| 1. |
- Barbosa, Edna J L, 1961, et al.
(author)
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Extracellular water and blood pressure in adults with growth hormone (GH) deficiency: a genotype-phenotype association study.
- 2014
-
In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 9:8
-
Journal article (peer-reviewed)abstract
- Growth hormone deficiency (GHD) in adults is associated with decreased extracellular water volume (ECW). In response to GH replacement therapy (GHRT), ECW increases and blood pressure (BP) reduces or remains unchanged. Our primary aim was to study the association between polymorphisms in genes related to renal tubular function with ECW and BP before and 1 year after GHRT. The ECW measures using bioimpedance analysis (BIA) and bioimpedance spectroscopy (BIS) were validated against a reference method, the sodium bromide dilution method (Br(-)).
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| 2. |
- Cha, Eunjung, 1985, et al.
(author)
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Cryogenic low-noise InP HEMTs: A source-drain distance study
- 2016
-
In: 2016 Compound Semiconductor Week, CSW 2016. - 9781509019649 ; , s. Article number 7528576-
-
Conference paper (peer-reviewed)abstract
- The scaling effect of the source-drain distance was investigated in order to improve the performance of low-noise InP HEMTs at cryogenic temperatures 4-15 K. The highest dc transconductance at an operating temperature of 4.8 K and low bias power was achieved at a source-drain distance of 1.4 mu m. The extracted HEMT minimum noise temperature was 0.9 K at 5.8 GHz for a 3-stage 4-8 GHz hybrid low-noise amplifier at 10 K.
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| 3. |
- Lantz, Emelie, et al.
(author)
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Serving the community while balancing multiple responsibilities : experiences of working as a paid part-time firefighter
- 2023
-
In: International Journal of Emergency Services. - : Emerald Group Publishing Limited. - 2047-0894 .- 2047-0908. ; :1, s. 17-38
-
Journal article (peer-reviewed)abstract
- PurposeThe purpose of this study was to describe experiences of working as a paid part-time firefighter (PTF) in Swedish rural areas.Design/methodology/approachAn inductive explorative design was used, based on interviews with 18 paid PTFs in Sweden. Data were analyzed using qualitative latent content analysis.FindingsThree themes emerged from the interviews and describe paid PTFs’ experiences. The findings provide insights into how firefighters share a strong commitment, how support plays a crucial role, and how training and call-outs contribute to their experiences. Paid PTFs’ experiences are nuanced, ranging from personal limitations and challenges to satisfaction and the contrast with ordinary life.Practical implicationsThe implications for fire and rescue service organizations are that they can encourage firefighters’ commitment and pride, as well as the commitment and support of their families and main employers. Further, highlighting the importance of support and facilitating flexibility when on call is crucial. Finally, acknowledging and promoting personal development and facilitating an inclusive culture are important factors for both motivation and satisfaction.Originality/valuePaid PTFs are under-represented in the literature, despite the reliance on them in Sweden, and this study begins to address the knowledge gap. To improve retention, it is vital to understand paid PTFs work situation: what motivates them, what barriers they face, and how those challenges influence their experiences.
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| 4. |
- Nilsson, Bengt, 1982-, et al.
(author)
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Distribution of logging residues at the clear-felled site after fuel adapted logging operations
- 2015
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In: Papers of the 23rd European Biomass Conference. - : ETA-Florence Renewable Energies. - 9788889407516 ; , s. 270-272
-
Conference paper (peer-reviewed)abstract
- During extraction of logging residues previous studies in Sweden have shown that up to 50% of the available logging residues will not reach the energy-conversion site. The remaining potential of the logging residues are therefore lost by handling either at the clear-felled site, during transportation or due to decomposition. An outtake of 100% is not possible or desired, since the Swedish Forest Agency recommends that at least 20% of the logging residues should be left at the clear-felled site after a fuel adapted logging operation. In this study the losses at the clear-felled area is examined by studying the distribution of the remaining logging residues under and between the harvester heaps as well amount of logging residues that are left at the roadside landing after comminution. The results show that most of the reaming logging residues are well distributed at the clear-felled area between the harvester heaps. Additional logging residues are left at the clear-felled area since the forwarder cannot gather all logging residues from under the harvester heaps. In addition to this a not insignificant amount of logging residues are left at the roadside landing.
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| 5. |
- Nilsson, Daniel, et al.
(author)
-
Amount of nutrients extracted and left behind at a clear-felled area using the fresh-stacked and dried-stacked methods of logging residue extraction
- 2018
-
In: Scandinavian Journal of Forest Research. - : Taylor & Francis Group. - 0282-7581 .- 1651-1891. ; 33:5, s. 437-445
-
Journal article (peer-reviewed)abstract
- Nutrient removal has been one of the key issues since the harvesting of logging residues started in Sweden. This study examined the actual removal of nutrients by measuring the amounts of biomass removed (from a forest products perspective) combined with their respective nutrient concentrations (N, P, Ca, K and Mg), from a clear-felled area when using the dried-stacked and fresh-stacked methods. The most important finding is that the two methods were very similar regarding nutrients remaining at the clear-felled area. Of the nutrients remaining there, most were found to be well distributed between the harvester heaps. Both methods fulfilled the requirements of the Swedish Forest Agency. A sensitivity analysis showed that even if the dried-stacked method left more needles, or the fresh-stacked method extracted more logging residues, there would only be a small impact on the levels of nutrients removed. The sensitivity analysis also showed that the amount of logging residues remaining between the harvester heaps seems to be much more important for nutrients left behind, regardless of extraction method. With this in mind, it is highly probable that improvements to the extraction of logging residues, without increasing nutrient removal, can be made.
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| 6. |
- Nilsson, Daniel, et al.
