1. |
- Vassilev, Vessen, 1969, et al.
(författare)
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A Swedish heterodyne facility instrument for the APEX telescope
- 2008
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 490:3, s. 1157-1163
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Tidskriftsartikel (refereegranskat)abstract
- In March 2008, the APEX facility instrument was installed on the telescope at the site of Lliano Chajnantor in northern Chile. The main objective of the paper is to introduce the new instrument to the radio astronomical community. It describes the hardware configuration and presents some initial results from the on-sky commissioning.The heterodyne instrument covers frequencies between 211 GHz and 1390 GHz divided into four bands. The first threebands are sideband-separating mixers operating in a single sideband mode and based on superconductor-insulator-superconductor (SIS) tunnel junctions. The fourth band is a hot-electron bolometer, waveguide balanced mixer. All bands are integrated in a closedcycle temperature-stabilized cryostat and are cooled to 4 K.We present results from noise temperature, sideband separation ratios, beam, and stability measurements performed on the telescope as a part of the receiver technical commissioning. Examples of broad extragalactic lines are also included.
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2. |
- Ekwall, Per Erik, et al.
(författare)
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Towards a unified affordance approach : searching for congruent meaning making in COVID-19 warning designs
- 2021
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Ingår i: Social Semiotics. - : Routledge. - 1035-0330 .- 1470-1219.
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Tidskriftsartikel (refereegranskat)abstract
- This case study on COVID-19 warning designs in a Swedish context illustrates how a unified affordance approach may contribute to an understanding of the meaning-making in reminders, instructions, cues and prompts that communicate the message “keep your distance.” The analysis combines semiotic and ecological affordance categories, taking both Gibson’s original theorizing on affordances and more recent affordance-informed research efforts into consideration. In so doing, the study aims to bridge a knowledge gap in the study of visual instructions and warning designs as well as in a more comprehensive way delineate the multimodal design strategies associated with COVID-19 warning designs. The analysis shows that Swedish COVID-19 warning designs of the keep-your-distance-kind belong to a non-standardized and emerging genre that is marked by great variation and ad-hoc design solutions, several of which combine physical blocking functions with verbally based messages. The analysis also highlights the tension between verbal and visual recourses, on one hand, and the signage placement and choice of materials, on the other hand. It is concluded that communication resources do not always appear to convey the same basic message, but in incongruent ways weaken what might be considered the intended main message. © 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
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3. |
- Eriksson, Per Erik, et al.
(författare)
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Procurement of Railway Infrastructure Projects : A European Benchmarking Study
- 2017
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Ingår i: Civil Engineering Journal. - : C EJ PUBLISHING GROUP. - 2476-3055. ; 3:4, s. 199-213
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Tidskriftsartikel (refereegranskat)abstract
- This benchmarking study compares how railway investments are procured in five European countries: Sweden, Norway, Germany, the Netherlands, and the UK. In total, 19 procurement managers and project managers were interviewed. This study compares the national rail clients' procurement strategies regarding: delivery system, reward system, contractor selection, and collaboration model. Historically, these clients have used in-house production. The first step towards a gradually increased usage of the market was to outsource the construction activities while keeping the design and development competence in-house. All five countries have mainly used Design-Bid-Build contracts in their initial outsourcing. However, the last few years there is a discernible trend in Sweden, Norway, the Netherlands and the UK towards allocating more design and development responsibilities to contractors (i.e. Design-Build contracts) and increasing the strategic focus on cooperation. The UK and the Netherlands are forerunners in this trend that can be viewed as a third step in the transition towards a market oriented railway sector. Norway and Sweden is in the middle of this transition, whereas Germany has not initiated this change. The transition towards a gradually increased usage of the market has two main dimensions; degree of cooperation and degree of contractor freedom, which differs among the countries. The UK and Sweden focus on increasing both these dimensions, while The Netherlands and Norway mostly focus on increasing the degree of contractor freedom. Germany still limits both dimensions by performing design and development in-house and letting contractors compete for construction work in Design-Bid-Build contracts. Due to historical and cultural reasons, Deutsche Bahn in Germany is very hesitant to engage in collaboration with external suppliers; focusing on competition is considered more appropriate and less controversial.
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4. |
- Gradin, Per A., et al.
(författare)
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Measurement of the Power Distribution in a Single Disc Refiner
- 1999
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Ingår i: Journal of Pulp and Paper Science. - 0826-6220. ; 25:11, s. 384-387
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Tidskriftsartikel (refereegranskat)abstract
- A vital parameter in the production of mechanical pulp through refining is the energy consumption. Until recently, the pulping industry has focused on the total energy consumed, without a full understanding of how this energy is distributed in the refiners. In this paper two methods are suggested by which it is possible to estimate the energy supplied at an arbitrary point along the disc radius on refiner segments. The methods are based on instrumented bar with strain gauges. In the first method, a bar is slotted so that the sensor can be viewed as consisting of a number of cantilever beams separated by slots. In the second method, the sensor consists of one continuous bar along the disc radius. The sensors are calibrated such that influence coefficients are obtained for the slotted case and an influence function is obtained for the continuous one. The tangential forces are obtained directly in the first method, while in the second they are given by an integral equation which can be solved numerically. From the knowledge of the tangential force the power distribution can be calculated. Experimental results from the use of the slotted sensor are also given.
