Identification of the biodiesel source using an electronic nose

Biodiesel is an important new alternative fuel. The feedstock used and the process employed determines whether it fulfills the required specifications. In this work, an identification method is proposed using an electronic nose (e-nose). Four samples of biodiesel from different sources and one of petrodiesel were analyzed and well-recognized by the e-nose. Both pure biodiesel and B20 blends were studied. Furthermore, an innovative semiquantitative method is proposed on the basis of the smellprints correlated by a feed-forward artificial neural network. The results have demonstrated that the e-nose can be used to identify the biodiesel source and as a preliminary quantitative assay in place of expensive equipment.

Hybrid modeling of convective laminar flow in a permeable tube associated with the cross-flow process

The confined flows in tubes with permeable surfaces arc associated to tangential filtration processes (microfiltration or ultrafiltration). The complexity of the phenomena do not allow for the development of exact analytical solutions, however, approximate solutions are of great interest for the calculation of the transmembrane outflow and estimate of the concentration, polarization phenomenon. In the present work, the generalized integral transform technique (GITT) was employed in solving the laminar and permanent flow in permeable tubes of Newtonian and incompressible fluid. The mathematical formulation employed the parabolic differential equation of chemical species conservation (convective-diffusive equation). The velocity profiles for the entrance region flow, which are found in the connective terms of the equation, were assessed by solutions obtained from literature. The velocity at the permeable wall was considered uniform, with the concentration at the tube wall regarded as variable with an axial position. A computational methodology using global error control was applied to determine the concentration in the wall and concentration boundary layer thickness. The results obtained for the local transmembrane flux and the concentration boundary layer thickness were compared against others in literature. (C) 2007 Elsevier B.V. All rights reserved.

Modeling the kinetics of the coalescence of water droplets in crude oil emulsions subject to an electric field, with the cellular automata technique

In this study, the concept of cellular automata is applied in an innovative way to simulate the separation of phases in a water/oil emulsion. The velocity of the water droplets is calculated by the balance of forces acting on a pair of droplets in a group, and cellular automata is used to simulate the whole group of droplets. Thus, it is possible to solve the problem stochastically and to show the sequence of collisions of droplets and coalescence phenomena. This methodology enables the calculation of the amount of water that can be separated from the emulsion under different operating conditions, thus enabling the process to be optimized. Comparisons between the results obtained from the developed model and the operational performance of an actual desalting unit are carried out. The accuracy observed shows that the developed model is a good representation of the actual process. (C) 2010 Published by Elsevier Ltd.

The importance of the industrialization of Brazilian shale when faced with the world energy scenario

This article discusses the importance of the industrialization of Brazilian shale based on factors such as: security of the national energy system security, global oil geopoliticsl, resources available, production costs, oil prices, environmental impacts and the national oil reserves. The study shows that the industrialization of shale always arises when issues such as peak oil or its geopolitics appear as factors that raise the price of oil to unrealistic levels. The article concludes that in the Brazilian case, shale oil may be classified as a strategic resource, economically viable, currently in development by the success of the retorting technology for extraction of shale oil and the price of crude oil. The article presents the conclusion that shale may be the driving factor for the formation of a technology park in Sao Mateus do Sul, due to the city`s economic dependence on Petrosix.

Phase equilibria of lysozyme precipitation with the volatile salt ammonium carbamate

Lysozyme precipitation induced by the addition of the volatile salt ammonium carbamate was studied through cloud-point measurements and precipitation assays. Phase equilibrium experiments were carried out at 5.0, 15.0 and 25.0 degrees C and the compositions of the coexisting phases were determined. A complete separation of the coexisting liquid and solid phases could not be achieved. Nevertheless it was possible to determine the composition of the solid precipitate through the extensions of experimental tie lines. The same precipitate was found at all temperatures. Lysozyme enzymatic activities of the supernatant and precipitate phases were also determined. The activity balance suggests that ammonium carbamate preserves lysozyme activity after the salting-out precipitation. (C) 2010 Elsevier B.V. All rights reserved.

