Effect of pH and oxalic acid on the reduction of Fe(3+) by a biomimetic chelator and on Fe(3+) desorption/adsorption onto wood: Implications for brown-rot decay

Fenton reaction is thought to play an important role in wood degradation by brown-rot fungi. In this context, the effect of oxalic acid and pH on iron reduction by a biomimetic fungal chelator and on the adsorption/desorption of iron to/from wood was investigated. The results presented in this work indicate that at pH 2.0 and 4.5 and in the presence of oxalic acid, the phenolate chelator 2,3-dihydroxybenzoic acid (2,3-DHBA) is capable of reducing ferric iron only when the iron is complexed with oxalate to form Fe mono-oxalate (Fe(C(2)O(4))(+)). Within the pH range tested in this work, this complex formation occurs when the oxalate:Fe(3+) molar ratio is less than 20 (pH 2.0) or less than 10 (pH 4.5). When aqueous ferric iron was passed through a column packed with milled red spruce (Picea rubens) wood equilibrated at pH 2.0 and 4.5. it was observed that ferric iron binds to wood at pH 4.5 but not at pH 2.0, and the bound iron could then be released by application of oxalic acid at pH 4.5. The release of bound iron was dependent on the amount of oxalic acid applied in the column. When the amount of oxalate was at least 20-fold greater than the amount of iron bound to the wood, all bound iron was released. When Fe-oxalate complexes were applied to the milled wood column equilibrated in the pH range of 2-4.5, iron from Fe-oxalate complexes was bound to the wood only when the pH was 3.6 or higher and the oxalate:Fe(3+) molar ratio was less than 10. When 2,3-DHBA was evaluated for its ability to release iron bound to the milled wood, it was found that 2,3-DHBA possessed a greater affinity for ferric iron than the wood as 2,3-DHBA was capable of releasing the ferric iron bound to the wood in the pH range 3.6-5.5. These results further the understanding of the mechanisms employed by brown-rot fungi in wood biodegradation processes. (C) 2009 Elsevier Ltd. All rights reserved.

Noise reduction in biomedical speech signal processing based on time and frequency Kalman filtering combined with spectral subtraction

The goal of this paper is to study and propose a new technique for noise reduction used during the reconstruction of speech signals, particularly for biomedical applications. The proposed method is based on Kalman filtering in the time domain combined with spectral subtraction. Comparison with discrete Kalman filter in the frequency domain shows better performance of the proposed technique. The performance is evaluated by using the segmental signal-to-noise ratio and the Itakura-Saito`s distance. Results have shown that Kalman`s filter in time combined with spectral subtraction is more robust and efficient, improving the Itakura-Saito`s distance by up to four times. (C) 2007 Elsevier Ltd. All rights reserved.

Positioning of Deadeners for Vibration Reduction in Vehicle Roof Using Embedded Sensitivity

The noise, vibration and harshness (NVH) performance of passenger vehicles strongly depends on the fluid-structure interaction between the air in the vehicle cavity and the sheet metal structure of the vehicle. Most of the noise and vibration problems related to this interaction come from resonance peaks of the sheet metal, which are excited by external forces (road, engine, and wind). A reduction in these resonance peaks can be achieved by applying bitumen damping layers, also called deadeners, in the sheet metal. The problem is where these deadeners shall be fixed, which is usually done in a trial-and-error basis. In this work, one proposes the use of embedded sensitivity to locate the deadeners in the sheet metal of the vehicle, more specifically in the vehicle roof. Experimental frequency response functions (FRFs) of the roof are obtained and the data are processed by adopting the embedded sensitivity method, thus obtaining the sensitivity of the resonance peaks on the local increase in damping due to the deadeners. As a result, by examining the sensitivity functions, one can find the optimum location of the deadeners that maximize their effect in reducing the resonance peaks of interest. After locating the deadeners in the optimum positions, it was possible to verify a strong reduction in resonance peaks of the vehicle roof, thus showing the efficiency of the procedure. The main advantage of this procedure is that it only requires FRF measurements of the vehicle in its original state not needing any previous modification of the vehicle structure to find the sensitivity functions. [DOI: 10.1115/1.4000769]

