| 1. |
- Zhang, Renyun, et al.
(author)
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Soap-film coating : High-speed deposition of multilayer nanofilms
- 2013
-
In: Scientific Reports. - Nature Publishing Group : Springer Science and Business Media LLC. - 2045-2322. ; 3, s. Art. no. 1477-
-
Journal article (peer-reviewed)abstract
- The coating of thin films is applied in numerous fields and many methods are employed for the deposition of these films. Some coating techniques may deposit films at high speed; for example, ordinary printing paper is coated with micrometre-thick layers of clay at a speed of tens of meters per second. However, to coat nanometre thin films at high speed, vacuum techniques are typically required, which increases the complexity of the process. Here, we report a simple wet chemical method for the high-speed coating of films with thicknesses at the nanometre level. This soap-film coating technique is based on forcing a substrate through a soap film that contains nanomaterials. Molecules and nanomaterials can be deposited at a thickness ranging from less than a monolayer to several layers at speeds up to meters per second. We believe that the soap-film coating method is potentially important for industrial-scale nanotechnology.
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| 2. |
- Andersson, Jan, et al.
(author)
-
Kartläggning av ägarskiften i företag : Utveckling och dokumentation av dataunderlag
- 2014
-
Reports (other academic/artistic)abstract
- Myndigheten för tillväxtpolitiska utvärderingar och analyser, Tillväxtanalys, har haft i uppdrag av regeringen att genomföra kartläggning och analys av ägarskiften i företag. Uppdraget omfattade även att göra jämförelser mellan generationsskiften och andra typer av ägarskiften som inte är åldersbaserade samt belysa möjligheten att följa upp företagens skifte och dynamik över tid. Tillväxtanalys lämnade i oktober 2013 en delrapportering av uppdraget som avser dels en kartläggning av åldersstrukturen i företagsstocken, dels en fördjupad analys av ägarskiften. Denna rapport är en redovisning av uppdragets sista del som innebär utveckling och dokumentation av dataunderlag för identifiering av ägarförändringar.SCB har på uppdrag av Tillväxtanalys undersökt möjligheten att bättre identifiera ägarskiften genom att integrera och göra en matchningskontroll av kompletterande uppgifter gällande delägare i fåmansaktiebolag som kan hämtas från Skatteverket, SKV, med redan befintlig information om företagsdynamik, vilken finns i Företagens och arbetsställenas dynamik, FAD, och den registerbaserade arbetsmarknadsstatisken, RAMS, på SCB. För att göra detta studeras företagens ägarskiften mellan åren 2010 och 2011. Uppdraget omfattar även att beskriva FAD gällande syfte, metodik och innehåll.Cirka 80 procent av samtliga företag oberoende av bolagsform överlevde mellan åren 2010 och 2011. Resterande företag har på något sätt förändrats. Företag läggs ned och andra startar som en del i strukturomvandlingen. Dessutom ser vi att många företag och arbetsställen byter ägare. Näringslivet visar på en stor dynamik och dynamiken omfattar många olika typer av förändringar.Bearbetningarna visar att det med hjälp av RAMS och SKV:s register går att följa och framställa uppgifter om ägarförändringar på ett bra sätt. Detta gäller både för fåmansaktiebolag, där det går att följa individuellt ägande, och för övriga juridiska former där förändringar i organisationsnummer kan spåras, vilket indikerar ändrade ägarförhållanden. Analysen visar att SKV:s register är ett bra komplement till RAMS och FAD och tillför ytterligare information. Samkörningen av dessa registerdata ger mer information än vad som kan fås ut av respektive registerkällor separat. Det går dessutom att koppla på annan information om anställda, omsättning och olika mått på lönsamhet från andra register.Tillväxtanalys rekommenderar därför att SCB får tillgång till register gällande ägarandelar från Skatteverket under en längre tidsperiod än enbart de undersökta åren. Detta för att kunna sammanställa en databas som möjliggör bättre och mer precisa analyser av olika dimensioner av näringslivsdynamik och ägarförändringar. Det vore dessutom önskvärt att denna databas görs tillgänglig för forskning och studier som ökar kunskapen om olika dimensioner av näringslivets strukturomvandling.
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| 3. |
- Andersson, Mattias, 1973-, et al.
(author)
-
Bättre avfallshantering i Sundsvall : Mittuniversitetets slutrapport från förstudien
- 2018
-
Reports (other academic/artistic)abstract
- Förstudien syftar till att tillsammans med MittSverige Vatten & Avfall (MSVA) ta fram verktyg för att informera om vinsterna med källsortering och påverka för att nå en bättre, mer hållbar avfallshantering i Sundsvall. En hållbar avfallshantering bidrar till att ge förutsättningar för en hållbartillväxt och god livsmiljö i Sundsvall. I förstudien presenteras exempel och förslag på hur visualiseringar kan bidra till att förbättra avfallshanteringen i Sundsvalls kommun. Inom ramen för studien har också en Återbruksfestival genomförts i syfte att undersöka och uppmärksamma vad som slängs samt ge konkreta exempel på återvinning och återbruk. Vidare genomfördes ett seminarium baserat på underliggande arbete kring hur papper och kartong kan användas som material för att ersätta hushållsförpackningar i plast. Förstudien utgör också en del i arbetet mot visionen att initiera forskning i samverkan med de aktörer i regionen som kan se nytta av design och visualisering i sin egen verksamhet. Förstudien har också bidragit till att ge underlag för framtida inriktningar, förutsättningar, och forskningsfrågor inom visualisering och design.
