| 1. |
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| 2. |
- Aad, G., et al.
(författare)
-
- 2012
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Ingår i: The European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6052. ; 72:10
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Tidskriftsartikel (refereegranskat)
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| 3. |
- Abrahamsson, Hans, 1966, et al.
(författare)
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A Turbulent Plane 2-Dimensional Wall-Jet in a Quiescent Surrounding
- 1994
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Ingår i: European Journal of Mechanics/B-Fluids. - 0997-7546 .- 1873-7390. ; 13:5, s. 533-556
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Tidskriftsartikel (refereegranskat)abstract
- An experimental investigation of the turbulence field in a plane two-dimensional wall-jet has been conducted. All measurements were carried out employing hot-wire techniques in a large scale experimental facility. Mean velocities, Reynolds stresses and wall shear stress were determined with slot Reynolds numbers of 1.0*104, 1.5*104 and 2.0*104. The wall-jet was found to be self-preserving, and an asymptotic scale matching was used to show the existence of a short inertial sub layer as compared with a wall boundary layer. Studies of the integral scale development and the turbulent diffusion of shear stress showed a strong interaction between the inner and outer regions of the wall-jet. Using momentum scaling, it was found that the streamwise development of the half-width and maximum mean velocity was independent of the slot Reynolds number.
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| 4. |
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| 5. |
- Abrahamsson, Hans, 1966, et al.
(författare)
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Turbulence in a Two-Dimensional Wall-Jet - Experiments and Modeling
- 1992
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Ingår i: 13th Turbulence Conference in Missouri-Rolla..
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Konferensbidrag (refereegranskat)abstract
- An experimental and numerical investigation of the turbulence field in a two-dimensional wall-jet has been carried out in a well-defined geometry. The measurements were performed using a hot-wire technique and the calculations were carried out with a standard k-ε model as well as an algebraic stress model (ASM), using elliptic solvers. For the mean velocity field, good agreements were found between the measurements and the calculations. The measurements of the turbulence intensities reveal two maxima in the stream-wise and span-wise components, while only one maximum was found in the normal component. Also in the shear stress two maxima were found. A comparison between calculations and measurements indicates that improved turbulence models are needed.
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| 6. |
- Abrahamsson, Hans, 1966, et al.
(författare)
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Turbulence Measurements in a Two-Dimensional Wall-Jet
- 1991
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Ingår i: Eight Turbulent Shear Flow Conference, München.
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Konferensbidrag (refereegranskat)abstract
- The high capacity of todays computers has enabled the extension of turbulence models to strongly anisotropic flow fields, i.e. the interest has been focused on the use of the models based on the transport equations for the Reynolds stresses (RST models). To improve these turbulence models well-defined, simple and fundamental experiments are needed, in which gradients of the different turbulence parameters are determined. Together with direct simulations of the Navier-Stokes equations these experiments yield a good base for the improvement of the modelling of different terms in the Reynolds equations. An excellent presentation of the closure problem and the terms of interest for the development of turbulence models has recently been published by Groth (1991). A fundamental, well-defined and simple flow case is the wall-jet, where an interaction between a wall boundary layer and a free shear layer forms the anisotropy as well as the inhomogeneous character of the flow field. A comprehensive literature survey of wall-jets was carried out already in the beginning of the eighties by Launder and Rodi (1980), who studied a large number of more or less well-defined wall-jet experiments. The main conclusion of this survey was a lack of well-defined experiments in simple and fundamental geometries. If the study is limited to the two-dimensional case, a further conclusion from the work of Launder and Rodi was that many of the studied flow cases did not fulfil the condition of two-dimensionality. Although more than ten years have passed since the work of Laundry and Rodi was presented, very few investigations have been reported in which fundamental wall-jets have been studied. Especially well-defined turbulence measurements are needed, since anisotropy of the two-dimensional wall-jet yields a case well suited for the evaluation of e.g. new dissipation models, see Hallbäck et al. (1990). The purpose of the present work was to determine the turbulence field of a two-dimensional wall-jet in a simple and also well-defined geometry without influence of an outer disturbing flow field. To accomplish these measurements was a wall-jet rig used. All turbulence measurements were carried out using hot-wire techniques, single- and cross wires. The measurements presented here were performed at a Reynolds number of ___, based on the slot height and the extensions of the measurements in the flow direction was in the range of x/h=25 through x/h=156 (x-coordinate in the main flow direction and h-slot height).
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| 7. |
- Andersson, Helge, 1950, et al.
(författare)
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Turbulence in the Vicinity of a Rotating Cylinder in a Quiescent Fluid
- 1991
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Ingår i: Eight Turbulence Shear Flow Conference, Munchen.
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Konferensbidrag (refereegranskat)abstract
- An experimental and numerical investigation of the turbulence field in the vicinity of a rotating cylinder in a quiescent fluid has been carried out. Radial distributions of mean velocity and non-vanishing Reynolds stress components have been measured using hot-wire technique, and corresponding components have been calculated with a low-Reynolds number second- moment closure model. From the measurements it can be concluded the turbulence field is established in the present set up at a Reynolds number which is roughly twenty times larger than earlier measurements have shown. Comparisons between calculations and measurements yield some deviations. However, a qualitatively good agreement is obtained. In the paper, different methods for the determination of the friction velocity are also described and discussed.
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| 8. |
- Ares-Blanco, Sara, et al.
(författare)
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Primary care indicators for disease burden, monitoring and surveillance of COVID-19 in 31 European countries: Eurodata Study
- 2024
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Ingår i: EUROPEAN JOURNAL OF PUBLIC HEALTH. - 1101-1262 .- 1464-360X.
