Cinética e caracterização físico-química do fermentado do pseudofruto do caju (Anacardium occidentale L.)

The production of cashew apple wine has the purpose of minimizing the wastage in the Brazilian cashew production. Knowing that the cashew apple fermentation produces a good cashew wine, a study of alcoholic fermentation kinetics of the cashew apple and the physico-chemical characterization of the product were made. The cashew wine was produced in an stirred batch reactor. The results of the physico-chemical analysis of volatiles, residual sugars, total acidity and pH of cashew wine showed that their concentrations were within the standard limits established by the Brazilian legislation for fruit wines.

Aspectos físico-químicos e biológicos relacionados à ocorrência de Biomphalaria glabrata em focos litorâneos da esquistossomose em Pernambuco

This study analyzes the physico-chemical and biological parameters of freshwater aquatic environments in coastal areas of the State of Pernambuco, Brazil, where snail vector foci and cases of schistosomiasis have been recorded. The tests were carried out using standard methods and sediments were analyzed using the X-ray fluorescence technique. The micro-algae were analyzed using conventional microscopy. The most abundant chemical elements in the sediments were Fe, Ca, Si and Al and there were high concentrations of electrolytes in comparison with data published in the literature. The mean values for salinity (7.7 g/L) and sulfate (489 mg/L) were much higher than normal for freshwater environments. The micro-algae identified are those that inhabit environments with higher levels of salinity. The snail Biomphalaria glabrata seems, therefore, to be more tolerant to salty environments and this constitutes a risk of spread of schistosomiasis.

On the application of knoevenagel condensation for the synthesis of benzylidene benzothiazine compounds and structural study

The synthesis and physico-chemical properties of new 6-acetylamino or 6-benzoyl-amino 2-benzylidene-4-methyl-4H-benzo[1,4]thiazin-3-ones and 6-benzoylamino or 6-nitro 2-benzylidene-4H-benzo[1,4]thiazin-3-ones are described. These benzylidene benzothiazine compounds were prepared by the Knoevenagel condensation with benzaldehydes. The configurations and conformations of benzylidene benzothiazine derivatives were optimised using the semi-empirical method AM1.

Biodiesel de babaçu (Orbignya sp.) obtido por via etanólica

Biodiesel was obtained by transesterification of babassu oil in anhydrous ethanol and methanol, employing NaOH as catalyst. The products obtained were characterized by physico-chemical and thermogravimetric analysis. It could be concluded that the properties of the two types of biodiesel (ethanolic and methanolic) are very similar when compared with diesel oil.

Composição centesimal do leite humano e caracterização das propriedades físico-químicas de sua gordura

Human milk fat is essential for development of newborn infants. Many studies detail chemical characteristics of human milk fat; however there are no studies about its physical properties. The objective of this work was to analyze the centesimal composition of human milk and to compare the calculated energy value with the estimated energy by the creamatocrit method. Chemical composition and physical properties of human milk lipids and Betapol - a structured lipid - were also studied. The results showed that energy values of human milk estimated by creamatocrit and calculated by the centesimal composition didn't present significant correlation. Human milk lipids and Betapol presented distinct physico-chemical properties.

Caracterização física, química e ecotoxicológica de efluente da indústria de fabricação de explosivos

The production and use of nitroaromatic explosives have resulted in their dissemination into the environment, where their presence in waterways and soil represents an ecological and health hazard. The hazardous characteristics of these compounds need to be carefully studied, so that the impact of their discharge on the environment can be better evaluated. This work presents the characterization of wastewater from Brazilian TNT industry using as analytical techniques mass spectroscopy, chromatography, toxicity assays and other physico-chemical analyses.

Funcionalização de nanotubos de Carbono

Carbon nanotubes are very stable systems having considerable chemical inertness due to the strong covalent bonds of the carbon atoms on the nanotube surface. Many applications of carbon nanotubes require their chemical modification in order to tune/control their physico-chemical properties. One way of achieving this control is carrying out functionalization processes where atoms and molecules interact (covalent or non-covalent) with the nanotubes. We review some of the progress that has been made in chemical functionalization of carbon nanotubes. Emphasis is given to chemical strategies, the most used techniques, and applications.

Lipídios estruturados obtidos a partir da mistura de gordura de frango, sua estearina e triacilgliceróis de cadeia média: I- Composição em ácidos graxos e em triacilgliceróis

The purpose of this study is to analyze the interactions that occur in binary and ternary fat blends between medium and long chain triacylglycerols and their structured lipids obtained by chemical interesterification through the analysis of their physico-chemical properties. The synthesized structured triacylglycerols presented from 14.8 to 58.4% medium chain fatty acids, from 15.7 to 37.2% saturated fatty acids, from 19.2 to 47.5% monounsaturated fatty acids, and from 6.7 to 15.2% essential fatty acids. Chemical interesterification modified the behavior of binary and ternary mixtures and new types of triacylglycerol groups were formed.