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| 4. |
- Andersson, Mattias, 1985, et al.
(author)
-
Dielectric strength of γ-radiation cross-linked, high vinyl-content polyethylene
- 2015
-
In: European Polymer Journal. - : Elsevier BV. - 0014-3057. ; 64, s. 101-107
-
Journal article (peer-reviewed)abstract
- We explore γ-radiation cross-linking of high vinyl-content low-density polyethylene (LDPE) and its potential use as a high-voltage insulation material. Of the three investigated resins containing 1, 0.5 and 0.17 vinyl groups per 1000 carbons, respectively, only the highest vinyl-content material featured a sufficiently high gel content of more than 70% and hot-set elongation below 175%, when cross-linked with a γ-radiation dose of at least 68 kGy. Differential scanning calorimetry (DSC) and small-angle X-ray scattering (SAXS) reveal that neither the crystallinity nor the lamellar thickness of the highest vinyl-content LDPE are negatively affected by γ-radiation cross-linking. As a result, we find that the dielectric strength, as characterized by electrical tree initiation experiments, can be maintained upon γ-radiation cross-linking.
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| 5. |
- Boström, Lena, 1960-, et al.
(author)
-
Digital visualisering i skolan : Mittuniversitetets slutrapport från förstudien
- 2018
-
Reports (other academic/artistic)abstract
- Den här studiens syfte har varit tvåfaldigt, nämligen att testa alternativa lärmetoder via ett digitalt läromedel i matematik i en kvasiexperimentell studie samt att tillämpa metoder av användarupplevelser för interaktiva visualiseringar, och därigenom öka kunskapen kring hur upplevd kvalitet beror på använd teknik. Pilotstudien sätter också fokus på flera angelägna områden inom skolutveckling både regionalt och nationellt samt viktiga aspekter när det gäller kopplingen teknik, pedagogik och utvärderingsmetoder inom “den tekniska delen”. Det förra handlar om sjunkande matematikresultat i skolan, praktiknära skolforskning, stärkt digital kompetens, visualisering och lärande samt forskning om visualisering och utvärdering. Den senare svarar på frågor om vilka tekniska lösningar som tidigare använts och med vilket syfte har de skapats samt hur visualiseringar har utvärderats enligt läroböcker och i forskningslitteratur. När det gäller elevernas resultat, en av de stora forskningsfrågorna i studien, så fann vi inga signifikanta skillnader mellan traditionell undervisning och undervisning med visualiseringsläromedlet (3D). Beträffande elevers attityder till matematikmomentet kan konstateras att i kontrollgruppen för årskurs 6 förbättrades attityden signifikans, men inte i klass 8. Gällande flickors och pojkars resultat och attityder kan vi konstatera att flickorna i båda klasserna hade bättre förkunskaper än pojkarna samt att i årskurs 6 var flickorna mer positiva till matematikmomentet än pojkarna i kontrollgruppen. Därutöver kan vi inte skönja några signifikanta skillnader. Andra viktiga rön i studien var att provkonstruktionen inte var optimal samt att tiden för provgenomförande har stor betydelse när på dagen det genomfördes. Andra resultat resultaten i den kvalitativa analysen pekar på positiva attityder och beteenden från eleverna vid arbetet med det visuella läromedlet. Elevernas samarbete och kommunikation förbättrades under lektionerna. Vidare pekade lärarna på att med 3D-läromedlet gavs större möjligheter till att stimulera flera sinnen under lärprocessen. En tydlig slutsats är att 3D-läromedlet är ett viktigt komplement i undervisningen, men kan inte användas helt självt. Vi kan varken sälla oss till de forskare som anser att 3D-visualisering är överlägset som läromedel för elevers resultat eller till de forskare som varnar för dess effekter för elevers kognitiva överbelastning. Våra resultat ligger mer i linje med de slutsatser Skolforskningsinstitutet (2017) drar, nämligen att undervisning med digitala läromedel i matematik kan ha positiva effekter, men en lika effektiv undervisning kan möjligen designas på andra sätt. Däremot pekar resultaten i vår studie på ett flertal störningsmoment som kan ha påverkat möjliga resultat och behovet av god teknologin och välutvecklade programvaror. I studien har vi analyserat resultaten med hjälp av två övergripande ramverk för integrering av teknikstöd i lärande, SAMR och TPACK. Det förra ramverket bidrog med en taxonomi vid diskussionen av hur väl teknikens möjligheter tagits tillvara av läromedel och i läraktiviteter, det senare för en diskussion om de didaktiska frågeställningarna med fokus på teknikens roll. Båda aspekterna är högaktuella med tanke på den ökande digitaliseringen i skolan. Utifrån tidigare forskning och denna pilotstudie förstår vi att det är viktigt att designa forskningsmetoderna noggrant. En randomisering av grupper vore önskvärt. Prestandamått kan också vara svåra att välja. Tester där personer får utvärdera användbarhet (usability) och användarupplevelse (user experience, UX) baserade på både kvalitativa och kvantitativa metoder blir viktiga för själva användandet av tekniken, men det måste till ytterligare utvärderingar för att koppla tekniken och visualiseringen till kvaliteten i lärandet och undervisningen. Flera metoder behövs således och det blir viktigt med samarbete mellan olika ämnen och discipliner.
