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71.
Claudia Nurra Edgar A. Franco Maria L. Maspoch Joan Salvadó Carles Torras 《Journal of Materials Science》2014,49(20):7031-7039
Among different strategies to reduce costs in microalgae dewatering process via cross-flow filtration, the one related to membrane material was investigated in order to be decreased. Several materials were tested, starting with the ones commonly used in membrane technology [ceramic, polysulfone (PSf) and polyacrylonitrile (PAN)] to the ones generally employed in packaging industry [acrylonitrile butadiene styrene (ABS), glycol-modified polyethylene terephthalate (PETG) and polylactic acid (PLA)], the latter being considerably cheaper. Experiments carried out showed promising results in terms of permeabilities for PSf–Pluronic® F127 blended membranes and PAN membranes (11 ± 1 L/h/m2/bar and 22 ± 1 L/h/m2/bar, respectively, instead of 2 ± 2 L/h/m2/bar of PSf membranes), but with high related costs. PLA membranes showed good mechanical properties, biodegradability and price, but low permeability values (5 ± 1 L/h/m2/bar). PETG membranes showed attractive results in terms of costs and permeability, but poor mechanical properties. The polymer that offered the best results was the ABS that reached membrane permeabilities of 19 ± 1 L/h/m2/bar, maintaining good mechanical properties while filtering the microalgae Phaeodactylum tricornutum Bohlin. Thus, a novel functionality was found for these not so common polymers in microalgae dewatering. This indicates that use of these materials could also be considered in other aqueous micro/ultrafiltration applications. In addition, the biodegradable PLA polymer introduces a new concept of cheap and environmental friendly membrane in this application. 相似文献
72.
Helio Fiori de Castro Katia Lucchesi Cavalca Lucas Ward Franco de Camargo Nicoló Bachschmid 《Mechanical Systems and Signal Processing》2010,24(6):1785-1798
This paper discusses the identification of parameters in rotary systems, namely, the unbalance magnitude, phase and position in the rotor system. These parameters can be identified using the measured orbits in the hydrodynamic bearings. The oil film forces are evaluated in the different positions of the orbit of the journal and are applied to the model of the shaft. The model, integrated in time domain, allows with an assumed unbalance, to simulate the orbits. The objective function is basically the difference between measured and simulated orbits, and its minimum corresponds to the identified unbalance amount, phase and position along the shaft. With respect to traditional model based identification procedures, this approach using oil film forces instead of oil film linearized stiffness and damping coefficients, and unfiltered orbits instead of 1X vibration components is suitable to deal with non-linear behaviour of the system. 相似文献
73.
Josefina Pérez-Arantegui Judit Molera Angel Larrea Trinitat Pradell Marius Vendrell-Saz Ilaria Borgia Brunetto G. Brunetti Franco Cariati Paola Fermo Marcello Mellini Antonio Sgamellotti Cecilia Viti 《Journal of the American Ceramic Society》2001,84(2):442-46
Luster is a decorative metallic film that was applied on the surface of medieval glazed pottery. It can be obtained via the low-temperature (∼650°C), controlled reduction of copper and silver compounds. In this paper, we show that luster is a thin layered film (200–500 nm thick) that contains metallic spherical nanocrystals dispersed in a silicon-rich matrix and has a metal-free outermost glassy layer that is 10–20 nm thick. Silver nanocrystals seem to be separated from those of copper, forming aggregates 5–100 μm in diameter. This composite structure exhibits optical properties that are dependent on both the particle size and the matrix. Luster is indeed the first reproducible nanostructured thin metallic film that was made by humans. 相似文献
74.
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76.
Increased HDL Size and Enhanced Apo A-I Catabolic Rates Are Associated With Doxorubicin-Induced Proteinuria in New Zealand White Rabbits
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Victoria López-Olmos Elizabeth Carreón-Torres María Luna-Luna Cristobal Flores-Castillo Miriam Martínez-Ramírez Rocío Bautista-Pérez Martha Franco Julio Sandoval-Zárate Francisco-Javier Roldán Alberto Aranda-Fraustro Elizabeth Soria-Castro Mónica Muñoz-Vega José-Manuel Fragoso Gilberto Vargas-Alarcón Oscar Pérez-Méndez 《Lipids》2016,51(3):311-320
The catabolism and structure of high‐density lipoproteins (HDL) may be the determining factor of their atheroprotective properties. To better understand the role of the kidney in HDL catabolism, here we characterized HDL subclasses and the catabolic rates of apo A‐I in a rabbit model of proteinuria. Proteinuria was induced by intravenous administration of doxorubicin in New Zealand white rabbits (n = 10). HDL size and HDL subclass lipids were assessed by electrophoresis of the isolated lipoproteins. The catabolic rate of HDL‐apo A‐I was evaluated by exogenous radiolabelling with iodine‐131. Doxorubicin induced significant proteinuria after 4 weeks (4.47 ± 0.55 vs. 0.30 ± 0.02 g/L of protein in urine, P < 0.001) associated with increased uremia, creatininemia, and cardiotoxicity. Large HDL2b augmented significantly during proteinuria, whereas small HDL3b and HDL3c decreased compared to basal conditions. HDL2b, HDL2a, and HDL3a subclasses were enriched with triacylglycerols in proteinuric animals as determined by the triacylglycerol‐to‐phospholipid ratio; the cholesterol content in HDL subclasses remained unchanged. The fractional catabolic rate (FCR) of [131I]‐apo A‐I in the proteinuric rabbits was faster (FCR = 0.036 h?1) compared to control rabbits group (FCR = 0.026 h?1, P < 0.05). Apo E increased and apo A‐I decreased in HDL, whereas PON‐1 activity increased in proteinuric rabbits. Proteinuria was associated with an increased number of large HDL2b particles and a decreased number of small HDL3b and 3c. Proteinuria was also connected to an alteration in HDL subclass lipids, apolipoprotein content of HDL, high paraoxonase‐1 activity, and a rise in the fractional catabolic rate of the [131I]‐apo A‐I. 相似文献
77.
