Biofuels and Sustainable Energy Development in Brazil

Through the assessment of three decades of the Alcohol Program in Brazil, the paper shows that adequate public policies regarding biomass production can deliver direct benefits like energy security improvement, foreign exchange savings, and local employment generation, reduced urban air pollution and avoided CO(2) emissions. Moreover, the paper shows that Brazilian produced ethanol has faced economies of scale, technical progress and productivity gains and is no longer dependent on subsidies to be competitive. The paper also examines the potential in Brazil for fostering other biofuels, namely biodiesel obtained from vegetable oils, as well as their implications on sustainable energy development. (C) 2011 Elsevier Ltd. All rights reserved.

Dissolved organic carbon in rainwater from areas heavily impacted by sugar cane burning

This work reports on rainwater dissolved organic carbon (DOC) from Ribeirao Preto (RP) and Araraquara over a period of 3 years. The economies of these two cities, located in Sao Paulo state (Brazil), are based on agriculture and related industries, and the region is strongly impacted by the burning of sugar cane foliage before harvesting. Highest DOC concentrations were obtained when air masses traversed sugar cane fields burned on the same day as the rain event. Significant increases in the DOC volume weighted means (VWM) during the harvest period, for both sites, and a good linear correlation (r=0.83) between DOC and K (a biomass burning marker) suggest that regional scale organic carbon emissions prevail over long-range transport. The DOC VWMs and standard deviations were 272 +/- 22 mu mol L-1 (n=193) and 338 +/- 40 mu mol L-1 (n=80) for RP and Araraquara, respectively, values which are at least two times higher than those reported for other regions influenced by biomass burning, such as the Amazon. These high DOC levels are discussed in terms of agricultural activities, particularly the large usage of biogenic fuels in Brazil, as well as the analytical method used in this work, which includes volatile organic carbon when reporting DOC values. Taking into account rainfall volume, estimated annual rainwater DOC fluxes for RP (4.8 g C m(-2) yr(-1)) and Araraquara (5.4 g C m(-2) yr(-1)) were close to that previously found for the Amazon region (4.8 g C m(-2) yr(-1)). This work also discusses whether previous calculations of the global rainwater carbon flux may have been underestimated, since they did not consider large inputs from biomass combustion sources, and suffered from a possible analytical bias. (c) 2008 Elsevier Ltd. All rights reserved.

Critical applications of SW 846 US EPA methods to evaluation of marine samples quality

Technical evaluation of analytical data is of extreme relevance considering it can be used for comparisons with environmental quality standards and decision-making as related to the management of disposal of dredged sediments and the evaluation of salt and brackish water quality in accordance with CONAMA 357/05 Resolution. It is, therefore, essential that the project manager discusses the environmental agency's technical requirements with the laboratory contracted for the follow-up of the analysis underway and even with a view to possible re-analysis when anomalous data are identified. The main technical requirements are: (1) method quantitation limits (QLs) should fall below environmental standards; (2) analyses should be carried out in laboratories whose analytical scope is accredited by the National Institute of Metrology (INMETRO) or qualified or accepted by a licensing agency; (3) chain of custody should be provided in order to ensure sample traceability; (4) control charts should be provided to prove method performance; (5) certified reference material analysis or, if that is not available, matrix spike analysis, should be undertaken and (6) chromatograms should be included in the analytical report. Within this context and with a view to helping environmental managers in analytical report evaluation, this work has as objectives the discussion of the limitations of the application of SW 846 US EPA methods to marine samples, the consequences of having data based on method detection limits (MDL) and not sample quantitation limits (SQL), and present possible modifications of the principal method applied by laboratories in order to comply with environmental quality standards.

Trypanocidal activity of Piper arboreum and Piper tuberculatum (Piperaceae)

In the scope of our ongoing research on bioactive agents from Brazilian flora, twenty-four extracts and fractions obtained from Piper arboreum Aub. and Piper tuberculatum Jacq. (Piperaceae) were screened for trypanocidal activity by using MTT colorimetric assay. The strongest activity was found in hexane fractions from the leaves of P. arboreum (IC50= 13.3 µg/ mL) and P. tuberculatum (IC50 = 17.2 µg/mL). Hexane fractions of the fruits of P. tuberculatum and P. arboreum showed potent toxic effects on epimastigote forms of Trypanosoma cruzi, with values of IC50 (µg/mL) of 32.2 and 31.3, respectively. Additionally, the phytochemical study of the hexane fraction of P. arboreum leaves furnished two pyrrolidine amides, piperyline (1) and 4,5-dihydropiperyline (2), which could be responsible, at least in part for the observed antiprotozoal activity.

