Publikationer från Linköpings universitet
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Electrical properties of ScN thin films controlled by defect engineering using oxygen ion implantation
No full textDefects tend to modify significantly the properties of semiconductors, such as transport properties, by increasing the scattering of electrons and phonons, or optical properties, by modifying the band structure and the Fermi level. The high interest of ScN thin films for thermoelectric applications results from the incorporation of oxygen, which is well known to be the source for their degenerate n-type state and their significant power factor. Indeed, oxygen acts as a donor defect when substituted to nitrogen. In this study, oxygen ion implantation was performed at a high damage level as a way to modify electrical properties through defect engineering. Hence, we measured the changes in electrical properties induced by oxygen implantation at room temperature. Two types of defects have been identified as being responsible for the change in resistivity, carrier concentration, mobility, and Seebeck coefficient. At first, the point-like defects, recombining from 440 K and onward, introduce localized states near the Fermi level, inducing a change in the conduction mode from a metallic-like to a hopping mechanism. The relationship between Mott's temperature and defect concentration has been clearly demonstrated through in situ resistivity measurements in the 80-750 K temperature range. Furthermore, these measurements highlight that oxygen induced defects result not only from ballistic effects, but also from chemical effects that are involved. Second, the complex-like defects introduce deep acceptor levels into the bandgap and act as scattering centers that modify the Debye temperature as well as the electron-phonon interactions. These complexes, likely between scandium vacancies and oxygen atoms (V-Sc-yO, y &lt;= 4), are primarily responsible for the increase of the Seebeck coefficient and the reduced mobility. The concentration of such defects can qualitatively be assessed as their formation introduces an additional term, independent of temperature, in the variation of resistivity, mobility, and also the Seebeck coefficient. The recovery of the complex-like defects takes place at a minimum temperature of 750 K. Results show that the effectiveness of oxygen in creating defects exceeds that of noble gases in terms of concentration, demonstrating the promise of this approach to control the electrical properties of ScN.Funding Agencies|French government program "Investissements d'Avenir" [ANR-18-EURE-0010, ANR-11-LABEX-0017-01, ANR-21-EXES-0013]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoeping University [200900971]; Knut and Alice Wallenberg Foundation through the Wallenberg Academy Fellows program [KAW-2020.0196]; Swedish Research Council (VR) [2021-03826]; Swedish Energy Agency [52740-1]</p
VariABLE to forecast : A review of definitions and context
No full textDespite a large body of research on the effects of IFRS adoption on analyst forecast accuracy, no study has explicitly examined the main variable definitions of analyst forecast accuracy. I conduct a systematic review of 43 articles pertaining to the effects of IFRS adoption on analysts’ forecasts to assess both definitions and cultural context of the studies. The study identifies four key categorizations of variable definitions, with one category standing out as a superior definition. I find that the definition is mostly used inthe context of the main IFRS adoption in the studied country, while factor-specific variables are increasingly used when the study purpose deviates from the generalized IFRS adoption. The importance of cultural context mostly derives from different enforcement regimes, with indications that factor-specific definitions lead to different and less confluent results throughout the literature. This review has implications for both future research and standard setters to assess the impact of future standard implementations.
