Parametric Analysis of a Heavy Metal Sorption Isotherm Based on Fractional Calculus

Heavy metals are widely recognized as being hazardous to human health and environmentally aggressive. The literature reports different approaches for lead removal, for example, water hyacinths. Heavy metal sorption isotherm modeling represents an important tool towards the study of equilibrium conditions. Fractional calculus represents a novel approach and a growing research field for process modeling, based on derivatives of arbitrary order. Recently, a novel isotherm based on fractional calculus was proposed for lead sorption using water hyacinth (Eichhornia crassipes). This paper reports a general procedure on error analysis and its influence on parameter estimation. It was applied to mathematical models based on fractional differential equations, focusing on a heavy metal novel isotherm sorption model. Parameter variance was calculated by using two different approaches (with the complete Hessian matrix and with a simplified Hessian matrix), and joint parameter confidence regions were generated, being successfully able to show that the fractional nature of the model is statistically valid

USO DA IMAGEM DIGITAL PARA QUANTIFICAÇÃO DE MISTURAS DE AZEITE DE OLIVA E ÓLEO DE CANOLA

O azeite de oliva possui alta qualidade nutricional devido aos benefícios para a saúde relacionados aos seus componentes, que atuam principalmente na prevenção de doenças coronarianas. Devido ao seu alto preço quando puro, o azeite é muitas vezes alvo de adulteração. Estes geralmente ocorrem adicionando óleos vegetais menos nobres como o soja. Este trabalho visa aplicar a análise de imagens para avaliação quantitativa da mistura de azeite de oliva e óleo de canola, combinando informações do espectro de absorbância UV-visível e de imagens digitais a partir de sua decomposição de cores, associando as características físicas destas misturas. Para fins de modelagem, foram utilizadas onze misturas de óleo de oliva e canola com fração mássica de azeite de oliva variando de 0 a 100% em intervalos de 10%. Para fins de validação, uma amostra independente de 25% da fração mássica de azeite de oliva foi considerada. Para este estudo, foram desenvolvidos modelos lineares considerando todas as combinações possíveis entre as variáveis independentes: os componentes de cor R (vermelho), G (verde), B (azul) e a absorbância nos comprimentos de onda selecionados 415nm, 440nm e 670nm. Considerando os resultados obtidos, observa-se que todos os modelos descrevem adequadamente os dados experimentais em função do ajuste do modelo e validação estatística. Concluiu-se que os modelos apresentados levaram a uma previsão muito próxima da amostra de teste em que o uso dos componentes R, G e B da imagem digital associada à UV-Visible representam uma informação mais global sobre a amostra, o que resulta na melhor previsão da amostra de validação como(24,4 ± 0,6)

PHYSICAL CHANGES OF TILAPIA FISH BURGER DURING FROZEN STORAGE

The effects of frozen storage on weight loss during freezing, cooking yield, dimensional changes, and instrumental texture parameters of tilapia fish burger were evaluated during 6 months. Frozen storage for 1 month significantly increased the fish burger shear force, hardness and thickness reduction. Weight loss during freezing (0.6 ± 0.1 %) did not increase with storage time. There was no hardness (29.9 ± 0.7 N) and shear force (5.5 ± 0.2 N) increase during the frozen storage from 1 to 6 months. Tilapia fish burger can be stored for up to 6 months with minor physical changes

Diffusion equations and different spatial fractional derivatives

We investigate for the diffusion equation the differences manifested by the solutions when three different types of spatial differential operators of noninteger (or fractional) order are considered for a limited and unlimited region.  In all cases, we verify an anomalous spreading of the system, which can be connected to a rich class of anomalous diffusion processes

Omental and pleural milky spots: different reactivity patterns in mice infected with Schistosoma mansoni reveals coelomic compartmentalisation

In vertebrate animals, pleural and peritoneal cavities are repositories of milky spots (MS), which constitute an organised coelom-associated lymphomyeloid tissue that is intensively activated by Schistosoma mansoni infection. This study compared the reactive patterns of peritoneal MS to pleural MS and concluded from histological analysis that they represent independent responsive compartments. Whole omentum, lungs and the entire mediastinum of 54 S. mansoni-infected mice were studied morphologically. The omental MS of infected animals were highly activated, modulating from myeloid-lymphocytic (60 days of infection) to lymphomyeloid (90 days of infection) and lymphocytic or lymphoplasmacytic (160 days of infection) types. The non-lymphoid component predominated in the acute phase of infection and was expressed by monocytopoietic, eosinopoietic and neutropoietic foci, with isolated megakaryocytes and small foci of late normoblasts and mast cells. Nevertheless, pleural or thoracic MS of infected mice were monotonous, consisting of small and medium lymphocytes with few mast and plasma cells and no myeloid component. Our data indicate that compartmentalisation of the MS response is dependent on the lymphatic vascularisation of each coelomic cavity, limiting the effects or consequences of any stimulating or aggressive agents, as is the case with S. mansoni infection

Sequential morphological characteristics of murine fetal liver hematopoietic microenvironment in Swiss Webster mice

Embryonic hematopoiesis occurs via dynamic development with cells migrating into various organs. Fetal liver is the main hematopoietic organ responsible for hematopoietic cell expansion during embryologic development. We describe the morphological sequential characteristics of murine fetal liver niches that favor the settlement and migration of hematopoietic cells from 12 days post-coitum (dpc) to 0 day post-partum. Liver sections were stained with hematoxylin and eosin, Lennert’s Giemsa, Sirius Red pH 10.2, Gomori’s Reticulin, and Periodic Acid Schiff/Alcian Blue pH 1.0 and pH 2.5 and were analyzed by bright-field microscopy. Indirect imunohistochemistry for fibronectin, matrix metalloproteinase-1 (MMP-1), and MMP-9 and histochemistry for naphthol AS-D chloroacetate esterase (NCAE) were analyzed by confocal microscopy. The results showed that fibronectin was related to the promotion of hepatocyte and trabecular differentiation; reticular fibers did not appear to participate in fetal hematopoiesis but contributed to the physical support of the liver after 18 dpc. During the immature phase, hepatocytes acted as the fundamental stroma for the erythroid lineage. The appearance of myeloid cells in the liver was related to perivascular and subcapsular collagen, and NCAE preceded MMP-1 expression in neutrophils, an occurrence that appeared to contribute to their liver evasion. Thus, the murine fetal liver during ontogenesis shows two different phases: one immature and mainly endodermic (<14 dpc) and the other more developed (endodermic-mesenchymal; >15 dpc) with the maturation of hepatocytes, a better definition of trabecular pattern, and an increase in the connective tissue in the capsule, portal spaces, and liver parenchyma. The decrease of hepatic hematopoiesis (migration) coincides with hepatic maturation