Controlling magnetic and transport properties of granular alloys through Joule heating

Melt-spun Cu-Co ribbons are annealed by linearly varying current Joule heating. During the annealing, the electrical resistance is measured in order to follow the structural transformations within the samples. The resistance versus current curves show a characteristic behavior for all samples studied. This fact is used to specify optimum conditions to obtain the best nanostructure which displays the maximum giant magnetoresistance ratio. (C) 1998 American Institute of Physics. [S0021-8979(98)04521-6].8495366536

Amphibians on the hotspot: Molecular biology and conservation in the South American Atlantic Rainforest

Amphibians are the focus of a recent debate and public attention owing to the global decline in their populations worldwide. Amphibians are one of the most threatened and poorly known groups of vertebrates in several geographic areas, even though they play a central role in their own ecosystems. At different levels, amphibians make their contribution to proper ecosystem functioning. They act as regulators of the food web and nutrient cycling, and they also provide several valuable ecosystem services, e.g., as a food source and as animal models for lab research. In this sense, it seems clear that the maintenance of amphibian diversity should be one of the major goals for the several countries where their population decline is observed. However, we are still struggling with the very first step of this process, i.e., the correct identification of the amphibian species diversity. Over the past few decades, research on molecular identification of amphibians using DNA barcoding has encountered some difficulties related to high variability in the mitochondrial genome of amphibians, and a research gap is noticeable in the literature. We herein evaluated both COI and 16S rRNA mitochondrial genes for the molecular identification of frogs and tadpoles in a large fragment of the South American Atlantic Rainforest in Rio de Janeiro, Brazil. Our results suggest that both COI and 16S rRNA are informative markers for the molecular identification of the amphibian specimens with all specimens unambiguously identified at the species level. We also made publicly available 12 new sequences of Atlantic Rainforest amphibian species for the first time, and we discussed some conservation issues related to amphibians within the Atlantic Rainforest domains in the state of Rio de Janeiro, Brazil.The authors benefited from grants provided to CFDR (304791/2010-5; 470265/2010- 8 and 302974/2015-6) from Conselho Nacional do Desenvolvimento Cientifico e Tecnologico (CNPq) and through "Cientistas do Nosso Estado" Program from FAPERJ to CFDR (process No. E-26/ 102.765.2012 E-26/202.920.2015). We would like to thank C. Haddad (Universidade Estadual Paulista) and M. L. Lyra (Universidade Estadual Paulista) for some of the specimens and the primers used in the present manuscript and L. A. Fusinatto, who kindly revised the manuscript offering helpful suggestions. FP was supported by the Portuguese Foundation for Science and Technology (FCT) [IF/01356/2012] and Northern Regional Operational Programme (NORTE2020) through the European Regional Development Fund (ERDF) [MARINFO NORTE-01-0145-FEDER- 000031]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

The Analyticity of a Generalized Ruelle's Operator

In this work we propose a generalization of the concept of Ruelle operator for one dimensional lattices used in thermodynamic formalism and ergodic optimization, which we call generalized Ruelle operator, that generalizes both the Ruelle operator proposed in [BCLMS] and the Perron Frobenius operator defined in [Bowen]. We suppose the alphabet is given by a compact metric space, and consider a general a-priori measure to define the operator. We also consider the case where the set of symbols that can follow a given symbol of the alphabet depends on such symbol, which is an extension of the original concept of transition matrices from the theory of subshifts of finite type. We prove the analyticity of the Ruelle operator and present some examples

Controlling Fe nanocrystallization in amorphous Fe86Zr7Cu1B6 by linear varying current Joule heating

Amorphous melt-spun Fe86Zr7Cu1B6 ribbons were annealed using the linear varying current Joule heating method. Experimental curves of resistance (R) and temperature (T) versus applied current (I) allow one to follow precisely the crystallization of alpha-Fe nanoparticles during annealing. This result proves that the applied current can be considered a reliable parameter to control the crystalline fraction in this alloy. A comparison between structural and magnetic measurements shows that the R(I) curve can be used as a guide to identify a condition for optimum soft magnetic properties of this alloy. (C) 2000 American Institute of Physics. [S0003-6951(00)02035-0].7791375137

Heteropoly acid catalysts in upgrading of biorenewables: Synthesis of para-menthenic fragrance compounds from α-pinene oxide