Verification that electrons are isothermal and protons adiabatic for ion-acoustic waves in unmagnetized collisionless PIC simulation plasma
No full textIon acoustic waves in collisionless plasma have a phase speed determined by the adiabatic constants of electrons and protons. Typically, the isothermal equation of state is assumed for electrons, resulting in an adiabatic constant γe=1, while the adiabatic equation of state with one degree of freedom is applied to protons, yielding γp=3. This selection has been experimentally validated in plasmas with hot electrons and cool ions. Here, we investigate whether this remains true in particle-in-cell (PIC) simulations, which generally exhibit noise levels significantly higher than those in real plasma. By comparing the power spectrum of simulation noise to the thermal noise spectrum and the dispersion relation of ion acoustic waves, we confirm that γe=1 and γp=3 are good approximations for the adiabatic constants that determine dispersive properties of ion acoustic waves in unmagnetized PIC simulation plasma with proton temperatures well below the electron temperature. Funding Agencies|Swedish Research Council; [2022-06725]; [2024]</p
Årsredovisning för Linköpings universitet avseende budgetåret 2024
No full textNär vi nu lägger ytterligare ett år till handlingarna och gör en tillbakablick kan vi med stolthet konstatera att år 2024 kanske har varit universitetets genom tiderna mest framgångsrika år. Ett spännande och händelserikt år där Linköpings universitet i många sammanhang har visat på styrka, nytänkande och attraktivitet i både utbildning och forskning. Att våra utbildningar är attraktiva och rustar studenter inför framtiden har högsta prioritet. För femte året i rad ökar studentantalet, 2024 hade vi fler än 45 700 studenter och forskarstuderande, vilket är rekord! Ett trendbrott är att det för första gången är fler som läser på distans än på något av våra campus. Det är i linje med vår strategi att stärka och utveckla utbildning inom det livslånga lärandet. Samtidigt är campusförlagda professionsprogram fortfarande ett starkt kännetecken för LiU. För första gången sedan 2015 når LiU takbeloppet, vilket innebär att vi uppfyller vårt utbildningsåtagande. Vårt deltagande i universitetsalliansen ECIU ökar. Under året har LiU stått värd för styrelsemöte, ledarskapsprogram och ett studentdrivet creathon. Genom att lärare och studenter engagerar sig i ECIU:s kurser och samarbeten är LiU med och påverkar utvecklingen av Europas framtida utbildningar. Våra forskare var under fjolåret återigen framgångsrika att erhålla externa forskningsmedel. Nästan 840 miljoner kronor landade på Linköpings universitet i beviljade forskningsansökningar, den högsta summan någonsin och är ytterligare ett bevis på den världsledande forskning som finns inom flera discipliner på LiU. Dessutom beviljades den svenska ansökan som LiU låg bakom för en av sju s.k. AI-fabriker i Europa för kommande fem år. Lägg därtill det nationella värdskap som finns sedan 2024 på LiU i och med starten av NAISS, den nya nationella organisationen för superdatorer och storskaliga beräkningar, och den kompletterande satsningen på EuroHPC, också den med LiU som värd, för en utökad europeisk beräkningsresurs för forskare inom akademi, industri och offentlig sektor i hela Europa. LiU har nått en ställning och fått en fantastisk möjlighet att bidra till framtidens forskning i hela Europa. Med superdatorerna på plats är det dags att ta nästa steg och utveckla samarbetet mellan lärosätena men också tillgodose att alla vetenskapliga områden ser de möjligheter som finns att bedriva forskning som inte tidigare har varit möjligt. Och att göra detta i en kultur där vi delar kunskap öppet med varandra över gränserna. Privata donationer fortsätter att vara ett betydelsefullt stöd till nydanande forskning och förblir så även i framtiden när statens resurser är begränsade. LiU var ett av det första i Sverige att förstå hur fundraising för både forskning och utbildning kan göra skillnad. Att det lönar sig att upprätthålla goda kontakter med våra alumner är föregående år ett bevis på. Flera nya donationer kom in till universitetet och LiU passerade en miljard kronor i privata donationer. Det är imponerande och hade inte varit möjligt utan det professionella arbete som LiU donation utför men är självklart också ett bevis på att våra forskare bedriver forskning som är angelägen för både människor och samhälle. Att LiU äntligen når takbeloppet innebär inte att vi kan slå oss till ro. Framtidens attraktiva utbildningar är viktigare än någonsin att finna när digitalisering och AI kommer med full kraft. Vårt Europasamarbete måste stärkas ytterligare särskilt i en värld där akademin och den fria forskningen nu också hotas i länder som USA. LiU är ständigt under förändring och så ska det vara men vi kanske har nått en punkt av viss växtvärk. Vi måste hitta smartare och mer flexibla lösningar, inte minst när det gäller hur vi ska nyttja våra lokaler mer effektivt i en tid av ökade hyreskostnader samtidigt som våra studenter av förståeliga orsaker önskar mer lokaler. Framtiden kräver med andra