| 1. |
- Branger, Erik, 1988-, et al.
(författare)
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Image analysis as a tool for improved use of the Digital Cherenkov Viewing Device for inspection of irradiated PWR fuel assemblies.
- 2014
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is a tool used to measure the Cherenkov light emitted from irradiated nuclear fuel assemblies stored in water pools. It has been approved by the IAEA for attended gross defect verification, as well as for partial defect verification, where a fraction of the fuel material has been diverted. In this report, we have investigated the current procedures for recording images with the DCVD, and have looked into ways to improve these procedures. Using three different image sets of PWR fuel assemblies, we have analysed what information and results can be obtained using image analysis techniques. We have investigated several error sources that distort the images, and have shown how these errors affect the images. We have also described some of the errors mathematically, and have discussed how these error sources may be compensated for, if the character and magnitude of the errors are known. Resulting from our investigations are a few suggestions on how to improve the procedures and consequently the quality of the images recorded with the DCVD as well as suggestions on how to improve the analysis of collected images. Specifically, a few improvements that should be looked into in the short term are:• Images should be recorded with the fuel assembly perfectly centered in the image, and preferably without any tilt of the DCVD relative to the fuel in order to obtain accurate measurements of the light intensity. Image analysis procedures that may aid the alignment are presented.• To compensate for the distorting effect of the water surface and possible turbulence in the water, several images with short exposure time should be captured rather than one image with long exposure time. Using image analysis procedures, it is possible to sum the images resulting in a final image with less distortions and improved quality.• A reference image should be used to estimate device-related distortions, so that these distortions are compensated for. Ideally, this procedure can also be used to calibrate individual pixels.• The background should be carefully taken into account in order to separate the background level from diffuse signal components, allowing for the background to be subtracted. Accordingly, each measurement campaign should be accompanied by at least one background measurement, recorded from a section in the storage pool where no fuel assemblies are present. Furthermore, the background level should be determined from a larger region in the image and not from one individual pixel, as is currently done.• A database of measurements should be set up, containing DCVD images, information about the applied DCVD settings and the conditions that the DCVD was used in. Any partial defect verification procedure at any time could then be tested against as much data as possible. Accordingly, a database can aid in evaluating and improving partial defect verification methods using DCVD image analysis.Based on the findings and discussions in this report, some long-term improvements are also suggested.
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| 2. |
- Branger, Erik, 1988-, et al.
(författare)
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Improved DCVD assessments of irradiated nuclear fuel using image analysis techniques
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is a tool for measuring the Cherenkov light intensity emitted from irradiated nuclear fuel in wet storage. It is currently used in nuclear facilities where authority inspectors perform attended gross defect verification to ensure the presence of irradiated fuel material, as well as partial defect verification to ensure that a fraction of the fuel material has not been diverted. In 2013, Uppsala University (UU), supported by the Swedish Radiation Safety Authority, initiated a PhD project aimed at gaining a better understanding of the underlying physics process of the Cherenkov light emission and its detection, in order to improve and enhance the capabilities of the DCVD. The scope of this research is broad and includes modelling, simulations and experiments. As a first step, expertise on image analysis was brought into the project with the purpose to identify image analysis related opportunities and challenges relevant to the DCVD. The investigations performed so far cover general aspects of image analysis as well as aspects specific for verification of PWR fuels, where the fuel geometry may be extra challenging. Resulting from the investigation are suggestions on how to improve the measurement procedure and consequently the image quality obtained with the DCVD. This presentation describes these results and expected outcomes of their implementation.
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| 3. |
- Branger, Erik, 1988-, et al.
(författare)
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Towards unattended partial-defect verification of irradiated nuclear fuel assemblies using the DCVD
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is a tool used by authority inspectors to verify irradiated nuclear fuel assemblies in wet storage by measuring the Cherenkov light emitted. The DCVD is approved by the IAEA for gross defect verification, and is one of the few inspection tools approved for partial defect verification.There is interest in adapting the DCVD to work in unattended mode, so that it can be used to verify large quantities of irradiated fuel assemblies prior to moving them to difficult-to-access storage locations. This work presents methods based on image analysis that can be used to reduce the effects of different types of distortions encountered when performing measurements with the DCVD. Implementing these methods will ensure that data of high quality is obtained. Verification prior to moving fuels to difficult-to-access storage may also require a dedicated measurement station to be built, and it is argued that by constructing these stations with the DCVD in mind, many distortions can be reduced or eliminated. Thus, by implementing safeguards-by-design, it is possible to ensure that the DCVD is used in near optimal conditions.
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| 4. |
- Andersson, Peter, 1981-, et al.
(författare)
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Design and initial 1D radiography tests of the FANTOM mobile fast-neutron radiography and tomography system
- 2014
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Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 756, s. 82-93
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Tidskriftsartikel (refereegranskat)abstract
- The FANTOM system is a tabletop sized fast-neutron radiography and tomography system newly developed at the Applied Nuclear Physics Division of Uppsala University. The main purpose of the system is to provide time-averaged steam-and-water distribution measurement capability inside the metallic structures of two-phase test loops for Light Water Reactor thermal-hydraulic studies using a portable fusion neutron generator. The FANTOM system provides a set of 1D neutron transmission data, which may be inserted into tomographic reconstruction algorithms to achieve a 2D mapping of the steam-and-water distribution. In this paper, the selected design of FANTOM is described and motivated. The detector concept is based on plastic scintillator elements, separated for spatial resolution. Analysis of pulse heights on an event-to-event basis is used for energy discrimination. Although the concept allows for close stacking of a large number of detector elements, this demonstrator is equipped with only three elements in the detector and one additional element for monitoring the yield from the neutron generator. The first measured projections on test objects of known configurations are presented. These were collected using a Sodern Genie 16 neutron generator with an isotropic yield of about 1E8 neutrons per second, and allowed for characterization of the instrument’s capabilities. At an energy threshold of 10 MeV, the detector offered a count rate of about 500 cps per detector element. The performance in terms of spatial resolution was validated by fitting a Gaussian Line Spread Function to the experimental data, a procedure that revealed a spatial unsharpness in good agreement with the predicted FWHM of 0.5 mm.
