The main archaeological features studied in this thesis are semi-subterranean house remains in the woodlands of middle northern Sweden, east of the high mountains and some 100 km from the coast. The period during which they were occupied has been delimited to 4500-2500 BC. The house remains consist of circular or sometimes rectangular depressions in the ground, surrounded by mounds of refuse and large amounts of fire-cracked stone. Eighty house remains of this kind have been discovered so far and 20 features have been excavated. They are found at 29 different localities that cover an area of more than 60,000 km2. The question put forward is whether these house remains show patterning in site location, economy and material culture, suggesting that they belonged to one people sharing a similar language and values. The majority of the locations include more than one house and because of the dug-out-floors and the large amounts of fire-cracked stone they are interpreted as winter villages. The distributions of the villages show a settlement pattern in which the locales are separated by a mean distance of approximately 35 km. In one of the regions, Vilhelmina parish, summer camps have been located by smaller lakes where the waterways from 3 different winter villages connect. Other possible summer camp sites are suggested, based on their location in areas where waterways connect two or three winter villages. The winter sites were associated with local bands, according to the social structure of hunting societies in North America, suggested by June Helm. Several local bands form a regional band that camp together during certain periods of the year. All regional bands form the tribe or the language family. No traces of social differences between groups or families have been revealed in the material and it is therefore assumed that the remains of the houses represent a hunting/gathering band society. Among the artifacts in the houses is a predominance of small scrapers of quartz and quartzite. There is also a very high representation of elk (moose) in the bone material from the house remains. Prehistoric and later pit-falls as well as paintings and carvings of elk are distributed within the same area. This shows that elk were a very important prey and this has been emphasized when discussing the explanations of the uniformity in house type and artefacts. Finally the importance of the slate tools, in particular those of red slate, is briefly discussed. The manufacture of slate tools increase during the neolithic period. In the inland of middle Norrland artifacts of red slate dominate over the grey and black slate artifacts in most of the houses and on many other sites. The raw material is, in most cases, found close to the high mountains, but the red slate is otherwise rare compared to the black and grey, which suggests that it has been highly valued. The knowledge of, and access to, red slate is suggested as having symbolized the unity of this band society. / digitalisering@umu

Der vorliegende Katalog dokumentiert in Band 1 in chronologischer Folge 3863 Drucke.

In Band 2 werden 36 Handschriften in chronologischer Folge sowie in alphabetischer Folge 132 Zeitschriften in 242 Bänden nachgewiesen.

published_or_final_version / Architecture / Master / Master of Architecture

Introduction. At low temperature the preservation of foodstuffs is one of the best ways of their storage and therefore this method is widely used in meat industry. The low temperature suppresses the activity of microorganisms and tissue ferments. Therefore the meat preserved by freezing keeps for a long time its initial properties and there are only minimal changes of food value and taste. At low temperature the activity of ferments slows down but does not stop. Work object. The work object is the determination of the change of physical-chemical properties of meat during freezing and keeping in - 180 C and - 860 C temperature. Work methodics. The research as fulfilled at the laboratory of the evaluation of the cattle meat properties and the meat quality. For the rersearch taken 14 Lithuanian white pig meat samples the mean weight of which was 500 g. were taken. They were put into special freezing bags and were frozen at temperature -180 C, and -860 C. Before freezing it the physical-chemical properties of the meat were determined. Two examples from each meat samples were researched. The determination of the physical-chemical properties of the meat was fulfilled every month. Also were was taken 6 Lithuanian white pig meat samples the mean weight of which was 500 g. Before freezing it the physical-chemical properties of the meat were determined. After that was made green tea extract, 500 ml. Water ant 50 g tea. All extract was inject in to the meat samples. They were put... [to full text]

