Long-period chromospheric oscillations in network bright points

The spatial variation of chromospheric oscillations in network bright points (NBPs) is studied using high-resolution observations in Ca II K3. Light curves and hence power spectra were created by isolating distinct regions of the NBP via a simple intensity thresholding technique. Using this technique, it was possible to identify peaks in the power spectra with particular spatial positions within the NBPs. In particular, long-period waves with periods of 4-15 minutes (1-4 mHz) were found in the central portions of each NBP, indicating that these waves are certainly not acoustic but possibly due to magnetoacoustic or magnetogravity wave modes. We also show that spatially averaged or low spatial resolution power spectra can lead to an inability to detect such long-period waves.

Multiplicative spectra of Banach spaces

The multiplicative spectrum of a complex Banach space X is the class K(X) of all (automatically compact and Hausdorff) topological spaces appearing as spectra of Banach algebras (X,*) for all possible continuous multiplications on X turning X into a commutative associative complex algebra with the unity. The properties of the multiplicative spectrum are studied. In particular, we show that K(X^n) consists of countable compact spaces with at most n non-isolated points for any separable hereditarily indecomposable Banach space X. We prove that K(C[0,1]) coincides with the class of all metrizable compact spaces.

Automated detection and tracking of solar magnetic bright points

Magnetic bright points (MBPs) in the internetwork are among the smallest objects in the solar photosphere and appear bright against the ambient environment. An algorithm is presented that can be used for the automated detection of the MBPs in the spatial and temporal domains. The algorithm works by mapping the lanes through intensity thresholding. A compass search, combined with a study of the intensity gradient across the detected objects, allows the disentanglement of MBPs from bright pixels within the granules. Object growing is implemented to account for any pixels that might have been removed when mapping the lanes. The images are stabilized by locating long-lived objects that may have been missed due to variable light levels and seeing quality. Tests of the algorithm, employing data taken with the Swedish Solar Telescope, reveal that approximate to 90 per cent of MBPs within a 75 x 75 arcsec(2) field of view are detected.

Turning solid aluminium transparent by intense soft X-ray photoionization

Saturable absorption is a phenomenon readily seen in the optical and infrared wavelengths. It has never been observed in core-electron transitions owing to the short lifetime of the excited states involved and the high intensities of the soft X-rays needed. We report saturable absorption of an L-shell transition in aluminium using record intensities over 10(16)W cm(-2) at a photon energy of 92 eV. From a consideration of the relevant timescales, we infer that immediately after the X-rays have passed, the sample is in an exotic state where all of the aluminium atoms have an L-shell hole, and the valence band has approximately a 9 eV temperature, whereas the atoms are still on their crystallographic positions. Subsequently, Auger decay heats the material to the warm dense matter regime, at around 25 eV temperatures. The method is an ideal candidate to study homogeneous warm dense matter, highly relevant to planetary science, astrophysics and inertial confinement fusion.

A study of magnetic bright points in the Na I D1 line.

High-cadence, multiwavelength, optical observations of solar magnetic bright points (MBPs), captured at the disk center using the ROSA and IBIS imaging systems on the Dunn Solar Telescope, are presented. MBPs manifesting in the Na I D-1 core are found to preferentially exist in regions containing strong downflows, in addition to cospatial underlying photospheric magnetic field concentrations. Downdrafts within Na I D-1 bright points exhibit speeds of up to 7 km s(-1), with preferred structural symmetry in intensity, magnetic field, and velocity profiles about the bright point center. Excess intensities associated with G-band and Ca II K observations of MBPs reveal a power-law trend when plotted as a function of the magnetic flux density. However, Na I D-1 observations of the same magnetic features indicate an intensity plateau at weak magnetic field strengths below approximate to 150 G, suggesting the presence of a two-component heating process: one which is primarily acoustic and the other predominantly magnetic. We suggest that this finding is related to the physical expansion of magnetic flux tubes, with weak field strengths (approximate to 50 G) expanding by similar to 76%, compared to a similar to 44% expansion when higher field strengths (approximate to 150 G) are present. These observations provide the first experimental evidence of rapid downdrafts in Na I D-1 MBPs and reveal the nature of a previously unresolved intensity plateau associated with these structures.

China’s New Approach to CSR in Congo: Is the leverage turning to China?

China has been the world’s fastest growing economy in the past 30 years with its enterprises rapidly emerging and becoming leading players globally. In particular, the progressive integration into the international system has been spurred by China’s entry into the global trading regime of the World Trade Organization (WTO) in 2001. The 'go global' policy has been facilitating the rapidly growing engagement on the African continent of Chinese multinational companies (MNCs). As a promising tri-polar global economic entity, its growth of relations with Africa has been both unprecedented and impressive. As the Sino-Africa economic and business partnership surges forward, the matter of corporate social responsibility (CSR) is increasingly becoming an imperative ingredient for any successful business. It is noteworthy that responsible corporate citizens should take account of the impact of their investment on both economic and social arenas. However, it still remains uncertain what role Chinese MNCs have been playing in the continent’s sustainable development.
A Sino-Congo deal seems a positive way forward, accelerating the Democratic Republic of Congo’s (hereinafter referred to as Congo) regional economy, depressed due to years of war. Meanwhile, the escalating investment into Congo has raised controversies for its no-attachment policy, with increasing pressure imposed on China’s MNCs to take CSR more seriously. Particular concerns are focused on the multinationals’ inadequate environmental and human rights protection. The recent massive infrastructure investment is arguably perceived as a different interpretation of CSR, which has aroused a hot debate about whether China is heading for status as a responsible stakeholder in the international community. It is conducive to clarifying the paradoxical issue by addressing whether China’s recent approaches have the potential to facilitate CSR initiatives or hinder them in the long run.

Turning Asteroids into Comets with ELTs

It is clear that ELTs will be able to detect extremely weak outgassing from Solar system bodies via a number of different methods. Occultations will allow probing for outgassing around 20 km main-belt asteroids. Imaging can reveal dust emission rates of only milligrams/second in the inner solar system, while sublimation rates of gasses should be measurable down to gram/second levels. Suitable targets will be identified via the coming all-sky surveys, through both the classical dynamical Tisserand Invariant and long-baseline lightcurves. It is possible that using these methods, ELTs may allow the discovery of much more activity throughout the Solar system than is presently known.

The Area Distribution of Solar Magnetic Bright Points

Magnetic bright points (MBPs) are among the smallest observable objects on the solar photosphere. A combination of G-band observations and numerical simulations is used to determine their area distribution. An automatic detection algorithm, employing one-dimensional intensity profiling, is utilized to identify these structures in the observed and simulated data sets. Both distributions peak at an area of approximate to 45,000 km(2), with a sharp decrease toward smaller areas. The distributions conform with log-normal statistics, which suggests that flux fragmentation dominates over flux convergence. Radiative magneto-convection simulations indicate an independence in the MBP area distribution for differing magnetic flux densities. The most commonly occurring bright point size corresponds to the typical width of inter-granular lanes.