 stages, yielding CuO as final residue.

Electron transfer by singlet excited state of porphyn and electron acceptor affinity in rigid medium: photoacoustic phase angle analysis

A espectroscopia fotoacústica obtém informações sobre amplitude e fase, da resposta de um sistema submetido a excitação por luz. Este artigo apresenta estudos do ângulo de fase no processo de transfereência de elétrons entre octaetilporfirina (OEP) e derivados de quinona ambos dispersos em uma matriz polimérica. Observou-se uma tendência no comportamento da fase para valores menores na região espectral próximo de 620 nm. Enquanto que para comprimentos de onda menores este efeito não foi apresentado. Estas medidas sugerem que a transferência de elétrons para o aceitador ocorreu com a participação do estado singleto excitado da octaetilporfirina.

Thermal behavior of corn starch granules modified by acid treatment at 30 and 50°C

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Study of the length of the mouthparts of Africanized, Caucasian and Africanized/Caucasian honey bee crosses, and relationships between glossa sizeand food gathering behavior

Os comprimentos das peças que constituem o aparelho bucal, glossa, paraglossa, estipite, gálea, palpo labial, palpo maxilar, cardo, lorum, mento e pré-mento foram estudados a nível unidimensional em abelhas caucasianas, africanizadas e nos descendentes F1. Somente a paraglossa, estipite, gálea, palpo maxilar, mento e pré-mento mostraram ser diferentes entre esses 2 tipos de abelhas. Essas 6 variáveis foram estudadas nos descendentes F1, tendo sido utilizados 2 tipos de cruzamentos: rainhas caucasianas x machos africanizados (cruzamento 1) e rainhas africanizadas x machos caucasianos (cruzamento 2). Análises multidimensionais também foram realizadas, tendo sido obtidas as distâncias generalizadas de Mahalanobis (D2) entre os parentais e os descendentes F1. Tanto nas análises unidimensionais como nas multidimensionais houve aparente dominância das abelhas africanizadas, mas o número de genes não pôde ser conhecido porque só havia a geração F1 e não houve controle da heterozigosidade das 2 colônias parentais. Os cálculos dos coeficientes de correlações de Spearman mostraram que as abelhas com glossae mais longas coletaram mais xarope de açúcar e voaram mais lentamente da colônia para a fonte de alimento.

Chromosomal similarity between the Scaly-headed parrot (Pionus maximiliani), the Short-tailed parrot (Graydidascalus brachyurus) and the Yellow-faced parrot (Salvatoria xanthops) (Psittaciformes: Aves): a cytotaxonomic analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Electrochemical behavior of metallic chromium in chloride media

The electrochemical behavior of metallic chromium in aqueous solutions containing chloride ions at different pH was studied by means of open-circuit potential vs. time measurements, cyclic voltammetry and electrochemical impedance spectroscopy. The composition of the surface oxides was analyzed by XPS. For solutions with pH<3 the formation of a passive layer occurs via a dissolution/precipitation process while for pH>3 the mechanism changes. XPS analysis revealed that Cr2O3 basically constitutes the passive layer.