| 1. |
- Agardh, Johannes, et al.
(författare)
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Designing Future Interaction with Today's Technology
- 1999
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Information Technology has an increasing part of our lives. In this thesis we will discuss how technology can relate to humans and human activity. We take our standing point in concepts like Calm Technology and Tacit Interaction and examine how these visions and concepts can be used in the process of designing an artifact for a real work practice. We have done work-place studies of truck-drivers and traffic leaders regarding how they find their way to the right addresses and design a truck navigation system that aims to suit the truck drivers work practice.
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| 2. |
- Andersson, Öivind, et al.
(författare)
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Crank Angle Resolved HC Detection Using LIF in the Exhausts of Small Two-Stroke Engines Running at High Engine Speed
- 1996
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Ingår i: SAE Transactions, Journal of Engines. - 0096-736X. ; 105:961927
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Tidskriftsartikel (refereegranskat)abstract
- In order to separate the HC-emissions from two-stroke engines into short-circuit losses and emissions due to incomplete combustion, Laser Induced Fluorescence (LIF) measurements were performed on the exhaust gases just outside the exhaust ports of two engines of different designs. The difference between the two engines was the design of the transfer channels. One engine had "finger" transfer channels and one had "cup handle" transfer channels. Apart from that they were similar. The engine with "finger" transfer channels was earlier known to give more short-circuiting losses than the other engine, and that behavior was confirmed by these measurements. Generally, the results show that the emission of hydrocarbons has two peaks, one just after exhaust port opening and one late in the scavenging phase. The spectral information shows differences between the two peaks and it can be concluded that the latter peak is due to short-circuiting and the earlier due to incomplete combustion. The flow outside the exhaust port was measured with Laser Doppler Velocimetry (LDV). These measurements confirm the occurrence of two emission peaks.
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| 5. |
- Björklund, Martin, et al.
(författare)
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Repetitive low-back-level arm activity to fatigue diminishes limb position sense
- 1999
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Konferensbidrag (refereegranskat)abstract
- Position sense awareness of the shoulder was determined for 9 males and 9 females before and after performing repetitive low-level arm activity to fatigue. The activity consisted of continuous horizontal internal and external rotations. Position sense awareness tests were performed with subjects blindfolded and seated with the arm in a motorized rig. The subjects were asked to actively reproduce test positions of 10°, 25°, 55° and 70° randomly assigned, while starting at 40° (relative to the sagittal plane). The tests were conducted immediately before and after the fatiguing activity. An ANOVA revealed that the absolute error, measured as test position minus reproduced position, was significantly increased following fatigue for the subjects as a group (p<0.001 ). Furthermore, females had overall higher error than males (p<0.05). The results indicate that repetitive low-level activity to fatigue leads to proprioceptive deficits. These deficits can create a non-optimized motor control, causing an increase in the co-activation of agonist and antagonist muscles and thus increasing the work-load. This could create an unfavorable cycle of events, which would further impact proprioception and thereby enhance the risks for muscle pain and injury. The higher incidence of injuries for female athletes compared to males may be attributed to gender differences in proprioception.
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| 6. |
- Brännström, Inger, 1945-, et al.
(författare)
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Co-operation, participation and conflicts faced in public health : lessons learned from a long-term prevention programme in Sweden
- 1994
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Ingår i: Health Education Research. - : Oxford University Press. - 0268-1153 .- 1465-3648. ; 9:3, s. 317-329
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Tidskriftsartikel (refereegranskat)abstract
- A comprehensive community-based programme for prevention of cardiovascular diseases (CVD) and diabetes was established in 1985 in a small municipality in northern Sweden. A cross-sectional survey to the general public was performed and semi-structured open-ended interviews were taken of actors at different levels. Notes from official records were also included in the study. The aim was to describe and discuss some factors that promote or constrain community participation in health programmes. The results generally confirmed that the right of definition concerning the health programme mainly remained with the health professionals. Community participation was mainly defined by the actors based on the medical and health planning approach and, thereby, as a means to transform health policy plans into reality by transmitting health knowledge and increasing consciousness among the citizens of the need for changing lifestyles. However, participation as a means of identifying problems and demonstrating power relationships and as elements in promoting local democracy was hardly represented among the actors at all. Overall, the CVD health programme was characterized by consensus between the actors. Despite this, debates and arguments about interpretations, social interests, personal conflicts and ideological constraints were observed. However, a majority of the public wanted the CVD preventive programme to continue.
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| 7. |
- Brännström, Inger, 1945-
(författare)
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Community participation and social patterning in cardiovascular disease intervention
- 1993
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study addresses health policy and public health in the field of cardiovascular disease (CVD) on the local level in Sweden. The overall aim is to contribute to the assessment of structural and social conditions within public health by analysing participation processes and outcome patterns in a local health programme. The northern Swedish MONICA study served as a reference area. The research strategy has been to integrate quantitative and qualitative methodologies and, thereby, focus on different aspects of the health programme under study.The mortality rate was excessive in the study area of Norsjö relative to both provincial and national figures over a period of more than 10 years. This finding formed the basis for a tenyear comprehensive and community-based health programme towards the prevention of CVD and diabetes.Even in this seemingly homogeneous area it was found that socio-economic circumstances were associated with the public health. Almost half of the study population had hypercholesterolaemia (;>6.5 mmol/1), 19% of men and 25% of women were smokers and 30% and 29%, respectively, had high blood pressure. Age had a strong impact on all outcome measures. After adjustments for age and social factors it was found that the relative risk of having hypercholesterolaemia dropped significantly in both sexes during the six years of intervention. The probability of being a smoker was significantly reduced only in highly educated groups. No statistically significant change over time could be found for the risk of suffering high blood pressure. In the reference area of northern Sweden there were no changes over time for any of the selected risk factors. The likelihood of self-assessed good health decreased with increasing risk factor load, with the exception of hypercholesterolaemia , in all social strata.The authorities, including the health and medical staff, were the main actors on the mediastage. Men in manual occupations were least affected by the media coverage. The actors and the public as well as the media viewed the health programme as orientated towards individual lifestyles. Community participation was mainly defined by the actors based on the medical and health planning approach. Differences in interpretations, social interests, personal conflicts and ideological constraints among the actors at local level were observed. Some critical attitudes towards the organization and management of the health programme were also noted among the citizens. However, a majority of the public wanted the health programme to continue. The present study underlines the importance of considering age, gender and social differences in the planning and evaluation of CVD preventive programmes.
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| 8. |
- Ekenberg, Martin, et al.
(författare)
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The Effect of Transfer Port Geometry on Scavenge Flow Velocities At High Engine Speed
- 1996
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Ingår i: SAE Special Publications. - 0148-7191. ; :SP-1131
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Konferensbidrag (refereegranskat)abstract
- 2-D LDV measurements were performed on two different cylinder designs in a fired two-stroke engine running with wide-open throttle at 9000 rpm. The cylinders examined were one with open transfer channels and one with cup handle transfer channels. Optical access to the cylinder was achieved by removing the silencer and thereby gain optical access through the exhaust port. No addition of seeding was made, since the fuel droplets were not entirely vaporized as they entered the cylinder and thus served as seeding. Results show that the loop-scavenging effect was poor with open transfer channels, but clearly detectable with cup handle channels. The RMS-value, "turbulence", was low close to the transfer ports in both cylinders, but increased rapidly in the middle of the cylinder. The seeding density was used to obtain information about the fuel concentration in the cylinder during scavenging.
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| 9. |
- 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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