DEVELOPMENT OF STATIC MIXERS FOR MISCIBLE FLUIDS IN LAMINAR FLOW WITH THE USE OF COMPUTATIONAL FLUID DYNAMICS (CFD)

Static mixers with improved performance were developed from CFD simulations in a stepwise approach. The relevant geometric features of simple mixer designs and the corresponding mixing mechanisms-laminar shear, elongational flow, and distributive mixing-were identified first. This information was used to formulate guidelines for the development of new geometries. The solid elements of the static mixer should: (a) provide restrictions to the flow; (b) deflect the flow; (c) be sequentially rotated around the flow direction to provide symmetry; (d) extend from the center of the pipe to the vicinity of the walls to avoid short-circuiting; and (e) distribute and remix the flow. Based on these guidelines, two improved mixer designs were developed: the DS A-I mixer has a good mixing efficiency and an acceptable pressure drop; the Fins 35 degrees mixer is more efficient and compact, but requires a larger pressure drop. Their performance indicates that their use is possible on industrial applications.

Variation of wood density and relationship with the tree-ring width of mahogany trees, Swietenia macrophylla, from Amazonian tropical forest of Peru

Mahogany trees, Swietenia macrophylla, occur in open rainforest, semi deciduous and deciduous and dense rainforest of Peruvian Amazonian tropical forest. They occur, preferentially, in areas with a defined dry season, with typical phenology and seasonal variation activity, forming distinct tree-rings. The present work had as aim to determine the wood density radial variation of 14 mahogany trees, of two populations of the Peruvian Amazonian tropical forest, through the X-ray densitometry and to evaluate their application as methodology, compared to the classic method of measurement table, for the determination of the treering width. The radial wood apparent density of the trees profiles rendered it possible to delimit the areas of juvenile-adult wood and of the heartwood-sapwood, relative to the anatomical structure and chemical composition differences, due to the extractives and the vessels obstruction by tyloses. The mean, minimum and maximum wood apparent density of the mahogany trees for the Populations A and B were of 0.70; 0.29; 1.01 g.cm(-3) and 0.81; 0.29; 1.19 g.cm(-3), respectively. The analysis of the variance and mean test indicate differences of mean wood density among the mahogany trees of each population, probably due to the age of the trees. There was no correlation between mean wood density of mahogany trees among the two populations, as well as, between the tree-ring width and the respective mean density. The X-ray densitometry technique is an important tool in the evaluation of the radial variation of wood apparent density and the delimitation of tree-ring boundaries, with correlations of 0.94 and 0.93 in relation to measurement table, for each sampled population.

Modeling soil organic carbon dynamics in Oxisols of Ibiruba (Brazil) with the Century Model

introduction of conservation practices in degraded agricultural land will generally recuperate soil quality, especially by increasing soil organic matter. This aspect of soil organic C (SOC) dynamics under distinct cropping and management systems can be conveniently analyzed with ecosystem models such as the Century Model. In this study, Century was used to simulate SOC stocks in farm fields of the Ibiruba region of north central Rio Grande do Sul state in Southern Brazil. The region, where soils are predominantly Oxisols, was originally covered with subtropical woodlands and grasslands. SOC dynamics was simulated with a general scenario developed with historical data on soil management and cropping systems beginning with the onset of agriculture in 1900. From 1993 to 2050, two contrasting scenarios based on no-tillage soil management were established: the status quo scenario, with crops and agricultural inputs as currently practiced in the region and the high biomass scenario with increased frequency of corn in the cropping system, resulting in about 80% higher biomass addition to soils. Century simulations were in close agreement with SOC stocks measured in 2005 in the Oxisols with finer texture surface horizon originally under woodlands. However, simulations in the Oxisols with loamy surface horizon under woodlands and in the grassland soils were not as accurate. SOC stock decreased from 44% to 50% in fields originally under woodland and from 20% to 27% in fields under grasslands with the introduction of intensive annual grain crops with intensive tillage and harrowing operations. The adoption of conservation practices in the 1980s led to a stabilization of SOC stocks followed by a partial recovery of native stocks. Simulations to 2050 indicate that maintaining status quo would allow SOC stocks to recover from 81% to 86% of the native stocks under woodland and from 80% to 91 % of the native stocks under grasslands. Adoption of a high biomass scenario would result in stocks from 75% to 95% of the original stocks under woodlands and from 89% to 102% in the grasslands by 2050. These simulations outcomes underline the importance of cropping system yielding higher biomass to further increase SOC content in these Oxisols. This application of the Century Model could reproduce general trends of SOC loss and recovery in the Oxisols of the Ibiruba region. Additional calibration and validation should be conducted before extensive usage of Century as a support tool for soil carbon sequestration projects in this and other regions can be recommended. (C) 2009 Elsevier B.V. All rights reserved.