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5. |
- Gradin, Per, et al.
(författare)
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Measuring forces in a refiner plate gap
- 2011
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Ingår i: Proceedings of International Mechanical Pulping Conference. - 9787501982516 ; , s. 81-83
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Konferensbidrag (refereegranskat)
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6. |
- Gradin, Per, et al.
(författare)
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Measuring Tangential Forces in a Pulp Refiner : A Novel Approach
- 2016
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Ingår i: Experimental techniques (Westport, Conn.). - : Springer Science and Business Media LLC. - 0732-8818 .- 1747-1567. ; 40:2, s. 789-793
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Tidskriftsartikel (refereegranskat)abstract
- To get some insight into the processes that are active during the refining of wood, the tangential force distribution in the plate gap is of interest. Over the years several designs of force sensors have been developed for this purpose. One drawback with these designs is that each sensormeasures forces over quite a small area such that in order to cover the whole disc with a reasonably good resolution, many sensors have to be used. Also, there are problems to protect the active parts of the sensors from the harsh environment in the plate gap. In this paper a different concept is presented, in that the sensor is continuous and consists of a hollow radial bar equipped with strain gages on the inside. The force sensor was calibrated before mounting by loading it with a known load in the tangential direction and in different positions while measuring the strains in the points where the gages are located. This makes it possible to determine the so-called influence (or Green) functions. Knowing these it is possible to determine the tangential force distribution from strain values measured during operation of the refiner. Guidelines for doing this are presented together with a detailed description of the load sensor and some experimental results.
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7. |
- Hagman, Karl, et al.
(författare)
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On the potential roles of ticks and migrating birds in the ecology of West Nile virus
- 2014
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Ingår i: Infection Ecology & Epidemiology. - : Informa UK Limited. - 2000-8686. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Mosquitoes are the primary vectors of West Nile virus (WNV). Ticks have, however, been suggested to be potential reservoirs of WNV. In order to investigate their role in the spread of the virus, ticks, which had been collected from birds migrating northwards from Africa to Europe, were analyzed for the potential presence of WNV-RNA.METHODS: On the Mediterranean islands Capri and Antikythira a total of 14,824 birds were captured and investigated from which 747 ticks were collected.RESULTS AND CONCLUSION: Most of the identified ticks (93%) were nymphs and larvae of Hyalomma marginatum sensu lato, most of which were or appear to be Hyalomma rufipes. Of these ticks 729 were individually screened for WNV-RNA. None of the ticks was found to be WNV positive. Thus, there was no evidence that Hyalomma marginatum s.l. ticks play a role in the spread of WNV from Africa to Europe.
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8. |
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9. |
- Hoffman, Tove, et al.
(författare)
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Alkhurma Hemorrhagic Fever Virus RNA in Hyalomma rufipes Ticks Infesting Migratory Birds, Europe and Asia Minor
- 2018
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Ingår i: Emerging Infectious Diseases. - Atlanta, United States : U.S. Department of Health and Human Services * Centers for Disease Control and Prevention. - 1080-6040 .- 1080-6059. ; 24:5, s. 879-882
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Tidskriftsartikel (refereegranskat)abstract
- Alkhurma hemorrhagic fever virus RNA was detected in immature Hyalomma rufipes ticks infesting northward migratory birds caught in the North Mediterranean Basin. This finding suggests a role for birds in the ecology of the Alkhurma hemorrhagic fever virus and a potential mechanism for dissemination to novel regions. Increased surveillance is warranted.
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10. |
- Kemetli, Levent, et al.
(författare)
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Temporal trends in the use of adjuvant systemic therapy in breast cancer : a population based study in Sweden 1976-2005.
- 2009
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Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 48:1, s. 59-66
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Both adjuvant therapy and mammography screening can decrease breast cancer mortality and there is a need of knowing to what extent those two modalities are used in the population. Screening coverage is well documented but there is a scarcity of population-based data on use of systemic adjuvant treatment. AIM: To describe the introduction, and trends in the use of adjuvant systemic therapy for breast cancer in two of six public health regions in Sweden. MATERIAL & METHODS: Population-based data on use of adjuvant therapy were available from databases with documented high quality and high coverage data for Stockholm (1976-2005) and North Sweden (1980-2003, and 2005). RESULTS: The use of systemic treatment was infrequent before the late 1980s in both regions, but increased during the 1990s. In 2005, the proportion of operable breast cancer patients treated with adjuvant endocrine therapy in the ages 40-59 was around 60 to 80%. The proportion adjuvant chemotherapy was less than 15% for the ages 70-74. For the north region the use of endocrine therapy increased successively over time, with an exception for age group 40-49 were a more rapidly increase occurred in the late 1990s. In Stockholm the increment was higher and more rapidly. There was no clear difference in chemotherapy use between the regions, and the use increased from the mid 1980s in age group 40-49, and in the early 1990s for women aged 50-59. In age group's 60-69 and 70-74 the use was relatively infrequent. CONCLUSIONS: Trends in, and levels of the use of adjuvant systemic therapy for breast cancer varied over time in the two study regions, particularly for endocrine therapy. We consider that the differences between the regions mainly reflect different interpretations of new scientific evidence. We stress the importance of a good documentation of all new treatment protocols.
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