Nanoflare Evidence from Analysis of the X-Ray Variability of an Active Region Observed with Hinode/XRT

The heating of the solar corona is one of the big questions in astrophysics. Rapid pulses called nanoflares are among the best candidate mechanisms. The analysis of the time variability of coronal X-ray emission is potentially a very useful tool to detect impulsive events. We analyze the small-scale variability of a solar active region in a high cadence Hinode/XRT observation. The dataset allows us to detect very small deviations of emission fluctuations from the distribution expected for a constant rate. We discuss the deviations in the light of the pulsed-heating scenario.Comment: 6 pages, 4 figure

Family firm internationalization: Past research and an agenda for the future

Although the study of family firm internationalization has generated considerable scholarly attention, existing research has offered varied and at times incompatible findings on how family ownership and management shape internationalization. To improve our understanding of family firm internationalization, we systematically review 220 conceptual and empirical studies published over the past three decades, structuring our comprehensive overview of this field according to seven core international business (IB) themes. We assess the literature and propose directions for future research by developing an integrative framework of family firm internationalization that links IB theory with conceptual perspectives used in the reviewed body of work. We propose a research agenda that advocates a cross-disciplinary, multi-theoretic, and cross-level approach to studying family firm internationalization. We conclude that family firm internationalization research has the potential to contribute valuable insights to IB scholarship by increasing attention to conceptual and methodological issues, including micro-level affective motivations, background social institutions, temporal perspectives, and multi-level analyses

Evidence for Anisotropic Vortex Dynamics and Pauli Limitation in the Upper Critical Field of FeSe1-xTex

We have determined HC2(T) for FeSe1-xTex (x=0.52) single crystals using resistivity measurements at high static and pulsed magnetic field, as well as specific heat measurements up to 9T. We find that the significant anisotropy of the initial slope of HC2(T) determined from resistivity measurements, is not present when HC2 is determined from the specific heat results. This suggests that the thermodynamic upper critical field is almost isotropic, and that anisotropic vortex dynamics play a role. Further evidence of anisotropic vortex dynamics is found in the behaviour in pulsed field. We also find that Pauli limiting must be included in order to fit the temperature dependence of HC2, indicating probably higher effective mass in FeSe1-xTex than in other Fe superconductors

Coronal Temperature Diagnostic Capability of the Hinode/X-Ray Telescope Based on Self-Consistent Calibration

The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray imager that observes the solar corona with unprecedentedly high angular resolution (consistent with its 1" pixel size). XRT has nine X-ray analysis filters with different temperature responses. One of the most significant scientific features of this telescope is its capability of diagnosing coronal temperatures from less than 1 MK to more than 10 MK, which has never been accomplished before. To make full use of this capability, accurate calibration of the coronal temperature response of XRT is indispensable and is presented in this article. The effect of on-orbit contamination is also taken into account in the calibration. On the basis of our calibration results, we review the coronal-temperature-diagnostic capability of XRT

Thermally-induced magnetic phases in an Ising spin Kondo lattice model on a kagome lattice at 1/3-filling

Numerical investigation on the thermodynamic properties of an Ising spin Kondo lattice model on a kagome lattice is reported. By using Monte Carlo simulation, we investigated the magnetic phases at 1/3-filling. We identified two successive transitions from high-temperature paramagnetic state to a Kosterlitz-Thouless-like phase in an intermediate temperature range and to a partially disordered phase at a lower temperature. The partially disordered state is characterized by coexistence of antiferromagnetic hexagons and paramagnetic sites with period $\sqrt3 \times \sqrt3$. We compare the results with those for the triangular lattice case.Comment: 4 pages, 2 figure

