Using a multimethod approach, including polarized light microscopy (PLM), scanning electron microscopy (SEM) with X-ray energy dispersive spectroscopy (EDS), SEM with mineral liberation analyzer (MLA), X-ray diffraction (XRD), and Raman spectroscopy, we examined sub-recent ferruginous crusts in the Xingu River in the Amazon Basin that have formed since the Early Pleistocene (<1.2 Ma), as indicated by (U-Th)/He dating of goethite. Although now preserved as goethite, the size and form of the smallest components of the ironstone (nanorods) and the nature of isomorphic substitution in the goethite point to very early transformation of the original precipitate, an unstable hydrous ferrous oxide (HFO) mineral, into goethite. The fine, multiply undulating laminae of the ironstone contain abundant filamentous microbial molds and casts that together support identification of the crusts as ferruginous microbialites and suggest a role of bioinduction/bioinfluence in ironstone precipitation, although inorganic precipitation is also evident. The Xingu Quaternary ironstones are the first evidence of ferruginous microbialite in a modern freshwater system in South America and may hold clues to the recent history of the Xingu River.

Synthetic peptide and peptido-mimetic filaments and tubes represent a diverse class of nanomaterials with a broad range of potential applications, such as drug delivery, vaccine development, synthetic catalyst design, encapsulation, and energy transduction. The structures of these filaments comprise supramolecular polymers based on helical arrangements of subunits that can be derived from self-assembly of monomers based on diverse structural motifs. In recent years, structural analyses of these materials at near-atomic resolution (NAR) have yielded critical insights into the relationship between sequence, local conformation, and higher-order structure and morphology. This structural information offers the opportunity for development of new tools to facilitate the predictable and reproducible de novo design of synthetic helical filaments. However, these studies have also revealed several significant impediments to the latter process – most notably, the common occurrence of structural polymorphism due to the lability of helical symmetry in structural space. This article summarizes the current state of knowledge on the structures of designed peptide and peptido-mimetic filamentous assemblies, with a focus on structures that have been solved to NAR for which reliable atomic models are available.

Chitosan has attracted significant attention in the past decade because of its potential applications in water engineering, the food and nutrition technology, the textile and paper industries, and drug delivery. Recently, a particularly interesting application of chitosan has been proposed in transparent flexible electronic devices, including memristors and transistors. In this work, the resistive switching (RS) effect of chitosan thin films in a capacitor-like structure with Ag and Al as alternative top electrodes was studied. Both the devices showed a bistable RS effect under an external electric field with a high endurance of 102. The electrical conduction and RS mechanisms of chitosan-based devices were investigated. The trap-controlled space charge–limited current was responsible for electrical transport at the low-resistance state of both devices, while direct tunneling and Schottky emission at the high-resistance state were related to Ag/chitosan/fluorine-doped tin oxide (FTO) and Al/chitosan/FTO, respectively. The RS mechanism of the Ag/chitosan/FTO device was attributed to the formation and dissociation of Ag filaments through the dielectric layer, whereas the change in the barrier height at the Al and chitosan interface under an external electric field could control the RS mechanism of the Al/chitosan/FTO device.

There is a strong correlation between coronal mass ejection transients and chromospheric H-α activity. Solar physicists hope to ascertain what causes coronal disturbances, and in our current investigation we are trying to address that problem by assessing the likelihood that a coronal disturbance is associated with other manifestations of the same abrupt, perturbing event such as a flare. The correlation, if any, between filament and flare can be derived by a method of image processing. Our next approach is to give the results of statistical research by studying a century of chromospheric Hα observations. This poster describes the concept and preliminary experiences of deriving the characteristics of a filament and a flare.

Our experiments show that external focusing and initial laser energy strongly influences filament generated by the femtosecond Ti–sapphire laser in air. The experimental measurements show the filament length can be extended both by increasing the laser energy and focal length of focusing lens. On the other hand, the plasma fluorescence emission can be enhanced by increasing the laser energy with fixed focal length or decreasing the focal length. In addition, the collapse distance measured experimentally are larger than the calculated ones owing to the group-velocity-dispersion effect. In addition, we find that the line widths of the spectral lines from $\text{N}_{2}$ is independent of filament positions, laser energies and external focusing.

