A decentralized approach for optimal reactive power dispatch using a Lagrangian decomposition method

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Photocatalytic decomposition of methylene blue via Fenton mechanisms by silicon wafer doped with Au and Cu: a theoretical and experimental study

In this work, we studied the photocatalytic and the structural aspects of silicon wafers doped with Au and Cu submitted to thermal treatment. The materials were obtained by deposition of metals on Si using the sputtering method followed by fast heating method. The photocatalyst materials were characterized by synchrotron-grazing incidence X-ray fluorescence, ultraviolet-visible spectroscopy, X-ray diffraction, and assays of H(2)O(2) degradation. The doping process decreases the optical band gap of materials and the doping with Au causes structural changes. The best photocatalytic activity was found for thermally treated material doped with Au. Theoretical calculations at density functional theory level are in agreement with the experimental data.

Aerobic fitness level typical of elite athletes is not associated with even faster VO2 kinetics during cycling exercise

The aim of this study was to address the question if the VO2 kinetics is further improved as the aerobic training status increases from trained to elite level athletes. Maximal oxygen uptake (VO(2)max), work-rate associated to VO(2)max (IVO(2)max) and VO2 kinetics of moderate (Mod) and maximal exercise (Max) were determined in fifty-five subjects. Then, they were assigned into three groups: low (LF), intermediate (IF) and high (HF) aerobic fitness level. In average, the VO(2)max of LF, IF and HF groups were, respectively, 36.0 +/- 3.1, 51.1 +/- 4.5 and 68.1 +/- 3.9 ml . kg . min(-1) (p <= 0.05 among each other). VO2 kinetics mean response time of both exercise intensities were significantly faster (p <= 0.05) in HF (Mod, 27.5 +/- 5.5 s; Max, 32.6 +/- 8.3 s) and IF (Mod, 25.0 +/- 3.1 s; Max, 42.6 +/- 10.4 s) when compared to LF (Mod, 35.7 +/- 7.9 s; Max: 57.8 +/- 17.8 s). We can conclude that VO2 kinetics is improved as the fitness level is increased from low to intermediate but not further improved as the aerobic fitness level increases from intermediate to high.

Sewage sludge coke estimation using thermal analysis

The imposition of more stringent legislation by CETESB in the State of So Paulo (Brazil) governing the disposal and utilization of sewage sludge, coupled with the growth in its generation has prompted a drive for alternative uses of sewage sludge. One option that is especially promising, due to its potential to valorize sludge, is its conversion into carbonaceous adsorbents or coke for industrial effluents treatment. Thus, a methodology is presented to estimate the coke produced from the sludge of a sewage treatment station using thermal analysis. The used sewage sludge, which comes from aerobic treatment, was collected in the wastewater treatment station of Barueri, one of the largest of the So Paulo metropolitan area. The sludge samples were collected, dried, ground, and milled until they passed an ABNT 200 sieve. The inert ambient used during its thermal treatment produces inorganic matter and coke as residual materials. Coke formation occurs in the 200-500 A degrees C range and, between 500 and 900 A degrees C, its thermal decomposition occurs. The highest formation of coke occurs at 500 A degrees C.

Physiological and Stroke Parameters to Assess Aerobic Capacity in Swimming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

TWO DECOMPOSITION APPROACHES APPLIED TO THE MULTI-AREA OPTIMAL REACTIVE POWER FLOW PROBLEM

This paper applies two methods of mathematical decomposition to carry out an optimal reactive power flow (ORPF) in a coordinated decentralized way in the context of an interconnected multi-area power system. The first method is based on an augmented Lagrangian approach using the auxiliary problem principle (APP). The second method uses a decomposition technique based on the Karush-Kuhn-Tucker (KKT) first-order optimality conditions. The viability of each method to be used in the decomposition of multi-area ORPF is studied and the corresponding mathematical models are presented. The IEEE RTS-96, the IEEE 118-bus test systems and a 9-bus didactic system are used in order to show the operation and effectiveness of the decomposition methods.

Studies on double selenates. I. Thermal decomposition of lanthanum and alkali metal double selenates

Thermogravimetry, differential thermal analysis and other methods of analysis have been used to study the decomposition of hydrated lanthanum and alkali metal double selenates up to 1300°C. The results showed slight variations in the initial temperature of the various intermediate decomposition stages of the double selenates, as compared with the initial temperature of the corresponding decomposition of the simple selenates. The results also permitted the suggestion of mechanisms of thermal decomposition of these compounds. © 1980.

Thermal decomposition of hydrated selenites of trivalent lanthanides and yttrium

Hydrated lanthanide(III) and yttrium(III) selenites were prepared. Simultaneous thermogravimetric and differential thermal analysis, classical differential thermal analysis, X-ray diffraction and other methods of analysis have been used in the characterisation as well as in the study of the thermal decomposition of these compounds. The results led to the composition and thermal stability and also to interpretations concerning the thermal decomposition mechanisms. © 1990.

Effects of vinasse upon the decomposition rate of Ocotea pulchella leaves in cerrado soil

Ocotea pulchella leaves placed on soil treated with vinasse lost 64.48% of their organic matter, whereas the leaves sampled in the control parcels lost 70.68%, after one year. -from Authors

Thermal decomposition of vanadyl Schiff-base compounds

The thermal stability and thermal decomposition of several Schiff bases coordinated to vanadyl, VO (Schiff base), were studied by thermogravimetry and conventional gas Chromatographic and X-ray analyses. The kinetics, the number of steps and, in particular, the final temperature of decomposition of these complexes depend on the equatorial ligand. © 1992.