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The aims and goals of the article are to discuss how typology can be misleading in the study of archaeological artefacts. The discussion is exemplified using transverse arrowheads in the late Scandinavian Mesolithic. One contemporary, and often accepted, typology of transverse arrowheads is presented along with a summary of typological development and debates. The concept of curation, first introduc
The influences of operating conditions and physical properties of the two phases on the hydrodynamics and mass transfer in a circular liquid-liquid microchannel have been investigated. The polytetrafluoroethylene (PTFE) microchannel has an internal diameter of 0.7 mm and a T-shaped mixing junction. Sodium hydroxide solution was used as the aqueous phase. N-hexane and toluene were employed as the o
The processing and disposal of sludge from wastewater treatment plants is an important topic of increasing environmental, ecological, technological, economic and social concern. The large amounts of sludge produced represent an urgent problem today, new treatment methods being very much needed. Reducing the volume of sludge can be achieved either by decreasing the amounts of it produced during the
Popular Abstract in Swedish Kisel (Si) förekommer i alla naturliga vatten i form av löst kisel och är ett näringsämne för många växt- och djurarter. Löst kisel kommer ursprungligen från kiselhaltiga mineral som har vittrat. Vid vittringen går det åt koldioxid (CO2) och på så vis finns det ett samband mellan omsättningen av kisel och kol. Både upptag och vittring av kisel bidrar till att fördelningSilicon (Si) is ubiqutious in natural waters as dissolved silica (DSi) and is used as a nutrient by many plant and animal species. DSi ultimately derives from the weathering of silicate minerals, a process which also consumes atmospheric CO2 and couples the silicon and carbon cycles. These processes, among others, impart observable fractionations to the stable isotopes of silicon, which makes the
OBJECTIVES: To study long-term patient-relevant outcomes after meniscectomy, a surgical procedure associated with a high risk of knee osteoarthritis (OA). Principal objectives were to compare traumatic with degenerative meniscal tear and partial with subtotal meniscectomy.METHODS: We studied a well-defined cohort of 205 patients who had undergone isolated unilateral meniscectomy between 1983 and 1
Pressurized liquid extractions were performed on eight sediments in order to investigate if a modified US EPA method (100 degrees C, 100 bar, n-heptane/acetone (1:1), 2 x 5 min) provided exhaustive extractions of polychlorinated biphenyls (PCBs) from sediment, and to study if the extractability of PCBs from the different sediments was affected by characteristics of the sediment. The recovery from
Popular Abstract in Swedish Organiskt avfall utgör ett problem men är samtidigt en resurs med dess innehåll av näringsämnen och energi. Ett sätt att ta om hand organiskt avfall är att bryta ned det anaerobt genom s.k. rötning. Det organiska materialet reduceras då samtidigt som biogas produceras. Biogas består till största delen av metan som är energirikt och kan ersätta fossila bränslen vid prodAnaerobic digestion of organic matter results in the production of biogas, which can be used to replace fossil fuels. There is potential for increased biogas production at wastewater treatment plants by digesting urban organic waste either separately or together with the sludge. Biogas production could also be increased by sludge pre-treatment. The objective of this work was to evaluate the poten
Two-step steam pretreatment of softwood on laboratory scale has previously been shown to result in higher yields than one-step steam pretreatment. In this study, these results are verified on a larger scale. In an industrial process filtration and washing of the material between the two pretreatment steps are difficult without release of pressure. A worst case without filtration or washing was thu
Portal hypertension was induced in rats by partial ligation of the hepatic branches of the portal vein. After 5 days of hypertension the portal veins were taken out and mounted for isometric and quick-release experiments. Portal veins from sham-operated normal rats served as controls. The ligated veins had an increased cross-sectional area, indicating smooth-muscle hypertrophy. Although the absolu
Return sludge from two Swedish and two Danish wastewater treatment plants were hydrolysed in laboratory reactors. Treatment plants with/without pre-sedimentation and with/without nitrification were represented. Soluble organic matter was produced from all types of sludge, but the yield was to a large extent dependent on what type of sludge was hydrolysed. Activated sludge from wastewater treatment
Popular Abstract in Swedish I september 1989 kom det till kanadensiska mi’kmaqindianers kännedom att ett enormt granitbrott (ett av de tre största i världen) planerades att öppnas vid Kellys Mountain på ön Cape Breton i östra Kanada. Mi’kmaqtraditionalister organiserade genast en fredlig trumceremoni på berget och en talesman deklarerade att det planerade granitbrottet var en förolämpning mot bådeThis dissertation seeks to explore historical changes in the lifeworld of the Mi’kmaq Indians of Eastern Canada. The Mi’kmaq culture hero Kluskap here serves as a key persona in discussing issues such as traditions, changing conceptions of land, and human-environmental relations. In order not to depict Mi’kmaq culture as timeless, two important periods in its history are examined. The first study
Interactions between metals and natural organic matter (NOM) are of great environmental importance and one of the key factors influencing hydrolysis, solubility, and speciation of the metals. However, studying geochemically relevant metals like Al, Fe, and Cu is sometimes associated with analytical problems; for example Fe and Cu are both redox active. Gallium (Ga) is a non-redox active metal that
Background Limited information is available regarding genetic contributions to valvular calcification, which is an important precursor of clinical valve disease. Methods We determined genomewide associations with the presence of aortic-valve calcification (among 6942 participants) and mitral annular calcification (among 3795 participants), as detected by computed tomographic (CT) scanning; the stu
We consider a class of pseudodifferential evolution equations of the form u(t) + (n(u) + Lu)(x) = 0, in which L is a linear smoothing operator and n is at least quadratic near the origin; this class includes in particular the Whitham equation. A family of solitary-wave solutions is found using a constrained minimization principle and concentration-compactness methods for noncoercive functionals. T
Wide-viscosity-range impellers have extensive demands and applications in process industry. The gas–liquid dispersion and mass transfer characteristics of wide-viscosity-range impellers including Large-double-blade (LDB) impeller, Fullzone (FZ) impeller and Maxblend (MB) impeller in water solutions of xanthan gum were investigated experimentally and compared. The influences of gas flow rate, impel
The aim was to develop a short version of the Swedish Process of Recovery Questionnaire (QPR-Swe) for use with people with severe mental illness and to investigate its internal consistency, construct validity, known-groups validity and any floor or ceiling effects. Two independent samples were used, the first (N = 226) to develop the short version and the second (N = 266) to test its psychometric
