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URI permanente para esta coleçãohttps://repositorio.fei.edu.br/handle/FEI/800
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- Biodiesel production from vegetal oil and ethanol via transesterification in supercritical conditions(2023-08-03) SIDI NETO, V.; DERENZO, S.; MARIN, M. P. DE A.; Luis Novazzi; João Guilherme Rocha Poço© 2023, The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química.Biodiesel, which is derived from renewable feedstock, has potential to replace fossil diesel. In this study, biodiesel production was carried out through the transesterification of soybean oil with ethanol (anhydrous and hydrated) under supercritical conditions in a batch reactor, with a temperature range of 280–340 °C and an oil/alcohol molar ratio of 1:40. The effects of both anhydrous and hydrated ethanol on the reaction were evaluated, as well as the direct esterification of oleic acid to produce ethyl ester. A first-order reversible kinetic model was proposed to describe the transesterification process. The results showed a good agreement between experimental data and the model. It was observed that temperature has an important effect on ester yield and hydrated ethanol improved this yield. After 120 min of reaction time at 310 °C with hydrated ethanol, transesterification led to 89.7% of ethyl ester. When compared to anhydrous ethanol, forward rate constants of hydrated ethanol suggested that water may have a catalytic effect on transesterification. Although the transesterification of soybean oil and ethanol under supercritical conditions is nearly irreversible at 280 °C, the reaction is limited by equilibrium at temperatures equal to or higher than 310 °C.
Artigo 6 Citação(ões) na Scopus Intraspecific variability of dihydrochalcone, chromenes and benzoic acid derivatives in leaves of Piper aduncum L. (Piperaceae)(2009-05-18) Andreia de Araújo Morandim Giannetti; KATO, M. J.; CAVALHEIRO, A. J.; FURLAN, M.Chemical analysis carried out in leaves of 18 specimens of Piper aduncum L. (Piperaceae) occurring at Ripasa Reserve, Araraquara, SP, Brazil indicated two distinct populations when investigated over a period of 14 months (January 2000 to February 2001) and then submitted to cluster analysis. The two groups were characterized by accumulation of prenylated benzoic acids, chromenes and dihydrochalcone, respectively. A total of seven compounds were identified by HPLC analysis and compared with standards including two prenylated benzoic acid [aduncumene (1) and 3-(3′-7′-dimethyl-2′-6′-octadienyl)- 4-methoxy-benzoic acid (5)], four chromenes [methyl 2,2-dimethyl-8-(3′- methyl-2′-butenyl)-2H-1-chromene-6-carboxylate (4), methyl 2,2-dimethyl-2H-1-chromene-6-carboxylate (2b), methyl 8-hydroxy-2,2-dimethyl-2H- 1-chromene-6-carboxylate (3) and 2,2-dimethyl-2H-1-chromene-6-carboxylic acid (2a)] and one dihydrochalcone [2′,6′-dihydroxy-4′-methoxy- dihydrochalcone (6)]. © 2009 Academic Journals.Artigo 0 Citação(ões) na Scopus Development of highly resistant fibers for use in solid phase micro extraction (SPME)(2010-01-05) RODRIGUES, J. C.; LEITE, D. W.; LANCAS, F. M.The commercially available fibers for solid-phase microextraction (SPME) made of optical fibers are fragile and can be easily broken. Thus, there is a clear need for the development of efficient, simple and highly resistant SPME fibers. This work describes the preparation of highly resistant fibers in which a polymer is coated onto an open tubular fused silica capillary tubing (0.360 mm O.D.) fitted with a stainless steel wire (0.200 mm O.D.) previously inserted and cemented into the capillary tube opening to guarantee higher mechanical resistance. The fiber was coated with 70-μm poly (dimethyl siloxane) (PDMS) and evaluated for the extraction of polycyclic aromatic hydrocarbons.Artigo 23 Citação(ões) na Scopus Composition and screening of antifungal activity against Cladosporium sphaerospermum and Cladosporium cladosporioides of essential oils of leaves and fruits of Piper species(2010-09-05) Andreia de Araújo Morandim Giannetti; PIN, A. R.; PIETRO, N. A. S.; ALECIO, A. C.; KATO, M. J.; YOUNG, C. M.; OLIVEIRA, J. E. DE; FURLAN, M.This study investigated the composition and antifungal activity against Cladosporium sphaerospermum and Cladosporium cladosporioides of essential oils of leaves of Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper solmsianum and Piper umbelata and fruits of P. cernuum and P. diospyrifolium. The essentials oils were analyzed by GC-MS and submitted of the antifungal activity tests. The