Microstructure of Carbon Fibres for Multifunctional Composites: 3D Distribution and Configuration of Atoms

Lightweight energy storage is a must for increased driving range of electric vehicles. “Mass-less” energy storage can be achieved by directly storing energy in structural components. In such multifunctional devices called structural composite batteries, carbon fibres carry mechanical load and simultaneously act as negative battery electrode by hosting lithium ions in its microstructure. Little is known of how the microstructure of carbon fibres is optimised for multifunctionality, and deeper understanding of the configuration and the distribution of atoms in carbon fibres is needed.Here synchrotron hard X-ray photoelectron spectroscopy and atom probe tomography are used to reveal the chemical states and three-dimensional distribution of atoms in commercial carbon fibres. This thesis presents the first ever guide for how to perform atom probe tomography on carbon fibres, and the first ever three-dimensional atomic reconstruction of a carbon fibre.The results show that the chemical states and distribution of nitrogen heteroatoms in carbon fibres affect the electrochemical performance of the fibres. Carbon fibres performed electrochemically better with higher amount of nitrogen with pyridinic and pyrrolic configurations. Additionally, the nitrogen concentration varies throughout the carbon fibre, which may suggest that the electrochemical properties also vary throughout the carbon fibre. The knowledge provided by this thesis can lead to future carbon fibre designs with enhanced electrochemical performance for multifunctional applications

Atoms in Lithiated Carbon Fibres

Carbon fibres are key constituents of structural batteries, in which electrochemical energy storage and mechanical load bearing are merged in one multifunctional device. Here carbon fibres simultaneously act as structural reinforcement by carrying load and as battery electrode by hosting lithium (Li)-ions in its microstructure. However, conventional carbon fibres are not designed to be multifunctional. To enable carbon fibres with optimised multifunctional capabilities, a fundamental understanding of their microstructure, chemical information and interaction with Li is required.In this thesis, mass spectrometry and electron spectroscopy techniques are developed and used to elucidate the atomic distribution, configuration, and interaction in commercial carbon fibres used in structural batteries. Here the methodology of analysing Li in carbon fibres with atom probe tomography (APT) and Auger electron spectroscopy (AES) is demonstrated. Synchrotron-based hard X-ray photoelectron spectroscopy (HAXPES) reveals that certain chemical states of N heteroatoms, pyridinic and pyrrolic, are connected to enhanced electrochemical performance of carbon fibres. AES shows that: Li distributes throughout the entire carbon fibre; the amount of trapped Li is higher and concentrated towards the centre of the fibre at increased discharge rates; Li is initially inserted in amorphous domains and with increased states of lithiation in crystalline domains; and Li plating can occur on individual fibres without spreading to adjacent fibres. APT on lithiated carbon fibres shows that: the distribution of Li is independent of the distribution of N heteroatoms; trapped Li is distributed uniformly in all domains; and Li agglomerates at elevated states of lithiation.The work presented in this thesis paves the way for analysis of carbon-based battery materials with APT and AES. Furthermore, the work unveils much of the interplay between carbon fibre and Li and deepens the understanding of the design parameters for tailoring multifunctional carbon fibres used in improved structural batteries

Best Practices for Analysis of Carbon Fibers by Atom Probe Tomography

Carbon fiber technology drives significant development in lightweight and multifunctional applications. However, the microstructure of carbon fibers is not completely understood. A big challenge is to obtain the distribution of heteroatoms, for instance nitrogen, with high spatial resolution in three dimensions. Atom probe tomography (APT) has the potential to meet this challenge, but APT of carbon fibers is still relatively unexplored. We performed APT on three types of carbon fibers, including one high modulus type and two intermediate modulus types. Here, we present the methods to interpret the complex mass spectra of carbon fibers, enhance the mass resolution, and increase the obtained analysis volume. Finally, the origin of multiple hit events and possible methods to mitigate multiple hit events are also discussed. This paper provides guidance for future APT studies on carbon fibers, and thus leads the way to a deeper understanding of the microstructure, and consequently advancements in wide applications of carbon fibers