ord fortsatta satsningar och prioriteringar. Vårt visionsarbete för framtiden är inte på långa vägar färdigt utan ska vara en ständigt pågående process. Vår förflyttningsresa måste hållas levande och vara transparent. Allas insatser är viktiga för vår fortsatta framgång. I det ingår också att låta våra studenter vara en vital del av universitetets fortsatta utveckling. Med det sagt vill vi be att få tacka alla som gjort det gångna året så framgångsrikt och understryka hur imponerade och stolta vi är över alla förträffliga prestationer. Det bådar gott inför framtiden: 2025 har vi all anledning att fira när universitetet fyller 50 år. Jan-Ingvar Jönsson, rektor Karin Axelsson, prorektorProduktion: Linköpings universitet, Kommunikations- och marknadsavdelningen.Tryck: Februari 2025:1, LiU-Tryck, Linköping.Foto omslag: Magnus Johansson.Foto inlaga: Cissi Säfström, David Brohede, Emma Busk Winquist, Jenny Widén, Peter Modin, Thor Balkhed.Foto Året som gått: Anna Nilsen, David Brohede, Magnus Johansson, Per Wistbo Nibell, Region Östergötland, Sandra Hummelgren, Thor Balkhed.</p
Diagnostic and patient aspects of axillary surgery in persons with breast cancer
No full textBreast cancer (BC) is the most common cancer in women. In western society many women are living with BC, with symptoms after treatment and the risk of recurrence. When a woman develops cancer all her relationships are affected. Today the survival rate is very high with nine out of ten surviving for five years, meaning that there are many lives affected by the out-come of BC. The most important prognostic factor in BC is the status of the lymph nodes in the axilla. However, surgery in the axilla is associated with significant arm morbidity. Thus, there is an urgent need to deescalate the effect of axillary surgery. This thesis investigates how to perform oncologically safe surgery with as little harm as possible. The main aim was to identify factors for predicting non-sentinel node metastases and investigate different methods for sentinel node (SN) identification in the primary and recurring BC setting as well as to explore patients’ trajectory through BC treatment including axillary surgery. Furthermore, to reduce unnecessary suffering due to axillary surgery. The first study aimed at identifying the clinicopathological predictive factors that are responsible for non-SN metastases. Using data from a large cohort from the National Quality Register for Breast Cancer (NKBC), we identified factors associated with non-SN metastasis. The findings showed how to differentiate between those with a risk for non-SN metastasis and in need of further axillary surgery and those with only a limited spread to the SN. A logistic regression model revealed statistically significant factors such as proportion of SN with macro metastases detected at SN biopsy, tumour size, HER2 positivity, lymphovascular invasion and multifocality as strong factors for non-SN metastasis. These factors were incorporated in a nomogram for predicting the risk of non-SN metastasis to avoid unnecessary axillary lymph node dissection. In the second study the aim was to determine whether scintigraphy imaging can improve the detection rate for SN, SN metastases and non-SN metastases. The study explored which technique is best for identifying the SN, in order to better visualize it and thus facilitating the surgery procedure. The difference in SN outcome using the conventional radioisotope technique, Technetium-99m (Tc99), when adding scintigraphy to the gamma probe and blue dye was also compared. The findings showed a small difference of 2.3% in favour of adding scintigraphy images. However, it is unclear as to whether this will have any effect in the clinical setting. The third paper adopted a person-centred approach to understand how healthcare professionals can facilitate women subjected to BC treatment including axillary surgery. An interview study was conducted using a phenomenological hermeneutical method. The main finding was that the women were in a state of acceptance and adaptation to their situation. When healthcare professionals provided structure and consistency, the women’s treatment and lived experience made sense. Uncertainty occurred when the women became lost in their own sense-making process, leading to low self-efficacy. The fourth study was a feasibility study to identify better options for women with recurrence. An investigation of BC patients with recurrence and earlier axillary surgery was conducted to scrutinize if it is feasible to identify the SN with the magnetic tracer, superparamagnetic iron oxide, SPIO, com-pared to conventional methods with radioisotope (Tc99) and blue dye. The study was conducted at two hospitals, Sahlgrenska University Hospital and Linköping University Hospital. The findings showed that SPIO had a higher detection rate and a concordance rate of 92%. In conclusion, SPIO is a tracer with a smoother transition and easier handling eliminating the need for the radioisotope which has a short half-life and of which there is a limited global supply. To conclude, this thesis emphasises the importance of being able to fine tune the factors that point to individual risk factors for non-SN metastases and transit to the next SN tracer with the magnetic technique. A person-centred approach during treatment and follow-up is warranted to support self-management among women with BC