The non-equilibrium nature of culinary evolution

Food is an essential part of civilization, with a scope that ranges from the biological to the economic and cultural levels. Here, we study the statistics of ingredients and recipes taken from Brazilian, British, French and Medieval cookery books. We find universal distributions with scale invariant behaviour. We propose a copy-mutate process to model culinary evolution that fits our empirical data very well. We find a cultural 'founder effect' produced by the non-equilibrium dynamics of the model. Both the invariant and idiosyncratic aspects of culture are accounted for by our model, which may have applications in other kinds of evolutionary processes.

Differential expression of HIF-1 alpha in CD44(+)CD24(-/) (low) breast ductal carcinomas

Background: Cancer stem cell (CSC) hypothesis postulates that tumors are maintained by a self-renewing CSC population that is also capable of differentiating into non-self-renewing cell populations that constitute the bulk of tumor. Stem cells renewal and differentiation can be directly influenced by the oxygen levels of determined tissues, probably by the reduction of oxidative DNA damage in hypoxic regions, thus leading to a friendlier microenvironment, regarding to clonal expansion and for resistance to chemotherapeutic regimens. Furthermore, there have been strong data indicating a pivotal role of hypoxic niche in cancer stem cells development. There are evidence that hypoxia could drive the maintenance of CSC, via HIF-1 alpha expression, but it still to be determined whether hypoxia markers are expressed in breast tumors presenting CD44(+)CD24(-/low) immunophenotype. Methods: Immunohistochemical analysis of CD44(+)CD24(-/low) expression and its relationship with hypoxia markers and clinical outcome were evaluated in 253 samples of breast ductal carcinomas. Double-immunolabeling was performed using EnVision Doublestain System (Dako, Carpinteria, CA, USA). Slides were then scanned into high-resolution images using Aperio ScanScope XT and then, visualized in the software Image Scope (Aperio, Vista, CA, USA). Results: In univariate analysis, CD44(+)CD24(-/low) expression showed association with death due to breast cancer (p = 0.035). Breast tumors expressing CD44(+)CD24(-/low) immunophenotype showed relationship with HIF-1 alpha (p = 0.039) and negativity for HER-2 (p = 0.013). Conclusion: Considering that there are strong evidences that the fraction of a tumour considered to be cancer stem cells is plastic depending upon microenvironmental signals, our findings provide further evidence that hypoxia might be related to the worse prognosis found in CD44(+)CD24(-/low) positive breast tumors.

Antimicrobial activity of Piper arboreum and Piper tuberculatum (Piperaceae) against opportunistic yeasts

In the scope of our ongoing research on bioactive agents from natural sources, 24 extracts and fractions obtained from Piper arboreum Aub. and Piper tuberculatum Jacq. ( Piperaceae) were screened for antifungal activity by using broth microdilution method. The current investigation reveals that P. arboreum extracts and fractions were more effective against Candida krusei and Candida parapsilosis than Cryptococcus neoformans. The growth of Candida albicans was weakly affected by all the tested extracts and fractions. The strongest effects were observed for hexane and ethyl acetate fractions from leaves of P. arboreum, with MIC values ( in mu g/ml) of 15.6 and 31.2 mu g/ml against C. krusei, respectively. Additionally, phytochemical investigation of the hexane fraction of P. arboreum leaves furnished 3 pyrrolidine amides; piperyline, 4,5-dihydropiperyline and tetrahydropiperyline, which could be responsible, at least in part for the observed antifungal activity. The most active compound, tetrahydropiperyline, displayed MIC values of 15.6 mu g/ml against C. krusei, C. parapsilosis and C. neoformans.

