Implementation of convective heating in Companhia Siderúrgica Nacional Blast Furnace runners

This paper describes the main characteristics and advantages of convective heating system for refractory lining, compared with conventional heating systems. In addition the main results obtained are presented with its implementation in CSN Blast Furnace #2 and 3 Runners, in terms of cost and equipment availability, as well as the need for ceramic coating to protect the lining against oxidation, arising from excessive air combustion. © 2012 Elsevier Ltd. All rights reserved.

Feasibility of solar heating systems composed of recyclable packaging for low-income rural communities

Solar heaters are an appropriate technology in tropical and sub-tropical climates to heat bath water by solar energy. Low-cost solar heaters meet the demand of low-income rural communities which currently do not have access to this technology. Current research analyzes the economic viability of solar heaters, built with recyclable materials, to reduce electric energy bill. A solar heating system was built consisting of recyclable materials in accordance with the manuals provided by the Secretariat of Environment of the state of Paraná (SEMA). Duration of use of electric showers by families of rural properties was determined to calculate expenses and billing of electricity. Simulation and material costs showed that the system was feasible. Commercial solar heaters could be replaced at a cost of R$ 22.61 per month during 13 months.

Fontes de fibra na alimentação do pacu: desempenho, composição corporal e morfometria intestinal

O objetivo deste estudo foi avaliar os efeitos da utilização de diferentes ingredientes fibrosos nas dietas sobre o desempenho, a composição corporal e a morfometria intestinal de juvenis de pacu. Foram avaliadas cinco dietas isoproteicas (23% de proteína digestível), isoenergéticas (3250kcal de energia digestível/kg) e isofibrosas (9% de fibra bruta), sendo a principal fonte fibrosa de cada constituída por farelo de soja, casca de soja, farelo de girassol e polpa cítrica; esta última em dois níveis de inclusão (30 e 45%). Foram utilizados 300 juvenis de pacu (25,12±0,78 gramas), alojados em 25 aquários (200 litros). Os melhores resultados de crescimento e conversão alimentar foram obtidos com as dietas contendo farelo de soja e farelo de girassol. As dietas contendo casca de soja e polpa cítrica prejudicaram o desempenho dos juvenis de pacu, e o efeito negativo foi acentuado com o aumento da inclusão de polpa cítrica. Além disto, somente nos peixes alimentados com a dieta com 45% de polpa cítrica foi observada diminuição na densidade de vilosidades por área no epitélio intestinal. A partir dos resultados obtidos, pode-se concluir que alguns ingredientes fibrosos podem afetar negativamente o desempenho e as características do epitélio intestinal de juvenis de pacu.

Rapid spot test analysis for the detection of urotropine in pharmaceutical preparations

The widespread falsification and/or adulteration of commercially available pharmaceutical preparations call for reliable methods of drug identification, preferably through selective and rapid sorting color tests that could be undertaken with minimum equipment remote from laboratory facilities. The present work deals with a convenient adaptation and refinement of a spot test devised by Feigl (1966) for urotropine, based on the hydrolytic cleavage of that substance in the presence of sulfuric acid, splitting out formaldehyde which is identified by its color reaction with chromotropic acid. A simple emergency kit was developed for the quick, efficient, inexpensive and easy performance of urotropine tests by semiskilled personnel even in the drugstore laboratory (or office) as well as in a mobile screening operation. It is shown that when the reagents are added according to the recommended sequence a self-heating system is generated, increasing substantially the reactions' rates and the test sensitivity as well. The identification limit found was 25 mug of urotropine, for both solid and liquid samples. The possible interference of 84 substances/materials was investigated. Interference was noted only for methylene blue, acriflavine, Ponceau Red, Bordeaux Red (these dyes are often included in urotropine dosage forms), pyramidone, dipyrone, quinine and tetracycline. A simple procedure for removing most of the interferences is described. Data for 8 commercial dosage forms and results obtained from their analysis are presented.

Análise comparativa da viabilidade econômica da utilização de coletores solar para aquecimento de água

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Desinfecção da água utilizando aquecimento solar

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Otimização de um forno de reaquecimento a óleo - controle de emissões e crédito de carbono

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Metodologia de curvatura de bambu laminado colado (BLAC) para fabricação de mobiliário: diretrizes para o design

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Análise da relação desempenho/custo de alguns coletores solares comerciais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da auto-suficiência energética de reatores anaeróbios no tratamento de esgoto sanitário e água cinza

