Depressed-cladding thulium-doped fiber for applications below 1800 nm.

We present a thulium-doped silica fiber, featuring a depressed cladding, for applications at wavelengths below 1800 nm. The depressed cladding is used as a distributed filter suppressing amplified spontaneous emission at longer wavelengths, which helps promote emission at shorter wavelengths. We describe the fiber design process that was carried out by using a combination of numerical methods.

Temperature-dependent cross section spectra for thulium-doped fiber lasers.

An investigation on the temperature dependence of spectroscopic parameters of trivalent thulium ions is important for the design of high-power, thulium-doped fiber lasers and amplifiers. In this Letter, the thulium absorption/emission cross sections are determined in the spectral range 700-2200 nm and in the temperature range from -196°C to 300°C. The spectra are obtained from the absorption and emission measurements of a thulium-doped fiber and from measured thulium concentration profiles.

Investigation and modelling of the pyrolysis kinetics of industrial biomass wastes.

Pyrolysis of the waste organic fraction is expected to be a central element to meet the primary energy demand in future: it increases the impact of renewable energy sources on the power generation sector and allows the amount of waste to be reduced, putting an end to landfills. In the present study, kinetic studies on the pyrolysis of biomass wastes are carried out. Two kinds of industrial organic waste are investigated: brewery spent grain (BSG) and medium-density fiberboard (MDF).

Active Optical Fibers and Components for Fiber Lasers Emitting in the 2-μm Spectral Range.

Laser sources emitting in the infrared range at around 2 µm are attracting great interest for a variety of applications like processing of transparent thermoplastic polymers in industry as well as plenty of applications in medicine, spectroscopy, gas sensing, nonlinear frequency conversion to the mid-infrared, to mention a few. Of late, fiber lasers compared to other kinds of lasers benefit from their all-fiber design, leading to a compact, robust, and well thermally manageable device. Particularly, thulium- and holmium-doped fiber lasers are the first choice in fiber lasers emitting light around 2 µm.

RMol: a toolset for transforming SD/Molfile structure information into R objects.

Background: The graph-theoretical analysis of molecular networks has a long tradition in chemoinformatics. As demonstrated frequently, a well designed format to encode chemical structures and structure-related information of organic compounds is the Molfile format. But when it comes to use modern programming languages for statistical data analysis in Bio- and Chemoinformatics, R as one of the most powerful free languages lacks tools to process Molfile data collections and import molecular network data into R.

Structural discrimination of networks by using distance, degree and eigenvalue-based measures.

In chemistry and computational biology, structural graph descriptors have been proven essential for characterizing the structure of chemical and biological networks. It has also been demonstrated that they are useful to derive empirical models for structure-oriented drug design. However, from a more general (complex network-oriented) point of view, investigating mathematical properties of structural descriptors, such as their uniqueness and structural interpretation, is also important for an in-depth understanding of the underlying methods.

Information indices with high discriminative power for graphs.

In this paper, we evaluate the uniqueness of several information-theoretic measures for graphs based on so-called information functionals and compare the results with other information indices and non-information-theoretic measures such as the well-known Balaban J index. We show that, by employing an information functional based on degree-degree associations, the resulting information index outperforms the Balaban J index tremendously. These results have been obtained by using nearly 12 million exhaustively generated, non-isomorphic and unweighted graphs.

The wavelength dependent model of extinction in fog and haze for free space optical communication.

The wavelength dependence of the extinction coefficient in fog and haze is investigated using Mie single scattering theory. It is shown that the effective radius of drop size distribution determines the slope of the log-log dependence of the extinction on wavelengths in the interval between 0.2 and 2 microns.

Nine-amino-acid transactivation domain: establishment and prediction utilities.

Here we describe the establishment and prediction utilities for a novel nine-amino-acid transactivation domain, 9aa TAD, that is common to the transactivation domains of a large number of yeast and animal transcription factors. We show that the 9aa TAD motif is required for the function of the transactivation domain of Gal4 and the related transcription factors Oaf1 and Pip2. The 9aa TAD possesses an autonomous transactivation activity in yeast and mammalian cells.