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Tidskriftsartikel (refereegranskat)abstract
- Background During the COVID-19 pandemic, the majority of patients received ambulatory treatment, highlighting the importance of primary health care (PHC). However, there is limited knowledge regarding PHC workload in Europe during this period. The utilization of COVID-19 PHC indicators could facilitate the efficient monitoring and coordination of the pandemic response. The objective of this study is to describe PHC indicators for disease surveillance and monitoring of COVID-19's impact in Europe.Methods Descriptive, cross-sectional study employing data obtained through a semi-structured ad hoc questionnaire, which was collectively agreed upon by all participants. The study encompasses PHC settings in 31 European countries from March 2020 to August 2021. Key-informants from each country answered the questionnaire. Main outcome: the identification of any indicator used to describe PHC COVID-19 activity.Results Out of the 31 countries surveyed, data on PHC information were obtained from 14. The principal indicators were: total number of cases within PHC (Belarus, Cyprus, Italy, Romania and Spain), number of follow-up cases (Croatia, Cyprus, Finland, Spain and Turkey), GP's COVID-19 tests referrals (Poland), proportion of COVID-19 cases among respiratory illnesses consultations (Norway and France), sick leaves issued by GPs (Romania and Spain) and examination and complementary tests (Cyprus). All COVID-19 cases were attended in PHC in Belarus and Italy.Conclusions The COVID-19 pandemic exposes a crucial deficiency in preparedness for infectious diseases in European health systems highlighting the inconsistent recording of indicators within PHC organizations. PHC standardized indicators and public data accessibility are urgently needed, conforming the foundation for an effective European-level health services response framework against future pandemics.
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| 9. |
- Arwidsson, Zandra, et al.
(författare)
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Remediation of Metal Contaminated Soil by Organic Metabolites from Fungi I—Production of Organic Acids
- 2008
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Ingår i: Water, Air and Soil Pollution. - Berlin, Germany : Springer. - 0049-6979 .- 1573-2932. ; 205:1-4, s. 215-226
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Tidskriftsartikel (refereegranskat)abstract
- Investigations were made on living strains offungi in a bioremediation process of three metal (lead)contaminated soils. Three saprotrophic fungi (Aspergillusniger, Penicillium bilaiae, and a Penicillium sp.) wereexposed to poor and rich nutrient conditions (no carbonavailability or 0.11 M D-glucose, respectively) andmetal stress (25 μM lead or contaminated soils) for5 days. Exudation of low molecular weight organicacids was investigated as a response to the metal andnutrient conditions. Main organic acids identified wereoxalic acid (A. niger) and citric acid (P. bilaiae).Exudation rates of oxalate decreased in response tolead exposure, while exudation rates of citrate were lessaffected. Total production under poor nutrient conditionswas low, except for A. niger, for which nosignificant difference was found between the poor andrich control. Maximum exudation rates were 20 μmoloxalic acid g^−1 biomass h^−1 (A. niger) and 20 μmolcitric acid g^−1 biomass h^−1 (P. bilaiae), in the presenceof the contaminated soil, but only 5 μmol organic acidsg^−1 biomass h^−1, in total, for the Penicillium sp. Therewas a significant mobilization of metals from the soilsin the carbon rich treatments and maximum release ofPb was 12% from the soils after 5 days. This was notsufficient to bring down the remaining concentration tothe target level 300 mg kg^−1 from initial levels of 3,800,1,600, and 370 mg kg^−1in the three soils. Target levelsfor Ni, Zn, and Cu, were 120, 500, and 200 mg kg^−1,respectively, and were prior to the bioremediationalready below these concentrations (except for Cu Soil1). However, maximum release of Ni, Zn, and Cu was28%, 35%, and 90%, respectively. The release of metalswas related to the production of chelating acids, but alsoto the pH-decrease. This illustrates the potential to usefungi exudates in bioremediation of contaminated soil.Nonetheless, the extent of the generation of organicacids is depending on several processes and mechanismsthat need to be further investigated.
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| 10. |
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| 11. |
- de Hoogh, Kees, et al.
(författare)
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Comparing land use regression and dispersion modelling to assess residential exposure to ambient air pollution for epidemiological studies
- 2014
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Ingår i: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 73, s. 382-392
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Tidskriftsartikel (refereegranskat)abstract
- Background: Land-use regression (LUR) and dispersion models (DM) are commonly used for estimating individual air pollution exposure in population studies. Few comparisons have however been made of the performance of these methods. Objectives: Within the European Study of Cohorts for Air Pollution Effects (ESCAPE) we explored the differences between LUR and DM estimates for NO2, PM10 and PM2.5. Methods: The ESCAPE study developed LUR models for outdoor air pollution levels based on a harmonised monitoring campaign. In thirteen ESCAPE study areas we further applied dispersion models. We compared LUR and DM estimates at the residential addresses of participants in 13 cohorts for NO2; 7 for PM10 and 4 for PM2.5. Additionally, we compared the DM estimates with measured concentrations at the 20-40 ESCAPE monitoring sites in each area. Results: The median Pearson R (range) correlation coefficients between LUR and DM estimates for the annual average concentrations of NO2, PM10 and PM2.5 were 0.75 (0.19-0.89), 0.39 (0.23-0.66) and 0.29 (0.22-0.81) for 112,971 (13 study areas), 69,591 (7) and 28,519(4) addresses respectively. The median Pearson R correlation coefficients (range) between DM estimates and ESCAPE measurements were of 0.74(0.09-0.86) for NO2; 0.58 (0.36-0.88) for PM10 and 0.58 (0.39-0.66) for PM2.5. Conclusions: LUR and dispersion model estimates correlated on average well for NO2 but only moderately for PM10 and PM2.5, with large variability across areas. DM predicted a moderate to large proportion of the measured variation for NO2 but less for PM10 and PM2.5.