Effects of Alkyl Spacer Length in Carbazole-Based Self-Assembled Monolayer Materials on Molecular Conformation and Organic Solar Cell Performance
No full textCarbazole-based self-assembled monolayer (SAM) materials as hole transport layers (HTL) have led organic solar cells (OSCs) to state-of-the-art photovoltaic performance. Nonetheless, the impact of the alkyl spacer length of SAMs remains inadequately understood. To improve the knowledge, four dichloride-substituted carbazole-based SAMs (from 2Cl-2PACz to 2Cl-5PACz) with spacer lengths of 2-5 carbon atoms is developed. Single crystal analyses reveal that SAMs with shorter spacers exhibit stronger intermolecular interactions and denser packing. The molecular conformation of SAMs significantly impacts their molecular footprint and coverage on ITO. These factors result in the highest coverage of 2Cl-2PACz and the lowest coverage for 2Cl-3PACz on ITO. OSCs based on PM6:L8-BO with 2Cl-2PACz as HTL achieved high efficiencies of 18.95% and 18.62% with and without methanol rinsing of the ITO/SAMs anodes, corresponding to monolayer and multilayer structures, respectively. In contrast, OSCs utilizing the other SAMs showed decreased efficiencies as spacer length increased. The superior performance of 2Cl-2PACz can be attributed to its shorter spacer, which reduces series resistance, hole tunneling distance, and barrier. This work provides valuable insights into the design of SAMs for high-performance OSCs.Funding Agencies|Swedish Research Council [2019-04683, 2020-05223, 2021-04798]; Swedish Research Council Formas [2020-01201, 2023-01008]; Swedish Energy Agency [P2021-90067, 2022-06725]; Wallenberg Foundation [2022.0192]; National Natural Science Foundation of China [12404480]; Guangdong Basic and Applied Basic Research Foundation [2022A1515010875]; Shenzhen Key Laboratory of Applied Technologies of Super-Diamond and Functional Crystals [ZDSYS20230626091303007]; Sino-Danish Center (SDC) for Education and Research; Chalmers Area of Advance Nano; Swedish Foundation for Strategic Research, SSF through the Lise Meitner Grant [SIP21-0044]; Carl Trygger Foundation [CTS 15.332]</p
The complexities of smartification : Exploring horizontal tensions in smart city governance
No full textSmart cities build on visions for using technology to optimise various infrastructural functions and make city management more efficient, sustainable, and reliable. However, scholarship on smart cities has drawn attention to how data-centric planning simplifies the complexity of the urban environment and how a dichotomous approach to smart cities as either top-down or bottom-up may be overly reductive. This paper attempts to remedy this divide by highlighting the horizontal tensions in smart city planning, where tensions around implementing smart technologies appear as multiple actors and discourses converge in creating complex governance structures. We offer a case study of how scalar, temporal and social tensions around implementing smart city technologies are negotiated, based on interviews with employees in a Swedish municipality and several municipal corporations. We elaborate on three themes around time, the role of the municipality and infrastructure to gain a deeper understanding of the governance of and attitudes towards smartification. The interviewees described the complexities of implementing smart technology in reality, spanning various scales and intermingling public and private interests. These issues matter for how the municipality and the municipal corporations work with implementing smart technologies, making it anything but a straightforward process.智慧城市建立在利用技术优化各种基础设施功能，并使城市管理更加高效、更可持续、更可靠的愿景之上。关于智慧城市的学术研究已经引起了人们对以数据为中心的规划如何简化城市环境复杂性的关注，以及对智慧城市采取自上而下或自下而上的二分法可能会过于简化的关注。本文试图通过强调智慧城市规划中的横向冲突来填补这种鸿沟。在智慧城市规划中，随着多个参与者和话语在创建复杂的治理结构时汇集，就会围绕智能技术的实施出现冲突。基于对瑞典一个市政当局和几家市政公司雇员的采访，我们进行了案例研究，探讨人们如何协商围绕智慧城市技术的实施出现的标量冲突、时间冲突和社会冲突。我们对时间、市政当局的角色和基础设施这三个主题进行了详细阐述，以更深入地了解对城市智慧化的治理和各种态度。受访者描述了在现实中实施智能技术的复杂性，涵盖了各种规模，并融合了公共和私人利益。这些问题关系到市政当局和市政公司如何实施智能技术，这使得这一过程绝不简单。Sustainability means inclusivity: Engaging citizens in early stage smart city developmen
Grön omställning i svenska små och medelstora industriföretag : Åtta strategier för ett verkningsfullt stödsystem
