Ciclo de produção e demanda térmica de clones da videira 'Concord' sobre diferentes porta-enxertos

O objetivo do trabalho foi determinar a duração do ciclo de produção e a necessidade térmica de seis clones de 'Concord' sobre três porta-enxertos no norte do Paraná. Foram avaliados os clones '22', '28', '49', '202', '211' e '225', obtidos pela Embrapa Uva e Vinho, e enxertados sobre os porta-enxertos 'IAC 766', 'IAC 572' e '420-A'. O trabalho foi realizado em área experimental pertencente ao Centro Tecnológico da COROL - Cooperativa Agroindustrial, localizado no município de Rolândia-PR. O experimento foi realizado em esquema fatorial (6 clones x 3 porta-enxertos), em delineamento inteiramente casualizado, com cinco repetições. As plantas foram conduzidas em sistema de latada, no espaçamento de 4,0 m x 2,0 m, e as avaliações foram realizadas nas safras de 2009/2010 e 2010/2011. Verificou-se que dentre os clones de 'Concord' avaliados, o '202' apresenta a menor duração do ciclo entre a poda e a colheita, sendo portanto o mais precoce. Dentre os porta-enxertos, o '420-A' induz a maior taxa de acúmulo diário de sólidos solúveis do mosto, proporcionando redução do ciclo total e da demanda térmica dos clones de 'Concord', enquanto o 'IAC 572' induz a menor taxa, promovendo aumento do ciclo e da demanda térmica dos clones.

EXIGÊNCIA TÉRMICA DE DUAS SELEÇÕES E QUATRO CULTIVARES DE MORANGUEIRO CULTIVADO NO PLANALTO CATARINENSE

RESUMO O objetivo do trabalho foi estimar a soma térmica e o filocrono de quatro cultivares e duas ‘seleções’ de morangueiro para o Planalto Sul- Catarinense. O experimento foi conduzido no Centro de Ciências Agroveterinárias, na Universidade do Estado de Santa Catarina. Foram utilizadas duas seleções de morangueiro em avançada fase de estudos, denominadas ‘SEL1’ e ‘SEL2’, utilizando mudas provenientes de um programa público de melhoramento genético da Itália e quatro cultivares: Camino Real e Camarosa, provenientes do Chile, e San Andreas eAlbion, provenientes da Argentina. O transplante das mudas foi realizado em 26-06-2012. O delineamento experimental utilizado foi o de blocos ao acaso, com três repetições, cada repetição composta de oito plantas, sendo utilizadas as quatro plantas centrais. O filocrono foi determinado a partir do inverso do coeficiente angular da regressão linear entre o número de folhas acumuladas na haste e a soma térmica acumulada após o transplante. Observou-se linearidade entre o desenvolvimento vegetal e a temperatura média do ar nas condições do estudo. Dentre as seleções e cultivares estudadas a ‘San Andreas’ apresenta o ciclo mais precoce, necessitando de menor acúmulo de temperatura (774,70 grausdia), e a cultivar Camarosa, o ciclo mais tardio, com maior acúmulo de soma térmica (1.137,75 graus-dia). A seleção Sel1 apresentou o menor filocrono, 69,96ºC dia1 folha-1, e a cultivar Albion maior valor, 135,61 oC dia1 folha-1. Durante o período estudado, a cultivar San Andreas apresentou maior produção de frutos.

Estudo cinético por TG e DSC da decomposição térmica de alguns adutos de haletos de cádmio

By DSC data, the kinetical parameters Ea , n and A were calculated for the thermal decomposition of the adducts CdCl2.2dmf, CdCl2.dmf and CdBr2.dmf (dmf= dimethylformamide) by using Rogers and Smith method. The found values were : Ea = 85, 176 and 101 kJ mol-1 , n= 0.23, 0.25, and 0.17, A= 2.40x10(9), 1.89x10(19) and 1.07x10(9) respectively. By TGA data, the kinetical patameters for the thermal decomposition of the adduct CdCl2.1,5 dmeu (dmeu=dimethylethyleneurea) were calculated by using five different methods.