The three main components of wood, namely, cellulose, hemicellulose, and lignin, can be used in various areas. However, since lignin covalently crosslinks with wood polysaccharides creating networks that is an obstacle for extraction, direct extraction of different wood components in high yield is not an easy matter. One potential approach to overcome such obstacles is to treat the wood with specific enzymes that degrade the networks by specific catalysis. However, the structure of wood is so compact that the penetration of the wood fibers by large enzyme molecules is hindered. Thus, the pretreatment of wood prior to the application of enzymes is necessary, for “opening” the structure. One pretreatment method that was performed in this thesis is based on kraft pulping, which is a well-established and industrialized technique. For untreated wood, the wood fibers cannot be attacked by the enzymes. A relatively mild pretreatment was sufficient for wood polysaccharides hydrolyzed by a culture filtrate. A methanol-alkali mixture extraction was subsequently applied to the samples that were pretreated with two types of hemicellulases, Gamanase and Pulpzyme HC, respectively. The extraction yield increased after enzymatic treatment, and the polymers that were extracted from monocomponent enzyme-treated wood had a higher degree of polymerization. Experiments with in vitro prepared lignin polysaccharide networks suggested that the increased extraction was due to the enzymatic untying. However, the relatively large loss of hemicellulose, particularly including (galacto)glucomannan (GGM), represents a problem with this technique. To improve the carbohydrate yield, sodium borohydride (NaBH4), polysulfide and anthraquinone were used, which increased the yields from 76.6% to 89.6%, 81.3% and 80.0%, respectively, after extended impregnation (EI). The additives also increased the extraction yield from approximately 9 to 12% w/w wood. Gamanase treatment prior to the extraction increased the extraction yield to 14% w/w wood. Sodium dithionite (Na2S2O4) is an alternative reducing agent for the preservation of hemicelluloses because it is less expensive than metal hydrides and only contains sodium and sulfur, which will not introduce new elements to the recovery system. Moreover, Na2S2O4has the potential to be generated from black liquor. Na2S2O4 has some preservation effect on hemicelluloses, and the presence of Na2S2O4 also contributed to delignification. The extraction yield increased to approximately 15% w/w wood. Furthermore, Na2S2O4 has been applied in the kraft pulping process of spruce. The yield and viscosity increased, while the Klason lignin content and kappa number decreased, which represents a beneficial characteristic for kraft pulp. The brightness and tensile strength of the resulting sheets also improved. However, the direct addition of Na2S2O4 to white liquor led to greater reject content. This problem was solved by pre-impregnation with Na2S2O4 and/or mild steam explosion (STEX) prior to the kraft pulping process. Following Na2S2O4 pre-impregnation and mild STEX, the obtained kraft pulp had substantially better properties compared with the properties exhibited after direct addition of Na2S2O4 to the white liquor. The wood structure opening efficiency of mild STEX alone was also tested. The accessibility of the wood structure to enzymes was obtained even at very modest STEX conditions, according to a reducing sugar analysis, and was not observed in untreated wood chips, which were used as a reference. The mechanical effect of STEX appears to be of great importance at lower temperatures, and both chemical and mechanical effects occur at higher STEX temperatures. / <p>QC 20140903</p>

本研究從風險傳播的觀點，以2013年台灣爆發的食用油事件為例，探討媒體如何再現食品安全事件的樣貌？報導中呈現哪些食品安全資訊？其中有哪些是與風險相關的資訊？不同媒體又有何不同的報導策略？本研究採用量化內容分析與新聞框架分析，分析《中國時報》、《自由時報》、《聯合報》與《蘋果日報》等四大報的食用油報導。研究發現，食用油報導高度仰賴政府消息來源，專家與民間的聲音相對微弱；新聞主題偏重事件調查與責任追究；新聞框架側重政治面向，而較不重視科學面向；風險評估資訊包含「影響危害」、「風險知識」、「安全處理」和「檢驗結果公布」等四個項目，含有風險評估資訊的報導佔整體報導數量六成，其中以「檢驗結果公布」比例最高，較缺乏「影響危害」與「安全處理」資訊。本研究根據研究發現，對新聞實務工作與未來研究提出建議，並指出食品安全報導應該提供哪些風險相關資訊，足以讓民眾評估風險，以避免恐慌。

The motivation of this project is found on the past trend of growing greenhouse gases emissions and, also growing, energy use over the world that still remains. This trend overlaps with a more recent increase in the awareness regarding the effects of human activities towards the Earth ecosystems. Thus, the upgrade of the already-in-use systems is necessary to move towards greener and more modern technologies that permit continue with the economic growth while building more sustainable societies. Thereby, the research focuses on the improvement of the ventilation system of a warehouse building and a cooking school located in the same plot, in an industrial area in Gävle, Sweden. The current system conditions, even consisting in some cases in recirculating air handling units, doesn’t permit the utilisation of the waste heat by bringing it back to the system. The strategy used during the project follows a case study scheme: looking the system, understanding it in a complete way and designing the proper solution that fulfils the requirements. The study was approached as an energy audit: with several meetings with the company, collecting airflows data with the thermo-anemometer device, sketching the required building drawings and designing the optimal solution for the company. Finally, the project resulted in the selection of the proper air handling unit, equipped with a heat recovery system, and the design of its ventilation duct system that permit a heat energy savings derived of the heat demand used to heat the makeup air of about 67 %. Furthermore, the occupancy study helped design the new scheduling for the ventilation periods that reduce the electricity demand of the ventilation system by 30 %. Thus, was obtained a significant energy use reduction that results in a sizeable energy cost saving.

