Avaliação de óleos comestíveis comercializados no Rio de Janeiro.

Procedeu-se a um levantamento das condições dos óleos vegetais comestíveis comercializados no Rio de Janeiro, aliando-se determinações tradicionais à cromatografia de gás. Utilizaram-se óleos de soja, milho, caroço de algodão, oliva, arroz e mistos. Observaram-se discrepâncias na composição em ácidos graxos principalmente nos óleos de oliva, resultantes provavelmente de misturas com óleo de coco ou babaçu e com soja.bitstream/item/65434/1/CTAA-DOCUMENTOS-13-AVALIACAO-DE-OLEO-COMESTIVEIS-COMERCIALIZADOS-NO-RIO-DE-JANEIRO-FL-02165.pd

Simulations and measurements of the TTF phase-1 injector gun

International audienceThe TTF phase-1 injector will use a conventional thermionic triode gun as its electron source. The temporal structure of the injector will be obtained by the application of fast (<1 ns) pulses to the gun cathode. As it is necessary to operate the injector at a fixed average macropulse current of 8 mA, while having the ability to vary the repetition frequency of the micropulses, the gun has to function at peak currents varying from 100 mA to 400 mA. We report on both measurements and simulations (using EGUN) of the current-voltage characteristics of the TTF gun. In addition we report on measurements of the emittance of the gun over a limited range of current and voltage. The emittance is seen to be dependent upon the operating perveance and is smallest for perveances closest to the space-charge limited valu

Transesterificação de óleos vegetais para fins combustíveis.

Amostras de óleos de soja, algodão, colza, girassol e amendoim, depois de refinação alcalina, foram submetidos à transesterificações com metanol e etanol. Observou-se que enquanto as reações com metanol ou etanol anidro p.a. se processam facilmente com altos rendimentos e recuperação quase total do glicerol, as reações com etanol anidro comercial são mais complicadas não havendo separação do glicerol, ocorrendo grandes perdas. Foi desenvolvido, na EMBRAPA-CTAA, um processo que permite a obtenção dos ésteres etílicos, com etanol anidro comercial com conversão quase completa dos triglicerídios e separação do glicerol por adição de uma certa quantidade de glicerol.bitstream/item/118260/1/transesterificacao-de-oleos-vegetais.pd

Transesterificação de óleo de soja com diversos catalisadores alcalinos.

Amostras de óleo de soja neutralizado e seco foram transesterificadas com etanol comercial a 99,5% na presença de quantidades equivalentes de hidróxido, metóxido, etóxido e gliceróxido de sódio como catalisadores. Com o uso dos três alcóxidos obteve-se a separação do glicerol formado durante a reação, o que não ocorreu com o uso de hidróxido de sódio. O rendimento de sódio, como catalisador na transesterificação, apresenta vantagens econômicas e tecnológicas quando comparado com o hidróxido de sódio.bitstream/item/65433/1/CTAA-DOCUMENTOS-12-TRANSESTERIFICACAO-DE-OLEO-DE-SOJA-COM-DIVERSOS-CATALISADORES-ALCALINOS-FL-021.pd

Evaluating the Potential of Using 5-Azacytidine as an Epimutagen

A number of early flowering lines were induced when 5-azacytidine was applied to germinating flax (Linum usitatissimum L.) seed. The genetics of these lines indicate that the induced changes are epigenetic and probably result from demethylation of the genomic DNA at loci that affect flowering age. Although the growth and development of three stable early flowering lines are altered and the percentage of filled seed was reduced in all three lines compared with controls, measures of seed productivity demonstrated that harvest index was unaffected in two of the lines. In the third, harvest index was lower than normal and both seed set per capsule and seed mass per 100 seed were reduced. Furthermore, six generations after induction this line began to display relatively high levels of polyembryony. The late appearance of this twinning and other aspects related to working with lines induced by 5-azacytidine and using 5-azacytidine as an epimutagen are discussed

Deficiências minerais em pastagens do Estado do Rio de Janeiro.

bitstream/item/65349/1/CTAA-DOCUMENTOS-8-DEFICIENCIAS-MINERAIS-EM-PASTAGENS-DO-ESTADO-DO-RIO-DE-JANEIRO-FL-02171.pd

Óleos de macaúba: uma alternativa para a oleoquímica.

bitstream/item/118253/1/oleos-de-macauba.pd

SED, Metallicity and Age of Halo Globular Clusters in M33

In this paper we study the properties of ten halo globular clusters in the nearby spiral galaxy M33. CCD images of M33 were obtained as a part of the BATC Colour Survey of the sky in 13 intermediate-band filters from 3800 to 10000{\AA}. By aperture photometry, we obtain the spectral energy distributions (SEDs) of these globular clusters. We estimate the ages of our sample clusters by comparing the photometry of each object with theoretical stellar population synthesis models for different values of metallicity. Our results suggest that eight of the ten sample halo globular clusters have ``intermediate'' ages, i.e. between 1 and 8 Gyrs.Comment: 9 pages, 3 figures, has been accepted for publication in Astronomy and Astrophysic

Linear Contraction Behavior of Low-Carbon, Low-Alloy Steels During and After Solidification Using Real-Time Measurements

A technique for measuring the linear contraction during and after solidification of low-alloy steel was developed and used for examination of two commercial low-carbon and low-alloy steel grades. The effects of several experimental parameters on the contraction were studied. The solidification contraction behavior was described using the concept of rigidity in a solidifying alloy, evolution of the solid fraction, and the microstructure development during solidification. A correlation between the linear contraction properties in the solidification range and the hot crack susceptibility was proposed and used for the estimation of hot cracking susceptibility for two studied alloys and verified with the real casting practice. The technique allows estimation of the contraction coefficient of commercial steels in a wide range of temperatures and could be helpful for computer simulation and process optimization during continuous casting. © 2013 The Minerals, Metals & Materials Society and ASM International