Cinética não-isotérmica na análise térmica de sólidos

In this work, a computer program called Thermal Kinetics was implemented to simulate thermal analysis experiments by numerical integration of the kinetics equations. The computer program was tested in two different examples: non-isothermal transformation of a Cu-Al alloy and non-isothermal decomposition of calcium oxalate monohydrated. In spite of the rather crude approximations of the model, the simulated profiles are very similar to the experimental curves. Both, the dalpha /dt and the dalpha /dT profiles reproduce the experimental transition temperatures with an error smaller than 25%.

Métodos analíticos ultrasensíveis: lente térmica e técnicas correlatas

Among the emergent laser based spectrometric methods, thermal lensing and other photothermal techniques present a great potential for solving a variety of problems in the fields of chemistry, physics and biology. Their main advantages are high concentration sensitivity, sensibility to physical-chemical properties of the medium, excellent spatial resolution and noninvasive characteristics. In this article, theoretical principles, main applications and practical hints as well as fundamental limitations of these techniques will be carefully described. It is hoped that this will give the reader a clear picture of this field of investigation as well as provide to the ones who are not specialists in the area, the necessary background to understand, implement and use photothermal techniques. In the final sections the development frontiers of photothermal spectrometry will be discussed.

Xerogel p-anisidinapropilsílica: estudo da estabilidade térmica e da resistência à lixiviação com solventes

The xerogel p-anisidinepropylsilica was obtained. This solid presents some residual paraffin and also a small fraction of high organofunctionalized material that was leached in polar solvent. The xerogel purification could be achieved by exhaustively washing with hexane and dichloromethane solvents, or submitting the xerogel to thermal treatment up to 300 ºC, in vacuum. The resulting purified xerogel material present an appreciable thermal stability and resistance to leaching by solvents.

Decomposição térmica do bicarbonato de sódio: do processo Solvay ao diagrama tipo Ellingham

A didactic experiment based on the thermal decomposition of sodium bicarbonate using a reagent found in the marketplace is proposed. The reaction products are identified by qualitative tests and stoichiometric calculations. The thermal stability of carbonates and the influence of lattice energies are discussed, emphasizing periodic trends in the alkali and alkaline earth families. The industrial importance of the reaction is also explored.

O efeito da granulometria na decrepitação durante a decomposição térmica de calcários e carvão

The use of fluidized bed combustors to burn coal is largely studied to permit the addition of limestone to capture SO2. The particle size for coal and limestone is an important parameter in this process. Thermogravimetry (TG) is used to elucidate the combustion and sulfation processes, but the experimental parameters must be evaluated to be representative in fluidized bed combustors. In the present study the effect of particle size is analyzed in the calcination of limestones and the combustion of coal through the thermogravimetric curve for limestone and derivative thermogravimetric curve for coal. Small peaks representing mass losses between 400 and 500 ºC are observed due to the jumping of particles out of the crucible. This effect, recognized as decrepitation is observed for mid-sized particles provoked by the release of water vapor trapped within their lattice.

Estudo de efeito dos sais precursores sobre as propriedades eletrocatalíticas de eletrodos de Ti-SnO2/Sb preparados por decomposição térmica

The physical and electrochemical properties of Ti-SnO2/Sb electrodes obtained by the thermal decomposition of solutions of the precursor salts SnCl2×2H2O/SbCl3 and SnSO4/Sb2(SO4)3 were investigated. The reversibility of the cyclic voltammetric response of the Fe(CN)6(4-)/Fe(CN)6(3-) redox couple was assessed using the obtained electrodes. Their catalytic activity for the oxygen-evolving reaction and maximum capacity for electronic transfer were also evaluated by potential and current linear scans in 0.5 mol L-1 H2SO4. Additionally, scanning electron microscopy analyses allowed the visualization of the morphology of the oxide films obtained. The best results were presented by the electrodes obtained from the chloride salt precursors.

