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- Berg, Annika, 1973-
(författare)
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Den gränslösa hälsan : Signe och Axel Höjer, folkhälsan och expertisen
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This dissertation investigates the mutual life project of Signe (1896-1988) and Axel Höjer (1890-1974), a married couple who were key actors in the construction of the Swedish welfare state. It emphasises the ways in which they went about asserting a special public health expertise in different contexts. As starting points I take the malleability of the concept folkhälsa (people’s health or population health) and the centrality of expertise in the governance of modern societies. Theoretical concepts such as gender, policy transfer, biopower and governmentality are central to the analysis. The dissertation includes three parts. The first part investigates how the Höjers agreed to coordinate their work and how they, with reference to ideas picked up in France and England at the end of World War I, attempted to reform mother and child health care in Sweden. Their strategies where rhetorical but also practical, using Hagalund outside Stockholm as their experimental ground. The second part investigates, firstly, how Axel Höjer, as General-Director of the Medical Board of Sweden (1935-52) asserted a sociomedical expertise, integrating the emerging social sciences and universalist views on the organisation of the welfare state into the realm of medicine, in order to launch ideas of a thorough reorganisation and expansion of the Swedish health care system. His focus was on preventive medicine and health care, with the complete physical, mental and social health of the whole population as an explicit goal. Secondly, it explores how Signe Höjer at the same time tried to launch ideas on health and wellbeing as a social politician and a public committee member. She also tried to define family policy as a specific policy area. However, despite her training as a nurse and a social worker, she was largely confined to asserting a particularly ”female” expertise, which made her position rather ambiguous in terms of authority. The third part investigates how the Höjers, in the 1950s and 60s, worked with international health, Axel mainly for the WHO in India and Ghana, Signe as a policy entrepreneur, primarily in the fields of childcare and family planning. My findings partly confirm theories that see development aid as an extension of domestic social policy, but they challenge the view of aid as a simple one-way process. I demonstrate how the Höjers at least tried to adapt their projects abroad to meet local circumstances, and also show how they brought lessons from the third world to a domestic public. In the latter case they did not primarily act as experts of Swedish-style social policy, but as experts on the developing countries and on development aid.
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| 3. |
- Enblom, Roger, et al.
(författare)
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Impact of non-elliptic contact modelling in wheel wear simulation
- 2008
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Ingår i: Wear. - : Elsevier BV. - 0043-1648 .- 1873-2577. ; 265:9-10, s. 1532-1541
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Tidskriftsartikel (refereegranskat)abstract
- Advances in simulation of railway wheel wear in the sense of material removal have drawn the attention to the importance of wheel–rail contact modelling. As a further step of enhancing the used simulation procedure in direction of increased generality and reduced need for application-dependent calibration, the focus of this investigation is the influence of non-elliptic contact models on the wheel wear rate and profile shape. To facilitate evaluation the semi-Hertzian contact procedure Stripes, developed by INRETS in France, has been implemented. To investigate the capabilities of Stripes to assess the contact area and pressure, shape comparisons have been made with other numerical methods for a set of wheel–rail contact situations. The referenced results are based on the linear elastic half-space assumption, elastic finite element analysis, and elastic–plastic finite element analysis. For reference also the elliptic contact area according to Hertz is shown as given by the contact data table of the multi-body simulation code. After exploring the properties of the Stripes procedure with respect to contact area estimation and pressure distribution, the focus is moved to the influence on wear rate, being the principal objective of this investigation. First the wear distribution over the contact patch is studied and compared to results using the elliptic model from the MBS code Gensys and the non-elliptic approach with Kalker's code Contact. Finally the evolution of the wheel profile is simulated for a few typical cases. This investigation of wear distributions over non-elliptic patches under different operating conditions indicates significant differences compared to both Contact and the applied Hertzian approach. The expansion from single contact occasions to complete simulations indicates comparable material removal rates but relocation towards the flange side. This tendency is apparent in all of the cases shown, however limited to initial wear in tangent run or reasonably mild curve negotiation.