Neutron Activation Analysis: A Primary (Ratio) Method to Determine SI-Traceable Values of Element Content in Complex Samples

The metrological principles of neutron activation analysis are discussed. It has been demonstrated that this method can provide elemental amount of substance with values fully traceable to the SI. The method has been used by several laboratories worldwide in a number of CCQM key comparisons - interlaboratory comparison tests at the highest metrological level - supplying results equivalent to values from other methods for elemental or isotopic analysis in complex samples without the need to perform chemical destruction and dissolution of these samples. The CCOM accepted therefore in April 2007 the claim that neutron activation analysis should have the similar status as the methods originally listed by the CCOM as `primary methods of measurement`. Analytical characteristics and scope of application are given.

Support Tool to the Validation Process of Functional Requirements

The activity of validating identified requirements for an information system helps to improve the quality of a requirements specification document and, consequently, the success of a project. Although various different support tools to requirements engineering exist in the market, there is still a lack of automated support for validation activity. In this context, the purpose of this paper is to make up for that deficiency, with the use of an automated tool, to provide the resources for the execution of an adequate validation activity. The contribution of this study is to enable an agile and effective follow-up of the scope established for the requirements, so as to lead the development to a solution which would satisfy the real necessities of the users, as well as to supply project managers with relevant information about the maturity of the analysts involved in requirements specification.

Design and Characterization of a Biomimetic Piezoelectric Pump Inspired on Group Fish Swimming Effect

Flow pumps are important tools in several engineering areas, such as in the fields of bioengineering and thermal management solutions for electronic devices. Nowadays, many of the new flow pump principles are based on the use of piezoelectric actuators, which present some advantages such as miniaturization potential and lower noise generation. In previous work, authors presented a study of a novel pump configuration based on placing an oscillating bimorph piezoelectric actuator in water to generate flow. It was concluded that this oscillatory behavior (such as fish swimming) yields vortex interaction, generating flow rate due to the action and reaction principle. Thus, following this idea the objective of this work is to explore this oscillatory principle by studying the interaction among generated vortex from two bimorph piezoelectric actuators oscillating inside the same pump channel, which is similar to the interaction of vortex generated by frontal fish and posterior ones when they swim together in a group formation. It is shown that parallel-series configurations of bimorph piezoelectric actuators inside the same pump channel provide higher flow rates and pressure for liquid pumping than simple parallel-series arrangements of corresponding single piezoelectric pumps, respectively. The scope of this work includes structural simulations of bimorph piezoelectric actuators, fluid flow simulations, and prototype construction for result validation.

Optimizing model predictive control of an industrial distillation column

The main scope of this work is the implementation of an MPC that integrates the control and the economic optimization of the system. The two problems are solved simultaneously through the modification of the control cost function that includes an additional term related to the economic objective. The optimizing MPC is based on a quadratic program (QP) as the conventional MPC and can be solved with the available QP solvers. The method was implemented in an industrial distillation system, and the results show that the approach is efficient and can be used, in several practical cases. (C) 2011 Elsevier Ltd. All rights reserved.

Nickel adsorption in two Oxisols and an Alfisol as affected by pH, nature of the electrolyte, and ionic strength of soil solution