Letters and cities: reading the urban environment with the help of perception theories

When wandering around a city such as Sao Paulo, we are surrounded by letters, numbers and symbols. These elements form part of an environment full of signs in many shapes and sizes that compete for our attention. Our perception of these elements contributes towards our spatial guidance and sense of place. The idea of `reading` the city, or urban environment, was introduced by Kevin Lynch, for whom reading the urban structure follows on from recognizing or identifying its numerous visual elements, not necessarily verbal ones. Beginning with a brief bibliographic review of perception theories, this article combines concepts from environmental psychology with concerns brought up by the fields of information design and epigraphy studies, setting out the basis of a methodological proposal for the study of typography and lettering in the urban environment.

Biomarkers of metabolic syndrome and its relationship with the zinc nutritional status in obese women

Introduction: Obesity is a chronic disease that induces risk factors for metabolic syndrome and, is associated with disturbances in the metabolism of the zinc. Therefore, the aim of this study was to investigate the existence of relationship between the biomarkers of metabolic syndrome and the zinc nutricional status in obese women. Method: Seventy-three premenopausal women, aged between 20 and 50 years, were divided into two groups: case group, composed of obese (n = 37) and control group, composed of no obese (n = 36). The assessment of the body mass index and waist circumference were carried out using anthropometric measurements. The plasmatic and erythrocytary zinc were analyzed by method atomic absorption spectrophotometry (lambda=213.9 nm). Results: In the study, body mass index and waist circumference were higher in obese women than control group (p < 0.05). The mean plasmatic zinc was 72.2 +/- 9.0 mu g/dl in obese women and 73.4 +/- 8.5 mu g/dl in control group (p > 0.05). The mean erythrocytary zinc was 36.4 +/- 15.0 mu g/gHb and 45.4 +/- 14.3 mu g/gHb in the obese and controls, respectively (p < 0.05). Regression analysis showed that the body mass index (t=-2.85) and waist circumference (t=-2.37) have a negative relationship only with the erythrocytary zinc (R(2)=0.32, p < 0.05). Conclusions: The study shows that there are alterations in biochemical parameters of zinc in obese women, with low zinc concentrations in erythrocytes. Regression analysis demonstrates that the erythrocytary zinc is influenced by biomarkers of the metabolic syndrome, presenting an inverse relationship with the waist circumference and body mass index.

Effects of margarines and butter consumption on lipid profiles, inflammation markers and lipid transfer to HDL particles in free-living subjects with the metabolic syndrome

Objective: Our purpose was to examine the effects of daily servings of butter, no-trans-fat margarine and plant sterol margarine, within recommended amounts, on plasma lipids, apolipoproteins (Apos), biomarkers of inflammation and endothelial dysfunction, and on the transfer of lipids to HDL particles in free-living subjects with the metabolic syndrome. Methods: This was a randomized, single-blind study where 53 metabolic syndrome subjects (62% women, mean age 54 years) received isocaloric servings of butter, no-trans-fat margarine or plant sterol margarine in addition to their usual diets for 5 weeks. The main outcome measures were plasma lipids, Apo, inflammatory and endothelial dysfunction markers (CRP, IL-6, CD40L or E-selectin), small dense LDL cholesterol concentrations and in vitro radioactive lipid transfer from cholesterol-rich emulsions to HDL. Difference among groups was evaluated by analysis of variance. Results: There was a significant reduction in Apo-B (-10.4 %, P = 0.043) and in the Apo-B/Apo-A-1 ratio (-11.1%, P = 0.034) with plant sterol margarine. No changes in plasma lipids were noticed with butter and no-trans-fat margarine. Transfer rates of lipids to HDL were reduced in the no-trans-fat margarine group: triglycerides -42.0%, (P<0.001 vs butter and sterol margarine) and free cholesterol -16.2% (P = 0.006 vs sterol margarine). No significant effects were noted on the concentrations of inflammatory and endothelial dysfunction markers among the groups. Conclusions: In free-living subjects with the metabolic syndrome consumption of plant sterol and no-trans-fat margarines within recommended amounts reduced, respectively, Apo-B concentrations and the ability of HDL to accept lipids. European Journal of Clinical Nutrition (2010) 64, 1141-1149; doi:10.1038/ejcn.2010.122; published online 21 July 2010