Post-treatment of effluents from the sulfate reduction process by anaerobic sequencing batch biofilm reactors

The main objective of this research was to evaluate the potential use of a bench-scale anaerobic sequencing batch biofilm reactor (ASBBR) containing mineral coal as inert support for removal Of Sulfide and organic matter effluents from an ASBBR (1.2 m(3)) utilized for treatment of sulfate-rich wastewater. The cycle time was 48 h, including the steps of feeding (2 h), reaction with continuous liquid recirculation (44 h) and discharge (2 h). COD removal efficiency was up to 90% and the effluents total sulfide concentrations (H(2)S, HS(-), S(2-)) remained in the range of 1.5 to 7.5 mg.l(-1) during the 50 days of operation (25 cycles). The un-ionized Sulfide and ionized sulfides were converted by biological process to elemental sulfur (S(0)) under oxygen limited conditions. The results obtained in the bench-scale reactor were used to design an ASBBR in pilot scale for use in post-treatment to achieve the emission standards (sulfide and COD) for sulfate reduction. The pilot-scale reactor, with a total volume of 0.43 m(3), the COD and total sulfide removal achieved 88% and 57%, respectively, for a cycle time of 48 h (70 days of operation or 35 cycles).

Tiering strategic environmental assessment and project environmental impact assessment in highway planning in Sao Paulo, Brazil

Constructing highways in dense urban areas is always a challenge. In Sao Paulo Metropolitan Region, heavy truck traffic contributes to clog streets and expressways alike. As part of the traffic neither originates nor head to the region, a peripheral highway has been proposed to reduce traffic problems. This project called Rodoanel, is an expressway approximately 175 km long. The fact that the projected south and north sections would cross catchments that supply most of the metropolis water demand was strongly disputed and made the environmental permitting process particularly difficult. The agency in charge commissioned a strategic environmental assessment (SEA) of a revamped project, and called it the Rodoanel Programme. However, the SEA report failed to satisfactorily take account of significant strategic issues. Among these, the highway potential effect of inducing urban sprawl over water protection zones is the most critical issue, as it emerged later as a hurdle to project licensing. Conclusion is that, particularly where no agreed-upon framework for SEA exists, when vertical tiering with downstream project EIA is sought, then a careful scoping of strategic issues is more than necessary. If an agreement on `what is strategic` is not reached and not recognized by influential stakeholders, then the unsettled conflicts will be transferred to project EIA. In such a context, SEA will have added another loop to the usually long road to project approval. (c) 2008 Elsevier Inc. All rights reserved.

Reduction of Chromium from Al(2)O(3)-CaO-SiO(2)-CrOx Slags by Carbon Dissolved in Liquid Iron

The goal of this work is to investigate the reduction of chromium from a quaternary slag by carbon dissolved in liquid steel. Laboratory scale experiments were conducted to study the reduction of chromium oxides in the slag by carbon dissolved in the melt. These experiments were made under different conditions of slag basicity and amount of added carbon. Thermodynamic calculations based on Double Sublattice model were applied using the commercial software Thermo-Calc, with the IRSID database. The results obtained showed good correlation with practical and calculated results, making it possible to predict equilibrium conditions of the system and to determine the activities of chromium oxides in the slag.

Study on Iron Formation During the Carbothermic Reduction of Iron Ore in Carbon Composite Pellets in the Temperature Range 1423 K-1623 K

The aim of this work is to study the reaction rate and the morphology of the intermediary reaction products during reduction of iron ore, when iron ore and carbonaceous material are agglomerated together as a carbon composite iron ore pellet. The reaction was performed at high temperatures, and in order to avoid heat transfer constraints small size samples were used. The carbonaceous materials employed were coke breeze and pure graphite. Portland cement was employed as a binder, and the pellets diameter was 5.2 mm. The experimental technique involved the measurement of the pellets weight loss, as well as interruption of the reaction at different stages in order to submit the partially reduced pellet to scanning electron microscopy. It has been observed that above 1523 K there is the formation of liquid slag inside the pellets, which partially dissolves iron oxides. The apparent activation energies obtained were 255 kJ/mol for coke breeze containing pellets, and 230 kJ/mol for those pellets containing graphite. It was possible to avoid heat transfer control of the reaction rate up to 1523 K by employing small composite pellets.

