2,901 research outputs found

    From vortex molecules to the Abrikosov lattice in thin mesoscopic superconducting disks

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    Stable vortex states are studied in large superconducting thin disks (for numerical purposes we considered with radius R = 50 \xi). Configurations containing more than 700 vortices were obtained using two different approaches: the nonlinear Ginzburg-Landau (GL) theory and the London approximation. To obtain better agreement with results from the GL theory we generalized the London theory by including the spatial variation of the order parameter following Clem's ansatz. We find that configurations calculated in the London limit are also stable within the Ginzburg-Landau theory for up to ~ 230 vortices. For large values of the vorticity (typically, L > 100), the vortices are arranged in an Abrikosov lattice in the center of the disk, which is surrounded by at least two circular shells of vortices. A Voronoi construction is used to identify the defects present in the ground state vortex configurations. Such defects cluster near the edge of the disk, but for large L also grain boundaries are found which extend up to the center of the disk.Comment: 15 pages, 10 figures, RevTex4, submitted to Phys. Rev.

    Bipolar HII regions - Morphology and star formation in their vicinity - I - G319.88++00.79 and G010.32-00.15

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    Our goal is to identify bipolar HII regions and to understand their morphology, their evolution, and the role they play in the formation of new generations of stars. We use the Spitzer and Herschel Hi-GAL surveys to identify bipolar HII regions. We search for their exciting star(s) and estimate their distances using near-IR data. Dense clumps are detected using Herschel-SPIRE data. MALT90 observations allow us to ascertain their association with the central HII region. We identify Class 0/I YSOs using their Spitzer and Herschel-PACS emissions. These methods will be applied to the entire sample of candidate bipolar HII regions. This paper focuses on two bipolar HII regions, one interesting in terms of its morphology, G319.88++00.79, and one in terms of its star formation, G010.32-00.15. Their exciting clusters are identified and their photometric distances estimated to be 2.6 kpc and 1.75 kpc, respectively. We suggest that these regions formed in dense and flat structures that contain filaments. They have a central ionized region and ionized lobes perpendicular to the parental cloud. The remains of the parental cloud appear as dense (more than 10^4 per cm^3) and cold (14-17 K) condensations. The dust in the PDR is warm (19-25 K). Dense massive clumps are present around the central ionized region. G010.32-00.14 is especially remarkable because five clumps of several hundred solar masses surround the central HII region; their peak column density is a few 10^23 per cm^2, and the mean density in their central regions reaches several 10^5 per cm^3. Four of them contain at least one massive YSO; these clumps also contain extended green objects and Class II methanol masers. This morphology suggests that the formation of a second generation of massive stars has been triggered by the central bipolar HII region. It occurs in the compressed material of the parental cloud.Comment: 32 pages, 28 figures, to be published in A&

    Produção de bebida obtida a partir da fração retida na microfiltração da polpa de açaí.

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    Carnitine partially improves oxidative stress, acrosome integrity, and reproductive competence in doxorubicin-treated rats

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    Doxorubicin has been largely used in anticancer therapy in adults, adolescents, and children. The efficacy of l-carnitine as an antioxidant substance has been confirmed both in humans and rats. Carnitine, present in testis and epididymis, is involved in sperm maturation. It is also effective in infertility treatment. As a continuation of a previous study, we evaluated whether some spermatic qualitative parameters, DNA integrity, chromatin structure, and fertility status, could be ameliorated by the carnitine treatment in adult rats, which were subsequently exposed to doxorubicin at pre-puberty. Pre-pubertal male rats were distributed into four groups: Sham ControlDoxorubicinl-carnitinel-carnitine+Doxorubicin (l-carnitine injected 1h before doxorubicin). At 100days of age, all groups were reassigned into two sets: One set was submitted to the evaluation of sperm motility, acrosome integrity, mitochondrial activity, sperm chromatin structure analysis (SCSA), and evaluation of the oxidative stress. The other set of rats was destined to the evaluation of reproductive competence. The percentage of spermatozoa with intact acrosome integrity was higher in the Carnitine+Doxorubicin group when compared with the Doxorubicin group. However, sperm motility and mitochondrial activity were not improved by carnitine pre-treatment. Both values of malondialdehyde and nitrite (indirect measurement of nitric oxide) concentrations were statistically higher in the only doxorubicin-treated group when compared to the Carnitine+Doxorubicin group. Fertility index and implantation rate were lower in Doxorubicin group, when compared to Carnitine+Doxorubicin group. Moreover, the percentage of spermatozoa with damaged DNA was higher in the Doxorubicin-treated group when compared to the Carnitine+Doxorubicin group. l-carnitine, when administered before doxorubicin, partially preserved the acrosome integrity, an important feature related to sperm fertilization ability that positively correlated with the reproductive competence and sperm DNA integrity at adulthood. In conclusion, l-carnitine attenuated the long-term alterations caused by doxorubicin in the germ cells and improved male reproductive capacity in adulthood.National Council for the Improvement of Higher Education (CAPES/Brazil)Fed Univ Sao Paulo UNIFESP, Lab Dev Biol, Dept Morphol & Genet, Botucatu St 740,Leitao da Cunha Bldg,2nd Floor, BR-04023900 Sao Paulo, SP, BrazilFed Univ Sao Paulo UNIFESP, Lab Dev Biol, Dept Morphol & Genet, Botucatu St 740,Leitao da Cunha Bldg,2nd Floor, BR-04023900 Sao Paulo, SP, BrazilWeb of Scienc

    Efeito da desidratação osmótica na redução da atividade de água de manga 'Tommy Atkins' seca.

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    O presente trabalho teve como objetivo avaliar a influência da desidratação osmótica na atividade de água (aw) da manga ?Tommy Atkins? seca

    Characterization of watermelon juice concentrated by reverse osmosis process.

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    Watermelon is a tropical fruit with excellent flavour, color, sweetness and succulence. Nowadays it is pointed out as an excellent source of lycopene, a carotenoid with antioxidant property. The objective of this work was to concentrate watermelon juice by reverse osmosis to obtain a concentrated product rich in lycopene. The juice was obtained by the depulping the fruits in a finisher with a 0.8 mm. Reverse osmosis was carried out in a pilot plant unit with composite membranes (conditioned in a plate and frame module. totalizing a permeate area of 0.72m2. The process was carried out at 30ºC, 60 bar and 650 L/h flow rate. Samples Lycopene content was determined by extraction with hexane measured in spectrophotometer at 503 nm. Antioxidant capacity s was evaluated by extraction with hexane followed by the quantification using ABTS as radical and Trolox as standard. The color loss was determined in spectrophotometer at 734nm after 15 min of reaction of the sample with the ABTS. The mean permeate flux was 22L1h1m
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