Modelling the maximum potential of nitrogen deposition and requirements of lysine for broilers

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

Modelling of the nitrogen deposition and dietary lysine requirements of Redbro broilers

The aim of this study was to determine the coefficients of the Goettingen model for Redbro birds and estimate the digestible lysine requirements. To determine the model parameters, three nitrogen balance trials were performed in Periods I (14-28 days), II (42-56 days) and III (70-84 days), using 42 birds per trial. The birds were individually housed and subjected to six diets with increasing levels of nitrogen, with lysine as the limiting amino acid (deficient by 20% in relation to other amino acids). Dietary nitrogen concentrations were 8, 16, 24, 32, 40 and 48 g/kg. A control diet was added to confirm lysine as the first limiting amino acid. Nitrogen balance trials were divided into 5 days of adaptation and two periods of excreta collection, each one of 5 days. The response of the birds to a control diet confirmed that lysine was the first limiting amino acid. The adjustment of the exponential functions between nitrogen retention or excretion and nitrogen intake allowed estimation of parameters of the Goettingen model. The maximum potential for nitrogen retention was 3276, 2585 and 2603 mg/BWkg0.67.day, nitrogen maintenance requirement was 225, 135 and 122 mg/BWkg0.67.day and efficiency of nitrogen utilisation was 313 x 10(-6), 406 x 10(-6) and 415 x 10(-6) in the phases of 14-28, 42-56 and 70-84 days. The digestible lysine intake for Periods I, II and III, based on 60% of the maximum potential for nitrogen retention, was 711, 989 and 1272 mg/day (1.225%, 1.137% and 1.09% of lysine in the diet for a daily feed intake of 58, 87 and 117 g/day), respectively.

Measurements and modeling of reactive nitrogen deposition in southeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative study using small-angle x-ray scattering and nitrogen adsorption in the characterization of silica xerogels and aerogels

A comparative study using small-angle x-ray scattering (SAXS) and nitrogen adsorption has been carried out in the structural characterization of silica xerogels and aerogels, obtained from tetraethoxysilane sonohydrolysis. The specific surface and the mean pore size as measured by both the techniques were found to be in notable agreement in all cases for aerogels and xerogels. According to the SAXS data, aerogels at 500 °C exhibit a mass fractal structure with fractal dimension D∼2.4 in the range between the correlation length ξ∼5.3 nm and a∼0.75 nm. An experimental method to probe the mass fractal structure of aerogels from exclusively nitrogen adsorption isotherms has been presented. For aerogels at 500 °C, we have found D∼2.4 in the range between the pore width 2rξ∼33 nm and 2ra∼4.5 nm, which is in notable agreement with the SAXS results (D ∼2.4, ξ∼5.3 nm, a∼0.75 nm) if we assign the pore width 2r probed by the Kelvin equation in the adsorption method to the Bragg distance 2π/q associated to the correlation length 1/q probed by SAXS.

Modelagem das respostas de frangos de corte submetidos a diferentes ingestões de lisina

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

Modelos de crescimento e das respostas de frangas de postura submetidas a diferentes ingestões de aminoácidos sulfurados

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Determinação da relação dos aminoácidos essenciais para juvenis de tilápia-do-Nilo, pelo método da deleção

Pós-graduação em Aquicultura - FCAV

Descrição do potencial de retenção de nitrogênio em frangas de postura por diferentes metodologias: máxima deposição e estimativas da ingestão de metionina+cistina

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

Relação ideal dos aminoácidos essenciais para mantença, crescimento e produção de aves

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

Thin films generated by plasma immersion ion implantation and deposition of hexamethyldisilazane mixed with nitrogen in different proportions

In this work, it was used a plasma system composed of a cylindrical stainless steel reactor, a radio-frequency (13.56MHz) power source fixed at either 25 W or 70 W, a power source with a negative bias of 10kV and a 100Hz pulse. The system worked at an operational pressure of 80mTorr which consisted of varying concentrations of the monomer HMDSN and gaseous nitrogen in ratios: HMDSN (mTorr)/nitrogen (mTorr) from 70/10 to 20/60 in terms of operational pressure. The structural characterization of the films was done by FTIR spectroscopy. Absorptions were observed between 3500 cm(-1) to 3200 cm(-1), 3000 cm(-1) to 2900 cm(-1), 2500 cm(-1) to 2000 cm(-1), 1500 cm(-1) to 700 cm(-1), corresponding, respectively, to OH radicals, C-H stretching bonds in CH2 and CH3 molecules, C-N bonds, and finally, strain C-H bonds, Si-CH3 and Si-N groups, for both the 70 W and the 25 W. The contact angle for water was approximately 100 degrees and the surface energy is near 25mJ/m(2) which represents a hydrophobic surface, measured by goniometric method. The aging of the film was also analyzed by measuring the contact angle over a period of time. The stabilization was observed after 4 weeks. The refractive index of these materials presents values from 1.73 to 1.65 measured by ultraviolet-visible technique.