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| 5. |
- Andersson, Peter, 1981-, et al.
(författare)
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Neutron tomography of axially symmetric objects using 14 MeV neutrons from a portable neutron generator
- 2014
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Ingår i: Review of Scientific Instruments. - : AIP Publishing. - 0034-6748 .- 1089-7623. ; 85:8, s. 085109-
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Tidskriftsartikel (refereegranskat)abstract
- In nuclear boiling water reactor cores, the distribution of water and steam (void) is essential for both safety and efficiency reasons. In order to enhance predictive capabilities, void distribution assessment is performed in two-phase test-loops under reactor-relevant conditions. This article proposes the novel technique of fast-neutron tomography using a portable deuterium-tritium neutron generator to determine the void distribution in these loops.Fast neutrons have the advantage of high transmission through the metallic structures and pipes typically concealing a thermal-hydraulic test loop, while still being fairly sensitive to the water/void content. However, commercially available fast-neutron generators also have the disadvantage of a relatively low yield and fast-neutron detection also suffers from relatively low detection efficiency. Fortunately, some loops are axially symmetric, a property which can be exploited to reduce the amount of data needed for tomographic measurement, thus limiting the interrogation time needed.In this article, three axially-symmetric test objects depicting a thermal-hydraulic test loop have been examined; steel pipes with outer diameter 24 mm, thickness 1.5 mm and with three different distributions of the plastic material POM inside the pipes. Data recorded with the FANTOM fast-neutron tomography instrument have been used to perform tomographic reconstructions to assess their radial material distribution. Here, a dedicated tomographic algorithm that exploits the symmetry of these objects has been applied, which is described in the paper.Results are demonstrated in 20 rixel (radial pixel) reconstructions of the interior constitution and 2D visualization of the pipe interior is demonstrated. The local POM attenuation coefficients in the rixels were measured with errors (RMS) of 0.025, 0.020 and 0.022 cm-1, solid POM attenuation coefficient. The accuracy and precision is high enough to provide a useful indication on the flow mode, and a visualization of the radial material distribution can be obtained. A benefit of this system is its potential to be mounted at any axial height of a two-phase test section without requirements for pre-fabricated entrances or windows. This could mean a significant increase in flexibility of the void distribution assessment capability at many existing two-phase test loops.
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| 6. |
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| 7. |
- Berg, Elisabeth Gräslund, et al.
(författare)
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Praktiker som gör skillnad : Om den verb-inriktade metoden
- 2013
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Ingår i: Historisk Tidskrift. - 0345-469X .- 2002-4827. ; 133:3, s. 335-354
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Tidskriftsartikel (refereegranskat)abstract
- This article discusses the so-called verb-oriented method and its role in the research project Gender and Work in early modern Sweden (GaW), which is based at Uppsala University. It provides a presentation of the GaW-database, which has been designed to allow analysis according to the verb-method. Finally, the article points out that this method can be combined with a number of different theoretical approaches as long as the focus is on practices. It is therefore compatible with the approaches of e.g., Judith Butler, Michel de Certeau, and Amartya Sen. Work is defined as "time-use with the purpose of making a living" and the article discusses why data on time-use, or actual work activities, are better suited for research into early modern Swedish working life than other types of data. It shows that activities are usually described in the sources by verb-phrases, and explains how and from what sources verb-phrases are collected and analyzed within the project. In order to allow for generalizations the verb-method presupposes large amounts of data. This is the rationale for the GaW-database, which at present includes around 5000 verb-phrases and 75000 data posts.
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| 8. |
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| 9. |
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| 10. |
- Blomberg, Jeanette, et al.
(författare)
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Inhibition of cellular FLICE-like inhibitory protein abolishes insensitivity to interferon-α in a resistant variant of the human U937 cell line
- 2011
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Ingår i: Apoptosis (London). - : Springer Science and Business Media LLC. - 1360-8185 .- 1573-675X. ; 16:8, s. 783-794
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Tidskriftsartikel (refereegranskat)abstract
- Type I interferons constitute a family of pleiotropic cytokines that have a key role in both adaptive and innate immunity. The interferon signalling pathways mediate transcriptional regulation of hundreds of genes, which result in mRNA degradation, decreased protein synthesis, cell cycle inhibition and induction of apoptosis. To elucidate regulatory networks important for interferon induced cell death, we generated interferon resistant U937 cells by selection in progressively increasing concentrations of interferon-α (IFN-α). The results show that IFN-α activates the death receptor signalling pathway and that IFN resistance was associated with cross-resistance to several death receptor ligands in a manner similar to previously described Fas resistant U937 cell lines. Increased expression of the long splice variant of the cellular FLICE-like inhibitor protein (cFLIP-L) was associated with the resistance to death receptor and IFN-α stimulation. Accordingly, inhibition of cFLIP-L expression with cycloheximide or through cFLIP short harpin RNA interference restored sensitivity to Fas and/or IFN-α. Thus, we now show that selection for interferon resistance can generate cells with increased expression of cFLIP, which protects the cells from both IFN-α and death receptor mediated apoptosis.
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| 11. |
- Bolinsson, Jessica, et al.