(author)
-
Nutrient removal after whole-tree harvesting with the traditional Swedish dried-stacked method for removal of logging residues
- 2015
-
In: Papers of the 23rd European Biomass Conference. - : ETA-Florence Renewable Energies. - 9788889407516 ; , s. 9-13
-
Conference paper (peer-reviewed)abstract
- Bioenergy from logging residues is an important contributor to Swedish energy supplies. Logging residues where long defined and regarded as the unmerchantable aboveground biomass left behind in the clear-felled area, consisting of branches, tops and small trees that are gathered after the round wood harvest, but logging residues are nowadays regarded as a third assortment next to timber and pulpwood with high economic value. However long-term experiments on removal of logging residues from Norway spruce (Picea abies (L.)Karst) stands have shown both growth reductions and growth increase in the next generation, because of decreasing amounts of nutrients. So an increased removal of logging residues requires some sort of compensation of nutrients. Therefore it is of importance to investigate how much nutrients that is removed from the stand after whole-tree harvesting.In this study the removal of the nutrients nitrogen (N), phosphorus (P), calcium (Ca), potassium (K) and magnesium (Mg) have been investigated by laboratory analysis of the nutrients together with the actual removal of stemwood, bark and logging residues. The study has also investigated the distribution of nutrients at the clear-felled area.The results show that approximately half of the total nutrient removed in whole tree harvesting is done with the removal of stemwood and bark. The results also show that approximately 30% of the total amount of nutrients is left at the clear-felled area.
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| 7. |
- Nilsson, Per-Åke, 1964, et al.
(author)
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An InP MMIC process optimized for low noise at Cryo
- 2014
-
In: Technical Digest - IEEE Compound Semiconductor Integrated Circuit Symposium, CSIC. - 1550-8781. - 9781479936229
-
Conference paper (peer-reviewed)abstract
- An InP MMIC process was developed and optimized for ultra-low noise amplifiers (LNAs) operating at cryogenic temperature. The amplifiers from the process are working up to 100 GHz. The processed wafers are 4" and can carry more than 4000 3-stage units. For a significant number of 6-20 GHz 3-stage LNAs we have measured an average noise temperature of 5.8 K at ambient temperature of 10 K, state of the art in this frequency range, and 66.3 K at 300K. Associated gain was 35.9 dB (10K) and 33.2 dB (300 K). The standard deviation at room temperature for 47 LNAs was 1.5 K for the noise and 0.3 dB for the gain.
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| 8. |
- Schleeh, Joel, 1986, et al.
(author)
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Cryogenic LNAs for SKA band 2 to 5
- 2017
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In: IEEE MTT-S International Microwave Symposium Digest. - 0149-645X. - 9781509063604 ; , s. 164-167
-
Conference paper (peer-reviewed)abstract
- Four ultra-low noise cryogenic MMIC LNAs suitable for the Square Kilometer Array (SKA) band 2 to 5 (0.95-13.8 GHz) have been designed, fabricated, packaged and tested. The LNAs are based on 4×50, 8×50 and 16×50 μm HEMTs, designed for stable cryogenic operation, allowing the combination of good noise performance and return loss. The lowest noise temperatures measured in the four bands were 1.0 K, 1.2 K, 1.6 K and 2.6 K, respectively.
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| 9. |
- Ahlroth Pind, Caroline, et al.
(author)
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Patient-reported signs of dampness at home may be a risk factor for chronic rhinosinusitis : A cross-sectional study
- 2017
-
In: Clinical and Experimental Allergy. - Hoboken : Wiley. - 0954-7894 .- 1365-2222. ; 47:11, s. 1383-1389
-
Journal article (peer-reviewed)abstract
- BACKGROUND: An association between dampness at home and respiratory conditions has been convincingly demonstrated in children. Fewer studies have been performed in adults, and data are lacking for chronic rhinosinusitis (CRS). With a prevalence of 10.9% in Europe, CRS imposes a significant burden on quality of life, as well as economy.OBJECTIVE: Our aim was to study CRS and other respiratory conditions in relation to dampness at home in a representative sample of adults.METHODS: The Swedish GA2 LEN questionnaire was answered by 26 577 adults (16-75 years) and included questions on respiratory symptoms, smoking, education and environmental exposure. CRS was defined according to the EP3 OS criteria. Dampness was defined as reporting water damage, floor dampness or visible moulds in the home during the last 12 months. The dampness score was ranked from 0 to 3, counting the number of signs of dampness reported.RESULTS: Dampness at home was reported by 11.3% and was independently related to respiratory conditions after adjustment for demographic and socio-economic factors and smoking: CRS odds ratio (OR) 1.71; allergic rhinitis OR 1.24; current asthma OR 1.21; wheeze OR 1.37; nocturnal dyspnoea OR 1.80; nocturnal coughing OR 1.34; and chronic bronchitis OR 1.64. The risk of CRS and most of the other respiratory conditions was further elevated in subjects reporting multiple signs of dampness.CONCLUSIONS AND CLINICAL RELEVANCE: This study demonstrated an independent association between dampness at home and CRS in adults. The high burden of this and the other respiratory conditions studied is a strong argument in favour of countering indoor dampness by improving building standards.
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| 10. |
- Allert, Camilla, 1972-, et al.