essential oils of fruits from P. cernuum and leaves of P. crassinervium and P. solmsianum showed potential antifungal activity against C. sphaerospermum and C. cladosporioides. In addition, this is the first report of the composition of essential oils of fruits of P. cernuum and P. diospyrifolium. © 2010 Academic Journals.Artigo 34 Citação(ões) na Scopus Composition and antifungal activity against candida albicans, candida parapsilosis, candida krusei and cryptococcus neoformans of essential oils from leaves of piper and peperomia species(2010-09-04) Andreia de Araújo Morandim Giannetti; PIN, A. R.; PIETRO, N. A. S.; OLIVEIRA, H. C. DE; MENDES-GIANNINI, M. J. S.; ALECIO, A. C.; KATO, M. J.; OLIVEIRA, J. E. DE; FURLAN, M.This study was addressed to investigate the composition and antifungal activity of essential oils from leaves of Piperaceae species (Piper aduncum, Piper amalago, Piper cernuum, Piper diospyrifolium, Piper crassinervium, Piper gaudichaudianum, Piper solmsianum, Piper regnellii, Piper tuberculatum, Piper umbelata and Peperomia obtusifolia) against Candida albicans, C. parapsilosis, C. krusei and Cryptococcus neoformans. The essential oils from P. aduncum, P. gaudichaudianum and P. solmsianum showed the highest antifungal activity against Cryptococcus neoformans with the MIC of 62.5, 62.5 and 3.9 mg.mL-1, respectively. The oil from P. gaudichaudianum showed activity against C. krusei with MIC of 31.25 mg.mL-1. © 2010 Academic Journals.Artigo 6 Citação(ões) na Scopus Study of salmonella typhimurium mutagenicity assay of (z)-piplartine by the ames test(2011-06-15) Andreia de Araújo Morandim Giannetti; Cotinguiba F.; REGASINI, L. O.; FRIGIERI, M. C.; VARANDA, E. A.; COQUEIRO, A.; KATO, M. J.; BOLZANI, V. S.; FURLAN, M.Phytochemical studies carried out with Piperaceae species have shown great diversity of secondary metabolites among which are several displayed considerable biological activities. The species Piper tuberculatum has been intensively investigated and a series of amides have been described. For instance, (E)-piplartine showed significant cytotoxic activity against tumor cell lines, especially human leukemia cell lines; antifungal activity against Cladosporium species; trypanocidal activity and others. Considering the popular use of P. tuberculatum and the lack of pharmacological studies regarding this plant species, the mutagenic and antimutagenic effect of (Z)-piplartine was evaluated by the Ames test, using the strains TA97a, TA98, TA100 and TA102 of Salmonella typhimurium. No mutagenic activity was observed for this compound. © 2011 Academic Journals.- Effects of caramelization and Maillard reaction products on the physiology of Saccharomyces cerevisiae(2023-01-05) ELIODORO, K. P.; PENNACCHI, C.; DE GOIS E CUNHA, G. C.; Andreia de Araújo Morandim Giannetti; GIUDICI, R.; BASSO, T. O.© 2023 British Mycological SocietyThe thermal treatment the sugarcane juice undergoes during its processing alters the medium's chemical composition through the so-called Maillard reactions and its products, which can affect the alcohol-producing yeast's physiology in steps following the processing. This study aims to describe and characterize the reactivity of the primary amino acids present in sugarcane with sucrose, as well as demonstrate the physiological effects of the reaction's products on the yeast Saccharomyces cerevisiae. The main amino acids in sugarcane (glutamine, asparagine, and aspartic acid) were chosen to be reacted with sucrose under similar conditions to the industrial sugarcane processing (pH 5 and temperature 100–120 °C). The physiological effect of Maillard and caramelization reaction on the S. cerevisiae CEN.PK-122 and PE-2 strains were tested in microplate experiments using a modified mineral media containing both the reacted and unreacted amino acid-sucrose systems and four modified synthetic molasses media. The results have shown that the presence of any amino acids drastically increases product formation. Furthermore, among the amino acids, aspartic acid was the most reactive. Meanwhile, asparagine and glutamine had similar results. In S. cerevisiae physiology, aspartic acid had the most significant effect on culture growth by reducing the maximum specific growth rate and optical density. The increase in the Maillard product concentration for synthetic molasses also evidenced the inhibitory effect on yeast growth compared to media in the absence of these products. We conclude that this initial investigation clarifies the inhibitory effect of the Maillard products on yeast physiology.