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| 6. |
- Brugés, Javier Mauricio
(author)
-
Surface characterization methods for quality assessment of polyethylene-coated paperboard
- 2021
-
Licentiate thesis (other academic/artistic)abstract
- In manufacturing processes, the quality of a product often depends on its surface, and careful control of surface properties is critical to meet customer requirements. A thin layer of polyethylene (PE) is applied to paperboard to increase barrier functionality and high optical quality of the product. For PE-coated paperboard, product quality inspection is performed at the end of the manufacturing process by taking a portion of the reel to the laboratory for quality inspection. These associated offline characterization methods are destructive and time consuming and are representative of only a small portion of the product.The overall goal of this thesis is to provide new methods to characterize the Surface properties of PE-coated paperboard. Specifically, to determine imaging techniques for measuring surface parameters that affect its barrier functionality and surface roughness.In this thesis, two methods for surface characterization of PE-coated paperboard are presented to quantify the two most important product-related quality parameters, i.e. barrier functionality and optical quality, which are affected by the presence of defects in the coating and by the surface roughness of the product, respectively. First, a full-Stokes imaging polarimeter (FSIP) is used to detect the presence of PE-coated material and to distinguish between coated and uncoated samples at the pixel level. Second, a three-dimensional scanning electron microscope (3D SEM) is employed to calculate the Surface roughness of PE-coated paperboard. These surface characterization techniques offer an advantage over the industry standard due to the high speed and non-contact nature of the measurement, while increasing the throughput of the sample surface parameters studied.A classification accuracy of 99, 74% is achieved using a FSIP to distinguish between PE- and non-PE-coated paperboard at pixel level. Using the 3D SEM technique to measure the topography of PE-coated samples results in a faster method that is comparable in accuracy to a chromatic confocal microscope (CCM). The surface roughness measured with the 3D SEM differs from the standard method by up to 6% and good agreement with statistical parameters is found.In general, surface analysis of PE-coated is often a complex and difficult task for imaging techniques and suitable methods need to be evaluated for their sensitivity to measure the desired surface parameters. The presented characterization techniques inspect larger areas of PE-coated paperboard compared to current industry standards. These methods provide a quantitative solution for surface characterization to inspect the surface parameters necessary to assure the product’s quality.
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| 7. |
- Brugés Martelo, Javier Mauricio, et al.
(author)
-
Surface topography characterization of high-quality PE coated paperboard using confocal chromatic microscope and 3D SEM stereo-photogrammetry technique
- 2017
-
Conference paper (peer-reviewed)abstract
- Coating paperboard enhances printability and optical quality of the product as well as other important properties like packaging performance and shelf-life. To obtain high quality products a quality control of the manufacturing process requires identifying those manufacturing parameters that affect it. Roughness measurement and characterization of coating thickness are examples of these control parameters. Optical instruments measuring these quantities range from laboratory equipment to in-line and on-line sensors. However, the variety of instruments and sometimes misunderstanding of their limitations generate uncorrelated measurements, which are no longer valid to their comparison. The new ISO 25178 standard for surface texture provides guidelines to metrologists to address some this problem. Here, we report a case study for surface characterization of high quality printing polyethylene (PE) coated paperboard for high quality printing, where surface roughness is a key parameter. Two imaging methods to create topographic measurements will be compared, i.e. a confocal chromatic microscope and a scanning electron microscope (SEM). For the latter, stereo photogrammetry is used and 3D topographic profiles are obtained from Alicona MeX software. Leach and Haitjema [Leach, R., & Haitjema, H. (2010). Bandwidth characteristics and comparisons of surface texture measuring instruments. Measurement Science and Technology, 21(3), 032001] addressed the topic on how to design comparisons when using different instruments for areal texture measurement. We use their bandwidth matching concept, since it provides an extension to the ISO 25178 guidelines, ensuring that the instrumentation used to characterize the samples are within its measuring limits and further analysis of the results can be correlated. It is important to adopt a good metrology practice in order to translate these parameters into our future work. We expect to extend these findings into a real-time optical sensor, which later can be implemented in an industrial manufacturing environment for high optical quality paper and paperboard.
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| 8. |
- Jauhiainen, Alexandra, 1981, et al.
