22 research outputs found

    Dating furniture and coopered vessels without waney edge – Reconstructing historical wood-working in Austria with the help of dendrochronology

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    AbstractIn the present study, 208 furniture and 168 coopered vessels from three Austrian museums were examined. Dendrochronology was used to date objects and to extract further information such as the necessary time for seasoning, wood loss through wood-working and methods of construction. In most cases sampling was done by sanding the cross section and making digital photographs using a picture frame and measuring digitally.The dendrochronological dates of the sampled furniture range between 1524 and 1937. The group of furniture includes cupboards, chests, tables, benches, commodes and beds. In many cases furniture was artfully painted and sometimes even shows a painted year. With the help of dendrochronology it was proved that some objects had been painted for some time after construction, or had been over-painted. Most furniture, however, was painted immediately after completion. In this case, the seasoning and storage time of the boards and the wood loss due to shaping can be verified. As an average value, 14 years have passed between the dendrochronological date of the outermost ring and the painting. The time span includes time of seasoning and storage and the rings lost by wood-working. This leads, on the one hand to a short storage time of less than 10 years and on the other hand to very little wood loss due to manufacturing. Those boards being less shaped turned out to be back panels of cupboards, therefore they are recommended to be sampled for dating.Coopered vessels were dated between 1612 and 1940. There was evidence that staves were split and not sawn in many cases. The staves were often split out of the outermost part of the tree and hardly any wood was worked away which was proved by the close dendrochronological dates of the single staves of a vessel.Since there is a short time of storage and only little wood loss through wood-working, dating of objects without a waney edge becomes reasonable

    Distinct Type of Transmission Barrier Revealed by Study of Multiple Prion Determinants of Rnq1

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    Prions are self-propagating protein conformations. Transmission of the prion state between non-identical proteins, e.g. between homologous proteins from different species, is frequently inefficient. Transmission barriers are attributed to sequence differences in prion proteins, but their underlying mechanisms are not clear. Here we use a yeast Rnq1/[PIN+]-based experimental system to explore the nature of transmission barriers. [PIN+], the prion form of Rnq1, is common in wild and laboratory yeast strains, where it facilitates the appearance of other prions. Rnq1's prion domain carries four discrete QN-rich regions. We start by showing that Rnq1 encompasses multiple prion determinants that can independently drive amyloid formation in vitro and transmit the [PIN+] prion state in vivo. Subsequent analysis of [PIN+] transmission between Rnq1 fragments with different sets of prion determinants established that (i) one common QN-rich region is required and usually sufficient for the transmission; (ii) despite identical sequences of the common QNs, such transmissions are impeded by barriers of different strength. Existence of transmission barriers in the absence of amino acid mismatches in transmitting regions indicates that in complex prion domains multiple prion determinants act cooperatively to attain the final prion conformation, and reveals transmission barriers determined by this cooperative fold

    Proposal of Conversion the Tugboat Engines to Diesel – LNG Operation

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    International shipping is the source of around 3% of global CO2 emissions. Liquefied natural gas (LNG) is currently considered the only reasonable and commercially advanced alternative to the petroleum-based ship fuels. Liquefied natural gas can make a significant contribution to the diversification of transport fuels, reducing the greenhouse gas emissions from ships and heavy vehicles. The introduction of LNG technology as a drive for inland ships is a complex process. It requires activities in various areas, including development, legislation, building infrastructure, construction of new ships or their reconstruction. The greatest problem now seems to be the certainty of investing in the new fleet or their reconstruction. It is therefore desirable to assure shipowners that the investment in renewing or reconstruction should be guaranteed. This paper provides a study of reconstruction of the inland tugboat (tug) to a dual fuel system (diesel – LNG). A tugboat used by Slovak shipping company was chosen as a model vessel. The results presented a comprehensive design of the main and auxiliary engine remodelling, as well as the design of the vessel’s tanks and show how the conversion affects the basic navigational characteristics of the tugboat. Finally, the results point to the conversion methodology which is partly applicable to another type of inland tug, considering the individual specificities
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