The Sun drives most events of space weather in the vicinity of the Earth. Because the activities of the Sun are complicated, a visualized chart with key objects of solar activities is needed for space weather forecast. This work investigates the key objects in research during the past forty years and surveys a variety of solar observational data. We design the solar synoptic chart (SSC) that covers the key objects of solar activities, i.e., active regions, coronal holes, filaments/prominences, flares and coronal mass ejections, and synthesizes images from different heights and temperatures of solar atmosphere. The SSC is used to analyze the condition of the Sun in March 2012 and October 2014 as examples. The result shows that the SSC is timely, comprehensive, concise and easy to understand. It has the potentiality for space weather forecast and can help in improving the public education.

A continuous observations near an small active region (AR) NOAA 10976 by the Solar Optical Telescope (SOT) and X-Ray Telescope (XRT) on board the Hinode satellite during Dec. 02 2007 from 15:50 UT to 19:59 UT. We observed that: (a) the filament formed by merging parallel fibrils into a twist structure. (b) the filament faded by reconnecting among its own loop structures, or being stripped into pieces.These process are always preceded by the brightening. (c) for the disappearance of the filament, it has close correlation with the activity, like untwisting or expanding, of its corresponding X-ray bright rope.

A new decomposition, the mutually aposyndetic decomposition of homogeneous continua into closed, homogeneous sets is introduced. This decomposition is respected by homeomorphisms and topologically unique. Its quotient is a mutually aposyndetic homogeneous continuum, and in all known examples, as well as in some general cases, the members of the decomposition are semi-indecomposable continua. As applications, we show that hereditarily decomposable homogeneous continua and path connected homogeneous continua are mutually aposyndetic. A class of new examples of homogeneous continua is defined. The mutually aposyndetic decomposition of each of these continua is non-trivial and different from Jones’ aposyndetic decomposition.

The manuscript presents a review of the results obtained by the author from fast sequential H-alpha filtergrams taken for a quiescent filament together with similar results of other authors. The revealed structure clearly shows that the foot elements of the filament are surrounded by a fishbone-like plage area (magnetic region). Some parts of the filament exist at the boundary of large supergranular cells of about 40′′ in diameter. It seems that the filament is formed due to mixing of magnetic elements of different polarities.

By investigating ten typical magnetic clouds (MCs) associated with large geomagnetic storms (Dst $\leq-100$ nT) from 2000 to 2003, the geoeffectiveness of MCs with various orientations is addressed. It is found that the Dst peak values during the geomagnetic storms are well estimated by applying flux rope model to these magnetic clouds. A high correlation between estimated and observed Dst values is obtained. Moreover, the effect of orientations of MCs on intensities of geomagnetic storms is studied. It is found that the favorable orientations of MCs are approximately at $\theta\sim70^{\circ}$ and $\phi\sim40^{\circ}$ in GSE coordinates to cause large geomagnetic storms. Further, by analyzing solar observations of four associated erupted filaments, the question who determine the orientations of MCs is studied. The likelihood of predicting the intensities of a geomagnetic storms several tens hours before their occurrences is also discussed.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Conventionally coronal mass ejections (CMEs) are categorized into flare-associated and filament-associated types. Since there are also many CMEs of the overlapping type, we classify CMEs into three types in order to compare their characteristics. It is found that the three types of CMEs have quite similar distributions of apparent speeds, with small difference in the average speeds.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

Les hautes propriétés spécifiques des matériaux composites à matrice d'alliage de titane renforcée unidirectionnellement par des filaments de carbure de silicium permettent d'envisager leur emploi pour des applications aéronautiques. Après une brève description des constituants et du mode d'élaboration, les principaux mécanismes d'endommagement sont présentés. Les ruptures de filaments sont observées dans le cas d'une sollicitation longitudinale tandis que la rupture de l'interface est mise en évidence dans le cas d'une sollicitation transverse. Diverses approches multiéchelles destinées au dimensionnement de pièces en composite SiC/Ti sont ensuite envisagées. Une analyse basée sur la description du mécanisme de rupture des filaments permet d'estimer la contrainte à la rupture dans le cas d'une sollicitation longitudinale. Une méthode de transformation de champ permet d'obtenir une loi de comportement prenant en compte les contraintes résiduelles de fabrication. Elle est utilisée pour le calcul d'un disque de compresseur de turboréacteur renforcé circonférentiellement par un composite SiC/Ti.