© 2018 Elsevier B.V. The isomerization of α-pinene oxide in the presence of Cs2.5H0.5PW12O40 (CsPW) heteropolysalt as solid acid catalyst is reported. The reactions were performed in various solvents, which allowed to obtain trans-carveol, trans-sobrerol and pinol in 60–80% yield each, which exceed the yields reported so far. The CsPW catalyst could be recovered and reused without loss of its activity and selectivity

Application of amorphous carbon based materials as antireflective coatings on crystalline silicon solar cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)We report on the investigation of the potential application of different forms of amorphous carbon (a-C and a-C:H) as an antireflective coating for crystalline silicon solar cells. Polymeric-like carbon (PLC) and hydrogenated diamond-like carbon films were deposited by plasma enhanced chemical vapor deposition. Tetrahedral amorphous carbon (ta-C) was deposited by the filtered cathodic vacuum arc technique. Those three different amorphous carbon structures were individually applied as single antireflective coatings on conventional (polished and texturized) p-n junction crystalline silicon solar cells. Due to their optical properties, good results were also obtained for double-layer antireflective coatings based on PLC or ta-C films combined with different materials. The results are compared with a conventional tin dioxide (SnO(2)) single-layer antireflective coating and zinc sulfide/magnesium fluoride (ZnS/MgF(2)) double-layer antireflective coatings. An increase of 23.7% in the short-circuit current density, J(sc), was obtained using PLC as an antireflective coating and 31.7% was achieved using a double-layer of PLC with a layer of magnesium fluoride (MgF(2)). An additional increase of 10.8% was obtained in texturized silicon, representing a total increase (texturization + double-layer) of about 40% in the short-circuit current density. The potential use of these materials are critically addressed considering their refractive index, optical bandgap, absorption coefficient, hardness, chemical inertness, and mechanical stability. (C) 2011 American Institute of Physics. [doi:10.1063/1.3622515]1104Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Brazilian financial research agency MCTConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

High Levels of Heavy Metal(loid)s Related to Biliary Hyperplasia in Hedgehogs (Erinaceus europaeus)

Simple Summary Heavy metal(loid)s are hazardous substances for humans, animals and ecosystems. The liver is one of the most affected organs, presenting lesions after being acutely or chronically exposed to these substances. In this study, hepatic metal(loid)s' concentrations were associated with biliary hyperplasia, which was the most common hepatic lesion found in a group of western-European hedgehogs from rescue centres in Portugal. With exception of arsenic (As), all metal(loid)s were present in higher concentrations in animals with biliary hyperplasia. Further research is necessary to support these results and clarify the molecular mechanisms that lead to hepatic lesions provoked by these compounds. Heavy metal(loid) pollution of ecosystems is a current One Health problem. The liver is one of the most affected organs in cases of acute or chronic exposure to abnormal amounts of these substances, inducing histopathologic lesions. In order to assess the influence of heavy metal(loids), forty-five European hedgehogs (Erinaceus europaeus) were submitted to necropsy, and liver samples were collected for a routine histopathology exam and metal(loid)s determination (As, Cd, Co, Cr, Cu and Pb) by ICP-MS. Age was estimated during the necropsy exam. Biliary hyperplasia was the most frequent lesion observed (16/45; 35.56%). No statistically significant associations were found between biliary hyperplasia and age or sex. Metal(loid)s' concentrations were higher in animals with biliary hyperplasia (except for As). There was a statistically significant difference for both Cd and Co. For As, Cd and Co, cubs and juveniles animals showed significantly lower concentrations than elder individuals. Only for Pb were significant differences found between females and males. As described in the literature, exposure to metal(loid)s may be a cause of biliary hyperplasia, although further research (including the use of biochemical methods) is needed to support these results. To the authors' knowledge, this is the first report of this association in hedgehogs.This work was supported by National Funds by the Portuguese Foundation for Science and Technology (FCT). The authors of the research unit CITAB (CJB and PAO) received funding from FCT-reference of the project: UIDB/04033/2020. The author of the research unit CECAV (FS) received funding from FCT-reference of the project: UIDB/CVT/00772/2020. CJB was supported by FCT due to the phD scholarship 2021.04520.BD. TLM was supported by UIDB/CVT/00772/2020 and LA/P/0059/2020 funded by FCT