| 2. |
- Leijon, Matti, 1970-
(författare)
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Activating People : Physical activity in the general population and referral schemes among primary health care patients in a Swedish county
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In this thesis the need for physical activity interventions is investigated in a general adult population, the characteristics of physical activity referral (PAR) scheme recipients and referral practitioners, and the effectiveness of PAR in a routine primary health-care (PHC) setting in the county of Östergötland, Sweden. The thesis consists of four papers: three papers are based on a quantitative, uncontrolled prospective PAR study and one paper is based on a population survey in the county of Östergötland, Sweden.In 2006, only one in four of the adult population, aged 18–84 years, in Östergötland was considered sufficiently active to meet the Swedish national public health recommendations, stated as “30 minutes of moderate physical activity a day”. More than one-third (37%) reported that they hade no intentions to change their physical activity levels, while 36% had thought about change, and 27% were determined to change. Although the individuals felt a large responsibility for their own physical activity, they also believed that this responsibility is partly shared by health-care providers. Among those who wanted to increase their physical activity level, almost one in seven of the total population and one in four among those reporting poor general health, with a BMI over 30 and those who were inactive reported that they wanted support to bring about this change. More than half of them wanted this support from their health-care provider.During 2004 and 2005, a total of 6300 patients received PARs as part of the Östergötland PAR scheme. Two-thirds of the patients were female and half of the patients were 45–64 years old. The PAR scheme reached a relatively high proportion of physically inactive people. PARrelated statistics, including the numbers of referrals made at individual PHC centres and by different professional categories, showed large differences in prescribing activities, both by patient categories, and by prescribing professionals, indicating great potential for further improvements of this scheme in the future.Half of the patients (51%) who received PARs were recommended home-based activities, such as walking. Patient follow-up showed that an increase in self-reported physical activity level was achieved by 52% of the patients at the 12-month follow-up. The proportion of inactive patients decreased from 33% at baseline to 20% at 12 months. The proportion of patients who were physically active on a regular basis increased from 22% at baseline to 32% at 12 months. Neither patient age, diagnosis/PAR reason nor the profession of the prescriber were associated with differences in effectiveness. Low activity levels at baseline and homebased activities were significantly associated with increased physical activity at 12 months. Half of the patients (50%) achieved adherence to PARs at the 12-month follow-up, with adherence assessed by simply asking the patients about their adherence to prescribed activity. Patients’ activity levels at baseline (being at least somewhat physically active) and being issued home-based activities were significantly associated with higher adherence at 12 months.
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| 3. |
- Salomonsson, Kent
(författare)
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Meso-Mechanical Modeling and Analysis of Adhesive Layers
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is concerned with the modeling, simulation and analysis of adhesive layers. By use of an in situ scanning electron microscopy study it is found that the adhesive studied in the present thesis has a very complex structure with two different compounds, a mineral and an epoxy/thermoplastic blend. A representative volume element (RVE) model is developed to study the behavior of the adhesive layer at the meso-level. It is a continuum model where interface finite elements are implemented at the boundaries of the continuum elements in order to enable crack initiation and propagation of micro cracks. On a structural level, two deformation modes, modes I and II, dominate the behavior of thin adhesive layers. With the RVE it is possible reproduce experimental stress-deformation relations from both modes. However, in a real structure, mixed mode loading usually occur. A range of mode mixes is studied, using the RVE, from an un-loaded state until fracture of the layer. The results indicate that the behavior of the interface elements dominate for mode mixes close to mode I and plasticity in the continuum elements dominates for mode II dominated mode mixes. Furthermore, effects of large root curvatures of the adherends is analyzed numerically by simulating plastically deforming double cantilever beam specimens using the finite element model. The developed RVE is implemented in the models to simulate the behavior of the adhesive layer. By this methodology, virtual experiments can be analyzed with extreme detail. It is shown that in-plane straining of the adhesive layer significantly influences the strength of adhesive joints at large plastic strain of the adherends. There is a never ending need in industries to minimize computational time. To this end, an interphase finite element for structural analyses is developed. The element considers in-plane straining of the adhesive layer due to large curvatures of surrounding substrates.
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