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| 12. |
- Eriksson, Anders, et al.
(författare)
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Accuracy of death certificates of cardiovascular disease in a community intervention in Sweden.
- 2013
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Ingår i: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 41:8, s. 883-889
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim was to investigate the possibility to evaluate the mortality pattern in a community intervention programme against cardiovascular disease by official death certificates.Methods: For all deceased in the intervention area (Norsjö), the accuracy of the official death certificates were compared with matched controls in the rest of Västerbotten. The official causes of death were compared with new certificates, based on the last clinical record, issued by three of the authors, and coded by one of the authors, all four accordingly blinded.Results: The degree of agreement between the official underlying causes of death in "cardiovascular disease" (CVD) and the re-evaluated certificates was not found to differ between Norsjö and the rest of Västerbotten. The agreement was 87% and 88% at chapter level, respectively, but only 55% and 55% at 4-digit level, respectively. The reclassification resulted in a 1% decrease of "cardiovascular deaths" in both Norsjö and the rest of Västerbotten.Conclusions: The disagreements in the reclassification of cause of death were equal but large in both directions. The official death certificates should be used with caution to evaluate CVD in small community intervention programmes, and restricted to the chapter level and total populations.
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| 13. |
- Eriksson, Martin, 1968, et al.
(författare)
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Flow Visualization and Turbulence Measurements in a Three-Dimensional Turbulence Wall Jet
- 1991
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Ingår i: First European Fluid Mechanics Conference in Cambridge September 16-20.
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Konferensbidrag (refereegranskat)abstract
- The modelling of turbulence has recently been directed towards the handling of anisotropic flow fiends, i.e. the interest has been focused on the use of models base on the transport equations for the Reynolds stresses (RST models). To improve these turbulence models well-defined, simple and fundamental experiments are needed in which gradients of the different turbulence parameters are determined. Together with direct simulations of the Navier-Strokes equations these experiments yield a good base for the improvement of different terms in the Reynolds equations.A fundamental, well-defined and simple flow case is the three-dimensional wall jet, where an interaction between a wall boundary layer and a free shear layer forms the anisotropy as well as the inhomogeneous character of the flow field.The purpose of the present work was to study the turbulence field of a three-dimensional wall jet, without an outer disturbing flow field. This was accomplisher by using smoke visualization and hot-wire technique for mean velocity and turbulence measurements. In the present measurement a Reynolds number104 was used, and the extension of the measurements in the flow direction was in the range x/h = 25 through x/h = 62 (x – coordinate in the flow direction and h – slot height.) Preston tubes were employed for the determination of friction of the friction velocity.The spreading rates in the normal as well as lateral direction were visualized for a rectangular and a circular orifice. Different sizes of the vertical wall perpendicular to the outlet were also tested. All spreading rates were determined for the outer boundary of the smoke plumes. It was found that the normal spreading rate was influenced by the wall size as well as the orifice geometry. High wall and circular orifice implied a reduction of the normal spreading. In the lateral direction, no significant difference could be noticed due to either wall size or orifice geometry.Profiles of mean velocities and turbulent quantities were determined at five positions on the centre-line. At three of these positions, equally spaced, the mean velocity and turbulence intensity were also determined at positions off the centre-line to enable the determination of the lateral spreading. From the measurements the normal spreading rate, based as usually on the half-width, was determined to 0.055 and the lateral spreading was estimated in the same way to 0.27. Considering the turbulence measurements, the typical two-point maxima can be found in the normal stress component. A comparison of the profiles for different orifice geometry yields that the orifice not seems to have any significant influence on the turbulence intensity. From the off centre-line measurements it can be noted that the profile shape is approximately the same as on the centre-line.Cross-wire technique was employed for the determination of shear stress profiles along the centre-line.
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| 14. |
- Fu, Michael, 1963, et al.
(författare)
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Optimizing the Management of Heart Failure with Preserved Ejection Fraction in the Elderly by Targeting Comorbidities (OPTIMIZE-HFPEF).
- 2016
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Ingår i: Journal of cardiac failure. - : Elsevier BV. - 1532-8414 .- 1071-9164. ; 22:7, s. 539-544
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Tidskriftsartikel (refereegranskat)abstract
- The pathophysiology of heart failure with preserved ejection fraction (HFPEF) is not fully understood. A recently proposed mechanism for HFPEF is that it is a systemic pro-inflammatory state induced by comorbidities, leading to microvascular endothelial dysfunction and subsequent cardiac remodelling and dysfunction. We hypothesize that targeting comorbidities will improve outcomes in elderly patients with HFPEF. Thus, the aim of this study is to determine whether the combination of systematic screening of patients with HFPEF and optimal management of comorbidities associated with HFPEF improves outcomes.
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| 15. |
- Guisado-Clavero, Marina, et al.
(författare)
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The role of primary health care in long-term care facilities during the COVID-19 pandemic in 30 European countries : A retrospective descriptive study (Eurodata study)
- 2023
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Ingår i: Primary Health Care Research and Development. - 1463-4236. ; 24
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Tidskriftsartikel (refereegranskat)abstract
- Background and aim: Primary health care (PHC) supported long-term care facilities (LTCFs) in attending COVID-19 patients. The aim of this study is to describe the role of PHC in LTCFs in Europe during the early phase of the pandemic. Methods: Retrospective descriptive study from 30 European countries using data from September 2020 collected with an ad hoc semi-structured questionnaire. Related variables are SARS-CoV-2 testing, contact tracing, follow-up, additional testing, and patient care. Results: Twenty-six out of the 30 European countries had PHC involvement in LTCFs during the COVID-19 pandemic. PHC participated in initial medical care in 22 countries, while, in 15, PHC was responsible for SARS-CoV-2 test along with other institutions. Supervision of individuals in isolation was carried out mostly by LTCF staff, but physical examination or symptom's follow-up was performed mainly by PHC. Conclusion: PHC has participated in COVID-19 pandemic assistance in LTCFs in coordination with LTCF staff, public health officers, and hospitals.