(författare)
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GaAs/AlGaAs heterostructure nanowires studied by cathodoluminescence
- 2014
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Ingår i: Nano Reseach. - : Springer Science and Business Media LLC. - 1998-0124 .- 1998-0000. ; 7:4, s. 473-490
-
Tidskriftsartikel (refereegranskat)abstract
- In this report we explore the structural and optical properties of GaAs/AlGaAs heterostructure nanowires grown by metalorganic vapour phase epitaxy using gold seed-particles. The optical studies were done by low-temperature cathodoluminescence (CL) in a scanning electron microscope (SEM). We perform a systematic investigation of how the nanowire growth-temperature affects the total photon emission, and variations in the emission energy and intensity along the length of the nanowires. The morphology and crystal structures of the nanowires were investigated using SEM and transmission electron microscopy (TEM). In order to correlate specific photon emission characteristics with variations in the nanowire crystal structure directly, TEM and spatially resolved CL measurements were performed on the same individual nanowires. We found that the main emission energy was located at around 1.48 eV, and that the emission intensity was greatly enhanced when increasing the GaAs nanowire core growth temperature. The data strongly suggests that this emission energy is related to rotational twins in the GaAs nanowire core. Our measurements also show that radial overgrowth by GaAs on the GaAs nanowire core can have a deteriorating effect on the optical quality of the nanowires. Finally, we conclude that an in situ pre-growth annealing step at a sufficiently high temperature significantly improves the optical quality of the nanowires.
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| 12. |
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| 13. |
- Engstrand, Thomas, et al.
(författare)
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Development of a bioactive implant for repair and potential healing of cranial defects
- 2014
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Ingår i: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 120:1, s. 273-277
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Tidskriftsartikel (refereegranskat)abstract
- The repair of complex craniofacial bone defects is challenging and a successful result is dependent on the size of the defect, quality of the soft tissue covering the defect, and choice of reconstruction method. The objective of this study was to develop a bioactive cranial implant that could provide a permanent reconstructive solution to the patient by stimulating bone healing of the defect. In this paper the authors report on the feasibility and clinical results of using such a newly developed device for the repair of a large traumatic and therapy-resistant cranial bone defect. The patient had undergone numerous attempts at repair, in which established methods had been tried without success. A mosaic-designed device was manufactured and implanted, comprising interconnected ceramic tiles with a defined calcium phosphate composition. The clinical outcome 30 months after surgery revealed a restored cranial vault without postoperative complications. Computed tomography demonstrated signs of bone ingrowth. Examination with combined 18F-fluoride PET and CT provided further evidence of bone healing of the cranial defect.
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| 14. |
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| 15. |
- Grape, Sophie, 1982-, et al.
(författare)
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Partial defect verification using the DCVD : a capability evaluation approach
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The Digital Cherenkov Viewing Device (DCVD) is a non-intrusive instrument available to theInternational Atomic Energy Agency (IAEA) for verifying spent nuclear fuel in storage pools. It iscurrently used for gross-defect evaluations, i.e. to verify that an item in a storage pool is anirradiated fuel assembly and not a fresh assembly or a dummy. This is done by recording images ofthe Cherenkov light emitted in the water surrounding the fuel. Currently, the instrument’s ability toalso detect partial defects at the 50% level or even lower is under study. Here, experimental work iscomplimented by modeling and simulations due to the limited availability of assemblies with partialdefects.Ideally, an IAEA inspector should be able to use the DCVD at e.g. a fuel storage site andimmediately after scanning obtain information on (1) whether an item is an irradiated fuel assemblyor not, and (2) whether the assembly is intact or suffers from a partial defect. This paper discusses adecision-making methodology intended for the latter purpose with the objective to implement it inthe DCVD software in order to facilitate smooth inspection procedures. Inspectors will thus not berequired to possess any expertise in the decision-making methodology.The paper also describes measurements performed during spring 2011 at the CLAB interim spentfuel storage in Sweden. The measurements were carried out with the objective to optimize theequipment handling and work flow during this type of measurement campaigns and to form a basisfor the evaluation of the DCVD’s ability to detect partial defects.
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| 16. |
- Gülfe, Anders, et al.
(författare)
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Rapid and sustained health utility gain in anti-TNF treated inflammatory arthritis. Observational data during seven years in southern Sweden.
- 2010
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 1468-2060 .- 0003-4967. ; 69:2, s. 352-357
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Rheumatoid arthritis (RA), psoriatic arthritis (PsA), and other spondylarthritides (SpA) impose great impact on the individual in addition to the costs on society, which may be reduced by effective pharmacological treatment. Industry independent health economic studies should complement studies sponsored by industry. OBJECTIVE: To study secular trends in baseline health utilities in patients commencing TNF blockade for arthritis in clinical practice over 7 years; to address utility changes during treatment; to investigate the influence of previous treatment courses; to study the feasibility of health utility measures, and to compare them across diagnostic entities. METHODS: /B> EuroQoL 5 Dimensions (EQ-5D) utility data were collected from a structured clinical follow-up program of anti-TNF treated patients with RA (N=2554), PsA (N=574) or SpA (N=586). Time trends were calculated. Completer analysis was used. RESULTS: /B> There were weak or non-significant secular trends for increasing baseline utilities over time for RA, PsA and SpA. Maximum gain in utilities occurred already after 2 weeks for all diagnoses and remained stable for patients remaining on therapy. First and second anti-TNF courses performed similarly. CONCLUSIONS: Utilities at inclusion remained largely unchanged for RA, PsA and SpA over 7 years. Improvement occurred early during treatment and not beyond 6 weeks at the group level. Improvement during the first course was not consistently greater than the second. There were no major differences between RA, PsA and SpA. EQ-5D proved feasible and applicable across these diagnoses. These "real world" data may be useful for health economic modelling.
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| 17. |
- Gülfe, Anders, et al.
(författare)
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Utility-based outcomes made easy: The number needed per QALY gained (NNQ). Observational cohort study from Southern Sweden of TNF blockade in inflammatory arthritis.