Understanding the role of value-focused thinking in idea management

In a couple of classical studies, Keeney proposed two sets of variables labelled as value focused thinking (VFT) and alternative-focused thinking (AFT). Value-focused thinking (VFT), he argued, is a creative method that centres on the different decision objectives and how as many alternatives as possible may be generated from them. Alternative-focused thinking (AFT), on the other hand, is a method in which the decision maker takes notice of all the available alternatives and then makes a choice that seems to fit the problem best. The impact of these two methods on idea generation was measured using a sample of employees. The results revealed that employees in the value-focused thinking condition (VFT) produced fewer ideas. Thus, value-focused thinking (VFT) is not only able to facilitate ideation fluency but also to constrain it. Factors such as cognitive effort and motivation may play a part here. However, the quality of the ideas was judged to be higher in terms of creativity and innovativeness. Hence, value-focused thinking (VFT) seems to have a positive impact on the quality of ideas in terms of creativity and innovativeness regardless of ideation fluency. Implications for the design of idea management systems are discussed

The effects of risk on initial trust formation

This paper seeks to expand our understanding of initial trust by looking at how variation in risk influences the nature of trust and the process of initial trust formation. Four hypotheses were tested in two experiments involving participants with and without work experience. A first hypothesis suggested a positive relationship between a general propensity to trust and initial trust; a second hypothesis, a negative relationship between risk and initial trust; whereas a third hypothesis posited that risk would increase the importance participants place on benevolence and integrity. A fourth hypothesis suggested that risk would have a positive and moderating influence on the effect of out-of-role behavior when presented after role-conformant in-role behavior. Findings are presented and discussed and practical implications suggested

Employee evaluation of leader-initiated crisis preparation

Crisis prevention plans are usually evaluated based on their effects in terms of preventing or limiting organizational crisis. In this survey-based study, the focus was instead on how such plans influence employees’ reactions in terms of risk perception and well-being. Five different organizations were addressed in the study. Hypothesis 1 tested the assumption that leadership crisis preparation would lead to lower perceived risk among the employees. Hypothesis 2 tested the conjecture that it would also lead to a higher degree of well-being. Both hypotheses were supported. The results and their implications are discussed

Behandling med gonadotropinfrigjørende hormon (GnRH) på rognkjeks (Cyclopterus lumpus L.) En undersøkelse av behandlingens effekt på klekkesuksess

Bruk av rensefisk i oppdrett har økt enormt de siste årene, fordi de spiser lakselus, en parasitt som lever på skinnet til laksefisk. Interessen for rognkjeks er spesielt stor, da den har vist seg å være en effektiv lusespiser, selv med lave temperaturer i havet. All rognkjeks som brukes i kommersielle oppdrettsanlegg i dag er etterkommere av foreldre som fangstes vilt. Årsaken er at rognkjeksen bruker to til tre år på å bli kjønnsmoden, samtidig som ytre faktorer i akvakultur kan påvirke fiskens reproduksjon negativt. Systematisk avl kan være løsningen for å få rognkjeksen bedre tilpasset et liv i oppdrett, samt føre til økt lusespising og redusert dødelighet hos rognkjeks. Dette studiet tar for seg om gonadotropinfrigjørende hormonbehandling kan være en løsning for å styre sluttmodningen hos rognkjeks. Kontroll på kjønnsmodningen er en viktig forutsetning for å kunne drive effektivt avlsarbeid. Forsøket var gjennomført på forsknings- og innovasjonsstasjon på Kraknes (FISK) fra mars til juli 2021. En stamfiskgruppe på 48 rognkjeks ble brukt hvorav halvparten fikk implantert GnRH-analog og den andre halvparten fikk implantert sham-pellet (implantat uten virkestoff) og fungerte som kontrollgruppe i forsøket. Hunnfisken hadde en gjennomsnittsvekt på 2746 (± 110) g, hannfisken hadde en gjennomsnittsvekt på 982 (± 39) g. Fisken ble fulgt opp daglig frem til en kontrollert gyting, opptil 52 dager etter implantering. Det var ni GnRH-behandlede og seks sham-behandlede fisk som gytte under forsøket. Av rognen ble det tatt ut to 5 ml prøver som ble inkubert i 520 ml inkubatorer i duplikat, i minimum 310 d°. Selv om det ikke ble funnet signifikant forskjell i gytetidspunkt mellom gruppene, hadde GnRH-gruppen i gjennomsnitt 12 dager tidligere gyting og mindre variasjon i gytetidspunktet (GnRH 19,89 (± 1,88) dager) sammenlignet med sham-gruppen (31,50 (± 5,69) dager). Resultatene fra forsøket viser at GnRH-behandlet rognkjeks gytte mer rogn og ovarievæske 5,4 (± 0,02) dl, enn fisk som fikk sham-behandling 4,0 (± 0,05) dl. Det ble ikke funnet noen forskjeller mellom GnRH- og sham-behandling på rognkornstørrelse eller hannfiskens vekt, GSI og spermatokritt. På klekkesuksess til rognen ble det funnet signifikant flere larver i rogn gytt av rognkjeks behandlet med GnRH 87,6 (± 3,0) % sammenlignet med de som hadde fått sham-behandling 59,0 (± 9,5) %. Det ble også funnet signifikant lavere andel uklekket rogn fra rognkjeks behandlet med GnRH med 8,8 (± 2,1) % enn i rognen fra sham behandlet hunnfisk med 22,8 (± 6,7) %. Forsøket viste at GnRH-behandling ga en tidligere og mindre variasjon i gytetidspunkt og høyere andel fiskelarver enn kontrollgruppen