Fertilizer distribution mechanisms and side dress nitrogen fertilization in upland rice under no-tillage system

Algumas culturas têm pouca adaptação ao sistema plantio direto (SPD), em vista da alta compactação da camada superficial do solo. Nesse caso, o mecanismo utilizado na semeadora para a abertura dos sulcos para deposição do fertilizante pode ter grande importância no sentido de facilitar a penetração das raízes. Avaliouse a influência do mecanismo de distribuição de fertilizante e da adubação nitrogenada na cultura do arroz de terras altas (Oryza sativa) no sistema plantio direto. O experimento foi conduzido nos anos agrícolas 2001/2002 e 2002/2003, em Botucatu-SP, Brasil. O delineamento experimental foi em blocos casualizados, com parcelas subdivididas e quatro repetições. As parcelas foram constituídas por dois mecanismos de distribuição de fertilizantes (haste sulcadora e disco duplo). Nas subparcelas, quatro níveis de N foram aplicados em cobertura (0, 40, 80 e 120 kg ha-1). Avaliou-se a profundidade de abertura do sulco e de deposição das sementes, a população de plantas, a altura de plantas, o número de colmos e de panículas m-2, o número total de espiguetas por panícula, a fertilidade das espiguetas, a massa de 1.000 grãos, a matéria seca da parte aérea, a produtividade e o teor de N na folha bandeira. O sucesso no estabelecimento da cultura do arroz de terras altas no SPD nas regiões de inverno seco do Brasil está diretamente ligado ao mecanismo de distribuição das semeadoras-adubadoras. A haste sulcadora promoveu maior profundidade de deposição de sementes, conseqüentemente reduzindo o estande, o número de panículas por área e a produtividade. A aplicação de N em cobertura no arroz de terras altas em SPD proporciona maiores produtividades quando a semeadura é realizada com mecanismo de disco duplo.

Amorphous carbon nitrogenated films prepared by plasma immersion ion implantation and deposition

In this work, an investigation was conducted on amorphous hydrogenated-nitrogenated carbon films prepared by plasma immersion ion implantation and deposition. Glow discharge was excited by radiofrequency power (13.56 MHz, 40 W) whereas the substrate-holder was biased with 25 kV negative pulses. The films were deposited from benzene, nitrogen and argon mixtures. The proportion of nitrogen in the chamber feed (R-N) was varied against that of argon, while keeping the total pressure constant (1.3 Pa). From infrared reflectance-absorbance spectroscopy it was observed that the molecular structure of the benzene is not preserved in the film. Nitrogen was incorporated from the plasma while oxygen arose as a contaminant. X-ray photoelectron spectroscopy revealed that N/C and O/C atomic ratios change slightly with R-N. Water wettability decreased as the proportion of N in the gas phase increased while surface toughness underwent just small changes. Nanoindentation measurements showed that film deposition by means of ion bombardment was beneficial to the mechanical properties of the film-substrate interface. The intensity of the modifications correlates well with the degree of ion bombardment. (c) 2006 Elsevier B.V. All rights reserved.

Plasma-polymerized hexamethyldisilazane treated by nitrogen plasma immersion ion implantation technique

This paper describes the effect of nitrogen Plasma Immersion Ion Implantation (PIII) on chemical structure, refraction index and surface hardness of plasma-polymerized hexamethyldisilazane (PPHMDSN) thin films. Firstly, polymeric films were deposited at 13.56 MHz radiofrequency (RF) Plasma Enhanced Chemical Vapour Deposition (PECVD) and then, were treated by nitrogen PIII from 15 to 60 min. Fourier Transformed Infrared (FTIR) spectroscopy was employed to analyse the molecular structure of the samples, and it revealed that vibrations modes at 3350 cm(-1), 2960 cm(-1), 1650 cm(-1), 1250 cm(-1) and 1050 cm(-1) were altered by nitrogen PIII. Visible-ultraviolet (vis-UV) spectroscopy was used to evaluate film refractive index and the results showed a slight increase from 1.6 to 1.8 following the implantation time. Nanoindentation revealed a surface hardness rise from 0.5 to 2.3 GPa as PIII treatment time increased. These results indicate nitrogen PIII is very promising in improving optical and mechanical properties of PPHMDSN films.

Straw decomposition of nitrogen-fertilized grasses intercropped with irrigated maize in an integrated crop-livestock system

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Low-temperature, self-nucleated growth of indium-tin oxide nanostructures by pulsed laser deposition on amorphous substrates

Indium-tin oxide nanostructures were deposited by excimer laser ablation in a nitrogen atmosphere using catalyst-free oxidized silicon substrates at 500 degrees C. Up to 1 mbar, nanowires grew by the vapor-liquid-solid (VLS) mechanism, with the amount of liquid material decreasing as the deposition pressure increased. The nanowires present the single-crystalline cubic bixbyite structure, oriented < 100 >. For the highest pressure used, pyramids were formed and no sign of liquid material could be observed, indicating that these structures grew by a vapor-solid mechanism. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.