No full textI detta Vinnovafinansierade forskningsprojekt, Interaktiv forskning för grön omställning, IFGO, har vi undersökt hur små och medelstora industriföretag (SMF) kan stöttas i sin gröna omställning för ökad resurseffektivitet, minskad klimatpåverkan och ökad konkurrenskraft. Forskningsprojektet genomfördes av Linköpings universitet under perioden september 2021 – december 2024. Projektet omfattar en förstudie och fyra efterföljande fördjupande delstudier som fokuserade olika aktörer som stöttar SMF (rapporteras i bilaga 1–5 i denna rapport). Samhällspolicyer på nationell och internationell nivå har ökat förväntningarna att näringslivet aktivt ska bidra till att lösa miljö- och hållbarhetsutmaningar. Många aktörer inklusive forskningsfinansiärer vill öka farten i denna gröna omställning. För att stötta SMF har ett stödsystem vuxit fram bestående av aktörer som på olika sätt hjälper företag och entreprenörer i deras omställningsarbete. Ett stödsystem kan definieras som ”alla aktörer, institutionella miljöer och resurser som hjälper entreprenörer att arbeta framgångsrikt med innovation och utveckling”. Några aktörer verkar på en övergripande nivå, andra främst regionalt eller lokalt. Rapporten fokuserar aktörer som är offentligt ägda eller delvis finansierade av offentliga medel. Granskning:Utkast av rapporten inklusive delrapporterna har granskats på publika seminarium vid tre tillfällen som den del av den forskningsmetodik författarna använt. Arbetssättet är beskrivet i rapporten. Finansiären Vinnova har granskat och kommenterat slutversionen.</p
Characterization of Inflammatory Bowel Disease Heterogeneity Using Serum Proteomics: A Multicenter Study
No full textBackground Recent genetic and transcriptomic data highlight the need for improved molecular characterization of inflammatory bowel disease (IBD). Proteomics may advance the delineation of IBD phenotypes since it accounts for post-transcriptional modifications. Aims We aimed to assess the IBD spectrum based on inflammatory serum proteins and identify discriminative patterns of underlying biological subtypes across multiple European cohorts. Methods Using proximity extension methodology, we measured 86 inflammation-related serum proteins in 1551 IBD patients and 312 healthy controls (HC). We screened for proteins exhibiting significantly different levels among IBD subtypes and between IBD and HC. Classification models for differentiating between Crohn's disease (CD) and ulcerative colitis (UC) were employed to explore the IBD spectrum based on estimated probability scores. Results Levels of multiple proteins, such as interleukin-17A, matrix metalloproteinase-10, and fibroblast growth factor-19, differed (fold-change &gt;1.2; false discovery rate &lt;0.05) between ileal versus colonic IBD. Using multivariable models, a protein signature reflecting the IBD spectrum was identified, positioning colonic CD between UC and ileal CD, which were at opposite ends of the spectrum. Based on area under the curve (AUC) estimates, classification models more accurately differentiated UC from ileal CD (median AUCs &gt; 0.73) than colonic CD (median AUCs &lt; 0.62). Models differentiating colonic CD from ileal CD demonstrated intermediate performance (median AUCs: 0.67-0.69). Conclusions Our findings in serum proteins support the presence of a continuous IBD spectrum rather than a clear separation of CD and UC. Within the spectrum, disease location may reflect a more similar disease than CD versus UC, as colonic CD resembled UC more closely than ileal CD.Funding Agencies|Swedish Research Council [2020-02021]; Swedish Foundation for Strategic Research [RB13-016]; OErebro University Hospital Research Foundation [OLL-986849, OLL-974710, OLL-962042]; Innovative Medicines Initiative 2 Joint Undertaking (JU) [831434 (3TR)]; European Union; EFPIA</p
Opinions on the use of welfare technologies by people with dementia -focus groups with people with dementia and their significant others
No full textDementia comprises global health issues, affecting families, healthcare systems, and broader society. Emerging technologies offer new tools for care and support that people living with dementia employ to manage their daily lives. We aim at exploring needs and ideas regarding digital technology and how it can be used to increase self-management and participation for people living with dementia. Ten participants took part in this study; five persons diagnosed with dementia and five spouses of people living with dementia. The data obtained in the individual interviews analyzed descriptively, by reviewing the protocols from the interviews. The data from the focus group session were analyzed for themes. All participants lived in ordinary housing but participated in group activities at a dementia center in Sweden. All participants used digital tools and owned and used smartphones and computers which indicates a baseline familiarity with digital tools. In results from the focus groups three themes emerged: (1) Digital tools as multifunctional resources, (2) Resources and barriers for using digital tools, and (3) Accounting for needs and wishes when planning for the future. The participants in both groups described the potential of digital tools to help mitigate future challenges regarding fears and concerns of future endeavors, e.g. as facilitators for staying in touch with family and friends and to be able to listen to familiar music. In conclusion, digital tools may prove vital in managing daily life and staying socially connected. However, digital reliance can also lead to challenges, especially as cognitive abilities decline.Funding Agencies|Forskningsradet for Halsa, Arbetsliv och Valfard [2022-01319]; Forskninsradet for Arbetsliv, Halsa och Valfard [2022-01319]</p