(author)
-
Distinct cytoplasmic and nuclear functions of the stress induced protein DDIT3/CHOP/GADD153
- 2012
-
In: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 7:4
-
Journal article (peer-reviewed)abstract
- DDIT3, also known as GADD153 or CHOP, encodes a basic leucine zipper transcription factor of the dimer forming C/EBP family. DDIT3 is known as a key regulator of cellular stress response, but its target genes and functions are not well characterized. Here, we applied a genome wide microarray based expression analysis to identify DDIT3 target genes and functions. By analyzing cells carrying tamoxifen inducible DDIT3 expression constructs we show distinct gene expression profiles for cells with cytoplasmic and nuclear localized DDIT3. Of 175 target genes identified only 3 were regulated by DDIT3 in both cellular localizations. More than two thirds of the genes were downregulated, supporting a role for DDIT3 as a dominant negative factor that could act by either cytoplasmic or nuclear sequestration of dimer forming transcription factor partners. Functional annotation of target genes showed cell migration, proliferation and apoptosis/survival as the most affected categories. Cytoplasmic DDIT3 affected more migration associated genes, while nuclear DDIT3 regulated more cell cycle controlling genes. Cell culture experiments confirmed that cytoplasmic DDIT3 inhibited migration, while nuclear DDIT3 caused a G1 cell cycle arrest. Promoters of target genes showed no common sequence motifs, reflecting that DDIT3 forms heterodimers with several alternative transcription factors that bind to different motifs. We conclude that expression of cytoplasmic DDIT3 regulated 94 genes. Nuclear translocation of DDIT3 regulated 81 additional genes linked to functions already affected by cytoplasmic DDIT3. Characterization of DDIT3 regulated functions helps understanding its role in stress response and involvement in cancer and degenerative disorders.
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| 9. |
- Johansson, Niklas, 1973-, et al.
(author)
-
Angular variations of reflectance and fluorescence from paper - the influence of fluorescent whitening agents and fillers
- 2012
-
In: Final Program and Proceedings - IS and T/SID Color Imaging Conference. - Springfield, USA : The Society for Imaging Science and Technology. - 9780892083039 ; , s. 236-241
-
Conference paper (peer-reviewed)abstract
- It has earlier been shown that light reflected from the bodyof paper exhibit anisotropic behavior. On the other hand, fluores-cence emission is often assumed to be distributed in a Lambertianmanner. The angular behavior of light reflected and fluorescedfrom paper is examined using measurements from a spectral go-niophotometer. The angular dependency of the radiance factorswas measured for a range of excitation wavelengths. Moreover,the influence of fillers and fluorescent whitening agents (FWA)on the anisotropy was studied. The measurements show that theanisotropy of the total radiance factor of paper decreases whenan increasing amount of FWA is added to the paper. The sameeffect was also observed when an increased amount of filler wasadded to the paper. In addition, it was shown that the presenceof fillers reduce the effect of the FWA. The results show that incomparison to the anisotropy of the total radiance factor from thepaper samples, the anisotropy of the fluorescence alone is negligi-ble. Hence, for paper samples containing FWA evenly distributedin the bulk, the fluorescence alone should not induce significantdifferences between color measuring instruments of different mea-surement geometries.
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| 10. |
- Johansson, Niklas, 1973-, et al.
(author)
-
Separation of surface and bulk reflectance by absorption of bulk scattered light
- 2013
-
In: Applied Optics. - : Optical Society of America. - 1559-128X .- 2155-3165. ; 52:19, s. 4749-4754
-
Journal article (peer-reviewed)abstract
- A method is proposed for separating light reflected from turbid media with a rough surface into a bulkand a surface component. Dye is added to the sample, thereby increasing absorption and canceling bulkscattering. The remaining reflected light is surface reflectance, which can be subtracted from the totalreflectance of an undyed sample to obtain the bulk component. The method is applied to paper wherethe addition of dye is accomplished by inkjet printing. The results show that the bulk scattered light isefficiently canceled, and that both the spectrally neutral surface reflectance and the surface topographyof the undyed paper is maintained. The proposed method is particularly suitable for characterization ofdielectric, highly randomized materials with significant bulk reflectance and rough surfaces, which aredifficult to analyze with existing methods. A reliable separation method opens up for new ways of analyzing,e.g., biological tissues and optical coatings, and is also a valuable tool in the development of morecomprehensive reflectance models.
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| 11. |
- Lantz, Mattias, 1971-, et al.
(author)
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Gamma spectroscopy methodology for large amounts of environmental samples in Sweden 30 years after the Chernobyl accident
- 2020
-
In: ND 2019. - : EDP Sciences. - 9782759891061
-
Conference paper (peer-reviewed)abstract
- In a Swedish citizen science project, more than 200 elementary school classes participated in collecting fungi, soil samples, and droppings from deer and wild boar, from all over Sweden. The samples have been sent to a laboratory at Uppsala University where they are being analyzed through gamma spectroscopy with a shielded HPGe detector. The main objective is to scan the samples for 137Cs from the Chernobyl accident and compare the data with measurements from 1986, but uptake of naturally occuring radionuclides like 40K and radon daughters will also be determined. Together with the soil samples, transfer factors will be derived, and correlations for these factors will be sought for different species of fungi and soil types. The potential for correlating the results with different biological processes will also be investigated, in part through the collected animal droppings. This is a work in progress where the present status of the experimental setup and methodology are presented. Issues with the initial approach for corrections are discussed and preliminary results are presented.
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| 12. |
- Sköld Gustafsson, Viktor, et al.
