23,718 research outputs found
Organophosphorus pesticides residues in cooked tomato (Licopersicum esculentum).
The study aimed to evaluate the residual concentrations of OP in tomato after different cooking times
Mesoscopic theory for size- and charge- asymmetric ionic systems. I. Case of extreme asymmetry
A mesoscopic theory for the primitive model of ionic systems is developed for
arbitrary size, , and charge, ,
asymmetry. Our theory is an extension of the theory we developed earlier for
the restricted primitive model. The case of extreme asymmetries
and is studied in some detail in a mean-field
approximation. The phase diagram and correlation functions are obtained in the
asymptotic regime and , and for infinite
dilution of the larger ions (volume fraction or less). We find a
coexistence between a very dilute 'gas' phase and a crystalline phase in which
the macroions form a bcc structure with the lattice constant . Such coexistence was observed experimentally in deionized aqueous
solutions of highly charged colloidal particles
Phase diagram of a random-anisotropy mixed-spin Ising model
We investigate the phase diagram of a mixed spin-1/2--spin-1 Ising system in
the presence of quenched disordered anisotropy. We carry out a mean-field and a
standard self-consistent Bethe--Peierls calculation. Depending on the amount of
disorder, there appear novel transition lines and multicritical points. Also,
we report some connections with a percolation problem and an exact result in
one dimension.Comment: 8 pages, 4 figures, accepted for publication in Physical Review
Avaliação do efeito da combinação de pectina, gelatina e alginato de sódio sobre as características de gel de fruta estruturada a partir de "mix" de polpa de cajá e mamão, por meio da metodologia de superfície de resposta.
Este trabalho teve por objetivo estabelecer procedimento tecnológico para produção de fruta estruturada a partir de ?mix? de polpa de cajá e mamão, procurando unir as propriedades sensoriais de cada uma das frutas e potencializar as características funcionais do produto final. Avaliou-se o efeito da combinação de pectina, gelatina e alginato de sódio, via metodologia de superfície de resposta, nas características do gel de fruta. As polpas de mamão e cajá e os estruturados obtidos foram caracterizados com relação aos compostos funcionais, avaliando-se o teor de taninos e carotenóides totais, além das análises de composição centesimal, pH, acidez titulável, sólidos solúveis, açúcares, atividade de água, carboidratos e valor energético total. Os resultados obtidos através do planejamento experimental indicam que para o estruturado misto de cajá e mamão, somente o aumento da concentração de gelatina afeta a firmeza do produto final. Os estruturados de frutas desenvolvidos apresentaram boa aceitação sensorial para todos os atributos avaliados. Com relação à intenção de compra, 70% dos provadores responderam que provavelmente ou certamente, comprariam o estruturado misto de cajá e mamão se o encontrassem à venda
Modelling of Heat Transfer in Radiating and Combusting Systems
T he solution of reactive¯ow problems with radiative heat transfer requires a radiation model which is simultaneously accurate, fast and compatible with the algorithm employed to solve the transport equations. In the present paper, a review of the most commonly used methods to predict radiative heat transfer in combustion chambers is presented. Among them, three methods that satisfy the above requirements are described in more detail; namely the discrete transfer, the discrete ordinates and the ® nite volume method. Some examples of results obtained for simple test cases are presented where predictions obtained with some of the most well known models are compared. An important issue within the radiation modelling domain is the evaluation of the radiative properties of gases and particulate matter that are commonly found in the combustion products. Therefore, in the second part of the paper, the problems related to the evaluation of the radiative properties of the combustion products, i.e. participating gaseous species and particles, are focused and the methods used to solve these problems are described
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