Mechanochemical Processing of Mn and Co Oxides: An Alternative Way to Synthesize Mixed Spinels for Protective Coating
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Andrea Masi Mariangela Bellusci Maurizio Carlini Stephen J. McPhail Franco Padella Priscilla Reale 《Journal of the American Ceramic Society》2016,99(1):308-314
High‐Energy Ball Milling (HEBM) is proposed as a cost effective and environmental friendly technique to produce Co‐ and Mn‐ based oxides suitable for application as protective coating. Mixtures of manganese and cobalt oxides in different molar ratio (Co:Mn = 1:1 and Co:Mn = 2:1) were subjected to mechanochemical treatment up to 100 h and morpho‐structural evolution was evaluated. XRD analysis results show that the HEBM treatment promotes the solid‐state reaction of the starting compounds, with the formation of different crystalline phases when compared to high‐temperature solid‐state synthesis. SEM observations and N2 adsorption measurements suggest that all processed powders are composed by aggregates of nanometric particles. While long milling time is required to complete the reaction, 10 hours are enough to activate the powders to obtain the desired phases after a mild thermal treatment, as evidenced by in situ thermal XRD analysis. Electrical conductivity measures performed with the Van der Pauw method on sintered pellets evidence a significant difference between the two compositions, related to the dual‐phase nature of Co:Mn = 1:1 material at intermediate temperatures (i.e., T < 700°C), Co:Mn = 2:1 sample showing higher conductivity values in the whole tested range (500°C–800°C). 相似文献
78.
Antioxidant ability of potato (Solanum tuberosum) peel extracts to inhibit soybean oil oxidation
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79.
Franco David Troncoso Ignacio Oscar Costilla Gabriela Marta Tonetto 《Journal of the American Oil Chemists' Society》2022,99(8):697-710
In the present work, Pt/γ-Al2O3 catalysts with high metal dispersion were prepared and characterized using chloroplatinic acid and platinum acetylacetonate as metal precursors. The activity and selectivity of the catalysts were evaluated in the hydrogenation of sunflower oil. A comprehensive analysis of the effects of key operational parameters on catalytic performance was carried out. The experimental variables were hydrogen pressure (275.8–551.6 kPa), temperature (160–200°C), and catalyst loading (0.005–0.015 kg Ptexp/m3oil). Platinum catalysts were active, with a double bond conversion of 28% at 2 h. The metal precursor affected catalyst selectivity. The catalyst prepared with chloroplatinic acid exhibited a lower formation of trans-isomers compared with Pt acetylacetonate. The γ-Al2O3 supported platinum catalyst with a metal loading of 0.51 wt.% and a metal dispersion of 98% maintained its initial catalyst activity and selectivity after 10 consecutive uses (1200 min accumulate operation time), without changes in its catalytic properties. The obtained results suggested that Pt catalysts are an attractive alternative to conventional nickel catalysts for the hydrogenation of vegetable oil. 相似文献
80.
Liana Franco Padilha Cristine Carretoni Ferreira Fabricio Machado Márcio Nele José Carlos Pinto 《应用聚合物科学杂志》2014,131(9)
In this work, NIRS is employed to provide compositions of α‐olefin copolymers, allowing for evaluation of the effects of certain key process variables on the final NIR spectral responses of obtained polymer materials. This work also introduces a new temperature programmed analytical technique, which combines NIRS measurements with partial fractionation of α‐olefin copolymers. The new proposed technique can be used for evaluation of polyolefin compositions, as presented here for poly(propene/1‐butene) copolymers. Besides, preliminary results obtained from thermal fractionation experiments indicate that this new proposed experimental technique can be employed for characterization of comonomer sequence distributions of α‐olefin copolymers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40127. 相似文献