(author)
-
Multipla naturhändelser i Sverige
- 2021
-
Reports (other academic/artistic)abstract
- Denna rapport syftar till att (i) redogöra för begreppet ’multipla naturhändelser’ och kunskapsläget kring interaktioner mellan olika naturhändelser, samt att (ii) fastställa vilka naturhändelser som är mest relevanta med hänsyn till beredskap och förmåga innanför Sveriges territoriala gränser. Översiktligt diskuteras dessutom förutsättningar för och behov av hantering av multipla naturhändelser. Rapporten innehåller en sammanställning av hur naturhändelser interagerar med varandra i vetenskaplig litteratur, en sammanställning av förekomst av naturhändelser i Sverige utifrån sekundärdata från myndigheter och en workshop med experter för att identifiera multipla naturhändelser med relevans för svenska förhållanden. Rapporten presenterar resultat från en första delstudie inom forskningsprojektet Effektiv hantering av multipla naturhändelser (EMMUNE), som finansieras av Myndigheten för samhällsskydd och beredskap (MSB) och Formas. Naturhändelser kan vara multipla på olika sätt. En primär naturhändelse kan direkt utlösa en eller flera andra naturhändelser. De sekundära händelserna kan sedan i sin tur orsaka ytterligare händelser, vilket skapar en kaskad av händelser. En naturhändelse kan också öka sannolikheten eller förutsättningen för en eller flera andra naturhändelser, exempelvis genom höga flöden eller långvarig torka. Det kan också inträffa flera naturhändelser som sammanfaller i tid och rum utan att händelserna är direkt relaterade till varandra. I rapporten redogörs för interaktioner mellan följande naturhändelser: jordbävning; tsunami; geofysiska jordrörelser och hydrologiska skred, ras och sättningar; vulkanutbrott; blixtnedslag; extremt höga respektive låga temperaturer; isstormar; översvämningar; torka; laviner; skogs- och markbränder; skadedjursangrepp; meteoriter; och geomagnetisk storm. En bedömning görs också av vilka naturhändelser som kan anses vara mest relevanta för Sverige i relation till vårt klimat och väder. Bedömningen grundar sig i litteraturstudien och det genomgångna materialet kring förekomst och magnitud och leder fram till att följande naturhändelser anses relevanta: laviner; kraftig vind; kraftig nederbörd; extrema temperaturer; blixturladdningar; översvämningar; ras och sättningar; torka; samt skog- och markbränder. De påverkas alla antingen direkt eller indirekt av klimategenskaper eller väderhändelser. Kunskapen om klimatförändringarnas påverkan på förekomsten av extrema väderförhållanden är varierande och innefattar olika grader av osäkerheter beroende av vilken typ av extremt förhållande det handlar om. I Sverige innefattar eller drivs multipla naturhändelser oftast av atmosfäriska eller hydrologiska händelser. De multipla naturhändelser som av experterna anses vara mest frekventa samt får allvarliga konsekvenser inkluderar antingen höga flöden eller skogsbrand i kombination med annan händelse. När det gäller kunskapsläget kring multipla naturhändelser visar litteraturstudien att det finns vetenskapligt stöd för en mängd olika interaktioner mellan naturhändelser. Experterna som deltog i vår workshop beskriver också att vissa naturhändelser, som exempelvis kustöversvämningar, oftast uppstår vid ”multipla” väderfenomen och att det finns många potentiella multipla interaktioner både kopplade till ett utgångsläge med långvarig torka och värme eller höga flöden i vattendrag. Sammantaget talar detta för att naturhändelser behöver betraktas mer utifrån ett multipelt perspektiv. Naturhändelser sker inte bara isolerat utan kan påverkas av eller påverka andra naturhändelsers förlopp, antingen genom ett direkt utlösande eller genom förändring av miljön som ökar sannolikheten för andra naturhändelser. I såväl forskning om naturhändelser och klimatförändringar som i forskning om hantering av naturhändelser har händelserna hittills främst betraktats en och en. Det genomgångna materialet indikerar inte att Sverige kommer att drabbas av några nya företeelser på nationell nivå, däremot är det troligt att frekvensen och magnituden för vissa av naturhändelserna kommer att öka i ett förändrat klimat. Det kan även finnas anledning att inkludera biologiska naturhändelser, såsom det gjordes i exempelvis MSB:s sammanställning av riskområden och scenarioanalyser (MSB 2015). För att öka medvetenheten om multipla naturhändelser beskrivs tre scenarier för multipla naturhändelser, 1. en situation med höga flöden i vattendrag där det oväntat inträffar ett kraftigt regn, 2. en situation med en torr sommar där det inträffar en värmebölja, och 3. en relativ nederbördsfattning senvinter och varm april med låg markfuktigheten där det uppstår en skogsbrand. Ett lågtryck drar sedan in som ger mycket kraftiga vindar varvid skogsbranden intensifieras och sprids. Redan när det gäller förekomst och omfattning av enskilda atmosfäriska eller hydrologiska händelser är det stora osäkerheter i befintliga prognoser och klimatförändringsprojektioner, även om det sannolikt kommer bli både starkare och mer frekvent förekomst av väderfenomen framgent. Att prognostisera och simulera multipla naturhändelser innefattar därmed ännu större osäkerheter. Beredskapen att hantera multipla naturhändelser kan gynnas av ett fortsatt fokus på konsekvensbaserade vädervarningssystem. Exempelvis att vid en period med höga flöden i vattendrag kunna informera att om detta fortsätter ökar risken för sekundära händelser exempelvis skred. Multipla naturhändelsers hantering skulle kunna underlättas genom att tillhandahålla information baserad på förutsättningar för olika naturhändelser på specifika platser, detta för att bedöma risken för sekundära naturhändelser under givna förutsättningar samt de möjliga konsekvenserna av multipla naturhändelser för en specifik plats. Det är därför viktigt att för de tänkta målgrupperna öka förmågan att kunna tolka sådan information och vädervarningar samt att målgrupperna i förväg haft möjlighet kartlägga tänkbara konsekvenser för olika naturhändelser så att behovet av insatser snabbare kan bedömas när en händelse inträffar.