- 2010
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Ingår i: Arthritis Care and Research. - : Wiley. - 2151-4658 .- 2151-464X. ; 62:10, s. 1399-1406
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE.: To introduce a novel, simple, utility based outcome measure, the Number Needed per Quality adjusted life year (QALY) gained (NNQ), and to apply it in clinical practice in anti-TNF treated patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), and spondylarthritis (SpA). METHODS.: The NNQ is the number of patients one has to treat in order to gain 1 QALY. It is calculated as the inverted value of the utility gain (area under curve) over 1 year in a cohort subjected to an intervention. EuroQoL-5-dimensions (EQ-5D) utility data from the South Swedish Arthritis Treatment Register was used. RESULTS.: 1001 RA, 241 PsA, and 255 SpA patients were eligible for the study. First, 2(nd) and 3(rd) treatment courses were studied. For RA, NNQ was 4.5, 6.4 and 5.2 for 1(st), 2(nd) and 3(rd) courses, respectively. For PsA and SpA, NNQ was 4.2-4.5 irrespective of treatment order. Treatment groups with N<50 were not analysed. During the study period 2002-2007, there were no secular trends of utility gains. CONCLUSION.: The NNQ is an easily derived and understandable, utility based outcome measure that may be useful for stakeholders, decision makers as well as for clinicians. It was readily applied in this study of TNF blockade across 3 arthritis diagnoses. NNQ varied little over diagnoses and treatment course order, with a possible exception in 2(nd) treatment course in RA.
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| 18. |
- Jacobsson, Christian, et al.
(författare)
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The Links Between Group Development and Health in Manufacturing Industry
- 2014
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Ingår i: Small Group Research. - : SAGE Publications. - 1046-4964 .- 1552-8278. ; 45:4, s. 400-415
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Tidskriftsartikel (refereegranskat)abstract
- This study focuses on the relation between levels of group development and three health-related aspects of working life: work satisfaction, emotional exhaustion, and sick leave. This article presents a study with 30 groups in a manufacturing company. Data were collected from 274 Group members of the 30 groups, using Group Development Questionnaire, self-reported measures of work satisfaction and emotional exhaustion, as well as company data on occurrence of sick leave occasions. The results indicate a strong relationship between levels of group development and work satisfaction, a moderately strong relation with emotional exhaustion, and a weaker or less clear relation with sick leave. Practical implications are discussed and future research suggested.
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| 19. |
- Jacobsson, Gunnar, 1960, et al.
(författare)
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Antibody responses in patients with invasive Staphylococcus aureus infections.
- 2010
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Ingår i: European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology. - : Springer Science and Business Media LLC. - 1435-4373 .- 0934-9723. ; 29:6, s. 715-25
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Tidskriftsartikel (refereegranskat)abstract
- Correlation between antibody response and clinical outcome in Staphylococcus aureus bacteremia has yielded conflicting results. Immunization schedules have failed in clinical trials. Is the humoral response toward S. aureus of protective nature? A prospective study was performed in patients with invasive S. aureus (ISA) infections during the period 2003-2005. The antibody levels were determined at the beginning and at the end of treatment and one month later (n = 96, n = 71, and n = 51, respectively). As controls, 115 healthy individuals were used. A quantitative enzyme-linked immunosorbent assay (ELISA) against eight purified antigens was performed. Bacterial isolates were grouped as to the production of alpha-toxin, agr type, and pulsed-field gel electrophoresis (PFGE) type. Large variations were seen in the antibody levels. The levels in the second sample were the highest. A correlation between agr group, PFGE group, alpha-toxin production, and initial antibody levels was observed. Patients with fatal outcome displayed lower initial antibody levels to all antigens and significantly so in regard to teichoic acid, lipase, enterotoxin A, and scalded skin syndrome toxin. In episodes with complicated bacteremia, initial significantly low levels to teichoic acid and lipase were registered. Low initial antibody levels against several antigens were associated with increased mortality and complicated bacteremia in invasive S. aureus infections. Bacterial properties, strain, and toxin production affected the antibody response.
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| 20. |
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| 21. |
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| 22. |
- Jacobsson, Lars, et al.
(författare)
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Tightness of flange joints for large polyethylene pipes – Part 2 Full scale experimental investigations
- 2011
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Rapport (refereegranskat)abstract
- Tightness of flange joints for large polyethylene pipes – Part 2 Full scale experimental investigations Leakage that sometimes occurs in flange joints in large size plastic pipelines for water supply is a serious problem. Research was undertaken in order to improve the knowledge about the function of such flange joints. The objectives were partly to find out the degree of sensitivity of the design, i e if small deviations from recommended practise is critical, partly to be able to suggest improved design and mounting procedures. One part of the investigation was a numerical (FEM) study of several geometries, which was reported in [2]. Use of a time-dependent material model made it possible to follow the development of deformations and flange surface pressures for long times. Although several important principal findings were made, the tightening procedure and exact material behaviour could not be modelled. Therefore a series of full-scale experiments were made on 630 mm pipes, for a number of combinations of flange dimension and gasket type. This second part of the research is reported here. Since four of the twenty bolts were instrumented, the bolt forces could be monitored and be related to the torque and to the pressure in the pipe over time. This resulted in novel, important information about the functioning of plastic flange joints. In short, the experiments were performed in the following way. First, the bolts were tightened in the recommended criss-cross fashion to pre-determined torque levels. Then the pressure in the pipe was increased until leakage occurred. For combinations of flanges, gaskets and torques where the joint was tight for pressures above 13 bars, the 13 bar pressure level was maintained for up to one week. The relationship between bolt force and torque does not agree at all with the frequently used rule of thumb formula, for the galvanized bolts used here. The bolt force was typically less than half the value obtained by the formula. Hence it is critical to verify the friction for the used combination of bolt material, surface treatment, and lubrication. The bolt forces also appear to be unevenly distributed, which is partly due to successive creep during the tightening procedure. For the high stresses in the flange creep is significant already for so short times as a few minutes, and the effect is increased by the fact that the bolts and backing rings are much stiffer than the plastic flange. For both the wide and the narrow (ISO) flange type used it appears that rubber gaskets perform better, in the sense that the joint is tight for lower applied torques. The hyper- elastic material properties help to smooth unevenness in the flange surface and to compensate for creep in the plastic. Use of SDR 17 pipes at pressure levels of 13 bars means considerable creep expansion of the pipe, although it is possible to obtain a tight joint. The expansion gives a wringing effect at the flange, also observed in [2], which contributes to concentrate the flange pressure to the outer parts of the flange surface. In summary, flange joints are possible to mount so that they are tight, also for 630 mm pipes. Since the design is a sensitive one it is vital to follow recommendations for 4 mounting of different combinations of flanges and gaskets. In particular, knowledge about the relationship between torque and bolt force is important.