(author)
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Voluntary first responders’ experiences of being dispatched to suspected out-of-hospital cardiac arrest in rural areas : an interview study
- 2024
-
In: BMC Cardiovascular Disorders. - : BioMed Central (BMC). - 1471-2261. ; 24:1
-
Journal article (peer-reviewed)abstract
- Background: Out-of-hospital cardiac arrest (OHCA) is a leading cause of death, and survival outcomes vary across countries and regions. To improve survival, the European Resuscitation Council Guidelines encourage the implementation of technologies like smartphone applications to alert voluntary first responders (VFRs) who are near a suspected OHCA. VFRs are of great importance in the ´chain of survival´, but there is still a lack of knowledge about their experiences; especially of those operating in rural areas. Understanding those experiences is crucial in developing appropriate interventions to train, encourage, and safeguard VFRs in their mission. Therefore, the aim of this study was to describe VFRs´ experiences of being dispatched to suspected OHCA in rural areas.Methods: The study used an inductive design. The data were collected using individual interviews with 16 VFRs and analysed using qualitative content analysis.Results: The results are presented in terms of six generic categories ‘‘Being motivated and prepared’’, ‘‘Having strategies to undertake the mission’’, ‘‘Collaborating with others’’, ‘‘Being ethically aware’’, ‘‘Supporting the family members’’, and ‘‘Coping with the mission’’, which formed the basis of the main category ‘Desire to save lives and help others’. The findings showed that VFRs had a genuine desire to contribute to save lives in this rural area. Regardless of the circumstances, they were prepared to leave everything and act to the best for the victim and their family members. In theirs’ missions they collaborated with others at the scene and were guided by ethics while they acted in complex circumstances.Conclusions: VFRs dispatched in rural areas express a desire to save lives. In their missions, they acted in complex situations and experienced both emotional and ethical challenges.The design, implementation, and evaluation of support interventions directed at VFRs should be prioritised, especially in rural areas, as it can contribute to more people becoming and remaining VFRs, which in turn could contribute to sustainable development.
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| 11. |
- Amiandamhen, Stephen, 1983-, et al.
(author)
-
Bioenergy production and utilization in different sectors in Sweden: A state of the art review
- 2020
-
In: BioResources. - : University of North Carolina Press. - 1930-2126. ; 15:4, s. 9834-9857
-
Research review (peer-reviewed)abstract
- In the continual desire to reduce the environmental footprints of human activities, research efforts to provide cleaner energy is increasingly becoming vital. The effect of climate change on present and future existence, sustainable processes, and utilizations of renewable resources have been active topics within international discourse. In order to reduce the greenhouse gases emissions from traditional materials and processes, there has been a shift to more environmental friendly alternatives. The conversion of biomass to bioenergy, including biofuels has been considered to contribute to the future of climate change mitigation, although there are concerns about carbon balance from forest utilization. Bioenergy accounts for more than one-third of all energy used in Sweden and biomass has provided about 60% of the fuel for district heating. Apart from heat and electricity supply, the transport sector, with about 30% of global energy use, has a significant role in a sustainable bioenergy system. This review presents the state of the art in the Swedish bioenergy sector based on literature and Swedish Energy Agency’s current statistics. The review also discusses the overall bioenergy production and utilization in different sectors in Sweden. The current potential, challenges, and environmental considerations of bioenergy production are also discussed.
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| 12. |
- Bao, Ling, 1980, et al.
(author)
-
U-Duality and the Compactified Gauss-Bonnet Term
- 2007
-
In: Journal of High Energy Physics.
-
Journal article (peer-reviewed)abstract
- We present the complete toroidal compactification of the Gauss-Bonnet Lagrangian from D dimensions to D-n dimensions. Our goal is to investigate the resulting action from the point of view of the "U-duality" symmetry SL(n+1,R) which is present in the tree-level Lagrangian when D-n=3. The analysis builds upon and extends the investigation of the paper [arXiv:0706.1183], by computing in detail the full structure of the compactified Gauss-Bonnet term, including the contribution from the dilaton exponents. We analyze these exponents using the representation theory of the Lie algebra sl(n+1,R) and determine which representation is the relevant one for quadratic curvature corrections. By interpreting the result of the compactification as a leading term in a large volume expansion of an SL(n+1,Z)-invariant action, we conclude that the overall exponential dilaton factor should not be included in the representation structure. As a consequence, all dilaton exponents correspond to weights of sl(n+1,R), which, nevertheless, remain on the positive side of the root lattice.
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| 13. |
- Boström, Pontus, 1982, et al.
(author)
-
SNARE proteins mediate fusion between cytosolic lipid droplets and are implicated in insulin sensitivity.
- 2007
-
In: Nature cell biology. - : Springer Science and Business Media LLC. - 1465-7392 .- 1476-4679. ; 9:11, s. 1286-93
-
Journal article (peer-reviewed)abstract
- The accumulation of cytosolic lipid droplets in muscle and liver cells has been linked to the development of insulin resistance and type 2 diabetes. Such droplets are formed as small structures that increase in size through fusion, a process that is dependent on intact microtubules and the motor protein dynein. Approximately 15% of all droplets are involved in fusion processes at a given time. Here, we show that lipid droplets are associated with proteins involved in fusion processes in the cell: NSF (N-ethylmaleimide-sensitive-factor), alpha-SNAP (soluble NSF attachment protein) and the SNAREs (SNAP receptors), SNAP23 (synaptosomal-associated protein of 23 kDa), syntaxin-5 and VAMP4 (vesicle-associated membrane protein 4). Knockdown of the genes for SNAP23, syntaxin-5 or VAMP4, or microinjection of a dominant-negative mutant of alpha-SNAP, decreases the rate of fusion and the size of the lipid droplets. Thus, the SNARE system seems to have an important role in lipid droplet fusion. We also show that oleic acid treatment decreases the insulin sensitivity of heart muscle cells, and this sensitivity is completely restored by transfection with SNAP23. Thus, SNAP23 might be a link between insulin sensitivity and the inflow of fatty acids to the cell.
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| 14. |
- Cabanettes, Frederic, 1982, et al.
