排序方式: 共有22条查询结果,搜索用时 31 毫秒
1.
Daciberg L. Gon?alves Mauro Spreafico Oziride Manzoli Neto 《Journal of Fixed Point Theory and Applications》2011,9(2):285-294
In this work, we show for which odd-dimensional homotopy spherical space forms the Borsuk–Ulam theorem holds. These spaces
are the quotient of a homotopy odd-dimensional sphere by a free action of a finite group. Also, the types of these spaces
which admit a free involution are characterized. The case of even-dimensional homotopy spherical space forms is basically
known. 相似文献
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Marcio Colombo Fenille Oziride Manzoli Neto 《Central European Journal of Mathematics》2010,8(3):421-429
Given a model 2-complex K
P
of a group presentation P, we associate to it an integer matrix Δ
P
and we prove that a cellular map f: K
P
→ S
2 is root free (is not strongly surjective) if and only if the diophantine linear system Δ
P
Y = $
\overrightarrow {deg}
$
\overrightarrow {deg}
(f) has an integer solution, here $
\overrightarrow {deg}
$
\overrightarrow {deg}
(f)is the so-called vector-degree of f 相似文献
4.
Eliangela de Morais Teixeira Ana Carolina Corrêa Alexandra Manzoli Fabio de Lima Leite Cauê Ribeiro de Oliveira Luiz Henrique Capparelli Mattoso 《Cellulose (London, England)》2010,17(3):595-606
Suspensions of white and colored nanofibers were obtained by the acid hydrolysis of white and naturally colored cotton fibers.
Possible differences among them in morphology and other characteristics were investigated. The original fibers were subjected
to chemical analysis (cellulose, lignin and hemicellulose content), X-ray diffraction (XRD) analysis, and scanning electron
microscopy (SEM). The nanofibers were analyzed with respect to yield, elemental composition (to assess the presence of sulfur),
zeta potential, morphology (by scanning transmission electron microscopy (STEM)) and atomic force microscopy (AFM), crystallinity
(XRD) and thermal stability by thermogravimetric analysis in air under dynamic and isothermal temperature conditions. Morphological
study of several cotton nanofibers showed a length of 85–225 nm and diameter of 6–18 nm. The micrographs also indicated that
there were no significant morphological differences among the nanostructures from different cotton fibers. The main differences
found were the slightly higher yield, sulfonation effectiveness and thermal stability under dynamic temperature conditions
of the white nanofiber. On the other hand, in isothermal conditions at 180 °C, the colored nanofibers showed a better thermal
stability than the white. 相似文献
5.
Henrique Peres Araújo Juliana Silva Flix Jos Eduardo Manzoli Marisa Padula Magali Monteiro 《Radiation Physics and Chemistry》2008,77(7):913-917
A gas chromatographic method to determine caprolactam in multilayer PA-6 films used for meat foodstuffs and cheese was developed and validated. A wide linear range (0.8–400 μg/ml), RSD4.1% and recovery higher than 90.0% were obtained for the chromatographic system, while precision and accuracy of the method showed RSD3.8%, recovery from 95.5–100.0% and LOQ of 32 μg/g. Irradiated (3, 7 and 12 kGy) and non-irradiated commercial films were analyzed. Most of them increased caprolactam levels with the increase of irradiation doses. 相似文献
6.