Trusting is for doing: on goals, mindsets, and trust

In this paper we seek to disentangle goals and trust, and argue that people’s goals while interacting with other people is likely to influence the experience of trust. This again builds on the assumptions that trust is not merely a basis for decisions but a factor that influences (often favorably) other valued outcomes. Our experience of trust helps us display trust which furthers relational goals (e.g. developing work-relationships). Thus, this paper adopts a pragmatic perspective on trust (Fiske, 1992; James, 1890): Paraphrasing Fiske (1992) and replacing thinking with trusting we argue that “trusting is for doing”. People’s experience of trust constitutes not only a basis for decisions but serves important ends in its own right, enabling people to interact with ease and confidence. People’s experience of trust not only influences peoples’ selection of goals but also influences peoples’ ability to attain those goals once selected. Trust enhances peoples’ ability to effectively influence other people in that people tend to trust people who trust (Williams, 2007, Weber, Malhotra & Murnighan, 2005). Trusting likewise reduces the load on peoples’ information processing capacity, and enables people to more effectively focus on task-interaction enhancing task performance (Schmeichel & Baumeister, 2004). The effects of goals on trust we suggest tend to be automatic, often unconscious and uncontrolled (Bargh & Williams, 2007)

Can intuitive and analytical decision styles explain managers' evaluation of information technology?

Purpose – The purpose of this paper is to clarify how IT managers' decision styles affect their evaluation of information technology. Design/methodology/approach – Four different decision styles were assessed in a leadership test directed towards IT managers. Each style included two dimensions: confidence judgment ability and decision heuristic usage. Participants belonging to each style were interviewed and their answers analysed with regard to their reasoning about central areas of IT management. Findings – Results suggest that a decision style combining intuitive and analytical capabilities lead to better evaluations of information technology. Originality/vale – The results of the present study are valuable for the understanding of how decision styles impact on IT management in everyday life

Mapping nitrogen heteroatoms in carbon fibres using atom probe tomography and photoelectron spectroscopy

Carbon fibres show great potential as multifunctional negative electrode for novel structural battery composites – a rechargeable electrochemical cell with structural function. The electrochemical performance of carbon materials can be enhanced with nitrogen heteroatoms, which conveniently are inherent in polyacrylonitrile (PAN)-based carbon fibres. However, it is not fully understood how the electrochemical performance is governed by microstructure and composition of the carbon fibres, particularly the distribution and chemical states of nitrogen heteroatoms. Here we reveal the atom-by-atom three-dimensional spatial distribution and the chemical states of nitrogen in three PAN-carbon fibre types (M60J, T800 and IMS65), using atom probe tomography (APT) and synchrotron hard X-ray photoelectron spectroscopy (HAXPES), and correlate the results to electrochemical performance. The findings pave the way for future tailoring of carbon fibre microstructure for multifunctional applications