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| 16. |
- Henriksson, Gunnar, et al.
(författare)
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Endoglucanase 28 (Cel12A), a new Phanerochaete chrysosporium cellulase.
- 1999
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Ingår i: European Journal of Biochemistry. - 0014-2956 .- 1432-1033. ; 259:1-2, s. 88-95
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Tidskriftsartikel (refereegranskat)abstract
- A 28-kDa endoglucanase was isolated from the culture filtrate of Phanerochaete chrysosporium strain K3 and named EG 28. It degrades carboxymethylated cellulose and amorphous cellulose, and to a lesser degree xylan and mannan but not microcrystalline cellulose (Avicel). EG 28 is unusual among cellulases from aerobic fungi, in that it appears to lack a cellulose-binding domain and does not bind to crystalline cellulose. The enzyme is efficient at releasing short fibres from filter paper and mechanical pulp, and acts synergistically with cellobiohydrolases. Its mode of degrading filter paper appears to be different to that of endoglucanase I from Trichoderma reesei. Furthermore, EG 28 releases colour from stained cellulose beads faster than any other enzyme tested. Peptide mapping suggests that it is not a fragment of another known endoglucanases from P. chrysosporium and peptide sequences indicate that it belongs to family 12 of the glycosyl hydrolases. EG 28 is glycosylated. The biological function of the enzyme is discussed, and it is hypothesized that it is homologous to EG III in Trichoderma reesei and the role of the enzyme is to make the cellulose in wood more accessible to other cellulases.
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| 17. |
- Johansson, Bert, et al.
(författare)
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Application of wedge-shaped hot-film probes in a gas-particle flow
- 2003
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Ingår i: Experimental Thermal and Fluid Science. - 0894-1777. ; 27:2, s. 187-191
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Tidskriftsartikel (refereegranskat)abstract
- A wedge-shaped hot-film probe is used to perform measurements of turbulence intensity and an estimate of the turbulent kinetic energy as well as the Eulerian spectra, macro- and micro-scales of the gas phase in a horizontal pipe flow carrying pulp fibres or spherical particles. In addition, the paper gives a summary of a method for handling the poor frequency response of the probe and discusses how to sort out "bad samples", occurring when the probe is hit by particles.
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| 18. |
- Johansson, Emma M.
(författare)
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Impact of root and mycorrhizal exudation on soil carbon fluxes : influence of elevated CO2 and metals
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. Our knowledge of exudation rates for tree roots and especially associated ECM is limited, and also factors influencing exudation rates. Two environmental factors, metal stress and elevated atmospheric CO2 level, have been investigated. Both are of great environmental concern, but function in different ways (detoxification and C allocation) and may be highly important for the C flux caused by root/ECM exudation. The project has been carried out with mycorrhizal and nonmycorrhizal (NM) Scots pine seedlings, or saprotrophic fungi, under both sterile and non-sterile (soil) conditions. Analytical determination of exudates and calculation of exudation rates have been major tools for assessment. Assessing the possibility of using naturally occurring chelating agents (e.g. citrate and oxalate) for bioremediation of metals contaminated soils and development and validation of analytical techniques have been additional foci. The results show that from soil-living fungi and ectomycorrhizal roots exudation rates of especially LMWOAs increase significantly at Cd and Pb stress (1-100 μM), while As (as arsenate) and mixtures of metals with As have little effect. The impact of ECM fungi is large and much higher exudation rates are found when the symbionts are present both for controls and metal treatments compared to NM plants. In soil systems there was a significant mobilization of metals from soils under presence of saprotrophic fungi. Both N as well as elevated CO2 (700 ppm) causes sizable increases in exudation rates, independent of biomass, and is a finding that suggests that the availability of easily degradable carbon in soil raises, which may be highly important for the carbon flux in soil. Mycorrhizal seedlings (10 months old) increased total soil respiration ~50% compared to controls without plants in non-sterile soil systems. Key words: amino acids, 13C, carbon cycle, ectomycorrhiza, elevated CO2, exudation, DOC, LMWOA, metal stress, monosaccharides, oxalate, Pinus sylvestris, saprotrophic fungi, soil respiration
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| 19. |
- Johansson, Håkan, 1965-
(författare)
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On Distribution Coefficients in Aquatic Systems
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis, different types of chemical and physical distribution coefficients are identified, examined and used to describe the fate and transport pathways of substances in aquatic systems.Observations from field experiments in streams with non-reactive and reactive tracers constituted the basis for development of an advection-dispersion model. Differences in the concentrations in both the water and sediment data for the tracers were due to the particle affinity of the reactive tracer. This difference in behaviour could be described by including an instantanous and a kinetically controlled sorption, which included distribution coefficients, in the water column (Kd) and in the streambed sediment (KB), respectively.The results presented in this thesis also include a model for the lake characteristic concentration of suspended particulate matter (SPM). The SPM-model can be used to describe mass flows of particles in lakes. The traditional distribution (or partition) coefficient Kd has been found to be unsuitable for interpretations of the particle association of solutes and also for distributing solute mass flows. Instead, the particulate or the dissolved fraction, PF and DF, defined as ratios of the particulate or dissolved concentration to the total concentration respectively, is recommended for mass-balance calculations. A new PF-model for phosphorus has meant that this part is no longer the most sensitive part of predicting concentrations of phosphorus in lakes using a more extensive dynamic model.New methods have also been developed to describe the shape of lakes. Together with the mixing depth of lakes, the shape of a lake can be transformed into a distribution coefficient that physically determines the portion of a lake that is exposed, both areally and vertically, to continuously mixing.