Large time existence for 3D water-waves and asymptotics

We rigorously justify in 3D the main asymptotic models used in coastal oceanography, including: shallow-water equations, Boussinesq systems, Kadomtsev-Petviashvili (KP) approximation, Green-Naghdi equations, Serre approximation and full-dispersion model. We first introduce a ``variable'' nondimensionalized version of the water-waves equations which vary from shallow to deep water, and which involves four dimensionless parameters. Using a nonlocal energy adapted to the equations, we can prove a well-posedness theorem, uniformly with respect to all the parameters. Its validity ranges therefore from shallow to deep-water, from small to large surface and bottom variations, and from fully to weakly transverse waves. The physical regimes corresponding to the aforementioned models can therefore be studied as particular cases; it turns out that the existence time and the energy bounds given by the theorem are always those needed to justify the asymptotic models. We can therefore derive and justify them in a systematic way.Comment: Revised version of arXiv:math.AP/0702015 (notations simplified and remarks added) To appear in Inventione

Produtividade e qualidade de frutos do meloeiro rendilhado sob diferentes doses de Co2 e de potássio aplicadas via irrigação.

Recentemente, o enriquecimento da água de irrigação com o CO2 tem se constituído mais uma alternativa para contribuir com a produtividade e a qualidade de culturas hortícolas. Segundo KIMBALL (1994), a aplicação de CO2 às culturas tende a melhorar o metabolismo e o equilíbrio hormonal, a reduzir a inibição da fotossíntese pelo oxigênio, a aumentar a fotossíntese líquida e a absorção de nutrientes, resultando em plantas mais produtivas. O meloeiro é mais cultivado no Nordeste brasileiro, onde a produtividade pode ultrapassar a 40 t ha-1 (SILVA et al., 2000). Para o Estado de São Paulo, o maior centro consumidor de melão do país, as condições climáticas limitam a exploração dessa cultura em campo aberto, podendo ser cultivado em ambiente protegido constituindo-se um agronegócio atraente. O meloeiro tem respondido bem à fertirrigação por gotejamento, principalmente, com nitrogênio e potássio. PINTO (1997) aplicou 180 kg ha-1 de K2O e 50 kg ha-1 de CO2 via irrigação no meloeiro amarelo rasteiro em ambiente protegido e obteve a PC de 23,68 t ha-1 de frutos contra 19,67 t ha-1, sem aplicação do CO2, com acréscimos na PC de 20,39%. Segundo LORENZO (2000), o aumento da concentração de CO2 em ambiente protegido gera incrementos produtivos variáveis, pois a concentração ambiental de CO2 é inferior a ótima biológica para a maioria das espécies hortícolas. O objetivo deste trabalho foi estudar os efeitos de CO2 e de potássio aplicados via irrigação na produtividade do meloeiro rendilhado em ambiente protegido. PINTO (1997) encontrou efeito significativo positivo do CO2 (50 kg ha-1), tanto para o número (14,35%), quanto para o peso médio de frutos comerciais (9,38%). O objetivo deste trabalho foi estudar o efeito de diferentes doses de dióxido de carbono (CO2) e de potássio (K2O), aplicadas através da irrigação por gotejamento sobre a produtividade e qualidade de frutos do meloeiro rendilhado cultivado em ambiente protegido

Mapeamento do uso e cobertura das terras e estoque de carbono no solo em área de floresta na bacia hidrográfica de Apuí/AM.

O objetivo deste trabalho foi mapear o uso e cobertura das terras e obter o estoque de carbono no solo em área de floresta na bacia hidrográfica localizada no município de Apuí, AM. Para isso, inicialmente foi feito o mapeamento que envolveu a delimitação e identificação do uso e cobertura das áreas. O mapeamento foi feito com o auxílio de ferramentas de edição vetorial do sistema de informação geográfica (SIG) Esri ArcGIS. As classes de uso e cobertura foram definidas a partir de padrões, seguindo classificação do Manual Técnico de Uso da Terra, do IBGE (2013). Após o mapeamento, foi feito o levantamento de literaturas focadas no estoque de carbono no solo no bioma Amazônia. Na bacia hidrográfica estudada observou-se maior ocorrência de floresta e pastagem, e o tipo de solo predominante encontrado foi o Latossolo, que estoca quantidade significativa de carbono