(author)
-
Evaluation of cam and roller surfaces and their manufacturing process by functional characterisation
- 2008
-
In: Proceedings of the Swedish Production Symposium 2008, Stockholm, Sweden. ; , s. 7-
-
Conference paper (peer-reviewed)abstract
- Friction and wear are constant problems encountered in camshaft development. Thecontact between roller and cam is a mix of sliding and rolling which leads to a wide rangeof failure modes. The uniqueness of this contact is also due to variations all around thecam of a multitude of parameters. A previous study described surface topography as afunction of cam shape. The different types of wear mechanisms are strongly linked tocontact pressures which are also dependent on roughness. The aim of the paper is toevaluate the quality of camshafts and rollers produced with different manufacturinghistories. The evaluation utilises standard roughness parameters as well as rough contactparameters. The surfaces measurements are made by a non-contact light interferometerand a set of 3D roughness parameters is evaluated for each measure. The Greenwood-Williamson contact model has been developed and also applied to the measurements inorder to collect characteristics of the microscopic pressures. The results of the study showthe significant effect of topography variations on the tribological behaviour of the camroller contact and rank the different manufacturing processes according to functionalcharacterization. The verification of the ranking using experiments is the continuity of thisstudy.
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| 15. |
- Cabanettes, Frederic, 1982, et al.
(author)
-
Evaluation of cam and roller surfaces by wear testing and functional characterisation
- 2008
-
In: Proceedings of the 35th Leeds Lyon Symposium on Tribology. ; , s. 8-
-
Conference paper (peer-reviewed)abstract
- Friction and wear are constant problems encountered in camshaft development. The contact between roller and camis a mix of sliding and rolling which leads to a wide range of failure modes. The uniqueness of this contact is also dueto variations all around the cam of a multitude of parameters such as load and radius. A previous study describedsurface topography as a function of cam shape. The different types of wear mechanisms are strongly linked to contactpressures which are also dependent on roughness. The aim of the paper is to develop a rough contact model which willbe utilized as a tool to rank surfaces and their ability to face wear problems. In order to verify the tool, rough contactresults are compared to roughness parameter variations due to wear produced in a cam roller rig test. The surfacemeasurements used for this study are made by a non-contact light interferometer. The Greenwood-Williamson contactmodel has been developed in a deterministic way and the elasto-plastic behaviour of the material has been integratedto the model. The outputs of the simulation give a ranking of surfaces which is compared to their roughness variationsdue to wear. The study shows that the model developed is a reliable tool to rank and define surface quality since theresults are correlated to wear. However, the results show as well some discrepancies which could be corrected in thefuture by integrating to the model two new features: a rough to rough contact including sliding between surfaces. Thisnew model should be verified by an accurate experimentation using relocation between unworn and worn surfaces.
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| 16. |
- Cabanettes, Frédéric, 1982-, et al.
(author)
-
Evaluation of cam surfaces by wear testing and functional characterization
- 2008
-
In: Synopses / 35th Leeds-Lyon Symposium on Tribology. - Leeds : Leeds University.
-
Conference paper (other academic/artistic)abstract
- Friction and wear are constant problems encountered in camshaft development. The contact between roller and cam is a mix of sliding and rolling which leads to a wide range of failure modes. The uniqueness of this contact is also due to variations all around the cam of a multitude of parameters such as load and radius. A previous study described surface topography as a function of cam shape. The different types of wear mechanisms are strongly linked to contact pressures which are also dependent on roughness. The aim of the paper is to develop a rough contact model which will be utilized as a tool to rank surfaces and their ability to face wear problems. In order to verify the tool, rough contact results are compared to roughness parameter variations due to wear produced in a cam roller rig test. The surface measurements used for this study are made by a non-contact light interferometer. The Greenwood-Williamson contact model has been developed in a deterministic way and the elasto-plastic behaviour of the material has been integrated to the model. The outputs of the simulation give a ranking of surfaces which is compared to their roughness variations due to wear. The study shows that the model developed is a reliable tool to rank and define surface quality since the results are correlated to wear. However, the results show as well some discrepancies which could be corrected in the future by integrating to the model two new features: a rough to rough contact including sliding between surfaces. This new model should be verified by an accurate experimentation using relocation between unworn and worn surfaces.
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| 17. |
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| 18. |
- Cabanettes, Frédéric, 1982-, et al.
(author)
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The evolution of surface topography of injection cams
- 2007
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In: Proceedings of the 11th International Conference on Metrology and Properties of Engineering Surfaces. - Huddersfield : Huddersfield University. - 9781862180574
-
Conference paper (peer-reviewed)
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| 19. |
- Cabanettes, Frederic, 1982, et al.
(author)
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The evolution of surface topography of injection cams
- 2007
-
In: Proceedings of Mets and Props conference 2007´, Huddersfield, UK. ; , s. 5-
-
Conference paper (other academic/artistic)abstract
- Friction and wear are constant problems encountered in camshaft development. Among a wide amount of factors, surface topography is an important feature to improve in this complex system. Four parts of different shapes can be differentiated on an injection cam profile. Therefore the machining of such component is quite particular. Considering the complex shape of an injection cam, this paper is divided in two studies: 1. Variations of surface topography around freshly produced cams in order to emphasize the particular profile of cams which leads to a complex machining. 2. Evolution of surfaces during run-in in order to discover the effects of wear process on a group of roughness parameters. The results show a variation of density of peaks along the freshly produced cam surface and highlight also the importance of roller type on the evolution of topography. Further results show that summits of the surface are rounded off but not removed during run-in.
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| 20. |
- Cabanettes, Frederic, 1982, et al.
