THERMAL-DECOMPOSITION OF THE HYDRATED BASIC CARBONATES OF LANTHANIDES AND YTTRIUM IN CO2 ATMOSPHERE

The hydrated basis carbonates of lanthanides and yttrium were prepared by precipitation from homogeneous solution via the hydrolysis of urea, without the addition of an auxiliary anion. Thermogravimetry, derivative thermogravimetry (TG-DTG), and differential thermal analysis (DTA) have been used in the study of these compounds in CO2 atmosphere. The results lead to the composition and thermal stability of the studied compounds, and also to a comparative study with reported results in air atmosphere.

Thermogravimetry on calcined mass basis - hydrated cement phases and pozzolanic activity quantitative analysis

When cement hydrated compositions are analyzed by usual initial mass basis TG curves to calculate mass losses, the higher is the amount of additive added or is the combined water content, the higher is the cement 'dilution' in the initial mass of the sample. In such cases, smaller mass changes in the different mass loss steps are obtained, due to the actual smaller content of cement in the initial mass compositions. To have a same mass basis of comparison, and to avoid erroneous results of initial components content there from, thermal analysis data and curves have to be transformed on cement calcined basis, i.e. on the basis of cement oxides mass present in the calcined samples or on the sample cement initial mass basis.The paper shows and discusses the fundamentals of these bases of calculation, with examples on free and combined water analysis, on calcium sulfate hydration during false cement set and on quantitative evaluation and comparison of pozzolanic materials activity.

Weekend ethanol consumption and high-sucrose diet: resveratrol effects on energy expenditure, substrate oxidation, lipid profile, oxidative stress and hepatic energy metabolism

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

Electro-precipitation of Fe(3)O(4) nanoparticles in ethanol

The preparation of superparamagnetic magnetite (Fe(3)O(4)) nanoparticles by electro-precipitation in ethanol is proposed. Particle average size can be set from 4.4 to 9 nm with a standard deviation around 20%. Combination of wide-angle X-ray scattering (WAXS), Electron energy loss spectroscopy (EELS) and Mossbauer spectroscopy characterizations clearly identifies the particles as magnetite single-crystals (Fe(3)O(4)). (C) 2008 Elsevier B.V. All rights reserved.

Atmospheric emission of reactive nitrogen during biofuel ethanol production

This paper evaluates emissions to the atmosphere of biologically available nitrogen compounds in a region characterized by intensive sugar cane biofuel ethanol production. Large emissions of NH(3) and NO,, as well as particulate nitrate and ammonium, occur at the harvest when the crop is burned, with the amount of nitrogen released equivalent to similar to 35% of annual fertilizer-N application. Nitrogen oxides concentrations show a positive association with fire frequency, indicating that biomass burning is a major emission source, with mean concentrations of NO, doubling in the dry season relative to the wet season. During the dry season biomass burning is a source of NH3, with other sources (wastes, soil, biogenic) predominant during the wet season. Estimated NO(2)-N, NH(3)-N, NO(3)(-)-N and NH(4)(+)-N emission fluxes from sugar cane burning in a planted area,of ca. 2.2 x 10(6) ha are 11.0, 1.1, 0.2, and 1.2 Gg N yr(-1), respectively.

The Brazilian experience of sugarcane ethanol industry

Biomass has gained prominence in the last few years as one of the most important renewable energy sources. In Brazil, a sugarcane ethanol program called ProAlcohol was designed to supply the liquid gasoline substitution and has been running for the last 30 yr. The federal government's establishment of ProAlcohol in 1975 created the grounds for the development of a sugarcane industry that currently is one of the most efficient systems for the conversion of photosynthate into different forms of energy. Improvement of industrial processes along with strong sugarcane breeding programs brought technologies that currently support a cropland of 7 million hectares of sugarcane with an average yield of 75 tons/ha. From the beginning of ProAlcohol to the present time, ethanol yield has grown from 2,500 to around 7,000 l/ha. New technologies for energy production from crushed sugarcane stalk are currently supplying 15% of the electricity needs of the country. Projections show that sugarcane could supply over 30% of Brazil's energy needs by 2020. In this review, we briefly describe some historic facts of the ethanol industry, the role of sugarcane breeding, and the prospects of sugarcane biotechnology.

Antioxidant Action of Mangrove Polyphenols against Gastric Damage Induced by Absolute Ethanol and Ischemia-Reperfusion in the Rat

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

Chemiluminescence induced in the laser-promoted reaction of ethanol with oxygen

The vibrational multiphoton excitation of ethanol in the presence of oxygen results in chemiluminescent reactions yielding CH* and C*2. The rise times of the chemiluminescence become progressively slower and the intensity increases with ad-O2 pressure. At 15 Torr of O2 the emission duration is longer than 10 μs. © 1983.