| 21. |
- Aspenberg, Magnus, et al.
(författare)
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On the asymptotics of the scenery flow
- 2015
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Ingår i: Discrete and Continuous Dynamical Systems. Series A. - : American Institute of Mathematical Sciences (AIMS). - 1553-5231. ; 35:7, s. 2797-2815
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Tidskriftsartikel (refereegranskat)abstract
- We study the asymptotics of the scenery flow. We give corrected versions with proofs of a certain lemma by Hochman, and study some related phenomena.
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| 22. |
- Bashir, Tariq, 1981-, et al.
(författare)
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Cellulosic Smart Textile Fibers based on Organic Electronics
- 2016
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Konferensbidrag (refereegranskat)abstract
- The paradigm shift of merging structural properties of materials with other functionalities prevails and cellulose based fibres are no exception. For the realisation of so called smart materials, including smart textiles, electrical conductivity is of special importance, enabling sensorics, signal transmission, energy supply, energy generation, and actuation. We here discuss taking use of the advancement within the organic electronics community of conjugated polymeric systems producing smart textile fibres for inclusion into garment as well as interior and technical textiles. Specifically, poly(3,4-ethylenedioxythiophene) known as PEDOT is studied as a model system. PEDOT has relevance being a working horse within the organic electronics community. Our emerging pilot line is based on creating conductivity by vapour polymerization of EDOT monomers on an oxidant coated textile fibre where these could be taken from arrange of materials. Here we focus on cellulose based fibres. It is shown that Tencell-Lyocell is a suitable substrate offering many anchoring sites and that multiple depositions with layers deposited directly on each other decreased the resistance from 5.1 (± 1.6) kΩ/10 cm to 1.0 (± 0.1) kΩ/10 cm, for one layer and multiple layers respectively. Furthermore, adding 15 wt. % of the copolymer PEG-PPG-PEG to the oxidant solution decreased the resistance from 6.8 (± 1.2) kΩ/10 cm to 3.9 (± 0.8) kΩ/10 cm.
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| 23. |
- Bolin, Sara, 1988-, et al.
(författare)
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Combined BET bromodomain and CDK2 inhibition in MYC-driven medulloblastoma
- 2018
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Ingår i: Oncogene. - : Nature Publishing Group. - 0950-9232 .- 1476-5594. ; 37:21, s. 2850-2862
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Tidskriftsartikel (refereegranskat)abstract
- Medulloblastoma (MB) is the most common malignant brain tumor in children. MYC genes are frequently amplified and correlate with poor prognosis in MB. BET bromodomains recognize acetylated lysine residues and often promote and maintain MYC transcription. Certain cyclin-dependent kinases (CDKs) are further known to support MYC stabilization in tumor cells. In this report, MB cells were suppressed by combined targeting of MYC expression and MYC stabilization using BET bromodomain inhibition and CDK2 inhibition, respectively. Such combination treatment worked synergistically and caused cell cycle arrest as well as massive apoptosis. Immediate transcriptional changes from this combined MYC blockade were found using RNA-Seq profiling and showed remarkable similarities to changes in MYC target gene expression when MYCN was turned off with doxycycline in our MYCN-inducible animal model for Group 3 MB. In addition, the combination treatment significantly prolonged survival as compared to single-agent therapy in orthotopically transplanted human Group 3 MB with MYC amplifications. Our data suggest that dual inhibition of CDK2 and BET bromodomains can be a novel treatment approach for suppressing MYC-driven cancer.
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| 24. |
- Boman, Christoffer, et al.