(author)
-
Tribological aspect of the surface topography variations for injection cams
- 2008
-
In: Proceedings of Nordtrib conference 2008, Tampere, Finland. ; , s. 16-
-
Conference paper (other academic/artistic)abstract
- In automotive industry, the environmental demands of low emissions, low fuel consumptions and long lifecycles lead to higher and higher engineering constraints. For example, high pressures on injection cams are needed for an improved combustion. Therefore friction and wear are constant problems encountered in camshaft development. The contact between roller and cam is a mix of sliding and rolling which leads to a wide range of failure modes. The uniqueness of this contact is also due to variations all around the cam depending on a multitude of parameters such as radius of curvature, load, sliding velocity. A previous study described surface topography as a function of cam shape and running time. The different types of wear mechanisms are strongly linked to contact pressures which are also dependent on roughness.This paper deals with the repercussion of observed variations of surface topography on the tribological behaviour of the cam roller contact. A number of cams have been mapped. The measurements are made by a non-contact light interferometer to monitor changes in the surface roughness. The Greenwood-Williamson contact model has been developed and applied to those measurements in order to collect characteristics of the microscopic pressures distribution.The results of the study show the significant effect of topography variations on the tribological behaviour of the cam roller contact. Cam angle roughness fluctuations arestudied as well as running time dependency. The flat part of the cams with a high amount of peaks of sharp radii gives the worst tribological conditions and the running-instudy shows the beneficial effect of peak smoothening on contact pressures. Tribological characteristics such as pressure distribution are valuable results which are helping to build characteristics of a recommended surface more able to face wear problems. In that case, an interesting prospect will be to virtually screen surfacesproduced with different finishing processes and find out the best ones in order to reduce wear. The study of different roller processes will be as well of great interest.
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| 21. |
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| 22. |
- Ghandriz, Toheed, 1982, et al.
(author)
-
Computationally Efficient Nonlinear One-and Two-Track Models for Multitrailer Road Vehicles
- 2020
-
In: IEEE Access. - 2169-3536 .- 2169-3536. ; 8, s. 203854-203875
-
Journal article (peer-reviewed)abstract
- This paper presents nonlinear mathematical models of one-and two-track multitrailer vehicles. We derive nonlinear equations of motion in the form of a system of implicit ordinary differential equations (ODEs) by using Lagrangian mechanics. The system of ODEs has the minimum number of states and equations that enables efficient computations yet maintains the most important nonlinear vehicle dynamic behavior and allows actuator coordination and energy consumption evaluation. As examples, we build different models of a 4-unit long combination vehicle, i.e., two-track 11-axle and single-track 6-axle nonlinear models as well as a linear single-track 6-axle model. We compare the performance of these models to experimental data of different driving maneuvers. The nonlinear single-track model demonstrates close dynamic behavior to the experiment, which makes it an efficient alternative to the two-track model. The vehicle equations can be generated automatically by using the code provided in this paper and subsequently used for conducting frequency analysis, evaluating energy consumption, deriving performance measures from simulations, and facilitating optimal control applications that involve combined steering, braking and propulsion control.
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| 23. |
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| 24. |
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| 25. |
- Ghandriz, Toheed, 1982, et al.
(author)
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Real-time Predictive Energy Management of Hybrid Electric Heavy Vehicles by Sequential Programming
- 2021
-
In: IEEE Transactions on Vehicular Technology. - 0018-9545 .- 1939-9359. ; 70:5, s. 4113-4128
-
Journal article (peer-reviewed)abstract
- With the objective of reducing fuel consumption, this paper presents real-time predictive energy management of hybrid electric heavy vehicles. We propose an optimal control strategy that determines the power split between different vehicle power sources and brakes. Based on the model predictive control (MPC) and sequential programming, the optimal trajectories of the vehicle velocity and battery state of charge are found for upcoming horizons with a length of 5-20 km. Then, acceleration and brake pedal positions together with the battery usage are regulated to follow the requested speed and state of charge that is verified using a vehicle plant model. The main contribution of this paper is the development of a sequential linear program for predictive energy management that is faster and simpler than sequential quadratic programming in tested solvers and gives trajectories that are very close to the best trajectories found by nonlinear programming. The performance of the method is also compared to two different sequential quadratic programs.
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| 26. |
- Ghandriz, Toheed, 1982, et al.
(author)
-
Trajectory-Following and Off-Tracking Minimization of Long Combination Vehicles: A Comparison Between Nonlinear and Linear Model Predictive Control
- 2024
-
In: Vehicle System Dynamics. - : Informa UK Limited. - 1744-5159 .- 0042-3114. ; 62:2, s. 277-310
-
Journal article (peer-reviewed)abstract
- In this paper, we compared the linear and nonlinear motion prediction models of a long combination vehicle (LCV). We designed a nonlinear model predictive control (NMPC) for trajectory-following and off-tracking minimisation of the LCV. The used prediction model allowed coupled longitudinal and lateral dynamics together with the possibility of a combined steering, propulsion and braking control of those vehicles in long prediction horizons and in all ranges of forward velocity. For LCVs where the vehicle model is highly nonlinear, we showed that the control actions calculated by a linear time-varying model predictive control (LTV-MPC) are relatively close to those obtained by the NMPC if the guess linearisation trajectory is sufficiently close to the nonlinear solution, in contrast to linearising for specific operating conditions that limit the generality of the designed function. We discussed how those guess trajectories can be obtained allowing off-line fixed time-varying model linearisation that is beneficial for real-time implementation of MPC in LCVs with long prediction horizons. The long prediction horizons are necessary for motion planning and trajectory-following of LCVs to maintain stability and tracking quality, e.g. by optimally reducing the speed prior to reaching a curve, and by generating control actions within the actuators limits.
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| 27. |
- Lars, Eliasson, et al.