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| 13. |
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| 14. |
- Öhlund, Thomas, 1973-, et al.
(author)
-
Effect of Paper Properties on Electrical Conductivity and Pattern Definition for Silver Nanoparticle Inkjet Ink
- 2012
-
In: Proceedings of LOPE-C 2012. - 9783000381225 ; , s. 115-119
-
Conference paper (peer-reviewed)abstract
- In this work, electrical conductivity and print pattern definition isstudied for silver nanoparticle ink, printed on ten commerciallyavailable paper substrates. Interrelations and correlations betweenelectrical conductivity, print pattern definition and a set ofmeasured paper properties are analyzed with a multivariatestatistical method. The papers are characterized in terms ofabsorption rate, porosity, apparent surface energy, surfaceroughness and surface material content. The statistical analysisshows that electrical conductivity and print pattern definition arecorrelated. Conductivity and print definition are correlatedpositively with absorption rate and negatively with surfaceroughness. A model based on projection to latent structures (PLS) isbuilt from the measurement data, showing adequate values of modelfit and predictive ability. This suggests that the chosen propertiesand methods for surface characterization are relevant in estimatingoverall performance of inkjet-printed conductors on paper.Additionally, a qualitative examination of the nanoparticle layercharacteristic is conducted with SEM cross section microscopy.Some of the properties and mechanisms of importance to theconductivity of the printed conductors are highlighted, of whichsome are crucial for achieving conductivity. Physical characteristicsof a suitable paper surface should ideally include large absorptioncapability for the ink carrier, but most importantly, a characteristicpore size and surface roughness amplitude that are both smallcompared to the dry ink layer thickness. If these criteria are met,paper media can be a low cost, comparably high performancealternative for metal nanoparticle inks in printed electronics applications.
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| 15. |
- Adegoke, Olutayo, et al.
(author)
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Scanning electron microscopy and atom probe tomography characterization of laser powder bed fusion precipitation strengthening nickel-based superalloy
- 2023
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In: Micron. - 0968-4328 .- 1878-4291. ; 171
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Journal article (peer-reviewed)abstract
- Atom probe tomography (APT) was utilized to supplement scanning electron microscopy (SEM) characterizationof a precipitation strengthening nickel-based superalloy, Alloy 247LC, processed by laser powder bed fusion (LPBF). It was observed that the material in the as-built condition had a relatively high strength. Using both SEMand APT, it was concluded that the high strength was not attributed to the typical precipitation strengtheningeffect of γ’. In the absence of γ’ it could be reasonably inferred that the numerous black dots observed in thecells/grains with SEM were dislocations and as such should be contributing significantly to the strengthening.Thus, the current investigation demonstrated that relatively high strengthening can be attained in L-PBF even inthe absence of precipitated γ’. Even though γ’ was not precipitated, the APT analysis displayed a nanometer scalepartitioning of Cr that could be contributing to the strengthening. After heat-treatment, γ’ was precipitated and itdemonstrated the expected high strengthening behavior. Al, Ta and Ti partitioned to γ’. The strong partitioningof Ta in γ’ is indicative that the element, together with Al and Ti, was contributing to the strain-age crackingoccurring during heat-treatment. Cr, Mo and Co partitioned to the matrix γ phase. Hf, Ta, Ti and W were found inthe carbides corroborating previous reports that they are MC.
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| 16. |
- Andersson, Mattias, 1973-
(author)
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Colour Calibration of Trichromatic Capturing Devices
- 2006
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Doctoral thesis (other academic/artistic)abstract
- In a time where there is an increasing demand for easily accessible and up-to-date information, digital printing has become a link between traditional printed media and electronic media. Over the last years, applications such as variable data printing, personalised printing and print on demand have changed the way in which printed matter is produced and handled. The print quality of products produced by digital printing systems has improved considerably in recent years. The main reason for this improvement is better printer hardware but the printing paper is still a very influential factor. The two major technologies, inkjet and electrophotography and their respective applications put very different demands on the paper, mechanically, chemically and optically. Nevertheless, the differences in print quality across digital printing systems are decreasing, except for one area − colour reproduction. The growth of the market of consumer colour imaging products, such as digital printers and desktop printers, has been enormous during the last years. As a consequence of this, consumer expectations on colour reproduction have risen significantly, as even very small failures in colour reproduction can drastically reduce the visual impression of an otherwise impeccably reproduced image. Therefore, as consumer expectations continue to rise, a high and repeatable quality of colour image reproduction is a growing challenge for producers of digital printing devices as well as for paper producers. However, this is impossible to achieve without precise methods and routines to measure colour reproduction quality. The use of spectrophotometers for colour measurements of printed substrates is widely spread among paper producers as well as within the printing industry. Spectrophotometers are precise instruments for point-wise measurements. However, the measurement procedure is very time-consuming and therefore, faster methods for colour measurements are longed-for. If the spectrophotometers used today could be replaced with trichromatic capturing devices such as flatbed scanners or digital cameras, colour characterisation would be not only faster, but also less expensive. In addition, if the trichromatic devices are colorimetrically calibrated, spatial image information can be combined with colour information, making it possible to measure quality attributes related to colour image rendering that are impossible to capture with point-wise measurements. Today, flatbed scanners and digital cameras provide robust and high-quality image capturing capabilities at a relatively low cost. Furthermore, scanner and camera-based systems for automated objective measurements of print quality parameters have already become widely used tools for print quality measurements of print-related properties such as print mottle, sharpness and bleeding. However, the colour calibration of trichromatic capturing devices is not free from obstacles. In colour calibrations, where the aim is to measure colour of printed matter, knowledge about the properties of the capturing device, the printing substrate, the printing process and the printer function are all of great importance. In the work presented here, methods for colour characterisation of printing processes are proposed as well as methods for colour characterisation and calibration of trichromatic capturing devices. Furthermore, the media dependency problem inherent to colour calibrations of trichromatic capturing devices is discussed. Examples are given on how properties of the printed substrate, such as the content of fluorescent whitening agents, influence colour calibrations as well as colour measurements in general.