Influence of Temperature, Basiscity and Particle Size on MnO Reduction

The aim of this work is to study MnO reduction by solid carbon. The influence of size of carbon particles, slag basicity, and bath temperature on MnO reduction was investigated. Fine Manganese ore particles were used as a source of MnO. Three sizes of carbon particles were used; 0.230 mm, 0.162 mm and 0.057 mm, binary basicity of 1 and 1.5 and temperatures of 1550, 1550 and 1600 degrees C. Curves were drawn for Mn content in the bath as a function of time and temperature for the several studied parameters. The MnO reduction rates were determined using these data. [doi:10.2320/matertrans.M2011007]

Strategic alignment and performance: Brazilian companies in the medical diagnostics sector

A gap has been identified in the literature on the diagnosis and monitoring of the degree of strategic alignment. The main objective of this article is to diagnose and analyze the strategic alignment profile using the alignment diagnostic profile (ADP) tool, which enables organizations to show visually their degree of strategic alignment. The methodological approach adopted is multiple-case studies, which were conducted at five organizations in the medical diagnostics sector. The results indicate that the ADP enables organizations to understand the steps required to improve their level of alignment and to identify and locate gaps and conflicts.

Optimization and Complexity Reduction of Switch-Reconfigured Antennas Using Graph Models

This letter addresses the optimization and complexity reduction of switch-reconfigured antennas. A new optimization technique based on graph models is investigated. This technique is used to minimize the redundancy in a reconfigurable antenna structure and reduce its complexity. A graph modeling rule for switch-reconfigured antennas is proposed, and examples are presented.

OPTIMIZATION OF THE TREATMENT PROCESS FOR RESIDUAL WATER FROM A BEER INDUSTRY

The optimization of the treatment process for residual waters from a brewery operating under the modality of an anaerobic reactor and activated sludge combination was studied in two phases. In the first stage, lasting for six months, the characteristics and parameters of the plant operation were analyzed, wherein a diversion rate of more than 50% to aerobic treatment, the use of two aeration tanks and a high sludge production prevailed. The second stage comprised four months during which the system worked under the proposed operational model, with the aim of improving the treatment: reduction of the diversion rate to 30% and use of only one aeration tank At each stage, TSS, VSS and COD were measured at the entrance and exit of the anaerobic reactor mid the aeration tanks. The results were compared with the corresponding design specifications and the needed conditions were applied to reduce the diversion rate towards the aerobic process through monitoring the volume and concentration of the affluent, while applying the strategic changes in reactor parameters needed to increase its efficiency. A diversion reduction from 53 to 34% was achieved, reducing the sludge discharge generated in the aerobic system from 3670mg TSS/l. with two aeration tanks down to 2947mf TSS/l using one tank keeping the same relation VSS:TSS (0.55) and an efficiency of total removal of 98% in terms of COD.

Mapping the Contemporary Studies on Alliances and Strategic Networks

The competition among the companies depends on the velocity and efficience they can create and commercialize knowledge in a timely and cost-efficient manner. In this context, collaboration emerges as a reaction to the environmental changes. Although strategic alliances and networks have been exploited in the strategic literature for decades, the complexity and continuous usage of these cooperation structures, in a world of growing competition, justify the continuous interest in both themes. This article presents a scanning of the contemporary academic production in strategic alliances and networks, covering the period from January 1997 to august 2007, based on the top five journals accordingly to the journal of Citation Report 2006 in the business and management categories simultaneously. The results point to a retraction in publications about strategic alliances and a significant growth in the area of strategic. networks. The joint view of strategic alliances and networks, cited by some authors a the evolutionary path of study, still did not appear salient. The most cited topics found in the alliance literature are the governance structure, cooperation, knowledge transfer, culture, control, trust, alliance formation,,previous experience, resources, competition and partner selection. The theme network focuses mainly on structure, knowledge transfer and social network, while the joint vision is highly concentrated in: the subjects of alliance formation and the governance choice.