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| 4. |
- Enblom, Roger, 1950-
(författare)
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On Simulation of Uniform Wear and Profile Evolution in the Wheel - Rail Contact
- 2006
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Numerical procedures for reliable wheel and rail wear prediction are rare. Recent development of simulation techniques and computer power together with tribological knowledge do however suggest computer aided wear prediction as possible. The present objective is to devise a numerical procedure able to simulate profile evolution due to uniform wear sufficiently accurate for application to vehicle dynamics simulation. Such a tool should be useful for maintenance planning, optimisation of the railway system and its components as well as trouble-shooting. More specifically, the field of application may include estimation of reprofiling frequency, optimisation of wheel – rail profile match, optimisation of running gear suspension parameters, and recognition of unfavourable profile evolution influencing the dynamic response of the vehicle. The research contribution accounted for in this thesis includes, besides a literature review, modelling of the wheel – rail interface, benchmarking against traditional methods, and validation with respect to full-scale measurements. The first part addresses wheel – rail contact conditions in the context of wear simulation as well as tribological environment and tractive forces. The current approach includes Archard’s wear model with associated wear maps, vehicle dynamics simulation, and railway network definition. One objective is to be able to include variations in operation conditions in the set of simulations instead of using scaling factors. In particular the influence of disc braking and varying lubrication conditions have been investigated. Both environmental factors like moist and contamination and deliberate lubrication need to be considered. As part of the associated contact analysis the influence of tangential elastic deformation of the contacting surfaces has been investigated and found to be essential in case of partial slip contact conditions. The influence on the calculated wear of replacing the Hertzian contact by a non-elliptic semi-Hertzian method has been investigated, showing relocation of material loss towards increased profile curvature. In the second part comparisons have been carried out with traditional methods, where the material loss is assumed to be directly related to the energy dissipated in the contact. Attention has been paid to the understanding of the principle differences between the investigated methods, comparing the distribution of friction energy, sliding velocity, and wear depth. As a prerequisite, contact conditions with dependence on wheelset guidance and curving performance as well as influence of tractive forces have been investigated. In the final part validation of the developments related to wheel wear simulation is addressed. Disc braking has been included and a wear map for moist contact conditions based on recent tests has been drafted. Good agreement with measurements from the reference operation, is achieved. Further a procedure for simulation of rail wear and corresponding profile evolution has been formulated. A simulation set is selected defining the vehicles running on the track to be investigated, their operating conditions, and contact parameters. Trial calculations of a few curves show qualitatively good results in terms of profile shape development and difference in wear mechanisms between gauge corner and rail head. The wear rates related to traffic tonnage are however overestimated. The impact of the model improvements accounted for in the first part of the thesis has been investigated, indicating directions for further development.
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| 5. |
- Enblom, Roger, et al.
(författare)
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Proposed procedure and trial simulation of rail profile evolution due to uniform wear
- 2008
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Ingår i: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit. - 0954-4097 .- 2041-3017. ; 222:1, s. 15-25
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Tidskriftsartikel (refereegranskat)abstract
- A procedure for numerical simulation of rail wear and the corresponding profile evolution has been formulated. The wear is assumed to be uniform in the sense that the profiles remain constant along the track portion to be investigated. A simulation set is selected defining the vehicles running on the track, their operating conditions, and contact parameters. Several variations of input data may be included together with the corresponding occurrence probability. Simulation of multi-body dynamics is used to calculate contact forces and positions, and Archard's wear equation is applied for the calculation of wear depth. Wear coefficients as a function of contact pressure and relative sliding velocity are collected from different test results. Trial calculations of four non-lubricated and two lubricated curves with radii from 303 to 802 m show qualitatively reasonable results in terms of profile shape development and difference in wear mechanisms between gauge corner and rail head. The wear rates related to traffic tonnage are, however, overestimated and the lubrication efficiency underestimated. It is expected that model refinements in terms of environmental influence and contact stress calculation are useful to improve the quantitative results.
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| 6. |
- Enblom, Roger, et al.
