Search

In this paper, we examine the exchange of crops and livestock through the application of strontium (87Sr/86Sr) isotope analysis on cereal grains and faunal tooth enamel from the regional center of Uppåkra and three nearby settlements in Scania, southern Sweden, dating to the first millennium AD. Around a third of the fauna have non-local 87Sr/86Sr values, indicating the import of livestock from several different regions. After cleaning, almost all of the cereal grains have non-local 87Sr/86Sr values, which is surprising given the nearby abundance of fertile agricultural soils. We therefore suggest considering non-locally grown crops to be those whose 87Sr/86Sr values fall outside the normal distribution; if this approach is used, around 20% of the analyzed crop samples are interpreted as having grown non-locally. This study demonstrates the potential of combining strontium isotopic data of archaeobotanical and zooarchaeological material for gaining insights into the movement of agricultural products in prehistory. [ABSTRACT FROM AUTHOR]

Shortly after a surface is submerged in the sea, a conditioning film is generally formed by adsorption of organic molecules, such as polysaccharides. This could affect transport of molecules and ions between the seawater and the surface. An artificial seawater model system was developed to understand how adsorbed polysaccharides impact copper binding by glutaraldehyde-crosslinked polyethyleneimine coatings. Coating performance was also determined when competed against copper-chelating EDTA. Polysaccharide adsorption and copper binding and distribution were investigated using advanced analytical techniques, including depth-resolved time-of-flight secondary ion mass spectroscopy, grazing incidence X-ray absorption near-edge spectroscopy, quartz crystal microbalance with dissipation monitoring and X-ray photoelectron spectroscopy. In artificial seawater, the polysaccharides adsorbed in a swollen state that copper readily penetrated and the glutaraldehyde-polyethyleneimine coatings outcompeted EDTA for copper binding. Furthermore, the depth distribution of copper species was determined with nanometre precision. The results are highly relevant for copper-binding and copper-releasing materials in seawater. [ABSTRACT FROM PUBLISHER]

Subfossil remains of Cannabis sativa L. (hemp) have been found at Lindängelund in the region of Malmö, southern Sweden. These represent the earliest robust evidence so far for hemp retting in Scandinavia. Finds of seeds, stems and pollen of C. sativa from a waterlogged context on a settlement dating to the Roman Iron Age demonstrate that the plant was locally cultivated and processed during the 1st-2nd centuries AD. An introductory phase in Scandinavia is proposed (c. AD 1-400) during which the cultivation of hemp was apparently small scale and processing was probably carried out within settlements. In the succeeding centuries, c. AD 400-550 (the Migration Period), remains of hemp are mostly found in pollen records from lake sediments, and less frequently in the archaeological record. This could indicate that the process of hemp retting relocated from settlements to lakes shores where activity became larger in scale and more integrated with the prevailing agricultural system. [ABSTRACT FROM AUTHOR]

Microfibrillated cellulose was utilized at low concentrations as a filler material, added prior to free radical polymerization, in cross-linked superabsorbent polysodium acrylate hydrogels. The effect of microfibrillated cellulose concentration on equilibrium swelling, shear modulus after synthesis, and shear modulus at equilibrium swelling was studied at different degree of cross-linking. For the characterization of the microfibrillated cellulose optical microscopy, atomic force microscopy, and transmittance analysis were used. The shear modulus of the samples was determined using uniaxial compression analysis. The swelling of the gels was determined using classical gravimetrical measurements. It was found that microfibrillated cellulose was highly efficient in increasing the shear modulus of the gels. Furthermore, the microfibrillated cellulose was found to have the same effect on the swelling and shear modulus at equilibrium swelling as the same mass of the conventional covalent cross-linker N,N'-methylenebisacrylamide (MBA), while in fact improving the fracture resistance of the gels. In conclusion, microfibrillated cellulose shows great potential as an additive to enhance the performance of soft materials. [ABSTRACT FROM AUTHOR]