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| 23. |
- Jacobsson, Lars, et al.
(författare)
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Tillfällig avstängning av plaströrsledningar genom sammanklämning - kunskapsläge
- 2014
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Rapport (refereegranskat)abstract
- Temporary closure of plastic pipes by squeeze-off - state of the art State of the art and present use of squeeze-off methods for temporary closure of polymer pipelines for water and gas was investigated by an enquiry and a literature study. A limited, supplementary series of tests was also performed. The aim was to find, if possible, general limitations for use in terms of temperature at squeezing, pipe dimensions and materials, and to identify important problems that have to be analysed before guidelines can be issued regarding the use of the method. Some producers, suppliers and users in Sweden, were interviewed by the aid of a questionnaire. Although the investigation was limited, the answers are so homogeneous that they are considered representative. The belief is that the technique is harmful. It is used mostly for PE 80 and PE 100 materials and when necessary, e. g. when no valves are available. Decisions and risk assessments are mostly made ad hoc. The performance is according to manuals from producers and suppliers. Design of equipment, geometry, and recommended squeeze rates varies among suppliers. The literature on pipes consists mainly of papers from the 80-ies and 90-ies and from some research groups in the USA. There is a heuristic knowledge about formation and appearance of damage, and to some extent about the influence on service life. Newer research on general damage and fracture in polymers is available that is not related to the specific conditions in squeezed pipes. Such models are lacking, which may be due to the complexity of the area and its hands-on character. The commonly used PE 80 and PE 100 materials are clearly damaged by squeezing, particularly so for high compression levels, but the pipes still fulfil the requirements for use. Stronger and more crystalline materials, and larger pipe sizes, seem to be more severely damaged. It is not known how the damages influence slow crack growth and life. Squeeze-off on PE pipes with external longitudinal scratches should strictly be avoided. Also squeeze-off on PE pipes with PP coating at low temperature should be conducted with precaution until the opposite have been proven as some damage cases were reported. Removing the PP coating is recommended by some in this case. The experiments, on one old PE 80 pipe and two new PE 100 pipes with dimensions from 315 to 355 mm confirm the picture of damage. Commercial equipment was used and according to the supplier’s manual. All the pipes show similar damage, with crack formation and unevenness. Those are less significant for thinner pipe walls than for thicker ones. There is no apparent difference between new and old pipes. A few pressure tests were carried out on the squeezed pipes as well as the untouched pipes. The results show that no significant reduction of the lifetime could be proven regardless when an interrelated comparison between a squeezes and not squeezed pipe was made or when the lifetimes were compared with those obtained in earlier available material classification tests for the actual materials.
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| 24. |
- Kacerovsky, Marian, et al.
(författare)
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Umbilical cord blood levels of cortisol and dehydroepiandrosterone sulfate in preterm prelabor rupture of membrane pregnancies complicated by the presence of histological chorioamnionitis.
- 2012
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Ingår i: The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians. - : Informa UK Limited. - 1476-4954.
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The main aim of this study was to determine the levels of cortisol and dehydroepiandrosterone sulfate (DHEA-S) and the cortisol/DHEA-S ratio in the umbilical cord blood according to the presence of histological chorioamnionitis and fetal inflammatory response in pregnancies complicated by prelabor rupture of membranes at fewer than 34 gestational weeks. Methods: Seventy-two women with singleton pregnancies complicated by preterm prelabor rupture of membranes between gestational ages 24+0 and 33+6 weeks were included in the study. The sample of blood was obtained from the umbilical cord after delivery of the newborn. The umbilical cord blood cortisol and DHEA-S levels were evaluated using commercial immunoassay kits. A cortisol/DHEA-S ratio was calculated. Results: The presence of histological chorioamnionitis was not associated with higher median levels of cortisol (32.1 nmol/L vs. 33.0 nmol/L; p = 0.53), DHEA-S (2.6 μmol/L vs. 2.5 μmol/L; p = 0.83), or cortisol/DHEA-S ratio (19.5 vs. 18.7;p = 0.90). Higher median levels of DHEA-S (3.1 μmol/L vs. 2.3 μmol/L; p = 0.03) but not cortisol (91.0 nmol/L vs. 32.0 nmol/L; p = 0.06) or cortisol/DHEA-S ratio (24.5 vs. 18.7; p = 0.46) were observed when fetal inflammatory response was present. Conclusions: The presence of fetal inflammatory response but not the presence of histological chorioamnionitis per se was associated with increased DHEA-S levels in the umbilical cord blood.
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| 25. |
- Krag Jakobsen, Ane, et al.
(författare)
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Is Nephrolithiasis an Unrecognized Extra-Articular Manifestation in Ankylosing Spondylitis? A Prospective Population-Based Swedish National Cohort Study with Matched General Population Comparator Subjects
- 2014
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 9:11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ankylosing spondylitis (AS) is associated with several extra-articular manifestations. Nephrolithiasis (NL) has not been recognized as one of those, however, several factors known to increase the risk of NL are at play in AS patients. The objective was to estimate rates and predictors of NL in Swedish patients with AS compared to the general population. Methods and Findings: We performed a prospective population-based nationwide cohort study based on linkage of data from Swedish registries. 8,572 AS patients were followed for 49,258 person-years (py) and 39,639 matched general population comparators were followed for 223,985 py. Patients were followed prospectively together with comparator subjects from January 2001 through December 2009. The first occurrence of NL during follow-up was the primary outcome. Hazard Ratios (HR) were used to compare these rates adjusting for comorbidities and treatment, and to assess predictors for NL. Mean age at study entry was 46 years (inter quartile range 36-56 years), 65% were males. Based on 250 vs. 466 NL events, the adjusted HR of NL in AS patients was 2.1 (95% CI 1.8 to 2.4). Predictors of NL within the AS group included prior diagnosis of inflammatory bowel disease (IBD) (HR 2.3; 95% CI 1.7 to 3.3), prior diagnosis of NL (HR 16.4; 95% CI 11.5 to 23.4), and patients receiving anti-TNF treatment (HR 1.6; 95% CI 1.2 to 2.1). Male sex was a risk factor for NL both in AS patients and in the general population. Limitations: The risk for residual confounding and inability to study the chemical nature of NL were considered the main limitations of the study. Conclusions: Patients with AS are at increased risk of NL, which may be considered a novel extra-articular manifestation. Previous history of NL, IBD, AS disease severity and male sex were identified as predictors of NL in AS.
