As more companies in the resource-intensive fashion industry start their transition journeys towards circular business models (CBMs), driven by social and regulatory pressures, understanding how companies navigate this transformative process is crucial. This thesis contributes to prevailing research by analysing the challenges faced by linear companies in the fashion industry when adopting more circular models through various initiatives, dividing them by the CBM they apply, and considering their corresponding solutions to these challenges. By interviewing nine companies and four industry experts, we investigated the CBMs: product life extension, circular supplies, resource recovery, and product-as-a-service. Our findings indicate some common challenges include uncertain market demands, high costs and complex logistics, which caused profitability concerns and impeded companies’ transitions. Meanwhile, some challenges were CBM or company-specific. Companies employing circular supplies and resource recovery models faced cost considerations related to material price and availability, while product life extension models struggled with material access and limitations within the organisation or network. Significant market challenges were observed for the product-as-a-service model. To cope with these challenges, companies maintained small-scale CBMs and/or gradually scaled them based on changing circumstances or built collaborative networks within the value chain. Strengthening internal human capital was another coping strategy.

Let G be a graph. For k ≥ d ≥ 1, a k/d -coloring of G is a coloring c of vertices of G with colors 0, 1, 2, . . ., k - 1, such that d ≤ | c(x) - c(y) | ≤ k - d, whenever xy is an edge of G. We say that the circular chromatic number of G, denoted χc(G), is equal to the smallest k/d where a k/d -coloring exists. In [6], Pan and Zhu have given a function μ(g) that gives an upper bound for the circular-chromatic number for every K4-minor-free graph Gg of odd girth at least g, g ≥ 3. In [7], they have shown that their upper bound in [6] can not be improved by constructing a sequence of graphs approaching μ(g) asymptotically. We prove that for every odd integer g = 2k + 1, there exists a graph Gg ∈ G/K4 of odd girth g such that χc(Gg) = μ(g) if and only if k is not divisible by 3. In other words, for any odd g, the question of attainability of μ(g) is answered for all g by our results. Furthermore, the proofs [6] and [7] are long and tedious. We give simpler proofs for both of their results.

Back in 1894 Lord Kelvin coined the term "chiral" in order to refer to molecules whose mirror images were not superimposable with themselves. Over the years, research has demonstrated the important role that chiral molecules play in life, chemistry, and biology as well as their importance in the development of new drugs and technologies. The efforts to understand chiral systems have been mainly driven by spectroscopic methods that leverage on the opposite responses that enantiomers have to linear or circularly polarized light of both handedness. More specifically, Electronic Circular Dichroism (ECD) which measures the differences in linear absorption of left and right circularly polarized light has been the method par excellence for the spectroscopic characterization of chiral compounds. Unfortunately, the fact that ECD is based on linear absorption severely limits the use of this method in the near to far UV region. This is mainly due to the interferences generated by the strong linear absorption of common organic solvents and buffers in this portion of the light spectrum. Nevertheless, the fact remains that many chiral biomolecules of interest related to deceases like Alzheimer and Parkinson, exhibit most of their linear absorption in the near to far UV region where ECD cannot be employed for their study. Therefore, it has become an urgent necessity to develop spectroscopic methods to study chiral molecules that can circumvent the limitations of ECD at shorter wavelengths. In order to overcome the existent limitations in linear chiral spectroscopy, the nonlinear equivalent of ECD arises as a promising alternative, i.e. Two-Photon Circular Dichroism (TPCD). Although, this phenomenon was theoretically predicted in 1975, it was not until 2008, with the introduction of the double-L scan, that a reliable and versatile method for the measurement of TPCD was introduced. The high sensitivity of this method is based on the use of "twin" pulses that allow accounting for fluctuations in the excitation source that prevented the experimental realization of the measurement. The first measurement of a full TPCD spectrum was performed on BINOL enantiomers and the results were supported and discussed with the help of theoretical calculations. After that seminal work, we embarked in expanding the understanding of the structure-property relationship of TPCD by performing, systematically, a series of theoretical-experimental studies in chiral biaryl derivatives and compounds with helical chirality. In Chapter 2 we present the theoretical-experimental study of the effect of the π-electron delocalization curvature on the TPCD of molecules with axial chirality. The targeted molecules for this part of our investigation were S-BINOL, S-VANOL, and S-VAPOL. Our findings revealed that an increase in the TPCD signal, within this series of compounds, was related to the curvature of the π–electron delocalization. The contributions of the different transition moments to the two-photon rotatory strength support our outcomes. Then, in Chapter 3 we introduce the development of the Fragment-Recombination Approach (FRA) for the calculation of the TPCD spectra of large molecules. This simple but powerful method is based on the additivity of the TPCD signal, and is subject to a strict conditional fragmentation approach. FRA-TPCD is demonstrated, theoretically, in two hypothetical molecular systems from the biaryl derivatives family. Afterward, in Chapter 4 we show the first experimental demonstration of FRA-TPCD through the conformational analysis of an axially-chiral Salen ligand in solution (AXF-155). The FRA-TPCD spectra calculated for the different isomers of AXF-155 allowed narrowing the number of possible isomers of this complex molecule in THF solution to only two. This represents a significant improvement from previously reported results using ECD. Subsequently, in Chapter 5 we present the study of the effect of intramolecular charge transfer (ICT) in S-BINAP, an axially dissymmetric diphosphine ligand with strong ICT. The evaluation of the performance of two different exchange-correlation functional (XCF) confirmed that in order to properly predict the theoretical TPCD spectrum of a molecule exhibiting strong ICT, it is required to use an XCF such as CAM-B3LYP. In addition, our findings revealed the importance of considering an adequate number of excited states in order to be able to fully reproduce the experimental TPCD spectrum, thus avoiding wrong assignments of theoretical transitions to experimental spectral features. Finally, and expanding on our previous study, in Chapter 6 we investigated the effect of the nature of ICT on two hexahelicene derivatives. Our investigation demonstrated that the TPCD signal of chiral molecules with strong ICT does not only depend on the strength of this effect but on its nature, i.e. extension of the π–electronic delocalization increasing beyond (EXO-ICT) or within (ENDO-ICT) the helicene core. In summary, with the results presented in this thesis we closed a first loop in the understanding of the structure-property relationship of TPCD. In the future, we expect to deepen in our knowledge of the structure-property relationship of this phenomenon by studying further helicene derivatives with donor-acceptor motif, and through the application of FRA-TPCD to the conformational analysis of amino acids in peptides. We foresee numerous applications of TPCD for the study of optically active molecules with implications in biology, medicine, and the drug and food industry, and applications in nanotechnology, asymmetric catalysis and photonics.