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| 17. |
- Andersson, Olov, 1979-
(author)
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Learning to Make Safe Real-Time Decisions Under Uncertainty for Autonomous Robots
- 2020
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Doctoral thesis (other academic/artistic)abstract
- Robots are increasingly expected to go beyond controlled environments in laboratories and factories, to act autonomously in real-world workplaces and public spaces. Autonomous robots navigating the real world have to contend with a great deal of uncertainty, which poses additional challenges. Uncertainty in the real world accrues from several sources. Some of it may originate from imperfect internal models of reality. Other uncertainty is inherent, a direct side effect of partial observability induced by sensor limitations and occlusions. Regardless of the source, the resulting decision problem is unfortunately computationally intractable under uncertainty. This poses a great challenge as the real world is also dynamic. It will not pause while the robot computes a solution. Autonomous robots navigating among people, for example in traffic, need to be able to make split-second decisions. Uncertainty is therefore often neglected in practice, with potentially catastrophic consequences when something unexpected happens. The aim of this thesis is to leverage recent advances in machine learning to compute safe real-time approximations to decision-making under uncertainty for real-world robots. We explore a range of methods, from probabilistic to deep learning, as well as different combinations with optimization-based methods from robotics, planning and control. Driven by applications in robot navigation, and grounded in experiments with real autonomous quadcopters, we address several parts of this problem. From reducing uncertainty by learning better models, to directly approximating the decision problem itself, all the while attempting to satisfy both the safety and real-time requirements of real-world autonomy.
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| 18. |
- Andersson, Olov, 1979-, et al.
(author)
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Real-Time Robotic Search using Structural Spatial Point Processes
- 2020
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In: 35TH UNCERTAINTY IN ARTIFICIAL INTELLIGENCE CONFERENCE (UAI 2019). - : Association For Uncertainty in Artificial Intelligence (AUAI). ; , s. 995-1005
-
Conference paper (peer-reviewed)abstract
- Aerial robots hold great potential for aiding Search and Rescue (SAR) efforts over large areas, such as during natural disasters. Traditional approaches typically search an area exhaustively, thereby ignoring that the density of victims varies based on predictable factors, such as the terrain, population density and the type of disaster. We present a probabilistic model to automate SAR planning, with explicit minimization of the expected time to discovery. The proposed model is a spatial point process with three interacting spatial fields for i) the point patterns of persons in the area, ii) the probability of detecting persons and iii) the probability of injury. This structure allows inclusion of informative priors from e.g. geographic or cell phone traffic data, while falling back to latent Gaussian processes when priors are missing or inaccurate. To solve this problem in real-time, we propose a combination of fast approximate inference using Integrated Nested Laplace Approximation (INLA), and a novel Monte Carlo tree search tailored to the problem. Experiments using data simulated from real world Geographic Information System (GIS) maps show that the framework outperforms competing approaches, finding many more injured in the crucial first hours.
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| 19. |
- Andersson Sundén, Erik, et al.
(author)
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Citizen Science and Radioactivity
- 2019
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In: Nuclear Physics News. - : Informa UK Limited. - 1050-6896 .- 1061-9127 .- 1931-7336. ; 29:2, s. 25-28
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Journal article (pop. science, debate, etc.)
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| 20. |
- Andersson, Torbjörn, et al.
(author)
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Juridikens termer
- 2015. - 10
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Book (other academic/artistic)abstract
- Juridikens termer är ett klassikt uppslagsverk som kortfattat förklarar centrala juridiska termer. Boken är sedan många år ett värdefullt hjälpmedel för verksamma jurister och studerande samt för alla andra som kommer i kontakt med frågor av juridisk natur.
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| 21. |
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| 22. |
- Brugés Martelo, Javier Mauricio, et al.
