Resource-efficient recycling of composites via pyrolysis

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Star formation in the giant HII regions of M101

The molecular components of three giant HII regions (NGC 5461, NGC 5462, NGC 5471) in the galaxy M101 are investigated with new observations from the James Clerk Maxwell Telescope, the NRAO 12-meter, and the Owens Valley millimeter array. Of the three HII regions, only NGC 5461 had previously been detected in CO emission. We calculate preliminary values for the molecular mass of the GMCs in NGC 5461 by assuming a CO-to-H_2 factor (X factor) and then compare these values with the virial masses. We conclude that the data in this paper demonstrate for the first time that the value of X may decrease in regions with intense star formation. The molecular mass for the association of clouds in NGC 5461 is approximately 3x10^7 Mo and is accompanied by 1-2 times as much atomic mass. The observed CO emission in NGC 5461 is an order of magnitude stronger than in NGC 5462, while it was not possible to detect molecular gas toward NGC 5471 with the JCMT. An even larger ratio of atomic to molecular gas in NGC 5471 was observed, which might be attributed to efficient conversion of molecular to atomic gas. The masses of the individual clouds in NGC 5461, which are gravitationally bound, cover a range of (2-8) x 10^5 Mo, comparable with the masses of Galactic giant molecular clouds (GMCs). Higher star forming efficiencies, and not massive clouds, appear to be the prerequisite for the formation of the large number of stars whose radiation is required to produce the giant HII regions in M101.Comment: 32 pages, 5 figures, accepted for publication in the Astrophysical Journa

Customized catalytic hydropyrolysis of biomass to high-quality bio-oil suitable for co-processing in FCC refining unit

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Interactive Information Visualization for Sensemaking in Power Grid Supervisory Systems

Operators of power grid supervisory control systems have to gather information from a wide variety of views to build situation awareness. Findings from a conducted field study show that this task is challenging and cogni-tively demanding. Visualization research for power grid supervisory control systems has focused on developing new visualization techniques for representing one aspect of the power system data. Little work has been done to demon-strate how information visualization techniques can sup-port the operator in the sensemaking process to achieve situation awareness. To fill this gap, and with support from a field study, we propose solutions based on multiple and coordinated views, visual interactive filtering and parallel coordinates

The Mass Function of Super Giant Molecular Complexes and Implications for Forming Young Massive Star Clusters in the Antennae (NGC 4038/39)

We have used previously published observations of the CO emission from the Antennae (NGC 4038/39) to study the detailed properties of the super giant molecular complexes with the goal of understanding the formation of young massive star clusters. Over a mass range from 5E6 to 9E8 solar masses, the molecular complexes follow a power-law mass function with a slope of -1.4 +/- 0.1, which is very similar to the slope seen at lower masses in molecular clouds and cloud cores in the Galaxy. Compared to the spiral galaxy M51, which has a similar surface density and total mass of molecular gas, the Antennae contain clouds that are an order of magnitude more massive. Many of the youngest star clusters lie in the gas-rich overlap region, where extinctions as high as Av~100 imply that the clusters must lie in front of the gas. Combining data on the young clusters, thermal and nonthermal radio sources, and the molecular gas suggests that young massive clusters could have formed at a constant rate in the Antennae over the last 160 Myr and that sufficient gas exists to sustain this cluster formation rate well into the future. However, this conclusion requires that a very high fraction of the massive clusters that form initially in the Antennae do not survive as long as 100 Myr. Finally, we compare our data with two models for massive star cluster formation and conclude that the model where young massive star clusters form from dense cores within the observed super giant molecular complexes is most consistent with our current understanding of this merging system. (abbreviated)Comment: 40 pages, four figures; accepted for publication in Ap