Caracterização físico-química de complexo de inclusão entre hidroximetilnitrofurazona e hidroxipropil-beta-ciclodextrina

Hydroxymethylnitrofurazone (NFOH) is a prodrug that is active against Trypanosoma cruzi. It however presents low solubility and high toxicity. Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) can be used as a drug-delivery system for NFOH modifying its physico-chemical properties. The aim of this work is to characterize the inclusion complex between NFOH and HP-beta-CD. The rate of NFOH release decreases after complexation and thermodynamic parameters from the solubility isotherm studies revealed that a stable complex is formed (deltaGº= 1.7 kJ/mol). This study focuses on the physico-chemical characterization of a drug-delivery formulation that comes out as a potentially new therapeutic option for Chagas disease treatment.

Análise multivariada de parâmetros físico-químicos em amostras de vinhos tintos comercializados na região metropolitana do Recife

The Brazilian legislation requires analysis of certain parameters to classify a wine and allow its commercialization. Some physico-chemical and some color parameters were determined in this work in samples of different red wines sold in the metropolitan area of Recife. Multivariate analysis comprising principal component analysis and hierarchical cluster analysis was employed to distinguish the analyzed wines. The results for pH, chloride concentration, color parameters and ammonium content were the most important variables for sample classification. It was also possible to classify the wines as soft or dry wines and amongst the soft wines we could determine two out of four winegrowing producers.

Aplicação de Zr/Ti-PILC no processo de adsorção de Cu(II), Co(II) e Ni(II) utilizando modelos físico-químicos de adsorção e termodinâmica do processo

The aim of this investigation is to study how Zr/Ti-PILC adsorbs metals. The physico-chemical proprieties of Zr/Ti-PILC have been optimized with pillarization processes and Cu(II), Ni(II) and Co(II) adsorption from aqueous solution has been carried out, with maximum adsorption values of 8.85, 8.30 and 7.78 x10-1 mmol g-1, respectively. The Langmuir, Freundlich and Temkin adsorption isotherm models have been applied to fit the experimental data with a linear regression process. The energetic effect caused by metal interaction was determined through calorimetric titration at the solid-liquid interface and gave a net thermal effect that enabled the calculation of the exothermic values and the equilibrium constant.

Propriedades e aplicações recentes das ciclodextrinas

Cyclodextrins (CDs) are cyclic oligosaccharides comprised of six or more glucose units connected by alpha-1,4 bonds. They have hydrophobic cavities with a hydrophilic exterior, and are versatile receptors for a variety of substrates. This ability allows them to be applied in many fields, as distinct as supramolecular chemistry, nanotechnology, pharmaceuticals, green chemistry, agrochemicals, analytical chemistry, toiletries, foods, and cosmetics. This review summarizes several aspects related to the physico-chemical properties of CDs and discusses their potential applications illustrated by recent examples. The prospects for their use in several areas are also described.

Purificação e caracterização da beta-lapachona e estudo de estabilidade dos cristais em diferentes condições de armazenamento

The beta-lapachone is a product obtained from the Ipê Roxo tree [Tabebuia avellandae], which has proved its excellent antineoplasic potential acting through a particular mechanism of apoptosis against various cancer types. This study aims at determining the identity card of beta-lapachone by means of physico-chemical and pharmaco-technical characterization. A purifying process has been performed, as well as the isolation of a contaminant, its isomer alpha-lapachone. A stability study was also performed, determining the ideal storing conditions for beta-lapachone, essential for the ongoing pre-formulation studies for obtaining the different classic pharmaceutical forms and modified release systems.

Aplicação de adsorção para remover amônia de efluentes suinícolas pré-tratados

The aim of this work is to evaluate the use of natural zeolites to remove the NH4+ that remains in effluents from swine facilities which were submitted to physico-chemical and biological treatments. Experiments were made in batch made adding 5% (w/w) of adsorbent (0.6-1.3 and 3.0-8.0 mm) to synthetic and real swine facilities effluents. The results show that ammonium removal is influenced by adsorbent particle size and the presence of other ions in the effluent. The adsorption equilibrium was described by Langmuir as well as Freundlich isotherms and the kinetic data fitted well a pseudo-second order model.

Avaliação da qualidade do corpo hídrico do rio Tibagi na região de Ponta Grossa utilizando análise de componentes principais (PCA)

The aim of this paper was to evaluate alterations in the quality of the water of the Tibagi River caused by the urban and industrial activities in the region of Ponta Grossa. The study involved the monitoring of physico-chemical and microbiological parameters of the water body, which were evaluated by a principal components analysis routine. Sample collections were carried out monthly during one year (October of 2005 to September of 2006), at 3 sampling points: upstream and downstream of the industrial district and downstream from the city of Ponta Grossa. The principal components analysis showed the effect of point sources associated with industrial activity, which contribute to the rise of total concentration of amoniacal nitrogen and the reduction of dissolved oxygen in the studied region.