Modeling of transpiration reduction in van Genuchten-Mualem type soils

We derive an analytic expression for the matric flux potential (M) for van Genuchten-Mualem (VGM) type soils which can also be written in terms of a converging infinite series. Considering the first four terms of this series, the accuracy of the approximation was verified by comparing it to values of M estimated by numerical finite difference integration. Using values of the parameters for three soils from different texture classes, the proposed four-term approximation showed an almost perfect match with the numerical solution, except for effective saturations higher than 0.9. Including more terms reduced the discrepancy but also increased the complexity of the equation. The four-term equation can be used for most applications. Cases with special interest in nearly saturated soils should include more terms from the infinite series. A transpiration reduction function for use with the VGM equations is derived by combining the derived expression for M with a root water extraction model. The shape of the resulting reduction function and its dependency on the derivative of the soil hydraulic diffusivity D with respect to the soil water content theta is discussed. Positive and negative values of dD/d theta yield concave and convex or S-shaped reduction functions, respectively. On the basis of three data sets, the hydraulic properties of virtually all soils yield concave reduction curves. Such curves based solely on soil hydraulic properties do not account for the complex interactions between shoot growth, root growth, and water availability.

LEAF AREA REDUCTION IN CORN GROWN IN A TROPICAL REGION OF BRAZIL AND ITS EFFECTS ON AGRONOMIC TRAITS

Global climate change may reduce leaf area in crop plants due to factors such as increasing occurrence of pests and diseases. The aim of this work was to estimate the impact of leaf area reduction on agronomic traits in corn. An experiment simulating leaf area reduction was carried out in a tropical region of Brazil. The agronomic performance of corn plants was evaluated at different percentages of leaf loss. It was observed that leaf area reductions over 41.01% significantly harm yield, mass of 1000 grains, cob density, and stem and root quality Crop improvement programs should take into account the development of genotypes resistant to factors that cause leaf area reduction in tropical crops.

Pleiotropic Effects With Equivalent Low-density Lipoprotein Cholesterol Reduction: Comparative Study Between Simvastatin and Simvastatin/Ezetimibe Coadministration

Background: Coadministration of any statin with ezetimibe is as effective as using high doses of the same statin in the reduction Of tow-density lipoprotein cholesterol (LDL-c). There may be other effects called pleiotropics. Objective: To compare the effectiveness of 2 different treatments that obtain equivalent LDL-c reductions (80 mg of simvastatin, once a clay and coadministration of 10 mg of simvastatin and 10 mg of ezetimibe, once a day) over endothelial function and inflammation. Methods: Twenty-three randomized patients with hypercholesterolemia in a 2 X 2 crossover protocol were Studied. Endothelial function was analyzed by ultrasound assessment of endothelial dependent flow-mediated vasodilation of the brachial artery, and inflammation was estimated by high-sensitivity C-reactive protein (hs-CRP). Results: LDL-c reduction was similar between the 2 treatments with simvastatin/ezetimibe and with simvastatin (P < 0.001); no difference between treatments was found (P = 0.968). Both treatments improved significantly the endothelial function [3.61% with simvastatin/ezetimibe (P = 0.003) and 5.08%. with simvastatin (P < 0.001)]; no difference was found between the 2 treatments (P = 0.291). hs-CRP had a 23% reduction with simvastatin/ezetimibe (P = 0.004) and a 30% reduction with simvastatin alone (P = 0.01), with no significant difference between the 2 treatments (P = 0.380). Conclusion: The 2 forms of treatment presented similar pleiotropic effects: improvement in endothelial function and decrease in hsCRP levels.