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The excavation of a low-temperature kiln structure at an affluent Iron Age regional center, Uppåkra, located in southern Sweden, revealed from archeobotanical samples and its context evidence of malting in the process to make beer. Carbonized germinated hulled barley grain (Hordeum vulgare) was recovered from the kiln structure itself and from the surrounding occupational surface. Located somewhat from the central area of the site, where previous excavations have uncovered hall-buildings, a ceremonial structure, and several smaller houses, the investigated kiln was situated in an area on the site that is absent of remains to indicate a living quarter. Activities using kilns have instead primarily been linked to this area and archeological finds are mainly of charred crops remains. In this paper, we argue that the germination of grain was deliberate and that the kiln was used to stop the germination process by drying or roasting the grain. If the malting process for large-scale beer production was carried out at a designated area of the site is discussed, as well as if this activity area was part of a structural organization observed elsewhere on the settlement. [ABSTRACT FROM AUTHOR]

A metric analysis on hulled barley grain from the Iron Age regional centre of Uppåkra and surrounding sites in southern Sweden has identified a variation in the size of the grain found on these archaeological sites. Large, high-quality grain was found more frequently at Uppåkra when compared to sites in the surrounding area, where smaller grain was more frequent. The observed large grain found at Uppåkra was, however, restricted to only a few house contexts, including hall-buildings, while other contexts on the site, such as areas dedicated to craft production, had barley assemblages containing smaller grain, similar to the size range found on the surrounding sites. The intra-site variation between different contexts at Uppåkra points to a degree of sorting for larger grain and that this variation between grain assemblages was the result of selection after the crop processing was completed. The distribution of grain size at Uppåkra shows a pattern that indicates that the high-quality barley grain was indented for specific individuals or households. The different contexts at Uppåkra have together produced a record spanning the first millennium ad, representing almost the whole existence of the site. The evidence for selection of larger grain can be seen in the hall-buildings throughout most of the first millennium ad, although less prominently during the Late Roman Iron Age (ad 200-400), while during the Migration Period (ad 400-550) several houses on the main site Uppåkra had assemblages of large grain size. The distribution of grain size at the regional centre Uppåkra shows a pattern that indicates that the handling of large high-quality barley grain was part of a spatial organization, and such organization is similar to other functions observed on the site. The long-term record of grain size patterns across time shows that a structure for handling grain was already in place during the early phase of the settlement and that it remained for centuries. This study indicates that the affluence otherwise seen at the regional centre Uppåkra from an abundance of high-status objects, could also include agricultural wealth, with extensive access to high-quality grain. [ABSTRACT FROM AUTHOR]

Charred seed conglomerates of Linum usitatissimum (flax) and Camelina sativa (gold of pleasure) were found at Uppåkra 2:25, a Roman Iron Age site in Skåne, southern Sweden. The conglomerates showed no mixing with each other, as they were almost pure flax and gold of pleasure respectively. Together with other archaeobotanical data from the site, they provide new evidence on the use, processing and cultivation of these two plants in early Iron Age in Scandinavia. Metric analyses were applied to flax seeds from both conglomerates and other contexts at this site, and compared to seed assemblages from other Roman Iron Age sites in Europe. The comparison showed that the flax cultivation at Uppåkra 2:25 was intended for the production of oil-rich seeds. The contextual relationship indicates that both flax and gold of pleasure seeds were processed in a similar way and used for oil. Furthermore, the pure seed conglomerate of gold of pleasure suggests that this plant was not a weed, but rather an intentionally grown crop which was cultivated separately from flax. [ABSTRACT FROM AUTHOR]

Three types of microfibrillated cellulose (MFC) with differences in structure and surface charge were used at low concentration as filler materials in polysodium acrylate superabsorbents (SAPs). The swelling of the composite hydrogels was determined in 0.9% NaCl solution as well as in deionized water. The shear modulus of the samples was determined through uniaxial compression analysis after synthesis and after swelling in 0.9% NaCl solution. Furthermore, the ability to retain filler effects after washing was investigated. The results showed that all of the investigated MFCs had a strong reinforcing effect on the shear modulus after synthesis. The filler effect on swelling and on the associated shear modulus of swollen samples showed a more complicated dependence on structure and surface charge. Finally, it was found that the filler effects were reasonably retained after washing and subsequent drying. The results confirm that MFC holds great potential as a filler material in superabsorbent applications. Furthermore, the results provide some insight on how the structural properties and surface charge of MFC will affect gel properties depending on swelling conditions. This information should be useful in evaluating the use of different types of MFC in future applications. [ABSTRACT FROM AUTHOR]

The NOx storage performance at low temperature (100–200 °C) has been studied for model NOx storage catalysts. The catalysts were prepared by sequentially depositing support, metal oxide and platinum on ceramic monoliths. The support material consisted of acidic aluminium silicate, alumina or basic aluminium magnesium oxide, and the added metal oxide was either ceria or barium oxide. The NOx conversion was evaluated under net-oxidising conditions with transients between lean and rich gas composition and the NOx storage performance was studied by isothermal adsorption of NO2 followed by temperature programmed desorption of adsorbed species. The maximum in NOx storage capacity was observed at 100 °C for all samples studied. The Pt/BaO/Al2O3 catalyst stored about twice the amount of NOx compared with the Pt/Al2O3 and Pt/CeO2/Al2O3 samples. The storage capacity increased with increasing basicity of the support material, i.e. Pt/Al2O3·SiO2 < Pt/Al2O3 < Pt/Al2O3 · MgO. Water did not significantly affect the NOx storage performance for Pt/Al2O3 or Pt/BaO/Al2O3. [ABSTRACT FROM AUTHOR]

Isothermal storage and reduction of NO2 with CO, C3H6 and H2 as reducing agents on a lean NOx adsorber was investigated by temperature programmed desorption (TPD) and temperature programmed reduction (TPR) studies. The reduction of NOx was clearly favoured with H2 as reducing agent. Carbon monoxide and C3H6 showed fairly low reduction of NOx. The NOx reduction at low temperatures with H2 as reducing agent was found to be effective, clearly much more effective than for CO. [ABSTRACT FROM AUTHOR]

One possible way to reduce NO x in lean exhausts is by using NO x trap catalysts. This paper addresses storage of NO x on such catalysts at temperatures below the catalyst light-off. Experiments carried out on commercial samples in synthetic exhausts revealed a large capacity for storage of NO x when NO2 was added at temperatures below 150°C. In contrast, when NO was added instead, no storage took place. CO was found to decrease the storage by reacting with NO2 and forming NO and CO2. Propene inhibited the reaction between NO2 and CO and therefore gave rise to larger NO x storage when CO was present. The paper concludes with a discussion of a possible mechanism for the storage of NO x at low temperatures. [ABSTRACT FROM AUTHOR]