Investigation of scaling properties of hysteresis in Finemet thin films

We study the behavior of hysteresis loops in Finemet Fe$_{73.5}$Cu$_1$Nb$_3$Si$_{18.5}$B$_4$ thin films by using a fluxometric setup based on a couple of well compensated pickup coils. The presence of scaling laws of the hysteresis area is investigated as a function of the amplitude and frequency of the applied field, considering sample thickness from about 20 nm to 5 $\mu$m. We do not observe any scaling predicted by theoretical models, while dynamic loops show a logarithmic dependence on the frequency.Comment: 2 pages, 2 figure

Structural, Magnetic And Transport Properties Of Discontinuous Granular Multi-layers

Results of structural, magnetic and transport properties of magnetic Co/SiO2 discontinuous multi-layers produced by sequential deposition are presented. Transmission electron microscopy (TEM) images show that the samples that are close to metal-insulation transition are composed by a connected network of metallic paths, and display an enhanced Hall Effect. The granular samples are composed by an almost periodic array of Co nanoparticles, and after annealing these samples show a clear evolution in the nanostructure, with increasing average Co grain sizes and decreasing size dispersion. Relationships between the nanostructure and magnetotransport properties are discussed and compared with previous results obtained in cosputtered films. © 2005 Elsevier B.V. All rights reserved.2942206212Abeles, B., Sheng, P., Coutts, M.D., Arie, Y., (1975) Adv. Phys., 24, p. 40Vázquez, M., Hernando, A., (1995) Adv. Mater., 7, p. 1021Herzer, G., (1993) Phys. Scripta T, 49, p. 307Hernando, A., Kulik, T., (1994) Phys. Rev. B, 49, p. 7064Denardin, J.C., Brandl, A.L., Knobel, M., Panissod, P., Pakhomov, A.B., Liu, H., Zhang, X.X., (2002) Phys. Rev. B, 65, p. 064422Milner, A., Gerber, A., Groisman, B., Karpovsky, M., Gladkikh, A., (1996) Phys. Rev. Lett., 76, p. 475Slawska-Waniewska, A., Gutowski, M., Lachowicz, H.K., Kulik, T., Matyja, H., (1992) Phys. Rev. B, 46, p. 14594Pakhomov, A.B., Yan, X., Zhao, B., (1995) Appl. Phys. Lett., 67, p. 3497Jing, X.N., Wang, N., Pakhomov, A.B., Fung, K.K., Yan, X., (1996) Phys. Rev. B, 53, p. 14032Denardin, J.C., Knobel, M., Pakhomov, A.B., Zhang, X.X., (2003) J. Magn. Magn. Mater., 262, p. 15Aronzon, B.A., Rylkov, V.V., Kovalev, D.Y., Meilikhov, E.Z., Ryl'Kov, V.V., Sedova, M.V., (2000) Phys. Stat. Solidi, 218, p. 169Aronzon, B.A., Granovskii, A.B., Kovalev, D.Y., Meilikhov, E.Z., Ryl'Kov, V.V., Sedova, M.V., (2000) JETP Lett., 71, p. 469Zhang, X.X., Wan, C.C., Liu, H., Li, Z.Q., Sheng, P., Lin, J.J., (2001) Phys. Rev. Lett., 86, p. 5562Wan, C.C., Sheng, P., (2002) Phys. Rev. B, 66, p. 075309Maurice, J.L., Briatico, J., Carrey, J., Petroff, F., Schelp, L.F., Vaures, A., (1999) Philos. Mag. A, 79, p. 2921Skumryev, V., Stoyanov, S., Zhang, Y., Hadjipanayis, G., Givord, D., Nogues, J., (2003) Nature, 423, p. 850L.M. Socolovsky, C.L.P. Oliveira, J.C. Denardin, M. Knobel, I.L. Torriani, unpublishedDa Silva, F.C.S., Ferrari, E.F., Knobel, M., (1998) J. Appl. Phys., 84, p. 5366Denardin, J.C., Knobel, M., Socolovsky, L.M., Brandl, A.L., Zhang, X.X., (2003) IEEE Trans. Magn., 39, p. 276