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| 20. |
- Johansson, Inger, et al.
(författare)
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Analysis of water leachable organic components in incineration residues
- 2000
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Ingår i: International Journal of Environmental Analytical Chemistry. - : Informa UK Limited. - 0306-7319 .- 1029-0397. ; 78:3-4, s. 305-313
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Tidskriftsartikel (refereegranskat)abstract
- The composition of water leachable organics in municipal solid waste incineration (MSWI) residues is not well known. Therefore the utilisation of ashes is restricted due to the concern about their long-term environmental impact. Previous studies have focused on some highly toxic organic compounds present only in trace amounts. It is also important to know the composition of the bulk organic matter since dissolved organic carbon can alter the leachability of metals. In order to characterise water leachable organic matter in incineration residues a fractionation procedure using polymeric adsorbents was successfully developed and applied. The technique uses XAD-8 and XAD-4 resins in tandem and has been implemented on bottom ash samples from two incineration plants in Sweden in order to characterise the bulk organic matter.
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| 21. |
- Johansson, Inger, et al.
(författare)
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Levels and patterns of polycyclic aromatic hydrocarbons in incineration ashes
- 2003
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 311:1-3, s. 221-231
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Tidskriftsartikel (refereegranskat)abstract
- Polycyclic aromatic hydrocarbons were analysed in weathered bottom ash from municipal solid waste incineration, fly ash from a mixed heating plant and an ash mixture from different kinds of biofuels. Although of different origin and age, all three ashes are evaluated in different small-scale fill applications. The ultimate goal is the usage of these ashes on a larger scale. The samples were Soxhlet extracted and analysed using GC/MS in the full scan mode. The sum of the 16 US EPA PAHs was found to vary from 140 mug/kg up to more than 77 000 mug/kg. Total amounts of PAHs were similar in bottom ash and in fly ash. The concentration in the mixed biofuel ash was more than 10 times higher, and exceeded the generic guidelines for PAHs in soil set by the Swedish Environmental Protection Agency. The patterns of the individual PAHs normalised to the total concentration of PAHs were found to be very similar for all the three ashes. Naphthalene and phenanthrene were the dominating PAHs for all ash samples, but the mixed biofuel ash also contained high levels of fluoranthene and pyrene. (C) 2003 Elsevier Science B.V. All rights reserved.
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| 22. |
- Johansson, Inger, et al.
(författare)
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Polycyclic aromatic hydrocarbons in weathered bottom ash from incineration of municipal solid waste
- 2003
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Ingår i: Chemosphere. - 0045-6535 .- 1879-1298. ; 53:2, s. 123-128
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Tidskriftsartikel (refereegranskat)abstract
- Polycyclic aromatic hydrocarbons (PAHs) were analysed in weathered bottom ash from different municipal solid waste incinerators. The sum of the 16 "USEPA" PAHs was found to vary from 480 to 3590 mug/kg. The amounts of carcinogenic PAHs were between 89 and 438 mug/kg ash. The maximum levels of carcinogenic PAHs exceed the Swedish generic guidelines for sensitive land use. The results showed that the amount of PAHs in fresh and weathered bottom ash are similar, indicating that the PAHs are strongly bound to the ash and only limited amounts are released to'the surroundings. (C) 2003 Elsevier Ltd. All rights reserved.
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| 23. |
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| 24. |
- Johansson, Marléne, 1953, et al.
(författare)
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Låt eleverna bestämma så lär de sig mer
- 1994
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Ingår i: Slöjdforum. ; :6, s. 30-32
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Artikel utifrån resultat från den fördjupade analysen av slöjdämnet i NU-03.
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| 25. |
- Johansson, Marléne, 1953, et al.
(författare)
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Slöjd. Huvudrapport : Skolverkets rapport nr 24
- 1993
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Huvudrapport från Skolverkets nationella utvärdering av den svenska grundskolan, Slöjd, (NU-92). Projektledare för slöjdämnet: Ann Carlberg & Bert Owe Lundqvist, medförfattare: Marléne Johansson
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| 26. |
- Johansson, Marléne, 1953, et al.
(författare)
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Slöjd på Kuba. Ämne med svenska anor
- 1996
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Ingår i: Slöjdforum. ; :2, s. 18-19
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Artikel om den kubanska slöjdens historia
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| 27. |
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| 28. |
- Johansson, Marléne, 1953, et al.
(författare)
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Teaching towards creativity in Sloyd
- 1996
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Ingår i: Paper, The second International Symposium of Handicraft Teaching, november 1996, Pinar del Rio, Kuba.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)
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| 29. |
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| 30. |
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| 31. |
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| 32. |
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| 33. |
- Ljus, Camilla, et al.
(författare)
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Turbulence modification by particles in a horizontal pipe flow
- 2002
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Ingår i: International Journal of Multiphase Flow. - 0301-9322. ; 28:7, s. 1075-1090
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Tidskriftsartikel (refereegranskat)abstract
- Measurements were made of turbulence intensities and turbulent energy spectra in a fully developed, turbulent air-particle pipe flow. The influence of the particles on the turbulence was studied. Measurements were made with spherical particles and particles with a large aspect ratio (pulp fibres). There is a significant change in turbulence intensity at higher particle concentrations with loading ratios of m = 0.1 and 0.03. The measurements show that the turbulence intensity increases close to the centre of the pipe while the turbulence intensity decreases close to the pipe wall for the spherical particles. These results are in agreement with earlier measurements found in the literature. For the fibres, the turbulence intensity decreases over the whole pipe cross-section. Fibre flocs, however, give variations in the mean velocity that result in the production of turbulence in the lower part of the channel.