(författare)
-
Development of innovative small(micro)-scale biomass-based CHP technologies
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- To enhance the overall efficiency of the use of biomass in the energy sector in Europe, the large electricity production potential from small-scale biomass heating systems should be utilised. So far, no technologically sound (in terms of efficiency and reliability) and economically affordable micro- and small-scale biomass CHP technologies are, however, available. Therefore, the present ERA-NET project (MiniBioCHP) aimed at the further development and test of new CHP technologies based on small-scale biomass combustion in the electric capacity range between some W and 100 kW. Within the project, an international consortium consisting of 12 partners from 4 countries, including university institutions, institutes and industry (both engineering and manufacturing), collaborated closely to perform high level R&D on three promising micro/small-scale biomass based CHP technologies which are covering a broad range of applications in the residential heating sector. The Austrian engineering company BIOS, coordinated the international project. The project was based on earlier basic research and development work related to these promising new technologies and aimed at the achievement of a technological level which allows a first (commercial) demonstration after the end of the project. The three CHP concepts included in the MiniBioCHP project were;1. Pellet stoves with a thermoelectric generator (TEG)2. Small-scale biomass boilers (10-30 kWth) with a micro-ORC process3. High temperature heat exchanger (HT-HE) for an externally fired gas turbine (EFGT)The Swedish part of the project was focused on the development of the concept of biomass based EFGT with dedicated R&D activities related to the development of the HT-HE system. The Swedish project consisted of the research partners Umeå University (project leader), Luleå University of Technology, Chalmers University of Technology and RISE Research Institutes of Sweden, together with the industrial partners Enertech AB/Osby Parca and Ecergy. The expertise of the Swedish partners regarding ash related problems, grate boiler combustion and modelling, deposit formation and high temperature corrosion, were combined with the know-how of a Polish partner regarding HT-HE design, construction, testing and optimisation.The HT-HE is the most crucial component in EFGT processes significantly influencing the investment costs, availabilities as well as the efficiencies that can be achieved. With a thermal capacity from several hundred kW up to 2-3 MWth) the CHP technology based on a biomass boiler and an EFGT is suitable for district heating systems, or process heat consumers. The electricity produced by the gas turbine (up to some 100 kWel) can be used to cover the own electricity consumption of a company and/or fed into the grid. Even though the concept of biomass based EFGT has been an interesting alternative for small-scale CHP production for some decades, and R&D activities have been undertaken, tackling both economic and technical aspects, only a few pilot-plants have been in operation and no initiative has so far reached the level of commercial implementation. Thus, the concept of EFGT fed with biomass is still considered to be in a rather early development stage and the main technical challenges are related to alkali deposit induced corrosion and thermal stress of the HT-HE material, turbine design/operation and system integration.Within the present project, a HT-HE prototype aimed for an EFGT system was therefore designed, constructed and successfully tested at flue gas temperatures up to 900°C. Thus, appropriate guidelines for a compact design of the HT-HE and recommendations have been worked out to minimize thermal stresses as well as ash related problems regarding ash deposit formation and high temperature corrosion in a biomass boiler system. Furthermore, different concepts for the overall biomass based EFGT system have been worked out and evaluated. The outcome of the project will hopefully be used in the further development work and form the basis for a first testing and demonstration plant within the coming years.
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| 25. |
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| 26. |
- Carlsson, Adrian, et al.
(författare)
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KAUDroid : A tool that will spy on applications and how they spy on their users
- 2018
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Our mobile phone is today our most precious and condential partof us. In many cases we do not only share phone number with it, butalso our most private information. This information is to some extensionnaively shared and gathered without our knowledge. As the number ofadvanced and sophisticated services increase the more sensitive informa-tion we seem to throw at them. To prevent privacy intrusions Googles'soperation system Android uses something called permissions. Permis-sions are a decision to allow an Android application access to a resourceon a specic device. Once a permission is granted there is no possibil-ity for a user to verify that the application does not take advantage ofthe given trust. With granted permissions applications can collect a vastamount of information without any connection to the service it provides.To highlight this problem we present the KAUDroid platform, a two part,Android application surveillance system. KAUDroid consists of an An-droid application that collect permission usage on phones and a centralserver responsible for data storage. Information is presented to the publicthrough a web user interface using graphs to visualize data in a under-standable manner. With this tool we hope to raise the general awareness ofhow third-party applications tend to abuse their trust and to help peoplerecapture their unconsciously lost privacy.
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| 27. |
- Cederberg, Christel, 1959, et al.
(författare)
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Beyond the borders – burdens of Swedish food consumption due to agrochemicals, greenhouse gases and land-use change
- 2019
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Ingår i: Journal of Cleaner Production. - : Elsevier BV. - 0959-6526. ; 214, s. 644-652
-
Tidskriftsartikel (refereegranskat)abstract
- The Authors Sweden's environmental policy aims to solve domestic environmental problems without increasing environmental and health impacts overseas. Realizing this aim requires an indicator system with a consumption-based (or “footprint”) perspective that captures both local and global impacts and their development over time. In this paper, we present a set of novel footprint indicators to measure environmental pressures from Swedish food consumption. The indicators are calculated by combining data and statistics on agrochemicals and deforestation emissions with EXIOBASE3, a global Multi-Regional Input Output (MRIO) database with a unique and high level of product detail across countries. We estimate the use of pesticides and antimicrobial veterinary medicines associated with current Swedish food consumption and compare those footprint indicators with the EU-28. Carbon emissions from deforestation are calculated with a land balance model and included in the overall carbon footprint of food. We find that Sweden, with its large reliance of food imports, exert a significant agro-chemical and climate footprint overseas, mainly in the EU and Latin America. We point to a need for better data and statistics on the use of pesticides, veterinary medicines and agrochemicals residuals (especially in developing countries) as well as improved spatial data on agricultural activity to further reduce uncertainty in the environmental footprint of Swedish food consumption.