(author)
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Paperboard Coating Detection Based on Full-Stokes Imaging Polarimetry
- 2021
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In: Sensors. - : MDPI AG. - 1424-8220. ; 21:1
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Journal article (peer-reviewed)abstract
- The manufacturing of high-quality extruded low-density polyethylene (PE) paperboard intended for the food packaging industry relies on manual, intrusive, and destructive off-line inspection by the process operators to assess the overall quality and functionality of the product. Defects such as cracks, pinholes, and local thickness variations in the coating can occur at any location in the reel, affecting the sealable property of the product. To detect these defects locally, imaging systems must discriminate between the substrate and the coating. We propose an active full-Stokes imaging polarimetry for the classification of the PE-coated paperboard and its substrate (before applying the PE coating) from industrially manufactured samples. The optical system is based on vertically polarized illumination and a novel full-Stokes imaging polarimetry camera system. From the various parameters obtained by polarimetry measurements, we propose implementing feature selection based on the distance correlation statistical method and, subsequently, the implementation of a support vector machine algorithm that uses a nonlinear Gaussian kernel function. Our implementation achieves 99.74% classification accuracy. An imaging polarimetry system with high spatial resolution and pixel-wise metrological characteristics to provide polarization information, capable of material classification, can be used for in-process control of manufacturing coated paperboard.
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| 23. |
- Brugés Martelo, Javier Mauricio, et al.
(author)
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Three-dimensional scanning electron microscopy used as a profilometer for the surface characterization of polyethylene-coated paperboard
- 2021
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In: Nordic Pulp & Paper Research Journal. - : Walter de Gruyter. - 0283-2631 .- 2000-0669. ; 36:2, s. 276-283
-
Journal article (peer-reviewed)abstract
- In food packaging, low-density polyethylene (PE) coating is applied to paperboards to act as a functional barrier and to provide the smoothness required to enhance printability. These characteristics are related to the material’s surface roughness, the parameter monitored during the manufacturing process. Measurement of surface roughness using optical profilometry has gained importance in the paper industry. The optical instruments used to measure surface roughness are limited spatially by the relationship with the light wavelength at which they operate. A scanning electron microscope (SEM) is an alternative for overcoming the spatial resolution limitation, and the use of stereo-photogrammetry on SEM images can be seen as an alternative profilometry technique to measure surface roughness. In this investigation, the surface topography of industrially manufactured high-quality PE-coated paperboard was studied, comparing the SEM stereo-photogrammetry technique with a reference profilometry method, i. e., chromatic confocal microscopy (CCM). We found close agreement between the calculated surface roughness and the results of the techniques used and compared them according to the new ISO 25178 Geometric Product Specifications. We concluded that SEM stereo-photogrammetry provides comparable accurate alternative profilometry method for characterizing the surface roughness of PE-coated paperboard in the micrometer scale.
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| 24. |
- Brunnström, Kjell, 1960-, et al.
(author)
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Latency impact on Quality of Experience in a virtual reality simulator for remote control of machines
- 2020
-
In: Signal processing. Image communication. - : Elsevier. - 0923-5965 .- 1879-2677. ; 89
-
Journal article (peer-reviewed)abstract
- In this article, we have investigated a VR simulator of a forestry crane used for loading logs onto a truck. We have mainly studied the Quality of Experience (QoE) aspects that may be relevant for task completion, and whether there are any discomfort related symptoms experienced during the task execution. QoE experiments were designed to capture the general subjective experience of using the simulator, and to study task performance. The focus was to study the effects of latency on the subjective experience, with regards to delays in the crane control interface. Subjective studies were performed with controlled delays added to the display update and hand controller (joystick) signals. The added delays ranged from 0 to 30 ms for the display update, and from 0 to 800 ms for the hand controller. We found a strong effect on latency in the display update and a significant negative effect for 800 ms added delay on latency in the hand controller (in total approx. 880 ms latency including the system delay). The Simulator Sickness Questionnaire (SSQ) gave significantly higher scores after the experiment compared to before the experiment, but a majority of the participants reported experiencing only minor symptoms. Some test subjects ceased the test before finishing due to their symptoms, particularly due to the added latency in the display update.
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| 25. |
- Brunnström, Kjell, 1960-, et al.
(author)
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Quality of experience of hand controller latency in a virtual reality simulator
- 2019
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In: IS and T International Symposium on Electronic Imaging Science and Technology. - Springfield, VA, United States : Society for Imaging Science and Technology.
-
Conference paper (peer-reviewed)abstract
- In this study, we investigate a VR simulator of a forestry crane used for loading logs onto a truck, mainly looking at Quality of Experience (QoE) aspects that may be relevant for task completion, but also whether there are any discomfort related symptoms experienced during task execution. A QoE test has been designed to capture both the general subjective experience of using the simulator and to study task performance. Moreover, a specific focus has been to study the effects of latency on the subjective experience, with regards to delays in the crane control interface. A formal subjective study has been performed where we have added controlled delays to the hand controller (joystick) signals. The added delays ranged from 0 ms to 800 ms. We found no significant effects of delays on the task performance on any scales up to 200 ms. A significant negative effect was found for 800 ms added delay. The Symptoms reported in the Simulator Sickness Questionnaire (SSQ) was significantly higher for all the symptom groups, but a majority of the participants reported only slight symptoms. Two out of thirty test persons stopped the test before finishing due to their symptoms.
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