Foundations of a new theory of topological manifolds

Summary We give here a generalization of the concept of topological manifold, which includes classical manifolds. Also, several properties of classical manifolds may be extended to the new class of manifolds, as shown here.     

Monoglycerides and Diglycerides Synthesis in a Solvent-Free System by Lipase-Catalyzed Glycerolysis

Five lipases were screened (Thermomyces lanuginosus free and immobilized forms, Candida antarctica B, Candida rugosa, Aspergillus niger, and Rhizomucor miehei) to study their ability to produce monoglycerides (MG) and diglycerides (DG) through enzymatic glycerolysis of soybean oil. Lipase from C. antarctica was further studied to verify the enzyme load (wt% of oil mass), the molar ratio glycerol/oil, and the water content (wt% of glycerol) on the glycerolysis reaction. The best DG and MG productions were in the range 45–48% and 28–30% (w/w, based on the total oil), respectively. Using immobilized lipases, the amount of free fatty acids (FFA) produced was about 5%. However, the amount of FFA produced when using free lipases, with 3.5% extra water in the system, is equivalent to the MG yield, about 23%. The extra water content provides a competition between hydrolysis and glycerolysis reactions, increasing the FFA production.     

A Comparison Between Lime and Alkaline Hydrogen Peroxide Pretreatments of Sugarcane Bagasse for Ethanol Production

Pretreatment procedures of sugarcane bagasse with lime (calcium hydroxide) or alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2³ factorial designs, with pretreatment time, temperature, and lime loading and hydrogen peroxide concentration as factors. The responses evaluated were the yield of total reducing sugars (TRS) and glucose released from pretreated bagasse after enzymatic hydrolysis. Experiments were performed using the bagasse, as it comes from an alcohol/sugar factory and bagasse, in the size, range from 0.248 to 1.397 mm (12–60 mesh). The results show that, when hexoses and pentoses are of interest, lime should be the pretreatment agent chosen, as high TRS yields are obtained for non-screened bagasse using 0.40 g lime/g dry biomass at 70 °C for 36 h. When the product of interest is glucose, the best results were obtained with lime pretreatment of screened bagasse. However, the results for alkaline peroxide and lime pretreatments of non-screened bagasse are not very different.     

Ethyl alcohol production optimization by coupling genetic algorithm and multilayer perceptron neural network

In this present article, genetic algorithms and multilayer perceptron neural network (MLPNN) have been integrated in order to reduce the complexity of an optimization problem. A data-driven identification method based on MLPNN and optimal design of experiments is described in detail. The nonlinear model of an extractive ethanol process, represented by a MLPNN, is optimized using real-coded and binary-coded genetic algorithms to determine the optimal operational conditions. In order to check the validity of the computational modeling, the results were compared with the optimization of a deterministic model, whose kinetic parameters were experimentally determined as functions of the temperature.     

Bioethanol Production Optimization: A Thermodynamic Analysis

In this work, the phase equilibrium of binary mixtures for bioethanol production by continuous extractive process was studied. The process is composed of four interlinked units: fermentor, centrifuge, cell treatment unit, and flash vessel (ethanol-congener separation unit). A proposal for modeling the vapor–liquid equilibrium in binary mixtures found in the flash vessel has been considered. This approach uses the Predictive Soave–Redlich–Kwong equation of state, with original and modified molecular parameters. The congeners considered were acetic acid, acetaldehyde, furfural, methanol, and 1-pentanol. The results show that the introduction of new molecular parameters r and q in the UNIFAC model gives more accurate predictions for the concentration of the congener in the gas phase for binary and ternary systems.     

First report of the in vitro antileishmanial properties of extremophile plants from the Algarve Coast

This work reports for the first time the in vitro anti Leishmania infantum activity of acetone and dichloromethane (DCM) extracts from 25 extremophile plants from Southern Portugal. DCM extracts from Inula chritmoides and Spergularia rubra were active against axenic promastigotes and intracellular amastigotes, had anti-inflammatory properties on lipopolysaccharide (LPS)-stimulated macrophages, inhibited acetylcholinesterase and had no haemolytic activity on human erythrocytes. Eleven phenolics were identified by high-performance liquid chromatography with diode-array detection (HPLC-DAD) in I. crithmoides and one phenolic in S. rubra. Isolation and identification of the active molecules is in progress.     

Derivations, isomorphisms, and second cohomology of generalized Witt algebras

Generalized Witt algebras, over a field of characteristic , were defined by Kawamoto about 12 years ago. Using different notations from Kawamoto's, we give an essentially equivalent definition of generalized Witt algebras over , where the ingredients are an abelian group , a vector space over , and a map which is linear in the first variable and additive in the second one. In this paper, the derivations of any generalized Witt algebra
, with the right kernel of being , are explicitly described; the isomorphisms between any two simple generalized Witt algebras are completely determined; and the second cohomology group for any simple generalized Witt algebra is computed. The derivations, the automorphisms and the second cohomology groups of some special generalized Witt algebras have been studied by several other authors as indicated in the references.