(author)
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Skotning av grot direkt efteravverkning eller efter hyggeslagring : Effekter på näringsuttag, barravfall och fukthalt
- 2015
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Reports (other academic/artistic)abstract
- Sedan 1980-talet har rekommendationen varit att grot ska hyggeslagras under en sommar för att torka och ”barra av”. Torkningen ökar det effektiva värmevärdet och därigenom det ekonomiska värdet för den levererade mängden grot samt minskar uttaget av näringsämnen, vilket kan påverka skogsproduktionen. Hyggeslagring innebär samtidigt att grotskotningen måste utföras av en annan maskin än den som skotade rundvirket, vilket medför en extra maskinflytt som i sin tur ökar kostnaden för grotuttaget. Att grotskotningen koncentreras till barmarksperioden innebär att markberedning inte kan utföras under sommaren efter avverkningen, eftersom grothögarna finns kvar på hygget. Intresset för att skota groten direkt efter avverkning och torka den i en välta vid väg har ökat, då det ses som ett sätt att undvika dessa nackdelar.En genomgång av befintlig litteratur har genomförts för att ge en översikt av effekterna av dessa två uttagsstrategier för grot:- Skotning av grot till välta vid väg direkt efter avverkning.- Hyggeslagring av grot under en sommar innan grotskotning till välta vid väg. Litteraturstudien visar att:- Oavsett uttagsstrategi så blir mer än 20 procent av groten kvar på hygget.- Hyggeslagring av groten är ingen garant för att barren faller av och näring utlakas.- Hyggeslagrad grot är inte torrare än vältlagrad vid leverans.- De eventuella effekter som valet av uttagstrategi har på den framtida tillväxten bör vara mindre än det man kan se i försöken med helträdsuttag.- Skotning av färsk grot frigör hygget för markberedning och återplantering redan första sommaren efter avverkning, d.v.s. minst ett år tidigare än om groten skall hyggeslagras.
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| 28. |
- Lööf, Pär-Johan, 1983-, et al.
(author)
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Virtual Evaluation of Gear Manufacture – To Use 3D Surface Data to Predict Performance
- 2014
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Conference paper (peer-reviewed)abstract
- The manufacturing and finishing of gears include several processes such as grinding, hobbing, shaving, honing, shot peening and phosphating. For the automotive industry it is a constant challenge to improve the durability and reduce the fuel consumption in a cost effective way by using robust processes for mass manufacturing. A better knowledge of the properties of the manufactured surfaces in gears, and especially how they interact in different combinations is an important knowledge when designing gearboxes for the future. The following paper proposes an efficient way for choosing the better manufacturing and predicting the behavior of new combinations of process parameters in the early stage of the design process based on simulations of 3D surface measurements. The simulation model uses two rough surfaces of counterpart gear teeth contacting and deforming elastically under a typically critical load during operation. Outputs from the simulations are the pressure distribution and real contact area later used for ranking the differently manufactured surfaces. Four different types of surfaces were taken from manufacturing; samples were extracted and measured on a coherence scanning interferometer. Two surface types were ground differently and two were shot-peened with different process parameters. The results show the shot-peened surfaces, especially the double shot-peened type B1, performed better than the ground ones manifested in larger real contact areas and lower/fewer pressure spikes. Based on the correlations of the 3D roughness parameters with the simulation outputs, some roughness parameters are suggested for more robust quality control.
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| 29. |
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| 30. |
- Nilsson, Bengt, 1982-
(author)
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Extraction of logging residues for bioenergy : effects of operational methods on fuel quality and biomass losses in the forest
- 2016
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Doctoral thesis (other academic/artistic)abstract
- Wood products play a key role in the transformation to a more sustainable society based on renewable bio-based resources, together with the positive effects on climate mitigation by replacing fossil fuels. However, to increase the use of forest fuel in practice it is important to understand the effects of handling and storage on its quality and removal of nutrients from the forest. This thesis addresses these effects with special focus on a comparative evaluation of the traditional dried-stacked with “new” and to some extent more controversial fresh-stacked methods for extraction of logging residues from Norway spruce (Picea abies (L.) Karst).The results indicate that a normal extraction of logging residues will leave at least 20% of logging residues at the clear-felled area, in accordance with Swedish Forest Agency recommendations. However, the results also indicate that the ambition of the dried-stacked method to leave the majority of the needles well spread over the clear-felled area does not meet these recommendations. In fact, the harvesting operation is more important than the extraction method, with respect to how much logging residues (nutrients) being left in the forest. The results also show that the quality of fuel yielded by the two handling methods differs only to minor extent, indicating that other factors have stronger effects, where “dried-stacked” and “fresh-stacked” logging residues from different clear-felling areas is often similar. Generally, logging residues stored over summer (regardless method), seem to provide sufficiently dry forest fuel, with a needle content of about 5–10%. There is a clear correlation between drying and effective loss of needles from twigs, but the loss does not necessarily mean that the needles will remain in the forest. However, needle color (green or brown) is not a strong indicator for a reduction in needle content.Acceptance of the fresh-stacked method would provide opportunities for the development of new technologies, more efficient use of machinery throughout the whole year, reduced costs, shorter lead times and increased amounts of logging residues extracted from each clear-felled area. This is mainly because it would enable extraction at optimal times from a logistical, financial and/or forestry perspectives.Written in English with summary and conclusion in Swedish.
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| 31. |
- Nilsson, Bengt, 1982-
(author)
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Frivilliga räddningsresurser : livsviktigt entreprenörskap på landsbygden
- 2020
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Other publication (pop. science, debate, etc.)abstract
- Vi lever i en tid där trygghet står högt på agendan, men vilka frågor som upplevs viktiga skiljer stort mellan stad och land. Tanken är att genom forskning synliggöra rådande förut-sättningar och samtidigt utveckla och sprida kunskap om hur organisationen kring frivillig-resurser kan utvecklas för att vara räddningstjänst och ambulans behjälplig vid stora och små krissituationer på landsbygden.
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| 32. |
- Nilsson, Bengt, 1982-, et al.
