Cover crops affecting levels of ammonium and nitrate in the soil and upland rice development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Studies on double selenates. Part 12. Thermal decomposition of ammonium selenate and of double selenates of lanthanide, and yttrium, and ammonium

Thermogravimetry (TG) up to 900°C, differential thermal analysis (DTA) up to 1100°C and gravimetric data up to 1200°C, have been used to study the thermal decomposition of ammonium selenate and of the double selenates of lanthanides, and yttrium, and ammonium. The results provided the composition and thermal stability and also an interpretation of the thermal decomposition mechanisms. © 1994.

Fontes e modos de aplicação do nitrogênio na cultura do milho

Pós-graduação em Agronomia - FEIS

A simple spectrophotometric method for the determination of captopril in pharmaceutical preparations using ammonium molybdate

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

AMMONIUM AND NITRATE IN SOIL AND RATOON SUGARCANE GROWN IN FUNCTION OF NITROGEN ON OXISOL

After harvest, sugarcane residues left on the soil surface can alter nitrogen (N) dynamics in the plant-soil system. In Oxisols, the nitrogen fertilizer applied had its effects on the levels of ammonium and nitrate in the soil, N concentration in the plant leaves, and on the growth and productivity of second ratoon plants. The N rates tested were of 0, 60, 120, 180, and 240 kg ha-1. Each treatment was replicated four times. Four months after the experiment was started, ammonium and nitrate concentration in the soil, N levels in plant leaves, and plant growth were evaluated. Productivity was evaluated 11 months after the experiment was set. By increasing the content of mineral N in soil, plant growth variables reflected differences in the production of stems; however, it did not affect foliar N. The use of leaf analysis was not important to assess the nutritional status of nitrogen in the ratoon sugarcane. Nitrogen concentration in soil was affected by nitrogen fertilization, but not the N content in leaves. The rate of 138 kg N ha-1enabled greater production of sugarcane stalks (140 t ha-1). © 2013 Copyright Taylor and Francis Group, LLC.

Adenosine deaminase activity as a biochemical marker of inflammatory response in goats infected by caprine arthritis-encephalitis virus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mineral supplementation and productivity of the Shiitake mushroom on eucalyptus logs

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

The Use of Response Surface Methodology in Optimization of Lactic Acid Production: Focus on Medium Supplementation, Temperature and pH Control

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

The importance of excretion by Chironomus larvae on the internal loads of nitrogen and phosphorus in a small eutrophic urban reservoir

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

Crystallization and preliminary X-ray diffraction analysis of XAC1151, a small heat-shock protein from Xanthomonas axonopodis pv. citri belonging to the alpha-crystallin family

The hspA gene (XAC1151) from Xanthomonas axonopodis pv. citri encodes a protein of 158 amino acids that belongs to the small heat-shock protein ( sHSP) family of proteins. These proteins function as molecular chaperones by preventing protein aggregation. The protein was crystallized using the sitting-drop vapour-diffusion method in the presence of ammonium phosphate. X-ray diffraction data were collected to 1.65 angstrom resolution using a synchrotron-radiation source. The crystal belongs to the rhombohedral space group R3, with unit-cell parameters a = b = 128.7, c = 55.3 angstrom. The crystal structure was solved by molecular-replacement methods. Structure refinement is in progress.

Thermal degradation of a composite solid propellant examined by DSC - Kinetic study

The thermal decomposition of ammonium perchlorate (AP)/hydroxyl-terminated-polybutadiene (HTPB), the AP/HTPB solid propellant, was studied at different heating rates in dynamic nitrogen atmosphere. The exothermic reaction kinetics was studied by differential scanning calorimetry (DSC) in non-isothermal conditions. The Arrhenius Parameters were estimated according to the Ozawa method. The calculated activation energy was 134.5 W mol(-1), the pre-exponential factor, A, was 2.04.10(10) min(-1) and the reaction order for the global composite decomposition was estimated in 0.7 by the kinetic Shimadzu software based on the Ozawa method. The Kissinger method for obtaining the activation energy value was also used for comparison. These results are discussed here.

Properties of a polynucleotide synthesized by strain 74a of Neurospora crassa

A polynucleotide (or a fragment of RNA) was purified to apparent homogeneity by HPLC from mycelium of the wild strain 74A of the mould Neurospora crassa, after growth on sucrose and in the presence of saturating amounts of inorganic phosphate (Pi) for 72 hr at 30 degrees. The M(r) was ca 20000 as determined by HPLC at pH 6.8. Polynucleotide synthesis ranged from 4.0 to 6.5 mu g polynucleotide per mg dry mycelium in mycelium of the wild strain 74A and the various phosphorus regulatory and structural mutant strains of the mould N. crassa. Kinetic data showed that the polynucleotide interacts with mycelial Pi-repressible alkaline phosphatase by inhibiting its p-nitrophenylphosphatase activity and by protecting the enzyme against thermal inactivation in the presence of high concentrations of ammonium sulphate.

Tin(II)-EDTA complex: kinetic of thermal decomposition by non-isothermal procedures

Tin on the oxide form, alone or doped with others metals, has been extensively used as gas sensor, thus, this work reports on the preparation and kinetic parameters regarding the thermal decomposition of Sn(II)-ethylenediaminetetraacetate as precursor to SnO2. Thus, the acquaintance with the kinetic model regarding the thermal decomposition of the tin complex may leave the door open to foresee, whether it is possible to get thin film of SnO2 using Sn(II)-EDTA as precursor besides the influence of dopants added.The Sn(II)-EDTA soluble complex was prepared in aqueous medium by adding of tin(II) chloride acid solution to equimolar amount of ammonium salt from EDTA under N-2 atmosphere and temperature of 50degreesC arising the pH similar to 4. The compound was crystallized in ethanol at low-temperature and filtered to eliminate the chloride ions, obtaining the heptacoordinated chelate with the composition H2SnH2O(CH2N(CH2COO)(2))(2).0.5H(2)O.Results from TG, DTG and DSC curves under inert and oxidizing atmospheres indicate the presence of water coordinated to the metal and that the ethylenediamine fraction is thermally more stable than carboxylate groups. The final residue from thermal decomposition was the SnO2 characterized by X-ray as a tetragonal rutile phase.Applying the isoconversional Wall-Flynn-Ozawa method on the DSC curves, average activation energy: E-a = 183.7 +/- 12.7 and 218.9 +/- 2.1 kJ mol(-1), and pre-exponential factor: log A = 18.85 +/- 0.27 and 19.10 +/- 0.27 min(-1), at 95% confidence level, could be obtained, regarding the loss of coordinated water and thermal decomposition of the carboxylate groups, respectively. The E-a and logA also could be obtained applying isoconventional Wall-Flynn method on the TG curves.From E-a and log A values, Dollimore and Malek procedures could be applied suggesting R3 (contracting volume) and SB (two-parameter model) as the kinetic model to the loss of coordinated water (177-244degreesC) and thermal decomposition of the carboxylate groups (283-315degreesC), respectively. Simulated and experimental normalized DTG and DSC curves besides analysis of residuals check these kinetic models. (C) 2003 Elsevier B.V. All rights reserved.

Application of Polysaccharide Hydrogels in Adsorption and Controlled-Extended Release of Fertilizers Processes

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

Wet deposition of major ions in a rural area impacted by biomass burning emissions

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