907 research outputs found
pulsar_spectra: A pulsar flux density catalogue and spectrum fitting repository
We present the pulsar_spectra software repository, an open-source pulsar flux
density catalogue and automated spectral fitting software that finds the best
spectral model and produces publication-quality plots. The Python-based
software includes features that enable users in the astronomical community to
add newly published spectral measurements to the catalogue as they become
available. The spectral fitting software is an implementation of the method
described in Jankowski et al. (2018) which uses robust statistical methods to
decide on the best-fitting model for individual pulsar spectra. pulsar_spectra
is motivated by the need for a centralised repository for pulsar flux density
measurements to make published measurements more accessible to the astronomical
community and provide a suite of tools for measuring spectra
CNT/PDMS composite membranes for H2 and CH4 gas separation
Polydimethylsiloxane (PDMS) composites with different weight amounts of multi-walled carbon nanotubes (MWCNT) were synthesised as membranes to evaluate their gas separation properties. The selectivity of the membranes was investigated for the separation of H2 from CH4 gas species. Membranes with MWCNT concentrations of 1% increased the selectivity to H2 gas by 94.8%. Furthermore, CH4 permeation was almost totally blocked through membranes with MWCNT concentrations greater than 5%. Vibrational spectroscopy and X-ray photoelectron spectroscopy techniques revealed that upon the incorporation of MWCNT a decrease in the number of available Si–CH3 and Si–O bonds as well as an increase in the formation of Si–C bonds occurred that initiated the reduction in CH4 permeation. As a result, the developed membranes can be an efficient and low cost solution for separating H2 from larger gas molecules such as CH4
Use of smear bacteria and yeasts to modify flavour and appearance of Cheddar cheese
The strains Staphylococcus saprophyticus DPC5671 and Corynebacterium casei DPC5298 were applied in combination with Debaryomyces hansenii DPC6258 to the surface of young Cheddar cheese curd to obtain two different smear-ripened cheeses. A surface microbiota developed over the incubation period, comprising of both yeast and bacteria; pulsed field gel electrophoresis confirmed that the inoculated strains of S. saprophyticus DPC5671 or C. casei DPC5298 were the dominant bacterial strains on the surface of the cheese at the end of the ripening period. The smear cultures changed the appearance and aroma, which were significantly different from the control cheese. The approach presented in this study represents a method for the development of new cheese varieties with novel aromas within a short ripening time
SAFEGUARDS AND NONPROLIFERATION CONSIDERATIONS RELEVANT TO FUELS REFABRICATION AND DEVELOPMENT PROGRAM
Early in the Fuels Refabrication and Development (FRAD) program, it was recognized that safeguards and nonproliferation design criteria were needed to provide guidance to equipment, process, and facility designers. This need was highlighted by the recent attention given safeguards and proliferation. Because of this heightened concern, it was found that design criteria that adequately address safeguards and nonproliferation do not now exist. For this reason, a three-day workshop was convened to attempt to collect and organize existing information regarding design criteria. This document is a result of that undertaking and the subsequent efforts required to structure the information. In summary, it was found that domestic and international goals and objectives are reasonably well established. Goals and objectives for evaluating the proliferation resistance of a facility are less firmly defined. A listing of design criteria for domestic and international safeguards has not been compiled. This document presents a summary of considerations that must be incorporated into design criteria but stops short of developing a comprehensive list of design criteria. One is certainly needed and should be funded as a follow-on effort. Following the development of the design criteria, the next logical steps are the development of evaluation methodologies and acceptance criteria. These also were proposed as logical follow-on activities which would be needed before a major FRAD design activity could be initiated
Multibeam Maser Survey of methanol and excited OH in the Magellanic clouds: new detections and maser abundance estimates
‘The definitive version is available at www.blackwell-synergy.com.’ Copyright Blackwell Publishing DOI: 10.1111/j.1365-2966.2008.12888.xPeer reviewe
- …