Structural And Magnetotransport Properties Of Discontinuous Co/sio 2 Multilayers

Results of structural, magnetic and transport properties of magnetic Co/SiO2 granular multilayers, consisting of successive planes of nanosized cobalt clusters embedded in SiO2 and produced by sequential deposition, are presented. Microscopy shows that samples can be composed of a periodical array of Co nanoparticles. Relationships between the nanostructure and magnetotransport properties are discussed. © 2004 Elsevier B.V. All rights reserved.1122-3 SPEC. ISS.120122Abeles, B., Sheng, P., Coutts, M.D., Arie, Y., (1975) Adv. Phys., 24, p. 40Vázquez, M., Hernando, A., (1995) Adv. Mater., 7, p. 1021Herzer, G., (1993) Phys. Scripta, T49, p. 307Hernando, A., Kulik, T., (1994) Phys. Rev. B, 49, p. 7064Denardin, J.C., Brandl, A.L., Knobel, M., Panissod, P., Pakhomov, A.B., Liu, H., Zhang, X.X., (2002) Phys. Rev. B, 65, p. 064422Milner, A., Gerber, A., Groisman, B., Karpovsky, M., Gladkikh, A., (1996) Phys. Rev. Lett., 76, p. 475Slawska-Waniewska, A., Gutowski, M., Lachowicz, H.K., Kulik, T., Matyja, H., (1992) Phys. Rev. B, 46, p. 14594Maurice, J.L., Briatico, J., Carrey, J., Petroff, F., Schelp, L.F., Vaures, A., (1999) Philos. Mag. A, 79, p. 2921Schelp, L.F., Fert, A., Fettar, F., Holody, P., Lee, S.F., Mourice, J.L., Petroff, F., Vaures, A., (1997) Phys. Rev. B, 56, pp. R5747Skumryev, V., Stoyanov, S., Zhang, Y., Hadjipanayis, G., Givord, D., Nogue's, J., (2003) Nature, 423, p. 85

Digestão do feno de capim-elefante anão (Pennisetum purpureum Schum. cv. Mott) sob diferentes níveis de consumo em ovinos Dwarf elephant grass hay (Pennisetum purpureum Schum. cv. Mott) digestion by sheep at different levels of intake

Foram utilizados doze ovinos Texel &times; Corriedale machos, castrados, com 12 meses de idade e peso vivo (PV) inicial médio de 27kg, mantidos em gaiolas de metabolismo, em um delineamento inteiramente casualizado, conduzido em dois períodos, para avaliar o efeito do nível de consumo (base matéria seca (MS)) de feno de capim elefante anão (CEA) (1,50; 1,75; 2,00; 2,25; 2,50% do PV e ad libitum) sobre a digestão nesses animais. A digestibilidade aparente da MS, da matéria orgânica (MO) e do nitrogênio (N), bem como a digestibilidade verdadeira do N, o teor de nutrientes digestíveis totais e a síntese de proteína microbiana ruminal não foram afetados, mas a retenção de N (em g dia-1 e como % do N consumido) foi sempre positiva e aumentou linearmente (P<0,01) com o aumento do consumo de CEA. No entanto, o aumento do consumo diminuiu linearmente a digestibilidade da fibra em detergente neutro (FDN), da fibra em detergente ácido (FDA) (P<0,05) e a digestibilidade verdadeira da MO (P<0,01). A taxa de passagem e o tempo de retenção no ceco-cólon não foram afetados, mas a taxa de passagem da digesta pelo retículo-rúmen aumentou e o tempo de retenção das partículas no retículo-rúmen (TRrr) e no trato digestivo total diminuiu (TRT) (P<0,05) com o aumento no consumo de feno. A redução do tempo de retenção do alimento no retículo-rúmen diminuiu a digestibilidade verdadeira da matéria orgânica e da parede celular da forragem. No entanto, não influenciou a digestibilidade aparente da matéria orgânica e, desse modo, não influenciou o valor energético da forragem.<br>Twelve one year old Texel x Corriedale castrated male sheep, with 27kg mean live weight (LW), housed in metabolic cages, were used in a completely randomized experiment, carried out in two periods, to evaluate the effect of level of intake (dry matter (DM) basis) of dwarf elephant grass (1.5; 1.75; 2.0; 2.25; 2.5% of LW and ad libitum) on digestion. DM, organic matter (OM) and nitrogen (N) apparent digestibility, as well as the N true digestibility, total digestible nutrients (TDN) contents and rumen microbial protein synthesis were not affected by level of hay intake. N retention (as g day-1 and as % of N intake) was always positive and increased linearly (P<0.05) as the level of hay intake increased. However, neutral (NDF) and acid detergent fiber (ADF) apparent digestibility, as well as OM true digestibility decreased linearly (P<0.05) with increasing intake. Passage rate and mean retention time in the cecum-colon were not affected, whereas passage rate through the reticulum-rumen increased and mean retention time decreased (P<0.05) as the level of intake increased. Fibre and OM true digestibility decreased as hay intake increased (P<0.05), mainly due to a decreasing in retention time of particles into the reticulo-rumen. However, OM apparent digestibility and, thus, the energetic value of dwarf elephant grass hay was not affected by the level of intake

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora