| 1. |
- Åman, Johan, et al.
(författare)
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Recent developments in large-area photomasks for display applications
- 2001
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Ingår i: Journal of the Society for Information Display. - San Jose, CA : Wiley. - 1071-0922. ; 9:1, s. 3-8
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Tidskriftsartikel (refereegranskat)abstract
- One of the most critical areas in the manufacturing process for FPD panels or shadow masks for CRTs is lithography. Most existing lithography technologies require high-quality large-area photomasks. The requirements on these photomasks include positioning accuracy (registration) and repeatability (overlay), systematic image quality errors ("mura" or display quality), and resolution (minimum feature size). The general trend toward higher resolution and improved performance, e.g., for TFT desktop monitors, has put a strong focus on the specifications for large-area-display photomasks. This article intends to give an overview of the dominant issues for large-area-display photomasks, and illustrates differences compared with other applications. The article will also present state-of-the-art methods and trends. In particular, the aspects of positioning accuracy over large areas and systematic image-quality errors will be described. New qualitative and objective methods have been developed as means to capture systematic image-quality errors. Results indicating that errors below 25 nm can be found early in the manufacturing process is presented, thus allowing inspection for visual effects before the actual display is completed. Positioning accuracy below 400 nm (3 sigma) over 720 × 560 mm have been achieved. These results will in the future be extended up toward 1 × 1 m for generation 4 in TFT-LCD production.
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| 2. |
- Gjertsen, Jan-Erik, et al.
(författare)
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Hemiarthroplasties after hip fractures in Norway and Sweden: a collaboration between the Norwegian and Swedish national registries
- 2014
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Ingår i: HIP International. - : SAGE Publications. - 1724-6067 .- 1120-7000. ; 24:3, s. 223-230
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Tidskriftsartikel (refereegranskat)abstract
- National registration of hemiarthroplasties after hip fractures has been established in both Norway and Sweden. We aimed to investigate differences in demographics, choice of implant selection, surgical approaches, and reoperations between the Norwegian Hip Fracture Register (NHFR) and the Swedish Hip Arthroplasty Register (SHAR). As part of the Nordic Arthroplasty Register Association (NARA) project a common hemiarthroplasty dataset has been established. 36,989 primary hemiarthroplasties (HAs) for acute hip fractures reported to NHFR (n = 12,761) and SHAR (n = 24,228) for the period 2005-2010 were included. Cemented prostheses were used in 78% of the operations in Norway and in 95% of the patients in Sweden. In Norway HAs almost exclusively had bipolar design (98%), whereas in Sweden HAs with unipolar design were used in 42% of the cases. Monoblock (non-modular) prostheses were uncommon, but still more frequently used in Sweden than in Norway (6.9% and 2.1% respectively). The lateral approach was more common in Norway (83%) than in Sweden (52%), where the posterior approach was used in 42% of the cases. The five-year survival of all HAs was 95.5% (95% CI: 94.8-96.2) in Norway and 94.8% (95% CI: 94.4-95.3) in Sweden. We concluded that surprisingly large differences between the two countries in demographics, implant design, and surgical technique had been revealed. This common dataset enables further investigations of the impact of these differences on revision rates and mortality.
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| 3. |
- Kiviloog, Jaan, 1975, et al.
(författare)
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EN STUDIE AV SMOLTVANDRING MED RADIOTELEMETRI OCH STRÖMNINGSMODELLERING
- 2004
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Ingår i: Proceedings Hidroenergía 04, Falkenberg, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A study on the effect of the flow field on downstream migration of smolts in a major northern Swedish river (Umeälv) is presented. The study comprises telemetric studies of downstream migrating smolts and three-dimensional computational fluid dynamics (CFD) studies of the flow. The CFD studies are validated with velocity data from field measurements with an Acoustic Doppler Profiler (ADP). The objective of this study is to determine the migration paths of salmon and trout smolts and relate these paths to the flow field. The results from the study can be used to improve smolt survival by taking appropriate measures to divert smolts from the turbines, e.g. by changing spill rules or installing bypass systems. Results from this telemetry show that the smolts move along the main stream of the river. Since this data only yield information on the smolt positions on a 2-dimensional plane it cannot directly be concluded whether the smolt migration is passive or active. Acomparison of the downstream migration speed of fish with the water velocities in the upper water column indicates that the downstream migration is passive.
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| 4. |
- Kiviloog, Jaan, 1975, et al.
(författare)
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Hydraulic modelling and validation for the study of smolt migration
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In order to assess the prerequisites for downstream migration of smolt the flow field upstream two hydropower stations in two large Swedish rivers have been made, and the simulations have been validated against stream velocities measured on site. The validated models have been used to compare the flow paths with the measured swimming paths of smolts. The simulations were done by solving the three dimensional Reynolds-averaged Navier-Stokes equations using the Fluent computational fluid dynamics (CFD) package. One of the studied rivers, Ume älv, whose main course is completely regulated, has a large unregulated tributary river, Vindelälven, which holds important spawning grounds for salmon (Salmo salar) and trout (Salmo trutta), and downstream of the confluence of the two rivers there is only one hydropower plant, the Stornorrfors power plant. This constitutes a major hindrance for fish migrating between the Bothnian Sea and the spawning grounds of the river Vindelälven. The juvenile fish, smolt, leaving the Vindelälven downstream towards the ocean can migrate either through the turbines and deep rock tunnels of the power plant or through the surface weirs at the regulating dam. Because of the flow regime during the migration period of smolts most smolts are believed to follow the main stream through the turbines leading to a mortality of approximately 25 %. The other studied river, Pite älv, also contain some spawning grounds in smaller tributaries upstream its first power plant. Although this plant is more like a-run-of-the-river plant most smolt passes the turbines instead of going over the spillways.The objective of the study is to determine the migration paths of salmon and trout smolts and relate their behaviour to hydraulic factors. The results from the study could then be used to improve smolt survival by taking appropriate measures to divert the smolts from the turbines, e.g. by changing spill rules or installing diversion systems.In Ume älv in Spring 2002, 22 salmon and 22 trout smolts were tagged with internal, individually coded radio transmitters (ATS). After the release approximately five kilometres upstream of the dam at Stornorrfors power plant their passages were registered at three stationary recorders and their movements tracked manually in the horizontal plane along their swimming paths. Simultaneously, velocity profiles were measured in selected cross-sections using an Acoustic Doppler Profiler (ADP). In spring 2003 16 smolt were tagged, released and tracked in the same way in Pite älv. In 2004 also the swimming depth was recorded.Results from the tracking, flow measurements and flow simulation indicate that the smolts move along the main stream of the river. In Ume älv the tracking data only yielded information on the smolt positions in the horizontal plane but it was found that the water velocities in the upper part of the water column along the smolts migration paths were close to the mean transport velocity of the smolt. In Pite älv Spring 2004 the swimming depth was measured to between 0.5 to 2 m below the surface. It can thus be concluded that the smolt migration is passive i.e. the smolt drift passively with the water.This study is part of a more extensive project that comprises studies of both upstream and downstream migration of fish. The objective of the project is to study the correlation between flow hydraulics and fish migratory behaviour. The ultimate goal is to create numerical fish models that are programmed to act as real fish in the CFD model. To get realistic models it is then first necessary to map real fish migratory behaviour to get to know the rules of the fish behaviour.
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| 5. |
- Rivinoja, Peter, et al.
(författare)
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Downstream migration of Salmo salar and S. trutta smolts in two regulated northern Swedish rivers
- 2004
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The downstream migration of Atlantic salmon and anadromous brown trout smolts was studied in two flow controlled northern Swedish rivers. The annual mean flow in Umeälven and Piteälven is c. 430 m3/s and c. 150 m3/s, respectively. Water power constructions located in the lower parts of these rivers may hinder or kill downstream migrating fish. Naturally produced salmon smolts in these rivers have two alternatives for passage of the water power constructions when they undertake their seasonally timed seaward migration in may-june: a) passing the turbines, or b) pass through the spill-way over the dam. Existing power-stations in Stornorrfors (Umeälven) use Francis turbines while Sikfors (Piteälven) use Kaplan turbines. In spring 2002 and 2003 a total of 90 Atlantic salmon and 56 brown trout two-year old hatchery-reared smolts were radio tagged with internal esophageal, individually coded radio transmitters (ATS). Trout were significantly larger (average length: 23.8 cm) than salmon (19.7 cm) (t-test, p<0.01). One to two days post-tagging the fish were released upstream the dammed areas, c. 5.0 km above Stornorrfors dam and c. 2.5 km above Sikfors dam, respectively. Their downstream migration routes were tracked both manually and with automatic listening stations in the horizontal plane (2-dimensional). Simultaneously, velocity profiles were measured in selected cross-sections using an Acoustic Doppler Profiler (ADP) applied to depth measurements giving a digitalised GIS-map over the dammed areas. Our main findings from the telemetry trackings, depth- and flow-measurements, and flow simulation show that the downstream migrating smolts move in the main flow in the river where the highest water velocities were registered. This subsequently resulted that fish entered the power-station, and did not pass downstream over spillways via dams or the fish ladders. The discharge ratio between power-station and spillway, with excess of water passing the power-station, guided fish to pass the turbines giving an extra mortality. Comparing the water velocities in the upper part of the water column with the estimated speed of smolts indicate that the downstream migration is passive. The average migration speed for downstream migrating smolts for the two species tested was found to be c. 0.4 m/s (c. 2 bodylengths/sec). Of the fish that passed trough the Sikfors power-station 83 % was registered downstream the turbine outlet. Remaining fish (17 %) that was not registered could have died or lost their tags in the power-station. Data from a Carlin-tagging study made during the years 98-99 in Piteälven (7450 tagged salmon smolts) is analysed and indicate a mortality of 20-30 % caused by the power-station. These results are discussed and compared to previously conducted studies at Umeälven and other regulated rivers.
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| 6. |
- Rogmark, Cecilia, et al.
(författare)
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Posterior approach and uncemented stems increases the risk of reoperation after hemiarthroplasties in elderly hip fracture patients.
- 2014
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Ingår i: Acta orthopaedica. - : Medical Journals Sweden AB. - 1745-3682 .- 1745-3674. ; 85:1, s. 18-25
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Tidskriftsartikel (refereegranskat)abstract
- Background Hemiarthroplasties are performed in great numbers worldwide but are seldom registered on a national basis. Our aim was to identify risk factors for reoperation after fracture-related hemiarthroplasty in Norway and Sweden. Material and methods A common dataset was created based on the Norwegian Hip Fracture Register and the Swedish Hip Arthroplasty Register. 33,205 hip fractures in individuals > 60 years of age treated with modular hemiarthroplasties were reported for the period 2005-2010. Cox regression analyses based on reoperations were performed (covariates: age group, sex, type of stem and implant head, surgical approach, and hospital volume). Results 1,164 patients (3.5%) were reoperated during a mean follow-up of 2.7 (SD 1.7) years. In patients over 85 years, an increased risk of reoperation was found for uncemented stems (HR = 2.2, 95% CI: 1.7-2.8), bipolar heads (HR = 1.4, CI: 1.2-1.8), posterior approach (HR = 1.4, CI: 1.2-1.8) and male sex (HR = 1.3, CI: 1.0-1.6). For patients aged 75-85 years, uncemented stems (HR = 1.6, 95% CI: 1.2-2.0) and men (HR = 1.3, CI: 1.1-1.6) carried an increased risk. Increased risk of reoperation due to infection was found for patients aged < 75 years (HR = 1.5, CI: 1.1-2.0) and for uncemented stems. For open surgery due to dislocation, the strongest risk factor was a posterior approach (HR = 2.2, CI: 1.8-2.6). Uncemented stems in particular (HR = 3.6, CI: 2.4-5.3) and male sex increased the risk of periprosthetic fracture surgery. Interpretation Cemented stems and a direct lateral transgluteal approach reduced the risk of reoperation after hip fractures treated with hemiarthroplasty in patients over 75 years. Men and younger patients had a higher risk of reoperation. For the age group 60-74 years, there were no such differences in risk in this material.
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