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| 26. |
- Kristensen, Lars Erik, et al.
(författare)
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Long-term work disability in patients with psoriatic arthritis treated with anti-tumour necrosis factor: a population-based regional Swedish cohort study
- 2013
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Ingår i: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 72:10, s. 1675-1679
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Tidskriftsartikel (refereegranskat)abstract
- Objective To study long-term work disability before and after tumour necrosis factor (TNF)-antagonist therapy in patients with psoriatic arthritis (PsA). Using the population-based South Swedish Arthritis Treatment Group Register, we identified 191 patients with PsA (median age 43years, range 18-58years, 54% men), who between January 2003 and December 2007 started treatment with adalimumab, etanercept or infliximab. We linked data to the Swedish Social Insurance Agency and calculated the proportion of work disability in 30-day intervals from 12months before the start of treatment until 3years after. For each patient with PsA we randomly selected four matched reference subjects from the general population. At treatment initiation 67% of the patients with PsA were work disabledthat is, either on sick leave (41.5%) or receiving a disability pension (25.3%). Patients sustaining treatment were, on average, work disabled 12.5days a month at treatment initiation declining to 10.6days a month after 3years of treatment. Patients for whom the first treatment course failed were work disabled 16.5days at treatment start decreasing to 15.6days after 3years. The background population were 2.5days and 3.0days off work each month, respectively. Regression modelling identified prior work disability status, anti-TNF treatment failure, higher age, female gender and longer disease duration as significant predictors of working disability. There was a decline in net work disability after initiation of anti-TNF treatment in patients with PsA. Patients withdrawing from treatment had a 50% increased risk of being work disabled. Prior work disability, higher age, female gender and longer disease duration were also associated with long-term work disability.
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| 27. |
- Kristensen, Lars Erik, et al.
(författare)
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Sick leave in patients with ankylosing spondylitis before and after anti-TNF therapy: a population-based cohort study.
- 2012
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Ingår i: Rheumatology (Oxford, England). - : Oxford University Press (OUP). - 1462-0332 .- 1462-0324. ; 51, s. 243-249
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To study levels of sick leave and disability pension before and after TNF-antagonist therapy in AS patients. Methods. Using the population-based South Swedish Arthritis Treatment Group register, we identified 139 AS patients (aged 18-58 years, 78% men), who between January 2002 and December 2008 started their first treatment with adalimumab, etanercept or infliximab. We linked data to the payment register by the Swedish Social Insurance Agency and calculated the proportion on sick leave in 30-day intervals from 12 months before treatment start until 12 months after. For each AS patient, we randomly selected four subjects from the general population matched for age, sex and area of residence. Results. One to 3 months before treatment, an average of 24% of AS patients were on sick leave. During the first 6 months after treatment start, this fraction dropped to 15%, and further declined to 12% at 12 months (P < 0.001). Comparing AS patients with the general population, the relative risk of being on sick leave 3 months before treatment, treatment start and 12 months after treatment start was 8.0 (95% CI 4.6, 13.9), 9.2 (95% CI 5.4, 15.7) and 4.0 (95% CI 2.1, 6.3), respectively. The decrease in sick leave was not substantially offset by changes in disability pension. Conclusion. There is a decline in sick leave during the first 12 months after initiation of TNF-antagonist treatment in AS patients not explained by societal factors or secular trends. The proportion of AS patients on disability pension remained unchanged during the observation period.
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| 28. |
- Löfmarck, Erik, 1974-
(författare)
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Den hand som föder dig : En studie av risk, mat och moderskap i Sverige och Polen
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This is a study of how mothers of young children relate to risk in everyday life, with an emphasis on the invisible risks associated with modernity in general, and with food in particular. It explores variations and similarities in how mothers deal with risk in two cultural contexts: Sweden and Poland. The study is based on twenty qualitative interviews with university educated mothers of small children in Stockholm and Warsaw. While risks more generally challenge how we “get on” with our lives, mothers of young children in particular have a special relationship to risk. During pregnancy and breastfeeding they are subject to all kinds of risk minimization efforts, and mothers are ultimately held "infinitely responsible" for their children's welfare by society. Women's transition to parenthood then makes for a particularly interesting case as to how risks manifest in everyday life. The theoretical framework draws on modernization theory, combined with insights from cultural theory. In addition, various contributions from sociological and psychological risk research, family sociology and research on parenting and motherhood are used to highlight contextual aspects and to interpret the empirical results. Two aspects of the mothers’ relationship to risk and food are examined in this study: firstly, their risk constructs, i.e. what they perceive as ‘risky’ with regards to food; and, secondly, their risk management strategies, i.e. how they deal with identified risks on a practical and cognitive level. The overall risk management depicted in this study is characterized by reflexivity, critical thinking, information retrieval, attention to scientific evidence, purposely transferred trust, confidence and the ability to make fairly sophisticated tradeoffs between risks and other aspects of life. Neither the Swedish nor the Polish mothers then conform to popular notions of ‘security junkies’ or ‘paranoid parenting’. Nonetheless, the comparative approach demonstrates how contextual differences, such as general trust levels and family policy, influence both the risk constructs and the employment of different risk management strategies.
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| 29. |
- Lönngren, Johanna, 1985-, et al.