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| 34. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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A Fast Simple Hot-Wire Method of Determining the Mean Velocity Vector of Complex Three-Dimensional Flows
- 1996
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Ingår i: Experiments in Fluids. ; 20, s. 398-400
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Tidskriftsartikel (refereegranskat)abstract
- A fast and simple method of determining the mean velocity vector of complex three-dimensional flow fields is outlined. Straight and slanted single hot-wires are rotated in two perpendicular planes. This method increases the angular resolution, which is of importance in flow situations where one of the velocity components dominates and the other changes rapidly from one point to another. The method was calibrated in a wind tunnel and assessed in the internal flow field at the outlet of a fan in a defroster channel. It is shown that the hot-wire method yields good agreement with corresponding flow visualizations determined using a textile thread, and an integration of the measured mean flow yields a flow rate which agrees within a few percent with corresponding direct measurements on an orifice plate.
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| 35. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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A Sensor Based on Silicon Technology for Turbulence Measurements
- 1989
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Ingår i: Journal of Physics E. Scientific Instruments. ; 22, s. 391-393
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Tidskriftsartikel (refereegranskat)abstract
- A very small and highly sensitive flow velocity sensor has been designed and fabricated using silicon microelectronic technology. To determine the performance of this silicon sensor, comparisons with a conventional hot-wire sensor were made in a well defined two-dimensional turbulent flat-plate boundary layer at a constant Reynolds number of 4.2*106. The silicon sensor was found to have a spatial and frequency resolutions that make it suitable for turbulence measurements. In the investigated flow field the new silicon sensor measures profiles of the mean velocity and the turbulence intensity with accuracy as the hot wire.
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| 36. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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A Silicon Transducer for the Determination of Wall-Pressure Fluctuations in Turbulent Boundary Layers
- 1993
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Ingår i: Applied Scientific Research. ; 51
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Tidskriftsartikel (refereegranskat)abstract
- Small and sensitive silicon sensors for turbulent wall-pressure fluctuation measurements have been designed and fabricated using microelectronic technology. For the detection of the pressure fluctuations piezoresistive gauges are placed on a diaphragm and the resistance of these gauges depends on the stresses in the diaphragm. For the determination of the performance of these pressure transducers comparisons with conventional microphones were carried out in a well-defined two-dimensional boundary layer. Power spectra from the silicon pressure transducer revealed a slope in the inertial sublayer corresponding approximately to the 1/3-law of Kolmogorov, and the normalized wall-pressure fluctuations agreed well with other direct measurements.
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| 37. |
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| 38. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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Determination of Derivative Moments using Two Slanted Hot-Wires and a Spectral method
- 1993
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Ingår i: Experiments in Fluids. ; 15, s. 393-400
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Tidskriftsartikel (refereegranskat)abstract
- A method to determine derivative moments using slanted hot-wires and a spectral method has been developed. The general idea is to minimize measuring volume by using only two hot-wires, and a post-processing of the measurement data. It is shown that the spectral method is equivalent to conventional determinations of correlations. The method developed has been tested in the self-preserving region of a plane wake by computing profiles of the Reynolds stresses as well as the derivative moments in the expression for the total energy dissipation. One term in this expression, which with conventional methods requires two triple-wires or four cross-wires, has been determined using the spectral method.
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| 39. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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Influence of Different Sensor Configurations on the Turbulent Quantities in a Complex Three-Dimensional Flow Field
- 1993
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Ingår i: ASME-Fluid Engineering Conference, Washington DC.
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Konferensbidrag (refereegranskat)abstract
- Measurements of the Reynolds stress tensor have been carried out in a complex three-dimensional boundary layer using different techniques. Single-, cross- and three-hot-wire probes were employed together with a silicon based double chip sensor. All measurements were performed at a Reynolds number of 1.2 x ___ per meter. The turbulent stresses were determined at a reference position in a two-dimensional part of the flow field and at three locations with different strength of the three-dimensionality. A good agreement was found in the turbulent quantities measured with the different methods, however, the influence of prong interference, measuring volumes and velocity gradients were noted.
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| 40. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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Measurement of the Enstrophy and the Vorticity Vector in a Plane Cylinder Wake using a Spectral Method
- 1994
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Ingår i: Fifth European Turbulence Conference in Siena, Italy, July 5-8 1994..
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Konferensbidrag (refereegranskat)abstract
- A method to determine derivative moments using only two slanted hot-wires and a spectral method has been employed for a complete determination of the enstrophy and the vorticity vector. The general idea behind the method is to minimize the measuring volume by use of only two hot-wires and to post-process the measured data. All measurements were conducted in the far wake of a cylinder at a Reynolds number of 1840. Comparisons between the spectral method and conventional measuring techniques are made, and the results justifies the approximation between enstrophy and dissipation. For the vorticity vector it was found that the components of the normal and lateral directions were considerably larger than the stream-wise ones.
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| 41. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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On the Reynolds number dependence of a plane two-dimensional wall jet
- 1994
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Ingår i: Proceedings of the 2nd International Conference on Experimental Fluid Mechanics (eds. Onorato), Levotto & Bella, pp. 271-278..
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Konferensbidrag (refereegranskat)abstract
- Measurements in a plane two-dimensional turbulent wall-jet has been conducted at different slot Reynolds numbers using hot-wire technique. The wall-jet was shown to be two-dimensional and self preserving. Using momentum scaling, based on viscosity and inlet momentum flux, the growth of the half-width and the decay of the maximum mean velocity were showed to be independent of the slot Reynolds number. It was also found that as compared to an ordinary wall boundary layer, the strong interactions between the inner and outer regions limited the extension of the logarithmic part of the mean velocity profile, and enhanced the turbulence level close to the wall.
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| 42. |
- Löfdahl, Lennart, 1948, et al.