The anaerobic treatment of sewage is widely employed in Brazil and it is an appreciated way for the treatment of effluents, helping to reduce the environmental impact in rivers. The methane gas obtained from the process can be applied to improve the energetic efficiency of the system, reducing the amount of waste and the cost of the treatment process. This work presents the net energy balance of anaerobic reactors applied to the treatment of sewage. The analysis was performed considering full-scale and laboratory-scale treatment systems. In laboratory scale, the results from three kinds of systems were compared regarding the biological treatment of greywater. Two of them (UASB7 and UASB12) were anaerobic and the other one was a combined anaerobic-aerobic system (UASB7/SBR6). Greywater methanization (compared to theoretical maximum) was calculated considering 100% removal (g BOD/day), the literature percentage removal and the anionic surfactant presence in the effluentt. For each of these three cases, the efficiencies were, respectively, 16.9%, 43.6% and 51.3% in UASB7 reactor, 25.6%, 50.3% and 59.2% in UASB12 reactor and 30.6%, 61.2% and 71.9% in UASB7/SBR6 reactor. The energetic potential was found to be 4.66x10-4, 7.77x10-4 and 5.12x10-4 kWh/L for the UASB7, UASB12 and UASB7/SBR6 reactors, respectively. The pumping system, the aeration (in the anaerobic-aerobic system) and the temperature controlled heating system were considered to calculate the energetic consumption. However, the third one was not employed since tropical regions like Brazil do not need heating systems and also because of its high energetic consumption. The calculated net energy balance in the reactors was negative in the case of greywater, respectively -0.16, -0.28 and -0.18 kWh/L for the reactors UASB7, UASB12 and UASB7/SRB6. In full scale (ETE Jardim das Flores - Rio Claro, SP), the average energy... (Complete abstract click electronic access below)

Estudo de causas de falhas em selos mecânicos de bombas centrífugas para circulação de óleo térmico

This study is about a heating line that uses thermal oil. It is located in a facility that produces interlayers used in cars windshields. A plastic resin is melted and is sent to a matrix called DIE where the interlayers are produced. The DIE needs to receive heat from the circulation of thermal oil in four different regions of its interior, to ensure the correct thickness of the interlayer. The thermal energy is provided by electric heaters and the flow of thermal oil is impelled by four mechanically sealed centrifugal pumps (one per region). The key point of this study is the fact that these four pumps of the system have reported successive failures in the mechanical seals. Apparently, a poorly designed project has burdened the system intermittently. The pumps operation condition is located in a region of low efficiency, according to the characteristic curves. This fact is the source of the noticeable reduced time between failures. Changes in the configuration of the facility and in the number of pumps will be proposed, aiming to achieve higher operational efficiency. The proposals will be mathematically analyzed according to the Hydraulic Institute criteria. At the same time, we will also keep focus on an in-depth study of a heating system structure, starting with a detailed approach for each component and discussion about its real need and economic viability. At the end of this paper it is shown that the gain in efficiency achieved with the new proposed configuration reflects not only in the reduction of maintenance costs, but also a potential improvement in energy efficiency. It is shown that these two aspects are closely related and together form the basis for the design of a reliable and efficient pumping system

Utilização de procedimentos multivariados no consumo de água e energia elétrica em habitações sociais com sistema de aquecimento solar

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

How can micelle systems be rebuilt by a heating process?

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Cathodic stripping voltammetric detection and determination at a hanging mercury-drop electrode of dye contaminants in purified biomaterials: study of the human serum albumin and reactive dye 120 system

Procion red HE-3B (RR120) is an example of dye currently used in affinity purification. A method is described for determining trace amounts of RR120 dye contaminant in human serum albumin by cathodic stripping voltammetry. The method is based on a measure of a well-defined peak at -0.58 V, obtained when samples of HSA protein (0.01-2% w/v) containing dye concentrations are submitted to a heating time of 330 min at 80degreesC in NaOH, pH 12.0 and the samples are removed to a solution containing Britton-Robinson buffer, pH 4.0. Using an optimum accumulation potential and tune of 0 V and 240 s, respectively, linear calibration curves were obtained from 1.0 X 10(-9) to 1.0 X 10(-8) mol 1(-1) for RR120 dye. Leakage/hydrolysis of reactive red 120 from an agarose support (e.g. at pH 2 or 12) can also be conveniently determined at very low levels (sub-mug ml(-1)) by means of cathodic stripping voltammetry, which involves adsorptive accumulation of the dye onto the hanging mercury-drop electrode. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Viscoelastic and Thermal Properties of Collagen-Xanthan Gum and Collagen-Maltodextrin Suspensions During Heating and Cooling

The purpose of this work was to investigate the viscoelastic properties of aqueous suspensions of crude collagen powder extracted from bovine hides and nonsubmitted to the hydrolysis reaction that leads to gelatin. The studied variables included the collagen concentration and the addition of xanthan gum or maltodextrin at varied concentrations during heating/cooling of the mixtures. Differential scanning calorimetry thermograms showed that the addition of polysaccharides decreased the endothermic peak areas observed at the denaturation temperature of collagen. The rheological properties of the pure collagen suspensions were highly dependent on concentration: 4% and 6% collagen suspensions presented a great increase in the storage modulus after heating/cooling, whereas for concentrations of 8% and 10% G' decreased during heating and did not recover its original value after heating/cooling. The frequency sweeps showed that the thermal treatment was responsible by the strengthening of the interactions that formed the polymer network. Addition of 0.1% xanthan gum to collagen suspensions increased the gel strength, especially after heating/cooling of the system, whereas increasing gum concentration to 0.3% resulted in a weaker gel, which could indicate thermodynamic incompatibility between the biopolymers. Mixtures of collagen and maltodextrin resulted in more fluid structures than those obtained with pure collagen at the same collagen concentration and the range of temperatures in which these mixtures behaved as a gel decreased with increasing concentrations of both collagen and maltodextrin, suggesting incompatibilities between the biopolymers.