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| 28. |
- da Silva, Joakim, et al.
(författare)
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Resolution characterization of a silicon-based, photon-counting computed tomography prototype capable of patient scanning
- 2019
-
Ingår i: Journal of Medical Imaging. - USA : SPIE - International Society for Optical Engineering. - 2329-4302 .- 2329-4310. ; 6:4
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Tidskriftsartikel (refereegranskat)abstract
- Photon-counting detectors are expected to bring a range of improvements to patient imaging with x-ray computed tomography (CT). One is higher spatial resolution. We demonstrate the resolution obtained using a commercial CT scanner where the original energy-integrating detector has been replaced by a single-slice, silicon-based, photon-counting detector. This prototype constitutes the first full-field-of-view silicon-based CT scanner capable of patient scanning. First, the pixel response function and focal spot profile are measured and, combining the two, the system modulation transfer function is calculated. Second, the prototype is used to scan a resolution phantom and a skull phantom. The resolution images are compared to images from a state-of-the-art CT scanner. The comparison shows that for the prototype 19 lp∕cm are detectable with the same clarity as 14 lp∕cm on the reference scanner at equal dose and reconstruction grid, with more line pairs visible with increasing dose and decreasing image pixel size. The high spatial resolution remains evident in the anatomy of the skull phantom and is comparable to that of other photon-counting CT prototypes present in the literature. We conclude that the deep silicon-based detector used in our study could provide improved spatial resolution in patient imaging without increasing the x-ray dose.
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| 29. |
- Denny, Michael, et al.
(författare)
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Impact of closely-coupled triple-pilot and conventional double-pilot injection strategies in a LD diesel engine
- 2019
-
Ingår i: Fuel. - : Elsevier BV. - 0016-2361. ; 246, s. 141-148
-
Tidskriftsartikel (refereegranskat)abstract
- Three injection strategies are compared in a light-duty (LD) diesel engine at a medium load point. One strategy, representative of a Euro 6 LD injection strategy, has a double-pilot/main/single-post sequence. There is a modest temporal spacing after the first pilot and second pilot. Additional strategies add a third pilot and greatly reduce the spacing after the pilots. These pilots are referred to as being “closely-coupled” to each other and the main injection. For the double-pilot strategy, there is significant undulation of the cylinder pressure around TDC. In contrast, the closely-coupled triple-pilot strategies show notably smaller undulations in their pressure traces. Despite increases in peak pressure rise rate, combustion noise is reduced in both triple-pilot strategies. An analysis of each strategy’s heat release rate (HRR) trace shows that the close spacing of the pilot injections drastically reduces the drop in HRR between each subsequent local peak in combustion from each injection. A new metric is developed in order toquantify these drops, called the Ratio of Reduced Heat Release (RRHR). It is found that in order to reduce combustion noise, the RRHR should be minimized. Further analysis into the combustion noise shows that the occurrence frequency of the local HRR peaks matches strong frequencies responsible for combustion noise, and furthermore that the reduction in combustion noise is not due to the geometry of the combustion chamber. The modification of the HRR trace by implementing closely-coupled triple-pilot injection strategies allows combustion to be phased earlier, improving efficiency while also reducing combustion noise.
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| 30. |
- Ekström, Fredrik, et al.
(författare)
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Hausdorff dimension of random limsup sets
- 2018
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Ingår i: Journal of the London Mathematical Society. - : Wiley. - 0024-6107. ; 98:3, s. 661-686
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Tidskriftsartikel (refereegranskat)abstract
- We prove bounds for the almost sure value of the Hausdorff dimension of the limsup set of a sequence of balls in Rd whose centres are independent, identically distributed random variables. The formulas obtained involve the rate of decrease of the radii of the balls and multifractal properties of the measure according to which the balls are distributed, and generalise formulas that are known to hold for particular classes of measures.
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