(författare)
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Reynolds Stress Measurements using Direction-Sensitive Double-Chip Silicon Sensors
- 1991
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Ingår i: Measurements Science and Technology. ; 2, s. 369-373
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Tidskriftsartikel (refereegranskat)abstract
- A small direction-sensitive double-chip silicon-based sensor has been designed and fabricated using microelectronic technology. To determine the performance of this sensor the Reynolds stresses in a two-dimensional flat plate boundary layer were determined at a Reynolds number of 4.2*106. Comparisons with conventional hot-wire sensors were made showing that the double-chip sensor was able to determine the turbulent stresses to the same accuracy as a cross hot wire.
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| 43. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Silicon Based Flow Sensors for Mean Velocity and Turbulence Measurements
- 1992
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Ingår i: Experiments in Fluids. ; 12, s. 391-393
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Tidskriftsartikel (refereegranskat)abstract
- Small and directional sensitive silicon based sensors for velocity measurements have been designed and fabricated using microelectronic technology. Single-chip as well as double-chip sensors for the determination of mean velocity and turbulent stresses have been developed. To determine the performance of these silicon sensors, comparisons with conventional hot-wire sensors were done in a well-defined two-dimensional flat plate boundary layer at a constant Reynolds number of 4.2*106. All the silicon sensors were found to have spatial and frequency resolution that makes them suitable for turbulence measurements. In the studied flow field the measured profiles of mean velocities and Reynolds stresses of all silicon sensors show the same accuracy and corresponding hot-wire measurements. The silicon sensors are also shown to operate with good resolution even when the temperature of the heated part of the chip is reduced considerably.
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| 44. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Silicon Based Sensors for the Measurement of Turbulence and Wall-Pressure Fluctuations in a Two-Dimensional Flat Plate Boundary Layer
- 1993
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Ingår i: International Conference on Near-wall Turbulent Flows, Tempe, Arizona.
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Konferensbidrag (refereegranskat)abstract
- Small and sensitive silicon based sensors for the measurement of turbulence and wall-pressure fluctuations have been designed and fabricated using microelectronic technology. To determine the performance of these sensors, comparisons with conventional hot-wires and microphones were carried out in a well-defined two-dimensional turbulent flat plate boundary layer. The velocity sensors were found to have a spatial and frequency resolution that makes them suitable for turbulence measurements. For the pressure transducers the same good resolution was found, and from the power spectrum, determined directly with a small silicon sensor, a slope in the inertial sub-layer in agreement with the 5/3-law of Kolmogorov was found.
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| 45. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Studies of the Turbulence Field in a Three-Dimensional Wall-Jet
- 1992
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Ingår i: Fourth European Turbulence Conference, Delft, Elsevier, Amsterdam.
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Konferensbidrag (refereegranskat)abstract
- Today, the interest in the modelling of turbulence is directed towards complex, three-dimensional and anisotropic flow fields. Successful models are usually based on the transport equations for the Reynolds stresses and terms containing derivatives of these stresses must be modelled. Direct simulations together with well-defined, simple and fundamental experiments, in which the gradients of the turbulent quantities are determined, yield a good base for the improvement of this turbulence modelling.Such a fundamental and simple flow case is the three-dimensional turbulent wall-jet (3DTWJ), where an interaction between a wall boundary layer and a free shear layer forms the anisotropy as well as the inhomogeneous character of the flow field. According to Launder and Rodi (1981) the first experiment on a 3DTWJ was carried out by Viets and Sforza (1970), and until today very few experimental studies on 3DWTJ have been reported. However, quite recently Matsuda et al. (1990) have published a work on coherent structures in a 3DTWJ. The purpose of the present work was to study the turbulence field of a three-dimensional wall-jet without an outer disturbing flow field. This was accomplished using a wall-jet rig which consisted of a fan, a settling chamber and a circular outlet located so that the flow is blowing tangentially along a horizontal flat plate. To define the boundary conditions a vertical wall is positioned perpendicular to the outlet and the flat plate. In an introductory part of this work, the shape of the jet outlet and the influence of the vertical wall were studied, see Löfdahl et al. (1991). From this study, a circular outlet and a vertical wall, of approximately the same size as the flat horizontal plate on which the three-dimensional wall-jet (3DTWJ) was formed, were chosen. Smoke visualisations as well as hot-wire measurements have been used in the investigation of the flow field. All measurements were carried out using hot-wire technique, using standard probes and conventional methods for the determination and the mean velocities and turbulent quantities, see Löfdahl (1991).In the present measurements Reynolds numbers based on the outlet diameter, d, in the range of 10000 through 40000 were studied. The extension of the measurements in the flow direction was in the range of x/d=33 through x/d=113, (x-coordinate in the flow direction) and an apex angle interval of 40 degrees in steps of 10 degrees. Profiles of the mean velocities, Reynolds stresses and triple correlations were determined along each “streamline”. In Figure 1 the turbulence intensity and the shear stress distribution, respectively, are shown at different locations along the centre line. The turbulence intensity shows the tendency of the expected two maxima, while in the shear stress only one positive maximum in the outer portion of the jet is captured due to the probe size. As an example of the energy redistribution in the 3DTWJ, the Reynolds stresses at location x/d=47 and x/d=87 are shown in Figure 2. A clear reduction in the fluctuating velocity normal to the wall can be noted as the wall jet is spread in the downstream direction. In the full paper all measured mean velocities, Reynolds stresses and triple correlations are shown together with studies of the turbulent structure at the centre line using the quadrant method.