- Direct oxidation of 3-picoline (3-methyl-pyridine) to nicotinic acid with pure HNO3(2023-07-17) GOMES, E. L.; FREITAS, D. A. DE; Rodrigo Condotta; João Guilherme Rocha Poço© 2023, The Author(s) under exclusive licence to Associação Brasileira de Engenharia Química.Nicotinic acid (NA) was synthesized by directly oxidizing 3-methylpyridine (3MP) with nitric acid. The reaction was performed in an instrumented PARR reactor. The effect of temperature (165 to 195 °C) and the molar composition of the initial reactive mixture were studied. Molar conversions of 3-methylpyridine ranged from 36 to 90%, with a yield of NA ranging from 31 to 62%. Better selectivities occur at low-time reactions and low conversion rates. At the same time, the HNO3 excess and temperature considerably affect 3MP conversion rate and NA yield rather than selectivity, especially at 180 °C, whereas an invariable selectivity of 80% was observed.
- Measurement and correlation of high-pressure volumetric properties of binary mixtures of 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) with alcohols(2023-10-05) HAUK, D. B.; Ricardo Torres; DANGELO, J. V. H.© 2023 Elsevier LtdNew experimental data for density-pressure–temperature measurements of binary mixtures of {1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([EMIM][NTf2]) + methanol, or + ethanol or + 1-propanol} have been measured using a vibrating tube densimeter at temperatures from T = (298.15 to 308.15) K and pressure range p= (0.1 – 40) MPa. The experimental density results have been correlated by the Tait-Tammann equation with the temperature and composition dependence parameters. The effects of the increase in the alkyl chains of the alcohols, temperature, and pressure on the density and volumetric properties have been analyzed. Moreover, the Extended Real Associated Solution Model (ERAS Model) has been used to correlate the experimental behavior of the excess molar volume of the studied systems.
- Fe3O4 nanoparticles and Rhizobium inoculation enhance nodulation, nitrogen fixation and growth of common bean plants grown in soil(2021-03-05) SOUZA-TORRES, A. DE; GOVEA-ALCAIDE, E.; GOMEZ-PADILLA, E.; MASUNAGA, S. H.; EFFENBERGER, F. B.; ROSSI, L. M.; LOPEZ-SANCHEZ, R.; JARDIM, R. F.© 2020 Elsevier B.V.The effects of Fe3O4 nanoparticles (NPs) and Rhizobium inoculation on nodulation, nitrogen fixation and plant growth of common bean (cv. Red Guama, Phaseolus vulgaris) plants were investigated in growth chambers. Plants were exposed to: Fe3O4 NPs (2000 mg/L) (T1), Rhizobium inoculation (T2) and Fe3O4 NPs + Rhizobium inoculation (T3); non-treated plants were considered as controls. Harvested 35-day-old treated plants showed improved symbiotic performance including increased nitrogenase activity (51.2–90.7%), nodule leghaemoglobin (44.8–80.9%) and iron content (83.4–84.2%), number of active nodules per plant (58.7–122%) and nodule dry weight (40.2–70.6%). This resulted in enhanced symbiotic nitrogen fixation,and increased shoot (26.5–50.2%) and root (24.1–48.2%) total nitrogen content in treated plants in comparison with the controls. The best result was obtained using treatment T3. Furthermore, Fe3O4 NPs were taken up by bean plants in treatments T1 and T3, and these accumulated in their organs, including in nodules. All treatments led to an increase in root (51.9–79.8%) and shoot (27.5–52.7%) lengths, in leaf area (10.9–16.8%) and in root (10.1–17.8%), stem (9.8–12.7%) and leaf dry weight (8–17.3%) compared to control plants. Thus applied treatments have the potential to improve common bean plant growth through enhancement of nodulation and nitrogen fixation during vegetative growth.This study also provides strong evidence that the presence Fe3O4 NPs in nodules improves the symbiotic performance between Rhizobium (leguminosarum CF1 strain) and the common bean plant, due to enhanced nodulation and nitrogen fixation.