(författare)
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Breaking Catch22 of Engineering Education for Sustainable Development : An Example of Parallell Learning of Teachers and Students
- 2012
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Konferensbidrag (refereegranskat)abstract
- Both research and practical experience show that teachers have trouble implementing Education for Sustainable Development (ESD) (Bursjöö 2011), especially in engineering education where a culture of value-neutrality and objectivity still seems to prevail (see for example Holmberg et al 2008). Consequently, the integration of ESD into engineerig curricula is often insufficient in respect to requirements set up by the Swedish Higher Education Act: graduates of engineering are expected to possess complex skills connected to ethics and sustainable development (Högskoleförordningen 1993).The purpose of this presentation is to provide a positive example of how these problems have been overcome in a specific engineering program at Lund University. We discuss the introduction of an innovative course by a group of students and faculty without substantive prior expertise or experience in Engineering Education for Sustainable Delopment (EESD). We (some of the course developers/course leaders) use collaborative action research methodology to discuss similarities and differences in teachers’ (ours) and students’ learning in the process of creating and subsequently improving this specific EESD-intervention. Our analysis is based on personal reflections and focus group discussions by the course developers/course leaders, as well as students’ course evaluations from three consecutive years, and EESD litterature.As an analytical lens, we use the concept of Communities of Practice(CoP). We identify two levels of CoPs: 1. The team of teachers (senior teachers in collaboration with highly motivated students) working with the course over the years, and 2. All actors involved in each years’ course cycle. This includes both a group of teachers and the enroled students. In relation to these CoPs, we also identify two (partly overlapping) cycles of action learningwhich relate, respectively, to the course development over the years, and our work with each specific course cycle. The purpose of this analysis and discussion is to uncover parallell learning of teachers and students as the course evolves.Another purpose is to facilitate the implementation of EESD. Therefore, we also reflect on the perceived prerequisite of teachers’ expertise for teaching sustainable development in engineering curricula. We discuss the specific conditions that allowed the creation and execution of our course with the aim to empower other teachers to venture on the undertaking of EESD in their courses by trusting the development of their own skills “by doing EESD”. Thus we hope to contribute to an icnreased integration of ESD into engineering programs in Sweden and abroad.
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| 30. |
- Rydbo, Niklas, 1962, et al.
(författare)
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The relationship between group dynamics and health in Swedish manufacturing industry
- 2013
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Ingår i: Presented at: "Work Group Development: Theory, Research & Practice“. March 8 - 10, 2013. Saint Joseph’s University, Philadelphia, PA.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The aim of the present study is to investigate the relationship between group dynamics and health related issues among employees in a Swedish manufacturing company. The study includes totally 170 teams of which 34 are management teams and 136 concerns teams with blue-color workers. Group dynamics, measured by Group Development Questionnaire, will be related to the company’s sick-leave data, employees’ self-reported health, work satisfaction and feeling of mastery. Furthermore, how team interventions with meagre resources in management teams affects group dynamics in management teams and group dynamics in work teams within the linking part of the organization will be tentatively studied and discussed.
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| 31. |
- Thörn, Ingrid, et al.
(författare)
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Applicability of IG/TCR gene rearrangements as targets for minimal residual disease assessment in a population-based cohort of Swedish childhood acute lymphoblastic leukaemia diagnosed 2002-2006.
- 2010
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Ingår i: European journal of haematology. - : Wiley. - 1600-0609 .- 0902-4441. ; 84:2, s. 117-27
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) detection during the early treatment phase has become an important stratification parameter in many childhood acute lymphoblastic leukaemia (ALL) treatment protocols. Here, we aimed to address the applicability of rearranged antigen-receptor genes as potential MRD markers using real-time quantitative polymerase chain reaction (RQ-PCR) in a Swedish population-based cohort. From 334 childhood ALL cases diagnosed during 2002-2006, we analysed 279 diagnostic samples (84%) by screening for rearranged immunoglobulin (IG) and T-cell receptor (TCR) genes. Allele-specific oligonucleotides were designed, and the sensitivity and quantitative level was determined for each target. Overall, clonal IG/TCR rearrangements were detected in 97% (236/244) of B-cell precursor ALL (BCP ALL) and 94% (33/35) of T-ALL. A sensitive RQ-PCR analysis (< or = 10(-4)) was obtained in 89% (216/244) of BCP ALL and in 74% (26/35) of T-ALL, whereas two sensitive targets were only available in 47% (115/244) of BCP ALL and 29% (10/35) of T-ALL cases. With the stratification threshold of > or = 10(-3), which is applied in the current Nordic treatment protocol (NOPHO-ALL 2008) for the identification of high-risk patients, 93% of BCP ALL and 86% of T-ALL reached this quantitative range by at least one target gene. Taken together, this national retrospective study demonstrates that an IG/TCR target for MRD monitoring can be identified in the majority of childhood ALL cases, whereas identification of a second sensitive target gene needs to be improved.
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| 32. |
- Thörnerup, Ingrid, et al.
(författare)
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Minimal residual disease assessment in childhood acute lymphoblastic leukaemia: a Swedish multi-centre study comparing real-time polymerase chain reaction and multicolour flow cytometry.
- 2011
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Ingår i: British Journal of Haematology. - : Wiley. - 0007-1048 .- 1365-2141. ; 152:6, s. 743-753
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Tidskriftsartikel (refereegranskat)abstract
- Minimal residual disease (MRD) assessment is a powerful prognostic factor for determining the risk of relapse in childhood acute lymphoblastic leukaemia (ALL). In this Swedish multi-centre study of childhood ALL diagnosed between 2002 and 2006, the MRD levels were analysed in 726 follow-up samples in 228 children using real-time quantitative polymerase chain reaction (RQ-PCR) of rearranged immunoglobulin/T-cell receptor genes and multicolour flow cytometry (FCM). Using an MRD threshold of 0·1%, which was the sensitivity level reached in all analyses, the concordance between RQ-PCR and FCM MRD values at day 29 was 84%. In B-cell precursor ALL, an MRD level of ≥0·1% at day 29 predicted a higher risk of bone marrow relapse (BMR) with both methods, although FCM was a better discriminator. However, considering the higher median MRD values achieved with RQ-PCR, a higher MRD cut-off (≥0·2%) improved the predictive capacity of RQ-PCR. In T-ALL, RQ-PCR was notably superior to FCM in predicting risk of BMR. That notwithstanding, MRD levels of ≥0·1%, detected by either method at day 29, could not predict isolated extramedullary relapse. In conclusion, the concordance between RQ-PCR and FCM was high and hence both methods are valuable clinical tools for identifying childhood ALL cases with increased risk of BMR.