(författare)
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Simulation of railway wheel profile development due to wear : influence of disc braking and contact environment
- 2005
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Ingår i: Wear. - : Elsevier. - 0043-1648 .- 1873-2577. ; 258:7-8, s. 1055-1063
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Tidskriftsartikel (refereegranskat)abstract
- This paper addresses issues related to braking and wheel-rail contact conditions in the context of wheel wear simulation. The KTH approach to the topic includes Archard's wear model with associated wear maps, vehicle dynamics simulation and railway network definition. In previous work at KTH certain variations in operating conditions have been accounted for through empirically estimated average scaling factors. The objective of the current research is to be able to include such variations in the set of simulations. In particular the influence of disc braking as well as varying friction and lubrication conditions are investigated. Both environmental factors like moist and contamination and deliberate lubrication need to be considered. As part of the associated contact analysis the influence of local elastic deformation on the sliding velocity has been separately investigated.
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| 7. |
- Henriksson, Roger, et al.
(författare)
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High-grade astrocytoma treated concomitantly with estramustine and radiotherapy.
- 2006
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Ingår i: Journal of neuro-oncology. - : Springer Science and Business Media LLC. - 0167-594X .- 1573-7373. ; 78:3, s. 321-6
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Tidskriftsartikel (refereegranskat)abstract
- Experimental and early clinical investigations have demonstrated encouraging results for estramustine in the treatment of malignant glioma. The present study is an open randomized clinical trial comparing estramustine phosphate (Estracyt) in addition to radiotherapy with radiotherapy alone as first line treatment of astrocytoma grade III and IV. The 140 patients included were in a good clinical condition with a median age of 55 years (range 22-87). Estramustine was given orally, 280 mg twice daily, as soon as the diagnosis was established, during and after the radiotherapy for a period of in total 3 months. Radiotherapy was delivered on weekdays 2 Gy daily up to 56 Gy. Eighteen patients were excluded due to misclassification, leaving 122 patients eligible for evaluation. Overall the treatment was well tolerated. Mild or moderate nausea was the most common side effect of estramustine. The minimum follow-up time was 5.2 years for the surviving patients. For astrocytoma grade III the median survival time was 10.6 (1.3-92.7) months for the radiotherapy only group and 17.3 (0.4-96.9+) months for the estramustine + radiotherapy group. In grade IV the corresponding median survival time was 12.3 (2.1-89.2) and 10.3 (0.3-91.7+) months, respectively. Median time to progress for radiotherapy only and radiotherapy and estramustin group in grade III tumours was 6.5 and 10.1 months, respectively. In grade IV tumours the corresponding figures were 5.1 and 3.3 months, respectively. Although there was a tendency for improved survival in grade III, no statistical significant differences were found between the treatment groups. No differences between the two treatment groups were evident with respect to quality of life according to the EORTC QLQ-protocol. In conclusion, this first randomized study did not demonstrate any significant improvement of using estramustine in addition to conventional radiotherapy, however, a trend for a positive response for the estramustine group was found in patients with grade III glioma.
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| 8. |
- Yngve, Agneta, 1953-, et al.
(författare)
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The Women's Health Initiative. What is on trial : nutrition and chronic disease? Or misinterpreted science, media havoc and the sound of silence from peers?
- 2006
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Ingår i: Public Health Nutrition. - 1368-9800 .- 1475-2727. ; 9:2, s. 269-272
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Tidskriftsartikel (refereegranskat)abstract
- The first results of the Women's Health Initiative dietary intervention trial were published in the USA in February. This is a colossal intervention designed to see if diets lower in fat and higher in fruits, vegetables and grains than is usual in high-income countries reduce the incidence of breast cancer, colorectal cancer, heart disease and other chronic diseases, in women aged 50-79 years. As interpreted by US government media releases, the results were unimpressive. As interpreted by a global media blitz, the results indicate that food and nutrition has little or nothing to do with health and disease. But the trial was in key respects not reaching its aims, was methodologically controversial, and in any case has not produced the reported null results. What should the public health nutrition profession do about such messes?
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