Background, aim, and scope The retention of potentially toxic metals in highly weathered soils can follow different pathways that variably affect their mobility and availability in the soil-water-plant system. This study aimed to evaluate the effects of pH, nature of electrolyte, and ionic strength of the solution on nickel (Ni) adsorption by two acric Oxisols and a less weathered Alfisol. Materials and methods The effect of pH on Ni adsorption was evaluated in surface and subsurface samples from a clayey textured Anionic `Rhodic` Acrudox ( RA), a sandy-clayey textured Anionic `Xantic` Acrudox (XA), and a heavy clayey textured Rhodic Kandiudalf (RK). All soil samples were equilibrated with the same concentration of Ni solution (5.0 mg L(-1)) and two electrolyte solutions (CaCl(2) or NaCl) with different ionic strengths (IS) (1.0, 0.1 and 0.01 mol L(-1)). The pH of each sample set varied from 3 to 10 in order to obtain sorption envelopes. Results and discussion Ni adsorption increased as the pH increased, reaching its maximum of nearly pH 6. The adsorption was highest in Alfisol, followed by RA and XA. Competition between Ni(2+) and Ca(2+) was higher than that between Ni(2+) and Na(+) in all soil samples, as shown by the higher percentage of Ni adsorption at pH 5. At pH values below the intersection point of the three ionic strength curves (zero point of salt effect), Ni adsorption was generally higher in the more concentrated solution (highest IS), probably due to the neutralization of positive charges of soil colloids by Cl(-) ions and consequent adsorption of Ni(2+). Above this point, Ni adsorption was higher in the more diluted solution (lowest ionic strength), due to the higher negative potential at the colloid surfaces and the lower ionic competition for exchange sites in soil colloids. Conclusions The effect of ionic strength was lower in the Oxisols than in the Alfisol. The main mechanism that controlled Ni adsorption in the soils was the ionic exchange, since the adsorption of ionic species varied according to the variation of pH values. The ionic competition revealed the importance of electrolyte composition and ionic strength on Ni adsorption in soils from the humid tropics. Recommendations and perspectives The presence of NaCl or CaCl(2) in different ionic strengths affects the availability of heavy metals in contaminated soils. Therefore, the study of heavy metal dynamics in highly weathered soils must consider this behavior, especially in soils with large amounts of acric components.

Biogas production and valorization by means of a two-step biological process

The scope of this research work was to investigate biogas production and purification by a two-step bench-scale biological system, consisting of fed-batch pulse-feeding anaerobic digestion of mixed sludge, followed by methane enrichment of biogas by the use of the cyanobacterium Arthrospira platensis. The composition of biogas was nearly constant, and methane and carbon dioxide percentages ranged between 70.5-76.0% and 13.2-19.5%, respectively. Biogas yield reached a maximum value (about 0.4 m(biogas)(3)/kgCOD(i)) at 50 days-retention time and then gradually decreased with a decrease in the retention time. Biogas CO(2) was then used as a carbon source for A. platensis cultivation either under batch or fed-batch conditions. The mean cell productivity of fed-batch cultivation was about 15% higher than that observed during the last batch phase (0.035 +/- 0.006 g(DM)/L/d), likely due to the occurrence of some shading effect under batch growth conditions. The data of carbon dioxide removal from biogas revealed the existence of a linear relationship between the rates of A. platensis growth and carbon dioxide removal from biogas and allowed calculating carbon utilization efficiency for biomass production of almost 95%. (C) 2009 Elsevier Ltd. All rights reserved.

Synthesis of (2S)-isopropyl-5-alkynylpyrimidin-2-ones: precursors of beta-aminoacids

The efficient palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of (2S)-isopropyl-5-iodo-2,3-dihydro-4(H)-pyrimidin-4-one with, arylethynyl-, heteroarylethynyl-, and alkylethynyltrifluoroborate salts is reported. The standard protocol was evaluated and optimized in order to gain access to suitable precursors of enantiopure 2-substituted beta-amino acids. The scope and limitations of this methodology are discussed. (C) 2010 Elsevier Ltd. All rights reserved.

Spatial aspects of trade liberalization in Colombia: A general equilibrium approach

This paper offers some preliminary steps in the marriage of some of the theoretical foundations of new economic geography with spatial computable general equilibrium models. Modelling the spatial economy of Colombia using the traditional assumptions of computable general equilibrium (CGE) models makes little sense when one territorial unit, Bogota, accounts for over one quarter of GDP and where transportation costs are high and accessibility low compared to European or North American standards. Hence, handling market imperfections becomes imperative as does the need to address internal spatial issues from the perspective of Colombia`s increasing involvement with external markets. The paper builds on the Centro de Estudios de Economia Regional (CEER) model, a spatial CGE model of the Colombian economy; non-constant returns and non-iceberg transportation costs are introduced and some simulation exercises carried out. The results confirm the asymmetric impacts that trade liberalization has on a spatial economy in which one region, Bogota, is able to more fully exploit scale economies vis--vis the rest of Colombia. The analysis also reveals the importance of different hypotheses on factor mobility and the role of price effects to better understand the consequences of trade opening in a developing economy.