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| 33. |
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| 34. |
- Vainorius, Neimantas, et al.
(författare)
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Observation of type-II recombination in single wurtzite/zinc-blende GaAs heterojunction nanowires
- 2014
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 89:16
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated a large set of individual wurtzite/zinc-blende GaAs heterojunction nanowires using transmission electron microscopy (TEM), photoluminescence (PL), and cathodoluminescence (CL). In several cases we have combined PL and TEM on the same wire. We find a fairly deep emission that shows a strong blueshift with increasing excitation power density. By using a variety of experiments we show that this emission is due to recombination across a heterojunction with a type II band alignment. The data give a valence band offset of about 100 meV, in excellent agreement with theoretical predictions. Spatially resolved CL data on heterojunction nanowires and PL data on pure wurtzite nanowires show that the band gap of wurtzite GaAs is very close to the band gap of zinc-blende GaAs.
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| 35. |
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| 36. |
- Witte, Anne-Barbara, et al.
(författare)
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Involvement of endogenous glucagon-like peptide-1 in regulation of gastric motility and pancreatic endocrine secretion
- 2011
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 0036-5521 .- 1502-7708. ; 46:4, s. 428-435
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To study the role of endogenous glucagon-like peptide-1 (GLP-1) on gastric emptying rates of a solid meal as well as postprandial hormone secretion and glucose disposal. Material and methods. In nine healthy subjects, gastric emptying of a 310-kcal radio-labelled solid meal and plasma concentrations of insulin, glucagon and glucose were measured during infusion of saline or the GLP-1 receptor antagonist exendin(9-39)amide (Ex(9-39)) at 300 pmol·kg−1·min−1. Results. Ex(9-39) infusion had no effect on the total gastric emptying curve, but changed the intra-gastric distribution of the meal. During infusion of Ex(9-39), more content stayed in the upper stomach (79.1 ± 2.5% of total during Ex(9-39) compared to 66.6 ± 5.7% during saline at 5 min). During Ex(9-39) infusion, higher concentrations of plasma glucagon were measured both before (after 40 min of Ex(9-39) infusion the glucagon level was 15.1 ± 0.7 pmol·L−1 compared to 5.4 ± 1.4 during saline) and after the meal, and postprandial GLP-1 levels increased. Basal insulin and glucose levels were not affected by Ex(9-39), but the postprandial rise of insulin and glucose enhanced during Ex(9-39). Conclusions. Endogenous GLP-1 is involved in the regulation of gastric motility in relation to meal intake and also in the regulation of postprandial insulin and glucose levels. Furthermore, endogenous GLP-1 seems to tonically restrain glucagon secretion.
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| 37. |
- Wu, Jun, et al.
(författare)
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Control of composition and morphology in InGaAs nanowires grown by metalorganic vapor phase epitaxy
- 2013
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Ingår i: Journal of Crystal Growth. - : Elsevier BV. - 0022-0248. ; 383, s. 158-165
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Tidskriftsartikel (refereegranskat)abstract
- InGaAs nanowires grown by Metalorganic Vapor Phase Epitaxy (MOVPE) are promising candidates in future device technologies. The control of the chemical composition of InGaAs nanowires is not trivial due to the In atom diffusion from the substrate, which causes significant variations in the chemical composition along the nanowire. In this work, we report on the growth of InGaAs nanowires on (111)B InAs substrates followed by the characterization using high-resolution x-ray diffraction (HRXRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) as well as scanning transmission electron microscopy (STEM) in combination with energy dispersive X-ray spectroscopy (EDS). By detailed analyses of the HRXRD spectra and their variations with nanowires grown for different times, fundamental insight was gained into tapering formation and chemical composition gradient of the nanowires. The measurements show that acceptable uniformity of In and Ga concentrations along InGaAs nanowires can be achieved, and the maximum achievable nanowire length without tapering depends on the nanowire density. Finally, by carefully choosing the growth conditions, the morphology of the InGaAs nanowire can be further optimized. (C) 2 013 Elsevier B.V. All rights reserved
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| 38. |
- Xiong, Shizhao, et al.
(författare)
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Analysis of the solid electrolyte interphase formed with an ionic liquid electrolyte for lithium-sulfur batteries
- 2014
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753. ; 252, s. 150-155
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the formation of the solid electrolyte interphase (SEI) on lithium electrodes in the presence of an ionic liquid electrolyte with a particular focus on the influence of polysulfides present in the electrolyte on the SEI. The electrochemical performance of symmetric cells with lithium electrodes and electrolytes composed of N-Methyl-(n-butyl)pyrrolidinium bis(trifluoromethanesulfonyl)imide (PYR14-TFSI) and LiTFSI, with and without the addition of polysulfides, were analyzed as well as the chemical composition of the SEI, before and after cycling. The cycling behavior of the symmetrical cells shows that the SEI films are relatively stable in the ionic liquid electrolyte, also in the presence of polysulfides. However, the presence of polysulfides results in a higher SEI layer resistance (R-SEI) and a higher activation energy. From X-ray photoelectron spectroscopy spectra (XPS), with argon-ion sputtering for depth profiling, we find that the SEI is formed by decomposition products from both cations and anions of the electrolyte. The XPS spectra show that the presence of polysulfides alters the decomposition process of the electrolyte, resulting in a SEI film with different chemical composition and structure, in line with the results from the electrochemical performance.
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| 39. |
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