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| 46. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
The Influence of Temperature on the Measurements of Reynolds Stresses in Shear Free Turbulence Near a Wall
- 1998
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Ingår i: Experiments in Fluids. ; 25, s. 160-164
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Tidskriftsartikel (refereegranskat)abstract
- Temperature changes have a significant influence on the measurements of Reynolds stresses in turbulent boundary layers. As compared to the spanwise velocity fluctuations the streamwise turbulence intensity is especially sensitive to temperature deviations. Although this is a general statement its importance is clearly elucidated in a shear-free turbulence near a solid wall, since the mixing due to turbulence production is minimized in this flow. A consequence of temperature influence on hot-wire measurements is that frictional heating from the wall has produced contradictory results in different experiments on shear-free turbulence. In the current paper, measurements of streamwise and spanwise turbulence intensities have been conducted at different wall temperatures, thereby simulating the contradictory results mentioned above. A simple model has been developed showing that the turbulence intensities are affected by both the rms. value of the temperature fluctuations and the correlation between fluctuating temperature and velocity. These correlations are measured and the developed model is used to explain deviations in earlier measurements on shear-free turbulence. Moreover, the individual magnitudes of the two correlations in the temperature correction are estimated and their individual importance is discussed.
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| 47. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Turbulence Measurements using Double-Chip Silicon Sensors
- 1990
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Ingår i: Third European Turbulence Conference, Stockholm, Springer Verlag, Heidelberg.
-
Konferensbidrag (refereegranskat)abstract
- A small directional sensitive double-chip silicon based sensor has been designed and fabricated using microelectronic technology. To determine the performance of this sensor the Reynolds stresses in a two-dimensional flat plate boundary layer were determined at a Reynolds number of ___. Comparisons with conventional hot-wire sensors were made and showed that the double-chip sensor was able to determine the turbulent stresses with the same accuracy as a cross-hot-wire.
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| 48. |
- Löfdahl, Lennart, 1948, et al.
(författare)
-
Turbulence measurements using sensors based on silicon technology
- 1989
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Ingår i: ICIASF ’89, Deutsche Forschungsanstalt für Luft und Raumfahrt, Research Center Göttingen,W.-Germany, September 18-21. ; , s. 95 - 103
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Konferensbidrag (refereegranskat)abstract
- A small and highly flow velocity has been designed and fabricated using silicon microelectronic technology. To determine the performance of this silicon sensor were done on a well-defined two dimensional turbulent flat plate boundary layer at a constant Reynolds number of 4.2*106.The silicon sensor was found to have a spatial and frequency resolution that makes it suitable for turbulence measurements. In the investigated flow field the new silicon sensor measure profiles of the measure profiles of the mean velocity and the turbulence intensity with the same accuracy as the hot-wire.Based on these results, three new sensors configurations have been designed. These sensors are also presented and discussed.
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| 49. |
- Olsson, Jan, et al.
(författare)
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Urea dilution of serum for reproducible anti-HSV1 IgG avidity index
- 2019
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Ingår i: BMC Infectious Diseases. - : BioMed Central. - 1471-2334. ; 19
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Tidskriftsartikel (refereegranskat)abstract
- Herpes simplex virus type 1 (HSV1), establishes life-long latency and can cause symptoms during both first-time infection and later reactivation. The aim of the present study was to describe a protocol to generate a reliable and discriminative avidity index (AI) for anti-HSV1 IgG content in human sera. Human serum from two distinct cohorts; one a biobank collection (Betula) (n = 28), and one from a clinical diagnostics laboratory at Northern Sweden University Hospital (NUS) (n = 18), were assessed for presence of IgG antibodies against HSV1 by a commercially available ELISA-kit. Addition of urea at the incubation step reduces effective binding, and the ratio between urea treated sample and non-treated sample was used to express an avidity index (AI) for individual samples. AI score ranged between 43.2 and 73.4% among anti-HSV1 positive biobank sera. Clinical samples ranged between 36.3 and 74.9%. Reproducibility expressed as an intraclass correlation coefficient (ICC) was estimated at 0.948 (95% CI: 0.900-0.979) and 0.989 (95% CI 0.969-0.996) in the biobank and clinical samples, respectively. The method allows for AI scoring of anti-HSV1 IgG from individual human sera with a single measurement. The least significant change between two measurements at the p < 0.05 level was estimated at 5.4 and 3.2 points, respectively, for the two assessed cohorts.
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| 50. |
- Rodriguez-Palmero, Agusti, et al.
(författare)
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DLG4-related synaptopathy : a new rare brain disorder
- 2021
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Ingår i: Genetics in Medicine. - : Elsevier BV. - 1098-3600 .- 1530-0366. ; 23:5, s. 888-899
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Tidskriftsartikel (refereegranskat)abstract
- PurposePostsynaptic density protein-95 (PSD-95), encoded by DLG4, regulates excitatory synaptic function in the brain. Here we present the clinical and genetic features of 53 patients (42 previously unpublished) with DLG4 variants.MethodsThe clinical and genetic information were collected through GeneMatcher collaboration. All the individuals were investigated by local clinicians and the gene variants were identified by clinical exome/genome sequencing.ResultsThe clinical picture was predominated by early onset global developmental delay, intellectual disability, autism spectrum disorder, and attention deficit–hyperactivity disorder, all of which point to a brain disorder. Marfanoid habitus, which was previously suggested to be a characteristic feature of DLG4-related phenotypes, was found in only nine individuals and despite some overlapping features, a distinct facial dysmorphism could not be established. Of the 45 different DLG4 variants, 39 were predicted to lead to loss of protein function and the majority occurred de novo (four with unknown origin). The six missense variants identified were suggested to lead to structural or functional changes by protein modeling studies.ConclusionThe present study shows that clinical manifestations associated with DLG4 overlap with those found in other neurodevelopmental disorders of synaptic dysfunction; thus, we designate this group of disorders as DLG4-related synaptopathy.
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