Efecto de solvente sobre la descomposición térmica de trans-3,6-dimetil-3,6-difenil-1,2,4,5-tetraoxaciclohexano en solución

The thermal decomposition reaction of trans-3,6-dimethyl-3,6-diphenyl-1,2,4,5-tetraoxacyclohexane (acetophenone cyclic diperoxide, DPAF), in different solvents (methanol, 1,4-dioxane, acetonitrile and 2-propanol/benzene mixtures) in the initial concentration and temperature ranges of (4.2-10.5) x 10-3 M and 140.0 to 185.0 ºC, respectively, follows a pseudo first order kinetic law up to at least 70% DPAF conversion. An important solvent effect on the rate constant values, activation parameters (DH# and DS#) and reaction products obtained in different solvents is detected, showing that the reaction is accelerated in alcohols.

Decomposição térmica de complexos de Zn e Cd com isomaleonitriladitiolato (imnt)

Thermal decomposition of [Bu4N]2[Zn(imnt)2] and [M(NH3)2(imnt)] complexes with M = Zn and Cd, and imnt = (bis 1,1-dicyanoethylene-2,2 dithiolate) in inert atmosphere was investigated by thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Pyrolysis studies at different temperatures, 300, 400, 500, and 600 ºC, in N2 atmosphere were performed and the products were characterized by X-ray diffraction (XRD), infrared and Raman spectroscopy, and scanning electron microscopy (SEM). The products were identified as sulfide sub-micron particles, along with amorphous carbon. Particle sizes estimated by SEM were ca. 50 nm for the cationic complexes and 500 nm for the neutral complexes.

Análise térmica aplicada ao estudo de materiais energéticos

This paper shows different aspects related to the application of different thermal analysis techniques in the study of energetic materials. The criteria used to choose the best technique and an exact approach to adjust the experimental data with a proper model are here discussed. The paper shows how to use the different thermal analysis results to help develop new compounds, to study the stability of some energetic materials and their compatibility, and the conditions necessary for a secure storing environment.

Decomposição térmica de espumas de poliuretano para fabricação de vitrocerâmica celular de Li2O-ZrO2-SiO2-Al2O3 (LZSA)

Characterization of the thermal decomposition of polyurethane (PUR) foams was performed by Fourier-transformed infrared (FT-IR) spectroscopy and thermogravimetric analysis (TGA). Three main weight loss paths were observed by TGA, the residue being lower than 3 wt.% for 3 different PUR foams analyzed. FT-IR spectra indicated CO2, CO, NH3 and isocyanides as main decomposition products. PUR foams of different cell sizes were immersed in a slurry of the parent glass ceramic of composition Li2O-ZrO2-SiO2-Al 2O3 (LZSA) and submitted to heat treatment. The LZSA cellular glass ceramics obtained after sintering and crystallization resembled the original morphology of the PUR foams.

Biomateriais: deposição de hidroxiapatita sobre superfície de Ti-cp modificada por aspersão térmica

The osseointegrated titanium implants are reliable and safe alternatives to treatments for long periods of time. For surface modification, thermal aspersion of TiO2 was used. The samples with and without TiO2 were treated with NaOH and SBF in order to obtain a layer of HA. Characterization was done by SEM and FTIR. The images of HA obtained by SEM show a uniform morphology and a porous structure with spherical particles. The IR spectra show that the surface of Ticp/ TiO2 is more favorable for the HA deposit, as can be seen by the increase of the crystalline structure and the very intense and defined bands of the OH group of HA that is verified about 3571 and 630 cm-1. Thus the Ticp/ TiO2 surface presents a satisfactory nucleation of HA when compared to Ticp.

Estudo da decomposição térmica de propelente sólido compósito de baixa emissão de fumaça

The thermal decomposition of hydroxyl-terminated polybutadiene (HTPB)/ammonium nitrate (AN) based propellants, so called smokeless formulations, and raw materials were investigated by differential scanning calorimetry (DSC) and thermogravimetry (TG). The thermoanalytical profile of different components and of propellant were evaluated and the Arrhenius parameters for the thermal decomposition of the propellant sample were determined by the Ozawa method. The kinetic parameters of the thermal decomposition of propellant samples were determined by DSC measurements. The values obtained for activation energy (Ea) and pre-exponential factor were 163 kJ mol-1 and 1.94x10(6) min-1.