Garaselet – Biostratigraphical studies of human impact during different periods of settlement from the Mesolithic to Medieval times

lnvestigations in collaboration with Skellefteå Museum are in progress on material representing different periods of settlement at Garaselet on the Byskeälven river in Västerbotten, northern Sweden. Archaeological excavations south and north of the bays Garaselviken and Lappviken revealed the existence of a Mesolithic dwelling site dated c. 8000 B.P. The area was occupied also during the Neolithic, Bronze, Iron and Middle Ages. Studies of minerogenic and organogenic material from the excavation area, together with peat from the nearby mires and sediments from the bays, are being carried out using pollen and diatom analysis, organic carbon measurements, total composition analysis and radiocarbon dating. Preliminary results indicate that the human impact on vegetation and water is registered in the sediments, but was only of minor significance as compared with the natural changes of the palaeoecological and palaeohydrological environment. Pollen analysis and radiocarbon datings of peat samples from the mires show that the organic sedimentation started contemporary with the immigration of alder (Alnus) after 8700 B.P., just after the deglaciation of the area. The spread of spruce (Picea) took place after 3600 B.P

The sustainability of communicative packaging concepts in the food supply chain. A case study: part 1. Life cycle assessment

Purpose In recent years, a new perspective for food packaging has emerged as a result of several issues like quality, safety, competitive prices or providing of useful information to consumers. This new perspective is called communicative packaging. Communicative packaging may influence consumers/companies on purchasing decisions. Since the environmental evaluation of such systems has not yet been performed, this paper is focused on the environmental evaluation of a flexible best-before-date (FBBD) communicative device on a packaging consumer unit and its implications on reducing environmental impacts related to fresh products. This consumer unit consists of a nanoclay-based polylactic acid tray filled with pork chops. Methods The environmental assessment of the consumer unit was made through life cycle assessment (LCA) using a cradle-to-gate approach. Environmental impacts were assessed according to the Eco-Indicator 99 v 2.1 methodology in Individualist (I) perspective. Results and discussion Several results were obtained from the LCA. With regard to environmental impacts of the FBBD, most of them were due to the paper substrate used for the manufacture of this communicative packaging concept as well as to the transports for delivering the components of the FBBD communicative device. On the other hand, when environmental impacts of packaging system with and without FBBD were compared, a large environmental load was detected for the system that has the communicative device affixed as a result of the higher weight of the package. However, the environmental load caused by the use of the FBBD was minimal in comparison with the total environmental load of the whole packaging system. On the contrary, the consumer unit that has the communicative device affixed showed less environmental burden than the consumer unit that has not affixed the device. This was due to the environmental benefits that the communicative device provides by reducing the amount of out-of-date packaged products at retailer outlets. Conclusions The use of a FBBD contributes to minimize environmental burdens related to the production, packaging and delivery of pork chops since it facilitates a dynamic control of out-of-date products even though the consumer unit with FBBD weighs 1 g more than the consumer unit that does not use the communicative device. Recommendations The results presented in this paper are estimated results of a specific case study for a prototype of communicative packaging device. Consequently, these results must be considered as a first approach according to future developments on communicative packaging

A modified Lax-Wendroff correction for wave propagation in media described by Zener elements

A modified Lax-Wendroff correction for wave propagation in attenuating and dispersive media described by Zener elements is presented. As opposed to the full correction, this new technique is explicit and offers large computational savings. The technique may be applied to a wide variety of hyperbolic problems. Here, the concept is illustrated for wave propagation in visco-acoustic medi

Admission control for Web server systems - design and experimental evaluation

evaluatio