Daniela Kunkel Muenchen Janine Martinazzo Alexandra Nava Brezolin Alana Marie de Cezaro Aline Andressa Rigo Mateus Nava Mezarroba Alexandra Manzoli Fábio de Lima Leite Juliana Steffens Clarice Steffens 《Applied biochemistry and biotechnology》2018,184(4):1061-1072
A highly efficient process for reducing the fatty acid (FA) content of high-acid rice bran oil (RBO) was developed by immobilized partial glycerides-selective lipase SMG1-F278N-catalyzed esterification/transesterification using methanol as a novel acyl acceptor. Molecular docking simulation indicated that methanol was much closer to the catalytic serine (Ser-171) compared with ethanol and glycerol, which might be one of the reasons for its high efficiency in the deacidification of high-acid RBO. Additionally, the reaction parameters were optimized to minimize the FA content of high-acid RBO. Under the optimal conditions (substrate molar ratio of methanol to FAs of 1.8:1, enzyme loading of 40 U/g, and at 30 °C), FA content decreased from 25.14 to 0.03% after 6 h of reaction. Immobilized SMG1-F278N exhibited excellent methanol tolerance and retained almost 100% of its initial activity after being used for ten batches. After purification by molecular distillation, the final product contained 97.86% triacylglycerol, 2.10% diacylglycerol, and 0.04% FA. The acid value of the final product was 0.09 mg KOH/g, which reached the grade one standard of edible oil. Overall, methanol was a superior acyl acceptor for the deacidification of high-acid RBO and the high reusability of immobilized SMG1-F278N indicates an economically attractive process. 相似文献
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Wilson A. Parejo Calvo Celina L. Duarte Luci Diva B. Machado Jose E. Manzoli Aurea Beatriz C. Geraldo Yasko Kodama Leonardo Gondim A. Silva Eddy S. Pino Elizabeth S.R. Somessari Carlos G. Silveira Paulo R. Rela 《Radiation Physics and Chemistry》2012,81(8):1276-1281
The radiation processing technology for industrial and environmental applications has been developed and used worldwide. In Latin America and the Caribbean and particularly in Brazil there are 24 and 16 industrial electron beam accelerators (EBA) respectively with energy from 200 keV to 10 MeV, operating in private companies and governmental institutions to enhance the physical and chemical properties of materials. However, there are more than 1500 high-current electron beam accelerators in commercial use throughout the world. The major needs and end-use markets for these electron beam (EB) units are R and D, wire and electric cables, heat shrinkable tubes and films, PE foams, tires, components, semiconductors and multilayer packaging films. Nowadays, the emerging opportunities in Latin America and the Caribbean are paints, adhesives and coatings cure in order to eliminate VOCs and for less energy use than thermal process; disinfestations of seeds; and films and multilayer packaging irradiation. For low-energy EBA (from 150 keV to 300 keV). For mid-energy EBA (from 300 keV to 5 MeV), they are flue gas treatment (SO2 and NOX removal); composite and nanocomposite materials; biodegradable composites based on biorenewable resources; human tissue sterilization; carbon and silicon carbide fibers irradiation; irradiated grafting ion-exchange membranes for fuel cells application; electrocatalysts nanoparticles production; and natural polymers irradiation and biodegradable blends production. For high-energy EBA (from 5 MeV to 10 MeV), they are sterilization of medical, pharmaceutical and biological products; gemstone enhancement; treatment of industrial and domestic effluents and sludge; preservation and disinfestations of foods and agricultural products; soil disinfestations; lignocellulosic material irradiation as a pretreatment to produce ethanol biofuel; decontamination of pesticide packing; solid residues remediation; organic compounds removal from wastewater; and treatment of effluent from petroleum production units and liquid irradiation process to treat vessel water ballast. On the other hand, there is a growing need of mobile EB facilities for different applications in South America. 相似文献
9.
Rafaella T. Paschoalin Clarice Steffens Alexandra Manzoli Elaine C. Paris Paulo S. P. Herrmann Jr 《Macromolecular Symposia》2012,319(1):48-53
Summary: This work evaluated the influence of the synthesis temperature on the polyaniline (PANI) properties obtained by in-situ polymerization onto a poly (terephthalate) (PET) substrate. The residual mass of these syntheses was dried under vacuum, obtaining PANI powders for each temperature investigated. PANI/PET thin films and PANI powders were characterized by atomic force microscopy (AFM), field emission scanning electron microscopy (FEG-SEM), X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis) and four-point probe techniques. The UV-Vis results showed that the synthesized PANI presents the emeraldine oxidation state. By means of XRD technique, it was possible to verify that the PANI powders present crystalline form. The AFM and FEG-SEM techniques showed that the decrease in PANI/PET and PANI powders electrical conductivity with increasing of the synthesis temperature is related to the polymeric aggregates morphology. 相似文献
10.
O.L. Manzoli 《Revista Internacional de Métodos Numéricos para Cálculo y Dise?o en Ingeniería》2011,27(3):180-188
This paper addresses the study of the quality and objectivity of responses obtained with the distinct formulations (symmetric and non-symmetric) of the discontinuity embedded finite elements, as well as with the local continuum approach (smeared model), in which the softening law dependent on the element size is combined with a scheme to track the discontinuity path. The study is based on the concepts of kinematic and static consistency of the embedded discontinuity formulations. 相似文献