Increased demand response is essential in order to boost the effectiveness of the Swedish power market. The all-embracing installation of automatic meter reading systems enables power suppliers to introduce hourly settlements in the residential sector. The aim of the study has been to assess the impact of electricity retailers' physical and financial risk in customer segments with different heating systems as well as to estimate the potential of the electricity contract “Fixed price with the right to return” in terms of economic consequences and risk management. To that end, computer simulations using empirical data have been employed. The results show that the physical price and volume risk, which constitute the greatest risk of suppliers, are most severe in households whose main heating system consists of a geothermal heat pump and less serious in households that are less dependent on electricity for heating. Hourly settlements in the residential electricity market have proven to be advantageous to retailers from both an economic and risk reducing point of view and provide a superior opportunity for customers, and those with an electric heating installation in particular, to lower their electricity expenses substantially. [ABSTRACT FROM AUTHOR]

The implementation of the EU Emission Trading Scheme (ETS) started on January 1st 2005 according to national plans for allocating emissions rights. The steel industry is one of the industrial sectors included in this scheme. The objective of this paper is to investigate and evaluate the optimum solution(s) for European steel plants to meet their emission allowance with low reduction cost. An optimization model based on a Swedish steel plant is developed and used. Three scenarios were created in the model, i.e., internal changes within the steel plant, EU ETS, and the Kyoto Protocol's clean development mechanism (CDM). For the last scenario, China was selected as a country of the non-Annex I Party for the emission trading by CDM. The modeling results show that the studied plant will face an emission gap between allowed and calculated emissions in the near future. Compared to EU ETS, the implementation of CDM projects will make the plant reduce CO2 emissions at a lower cost. The internal changes within the plant will also play an important role for the solution of low abatement cost. The model developed could serve as a benchmark for the future emission trading simulation's purpose within the European steel industry. [ABSTRACT FROM AUTHOR]

During the years 2001–2002, a comprehensive study regarding CO 2 emissions related to the steel production for the integrated steel making production route, was carried out. The study was financed by SSAB and carried out by a research group with members from SSAB, MEFOS and LTU. The aim was to study the emissions from the existing system and how these could be influenced by process changes and by process modifications. The calculations were made using a global spreadsheet model for calculating the CO 2 emissions, developed from an existing Energy and Process Integration model of the same system. The calculated cases included the existing BF/BOF route as well as integration of other processes, e.g., an electric arc furnace, DR processes, COREX and a new future smelting reduction process concept (Sidcomet). All new existing alternative ore based process technologies would increase the specific CO 2 emission from the system. A technology transfer to scrap based metallurgy would significantly decrease the emission level, but is not feasible for SSAB, due to the future product mix and the structure of scrap availability. In a 5–20 year perspective, the existing steel making process route with the use of magnetite ore for pellet production has the lowest specific CO 2 emission. In a long-term perspective, 20–50 years, alternative process routes, e.g., based on H 2 and DRI, could be of interest. Studies on such changes are, however, big projects and should be carried out as joint European and/or international efforts. [ABSTRACT FROM AUTHOR]

Residue materials generated in the metallurgical industry have gained an increasing importance, both from the points of view of energy and material supply. A joint process integration model for the integrated steel plant system is developed and used in this paper. It takes into account both residue materials and energy recirculation for the system. The potential for increased recirculation and the effect on the system from an environmental point of view is presented, and implementations and practical experiences are discussed. The model developed can serve as a benchmark for different steelmaking operations and constitute a basis for the continuous work involved in material, energy, environment or economic analyses for the steel production system. [ABSTRACT FROM AUTHOR]

It is crucial for a steel making production system to operate at the lowest possible production cost, while satisfying stability and reliability conditions. To plan future production strategies, it is therefore important to be able to model the system behaviour when internal and external parameters are changed. In this study the sensitivity and stability of an optimised solution, of an integrated steel plant, have been investigated. The solution’s sensitivity has been analysed taking both internal process changes and external price variations into account, through applying both simulation and optimisation. The analysis also includes both costs and environmental issues such as carbon dioxide and sulphur emissions. Based on the methodology suggested, it is possible to determine the stability of the system solution, including both economic and environmental performance. [ABSTRACT FROM AUTHOR]