(author)
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Hanteringens inverkan på skogsbränslets barrandel och fukthalt : – en jämförande studie mellan grönrisskotning och traditionell brunrisskotning av grot
- 2011
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Reports (other academic/artistic)abstract
- I föreliggande studie har vi analyserat hur grotens barrandel påverkas av grönrisskotning jämfört med traditionell brunrisskotning. En hypotes har varit att den traditionella brunrisskotningen inte medför så stort barravfall som man tidigare trott. Om grönrisskotning skulle accepteras skulle det öppna möjligheter för nya tekniker, minskade kostnader, kortare ledtider samt ett större totalt uttag från den enskilda avverkningstrakten. Observera att även grönrisskotning ger ett torkat bränsle och inte skall förväxlas med färsk grot. Bestämning av fraktionsfördelning och fukthalt har genomförts i det material som levereras till den energiomvandlande industrin i anslutning till flisning av groten. Resultaten visar att grönrisskotning medför en kraftig avbarrning och innehåller betydligt mindre andel barr än färsk grot. Resultatet visar även att traditionellt brunrisskotad grot innehåller en hel del barr. I praktiken innebär det att grönrisskotad grot innehåller dubbelt så mycket barr (ca 8 % av grotens total torrmassa) som den traditionellt brunrisskotade (ca 4 % av grotens total torrmassa) vid leverans till den energiomvandlande industrin. Både grönrisskotning och brunrisskotning ger en tillfredsställande torkning och resultatet visar att det endast skiljer 5 procentenheter i medelfukthalt mellan grönrisskotad (36 %) för och brunrisskotad (31 %) grot. Det har även kunnat konstaterats att groten behöver ligga större delen av sommaren i små processorhögar för att uppnå den rekommenderade avbarrningen. All grot som skotas ihop tidigare än augusti månad är därmed att betrakta som mer eller mindre grönrisskotad. Slutsatsen blir att en stor del av den grot som idag levereras till den energiomvandlande industrin snarare är grönrisskotad än brunrisskotad och innehåller ca 5–10 % barr.
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| 33. |
- Nilsson, Bengt, 1982-, et al.
(author)
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Potential of forest fuel in the county of Småland : the woodshed of Sweden
- 2012
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In: World Bioenergy 2012, 29-31 May, Jönköping, Sweden.
-
Conference paper (other academic/artistic)abstract
- The county of Småland in southern Sweden is often labeled the woodshed of Sweden. The largest potential to increase has forest fuel from final fellings, in the form of logging residuals (branches and tops) and stumps. This study shows that logging residuals, stumps and by-products from sawmills have the potential to contribute with 5.9 TWh per year, equivalent to 88% of the total use of wood fuel in Småland today. The results also show distribution of forest fuel on municipality level.
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| 34. |
- Nilsson, Bengt, 1982-, et al.
(author)
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Regional Amount of Forest Fuel in Sweden
- 2008
-
Reports (other academic/artistic)abstract
- Föreliggande rapport är ett delprojekt i Work Package 5 i CHRISGAS (Clean Hydrogen-RIch Synthesis GAS). CHRISGAS är finansierat av Europeiska Unionen och SvenskaEnergimyndigheten. Projektet syftar till att demonstrera framställning av väterik syntetiskgas för tillverkning av fordonsbränsle. Framställningen skall ske genom förgasning avbiomassa i en pilotanläggning, VVBGC (Växjö Värnamo Biomass Gasification Centre) i Värnamo. Syftet med denna studien är att visa hur mycket biomassa lämpat förenergiomvandling det svenska skogsbruket kan bidra med på regional nivå i form avhyggesrester, stubbar och biprodukter från sågverken. Den regionala indelningen är delsgjord på länsnivå i Sverige, samt en fördjupning beträffande upptagningsområdet förförgasningsanläggningen VVBGC (100 km radie från Värnamo).Enligt Energimyndigheten (2007) var Sveriges totala energitillförsel 640 TWh under2005, av detta utgjorde biobränslen, inklusive torv och avfall 109 TWh. Kommissionenmot oljeberoende (2006) har även sammanställt olika aktörers bedömningar om hur storökningspotentialen är för produktion av råvara för bioenergi. De har sedan gjort enbedömning att till år 2020 skall Sverige använda 154 TWh bioenergi och år 2050 skallanvändningen av bioenergi uppgå till 228 TWh, varav skogsbränsle utgör en betydande del.Behovet av förnyelsebar energi ökar i hela världen då utsläppen av växthusgaser skaminska och de fossila energikällorna inte räcker för all framtid. Sveriges skogar får i och med det ökande gröna energibehovet en allt mer betydande roll i framtidensenergiförsörjning. Effektiviteten i uttaget måste bli bättre för att på bästa sätt förvalta denråvara som finns och på det sättet få ut mer energi till en låg kostnad. Enligt Skogsstatiskårsbok (2007) utgör ägoslaget skogsmark ca 23 miljoner hektar, eller 55 % av Sverigestotala landareal. I skogsvårdslagens §1 fastslås: ”Skogen är en nationell tillgång som skallskötas så att den uthålligt ger en god avkastning samtidigt som den biologiskamångfalden behålls. Vid skötseln skall hänsyn tas även till andra allmänna intressen”.Denna lag lägger grunden för hur den svenska skogen får utnyttjas och hur det svenskaskogsbruket skall skötas. Det som blir allra mest påtagligt för skogsbränsleuttag är delensom säger att skogen skall skötas så att den uthålligt ger en god avkastning. Ett uttag avskogsbränsle får därför inte äventyra uthålligheten i skogsbruket i form avnäringsförluster.För att beräkna potentialen av hur mycket grot respektive stubbved som finns per hektaranvänds de biomassafunktioner som Marklund (1988) har utvecklat för trädslagen tall,gran och björk. Den potential som beräknas är den biomassa som finns i det växandeträdet, därefter tillkommer hantering och lagringsförluster av biomassan. Hur mycketgrot som kan levereras till den energiomvandlande industrin påverkas av hur effektiva deolika hanteringsmetoderna är vid hopsamlandet och hanteringen av skogsbränslet iskogen till industrin. Beroende på vilken hanteringsmetod som används försvinnermellan 30-50 % torrmassa av den potentiella mängd som finns på hygget vidavverkningen (Nilsson 2007). Förutom avverkningsresterna finns det även mycket skogsbränsle att hämta från sågverkens biprodukter. Enligt Sågverksinventeringen (2002)producerar sågverken årligen drygt 16 miljoner m3 sågad vara, den sågade varan utgörknappt hälften