Exploring diffrent design spaces - VR as a tool during building design

During the design process of a building different medias are often used to depict the design. Traditional media, especially 2D requires high spatial skill and cognitive demand on the designers. For inexperienced designers, this process can be demanding, be difficult and can cause potential biased designperceptions that are significantly different from the reality. However, studies have also shown that different media and representation facilitates different cognitive reasoning processes about the design. Immersive Virtual Reality (VR) is assumed to give another level of understanding and perception of design space from an egocentric perception than 2D plan drawings or bird-eye views, which have been argued to provide opportunities for better pattern and object recognition that is suitable when studying spatial organization in an allocentric reasoning process. This paper investigates, the different design medias and spatial space explorations further, by studying how students used the different representations and medias (e.g. sketches, 3d-models and VR) during their design process. By combining and using both of these two design space representations, (e.g. egocentric and allocentric) in the design process, it gives a possibility to achieve a more developed design outcome. The methods used in this study were observations and un-structured interviews during the design process and a follow up questionnaire at the end of the design project. The result show, by combining and using both VR and traditional design sketching tools that it is possible to support the two design space representations together and give the designer the possibilities to explore, understand, discuss and work with the design in a more elaborate way from both an egocentric and allocentric perspective. The paper also presents in what way VR can contribute to the Evidence Based Design (EBD) criteria and how the students used different design spaces representations for design and spatial reasoning about the healthcare design of the psychiatric facility they were designing

Entrained Flow Gasification of Polypropylene Pyrolysis Oil

Petrochemical products could be produced from circular feedstock, such as waste plastics. Most plants that utilize syngas in their production are today equipped with entrained flow gasifiers, as this type of gasifier generates the highest syngas quality. However, feeding of circular feedstocks to an entrained flow gasifier can be problematic. Therefore, in this work, a two-step process was studied, in which polypropylene was pre-treated by pyrolysis to produce a liquid intermediate that was easily fed to the gasifier. The products from both pyrolysis and gasification were thoroughly characterized. Moreover, the product yields from the individual steps, as well as from the entire process chain, are reported. It was estimated that the yields of CO and H(2) from the two-step process were at least 0.95 and 0.06 kg per kg of polypropylene, respectively, assuming that the pyrolysis liquid and wax can be combined as feedstock to an entrained flow gasifier. On an energy basis, the energy content of CO and H(2) in the produced syngas corresponded to approximately 40% of the energy content of the polypropylene raw material. This is, however, expected to be significantly improved on a larger scale where losses are proportionally smaller

Exploring the Effect of Silicon on the High Temperature Corrosion of Lean FeCrAl Alloys in Humid Air

A new approach to reduce the chromium and aluminium concentrations in FeCrAl alloys without significantly impairing corrosion resistance is to alloy with 1-2 wt.% silicon. This paper investigates the "silicon effect" on oxidation by comparing the oxidation behavior and scale microstructure of two FeCrAl alloys, one alloyed with silicon and the other not, in dry and wet air at 600 degrees C and 800 degrees C. Both alloys formed thin protective oxide scales and the Cr-evaporation rates were small. In wet air at 800 degrees C the Si-alloyed FeCrAl formed an oxide scale containing mullite and tridymite together with alpha- and gamma-alumina. It is suggested that the reported improvement of the corrosion resistance of Al- and Cr-lean FeCrAl\u27s by silicon alloying is caused by the appearance of Si-rich phases in the scale

Exploring failure modes of alumina scales on FeCrAl and FeNiCrAl alloys in a nitriding environment

Two high-temperature FeCrAl and FeNiCrAl alloys were exposed in a strongly nitriding environment at 900 \ub0C and the morphology of nitridation was studied. Quasi-in-situ experiments revealed that nitridation started at specific surface sites directly related to the alloy microstructure where the alumina scale was permeable to nitrogen. FeCrAl alloy grains with (112) orientation formed outward-growing alumina scales and were susceptible to nitridation. Outward-growing scales and substrate nitridation was also observed at chromium carbide precipitates in the FeNiCrAl alloy. Both alloys suffered nitridation at reactive element-rich (Y and Zr) inclusions larger than a certain critical size. The latter type of attack is caused by cracks and pores in the scale. The findings open new avenues of research for developing the next generation of high temperature alloys with superior properties

Knowledge and practice among dietitians in four Western European countries regarding malnutrition, starvation, cachexia and sarcopenia

Adequate distinction between malnutrition, starvation, cachexia and sarcopenia is important in clinical care. Despite the overlap in physical characteristics, differences in etiology have therapeutical and prognostic implications. We aimed to determine whether dietitians in selected European countries have ‘proper knowledge’ of malnutrition, starvation, cachexia and sarcopenia, and use terminology accordingly