Intrinsic Dissolution as a Tool for Evaluating Drug Solubility in Accordance with the Biopharmaceutics Classification System

The Biopharmaceutics Classification System (BCS) is a tool that was created to categorize drugs into different groups according to their solubility and permeability characteristics. Through a combination of these factors and physiological parameters, it is possible to understand the absorption behavior of a drug in the gastrointestinal tract, thus contributing to cost and time reductions in drug development, as well as reducing exposure of human subjects during in vivo trials. Solubility is attained by determining the equilibrium under conditions of physiological pH, while different methods may be employed for evaluating permeability. On the other hand, the intrinsic dissolution rate (IDR), which is defined as the rate of dissolution of a pure substance under constant temperature, pH, and surface area conditions, among others, may present greater correlation to the in vivo dissolution dynamic than the solubility test. The purpose of this work is to discuss the intrinsic dissolution test as a tool for determining the solubility of drugs within the scope of the Biopharmaceutics Classification System (BCS).

Comparison of the Salmonella/Microsome Microsuspension Assay with the new Microplate Fluctuation Protocol for Testing the Mutagenicity of Environmental Samples

The objective of this study was to compare the responses of the Salmonella/microsome microsuspension assay with the new microplate fluctuation protocol (MPF) for the evaluation of the mutagenic activity of environmental samples. Organic extracts of total particulate atmospheric air samples, surface waters, and effluents were tested in dose-response experiments. The assays were performed with strain TA98 in the absence and presence of S9 mix. Both protocols produced similar results, despite the fact that the maximum score of the MPF is limited to 48 wells, whereas in the regular plate assay it is possible to count up to 1,500 colonies using an automatic counter. Similar sensitivities based on the lowest dose that resulted in a positive response were obtained for both assays. The MPF procedure is less laborious (e.g., all-liquid format, use of multi-channel pipettors) and allows for automation of the pipetting and dispensing steps, thus, reducing time of the analysis which is particularly important in environmental quality monitoring programs or in effect-directed analysis. The results show that the MPF procedure is a promising tool to test environmental samples for mutagenic activity. Environ. Mol. Mutagen. 51:31-38, 2010. (C) 2009 Wiley-Liss, Inc.

Photoinduced Nitric Oxide and Singlet Oxygen Release from ZnPC Liposome Vehicle Associated with the Nitrosyl Ruthenium Complex: Synergistic Effects in Photodynamic Therapy Application

Under continuous photolysis at 675 nm, liposomal zinc phthalocyanine associated with nitrosyl ruthenium complex [Ru(NH.NHq)(tpy)NO](3+) showed the detection and quantification of nitric oxide (NO) and singlet oxygen ((1)O(2)) release. Photophysical and photochemical results demonstrated that the interaction between the nitrosyl ruthenium complex and the photosensitizer can enable an electron transfer process from the photosensitizer to the nitrosyl ruthenium complex which leads to NO release. Synergistic action of both photosensitizers and the nitrosyl ruthenium complex results in the production of reactive oxygen species and reactive nitrogen species, which is a potent oxidizing agent to many biological tissues, in particular neoplastic cells.

Alterations triggered by steroid gonadal hormones in triglycerides and the cellular immune response of Calomys callosus infected with the Y strain of Trypanosoma cruzi

Calomys callosus is a wild rodent found naturally infected with different Trypanosoma cruzi strains. In the work described here, groups of male and female C callosus were subjected to orchiectomy, ovariectomy and sham operation. One month after surgery, animals were inoculated intraperitoneally (i.p.) with 4 x 10(4) blood trypomastigotes of the ""Y"" strain of T. cruzi. Parasitemia, triglycerides, nitric oxide (NO) and concanavalin A (ConA)-induced proliferation were evaluated. Parasitemia during the course of infection was significantly higher in infected and sham operated animals as compared to infected orchiectomized animals. The opposite was observed in the ovariectomized and infected group. Orchiectomized and infected animals displayed elevated triglyceride levels, as well as a more vigorous immune response, with higher splenocyte proliferation and elevated concentrations of NO. Ovariectomy resulted in an impaired immune response, as observed by a reduction of splenocyte proliferation and NO concentration. The results suggest a pivotal role for gonadal hormones in the modulation of triglyceride levels and the magnitude of the immune response during the acute phase of T. cruzi infection. (C) 2008 Published by Elsevier B.V.