A promising and novel solar concentrator design has been thoroughly investigated and optimised. A prototype concentrator based on this novel geometry was validated using ray tracing techniques. This ray tracing demonstrated the comparative performance of this novel concentrator in regards to equivalent parabolic dishes. The effect of mirror surface normal errors on performance was established using Monte-Carlo based ray tracing code, which agreed well with the optical performance of this prototype which was determined experimentally. A need for low-cost solar cookers to replace bio-mass worldwide was identified, and the concentrator design was then developed as a low-cost solar oven. Despite existing in some number, no current design is able to achieve high performance at low-cost. An industrial partner, Dytecna, was initially involved in the process of this development of the system as a solar cooker. In support of a field trial for the solar cooker developed with Dytecna, a detailed thermal model of the oven was developed. A low-cost lightmeter was constructed and calibrated in order to measure the direct normal irradiance during the field trial in Italy. Laboratory work provided baseline results for the heating of various thermal masses in the oven. The Italian field trials provided a wealth of feedback into the design of the system and many valuable results. The solar cooker was able to bring 0.75L of water to the boil in 33 minutes with an average heat throughput of 203W. Important benchmark results and practical experience of several competing receiver materials was obtained; further lab testing provided more accurate measurements of the receivers' performances. The experiences of the Italian field trial were fed back into the design of a subsequent prototype, intended for a much larger field trial in Tanzania. Improvements in the hotplate, receiver material, and the oven were all incorporated into the design. Additionally, the structure of the solar cooker was redesigned to incorporate a low-cost wooden construction. Supporting work was conducted for the month long trial in which 8 solar cookers would be distributed to families in Tanzania. The field trial in Tanzania provided a wealth of user feedback into the design. At the same time the new solar cooker exceeded previously established performances in Italy. The new design was able to provide an average of 246W of heat to 1kg of water, which was brought to boiling point in 25 minutes. This represents a heating efficiency of 66&percnt; compared to the incident solar flux on the hotplate. In response to findings during the Tanzanian trials, further laboratory work was conducted into establishing the reflectivities of low-cost candidate mirror materials. Throughout all phases of the project the design of the solar cooker was refined and improved with the goal of a solar cooker design that could reach price-point, performance, and usability standards which would ensure market success.

La valorisation de la biomasse lignocellulosique est aujourd’hui un enjeu majeur du fait de la réduction des ressources fossiles. Séparer chaque constituant pour les valoriser de la meilleure façon possible est l’objectif des bioraffineries papetières. L’effluent papetier, la liqueur noire, est actuellement brûlé pour produire de l’énergie, mais sa gazéification permettrait d’augmenter ces rendements énergétiques. Mais pour cela une cuisson sans soufre du bois est nécessaire, le soufre inhibant la gazéification.Cette étude a donc porté en premier lieu sur la faisabilité d’un fractionnement sans soufre du bois, plus ardu qu’un procédé kraft traditionnel contenant du soufre. Le travail a été effectué sur les bois résineux, ceux-ci étant plus difficiles à délignifier que les bois feuillus. Une étape d’autohydrolyse du bois, préalable au fractionnement à la soude, a été effectuée afin d’extraire les hémicelluloses pour une valorisation ultérieure. Les travaux ont montré que ce prétraitement permettait de délignifier le bois plus facilement et ainsi d’envisager un fractionnement sans soufre. La cellulose obtenue par ce procédé présente une pureté et un degré de polymérisation suffisants pour envisager son utilisation pour de la viscose ou pour des applications chimiques.La lignine ne présentant pas de différences structurelles majeures entre du bois préhydrolysé ou non, les complexes entre la lignine et les hydrates de carbone (LCC) ont été analysés. Il a été montré que la préhydrolyse modifie significativement la quantité et la composition de ces complexes, permettant d’expliquer par là les résultats obtenus. / The valorization of lignocellulosic biomass is nowadays a major issue due to the reduction of fossil resources. Separating each component to valorize them the best way as possible is the goal of the pulp and paper biorefineries. The effluent of the mill, called the black liquor, is currently burnt to produce energy, but gasification would increase the energy efficiency. For this, a sulfur-free cooking of wood is necessary, as sulfur inhibits gasification.Therefore this study first focused on the feasibility of cooking without sulfur, which is more difficult than a conventional kraft cooking containing sulfur. The work was done on softwood which is more difficult to delignify than hardwood. The wood was first pretreated with an autohydrolysis to remove hemicelluloses for further valorization.The results were conclusive for the production of cellulose pulp for chemical applications. To explain the differences obtained, structural differences of wood components were looked for. Lignin did not show major differences whether the wood was prehydrolyzed or not, whereas the complexes between lignin and carbohydrates (LCCs) showed significant differences, which would explain the results obtained.