den totala volym virke som tillförs produktionen. Sågverket säljer dock enstor del av detta till andra industrier, främst till massaindustrin. Den biomassa som blirtillgänglig för övriga aktörer på energimarknaden är därmed endast ca 12 % av den ingående biomassan.När biomassan som kan bli tillgängligt för energiomvandling från grot, stubbar samtsågverkens biprodukter summeras blir den totala biomassan ca 6,7 miljoner tontorrmassa per år i hela Sverige. Detta motsvarar ca 32 TWh per år, fördelat på 18,3 TWhgrot, 6,5 TWh stubbar samt 7,6 TWh biprodukter från industrin. För att bedömaökningspotentialen av tillgängligt skogsbränsle måste den totala potentialen sättas irelation till hur mycket skogsbränsle av olika sortiment som används redan idag. EnligtBioenergiutredning (2004) förbrukas årligen 8,4 TWh avverkningsrester (grot) i Sverige.Det betyder att ökningspotentialen är ca 10 TWh från grot, om barren tillåts ingå iuttaget. Om man istället vill ha ett avbarrat grot minskar den tillgängliga biomassan ochökningspotentialen från grot halveras och blir endast ca 5 TWh. En sådan minskning avdet totala utbudet är inte att förringa, men det är inte heller troligt att alla grotuttag alltidkommer att innefatta barren. Ett rimligt antagande torde vara att hälften av allt grotuttagkommer att kunna innehålla barr vilket totalt skulle ge ca 16 TWh grot. Den verkligaökningspotentialen för grot skulle därför vara drygt 7 TWh. Vad gäller stubbar ärbrytningen idag marginell. Det gör att all framtida stubbrytning i princip utgör enökningspotential motsvarande drygt 6 TWh sett till hela Sverige. Den störstabegränsande faktorn i ökningspotential från stubbrytning utgörs av hur stora arealer somverkligen kan bli aktuella. Beträffande sågverkens biprodukter används i princip allt redanidag. Det som inte blir cellulosaflis eller går till skivtillverkning, eldas upp för internt brukeller säljs vidare till värmeverk eller pelletstillverkare. Det betyder att om nya aktörer påmarknaden vill använda sågverkens biprodukter måste man konkurrera med redan befintliga aktörer.Den regionala indelningen i föreliggande rapport visar tydligt vilka delar av Sverige somhar mest tillgång på skogsbränsle, vilket torde vara intressant om man vill anlägga nyaförgasningsanläggningar. De områden med mest tillgängligt skogsbränsle utgörs avJönköpings, Kalmar och Kronobergs län. Ett annat område som skulle kunna varaintressant är Svealand där det finns ett tydligt område med mycket skogsbränsle iförhållande till totalarealen (se figur 10).De allra flesta värmeverk vill ofta ha ett avbarrat skogsbränsle, vilket begränsar det totalautbudet samtidigt som det uppstår dyra ”förädlingskostnader” då barren skall lämnas iskogen. CHRISGAS borde som pionjär inom förgasningstekniken se över möjlighetenatt även förgasa grot med barr. Inte bara för att tillgången på skogsbränsle skulle öka,utan även för att hålla kostnaderna nere. Genom någon form av buntning skullekostnaden kunna sänkas med 25–30 % (Nilsson 2007).
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| 35. |
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| 36. |
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| 37. |
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| 38. |
- Svensson, Anders, 1977-, et al.
(author)
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Response times in rural areas for emergency medical services, fire and rescue services and voluntary first responders during out-of-hospital cardiac arrests
- 2024
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In: Resuscitation Plus. - : Elsevier. - 2666-5204. ; 17
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Journal article (peer-reviewed)abstract
- Aim: To increase survival in out-of-hospital cardiac arrests (OHCA), great efforts are made to improve the number of voluntary first responders (VFR). However, evidence of the potential utility of such efforts is sparse, especially in rural areas. Therefore, the aim was to describe and compare response times for emergency medical services (EMS), fire and rescue services (FRS), and VFR during OHCA in relation to population density. Methods: This observational and comparative study was based on data including positions and time stamps for VFR and response times for EMS and FRS in a region in southern Sweden. Results: In total, 285 OHCAs between 1 July 2020 and 31 December 2021 were analysed. VFR had the shortest median response time in comparison to EMS and FRS in all studied population densities. The overall median (Q1–Q3) time gain for VFR was 03:07 (01:39–05:41) minutes. A small proportion (19.2%) of alerted VFR accepted the assignments. This is most problematic in rural and sub-rural areas, where there were low numbers of alerted VFR. Also, FRS had shorter response time than EMS in all studied population densities except in urban areas. Conclusion: The differences found in median response times between rural and urban areas are worrisome from an equality perspective. More focus should be placed on recruiting VFR, especially in rural areas since VFR can potentially contribute to saving more lives. Also, since FRS has a shorter response time than EMS in rural, sub-rural, and sub-urban areas, FRS should be dispatched more frequently.
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| 39. |
- Uhlén, Mathias, et al.
(author)
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A pathology atlas of the human cancer transcriptome
- 2017
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In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 357:6352, s. 660-
-
Journal article (peer-reviewed)abstract
- Cancer is one of the leading causes of death, and there is great interest in understanding the underlying molecular mechanisms involved in the pathogenesis and progression of individual tumors. We used systems-level approaches to analyze the genome-wide transcriptome of the protein-coding genes of 17 major cancer types with respect to clinical outcome. A general pattern emerged: Shorter patient survival was associated with up-regulation of genes involved in cell growth and with down-regulation of genes involved in cellular differentiation. Using genome-scale metabolic models, we show that cancer patients have widespread metabolic heterogeneity, highlighting the need for precise and personalized medicine for cancer treatment. All data are presented in an interactive open-access database (www.proteinatlas.org/pathology) to allow genome-wide exploration of the impact of individual proteins on clinical outcomes.
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