The induced circular dichroism (ICD) of several chiral nitrosamines and various chiral reagents has been investigated. The interaction is attributed to a 1:1 hydrogen bonded complex between the NO group of the nitrosamine and the hydroxyl groups of alcohols and polyols, or the amino group of amines. Only those chiral reagents possessing large differences in size of the groups about the hydrogen bonding site contributed to CD anomalies. The acyclic 2-octanols did not give observable Cotton effects, presumably due to the similarity in size of the methyl and methylene groups and rotational freedom of the acyclic system. The signs of the Cotton effects could be correlated with the absolute configuration of the sterically hindered alcohols and amines. Only the alpha, axial hydrogens of conformationally biased, heterocyclic nitrosamines were found to undergo selective hydrogen-deuterium exchange, suggesting that this feature is critical for nitrosamine carcinogenicity.

The Circular Economy is on the top of the corporate agenda and provokes the interest of the academic community, governments, and policymakers. The Circular Economy paradigm is seen as a better solution and more sustainable alternative to the current linear system. To realize the benefit of the CE, new thinking and new business models are required. So far, there is limited progress has been achieved regarding the implementation of the Circular Economy. Therefore, scholars strive to understand the phenomena, providing conceptualizations, new strategies, and new business models, lacking empirical testing. The purpose- this study is mainly conducted to test empirically a set of influencing factors that include drivers which stimulate SMEs to implement Circular Business Models and the barriers that prevent or complicate the implementation process. Methodology- in order to fulfill the research objective, qualitative research with a multiple-case study approach is employed, focusing on three Swedish SMEs that operate in three different sectors. Findings- the outcome empirically confirmed that organizational drivers related to leadership and organizational culture, resource availability including technology and knowledge, financial factors, product and process development, society, environment, and stakeholder pressure, geographical proximity, entrepreneurship, and bran strengthening are seen as driving and facilitating factors to implement Circular business model. While, the lack of supportive regulation and policies, consumer behaviors related to single-use culture, the nature of the product and material, and the presence of incompatibility and monopoly in the supply chain are observed as major barriers.

Yes / The role of closed loop supply chains (CLSC) for creating and recovering value is widely acknowledged in supply chain management and there are many examples, mainly in the business-to-business sector, of successful OEM remanufacturing. The integration of value creation and recovery activities into retail customer value propositions is, however, under researched and raises many challenges, especially in Fast Moving Consumer Goods (FMCG) retail where few real world examples have been published. The recent emergence of the term ‘circular economy’ has initiated further debate about closed loop value propositions and closed loop supply chain implications. This paper selects four circular economy-led closed loop product case examples from a major European FMCG company, and assesses, at a high level, how these cases created value, for whom value was created, and key challenges in their implementation. The findings highlight that each case is different. Closing loops and creating successful value propositions is complex and requires simultaneous reconfiguration of key building blocks to ensure customer acceptance and business viability. The paper proposes the term ‘circular supply chain’ for cases where circular economy principles are explicitly incorporated in CLSC for value creation.

Yes / Circular supply chain (CSC) emphasises surge in application of reuse, recycling, remanufacturing and thereby promotes transformation from linear to circular model of flow of products. Supply chains of manufacturing industries have become global over the years. Products manufactured in developing nations are being sent to developed nations for mass consumption. Developed nations have regulatory policies, technological knowhow and modern infrastructure to adopt CSC model. Their counterpart is trailing in these aspects. In literature, limited work has been performed on identifying challenges of implementing CSC in developing nations. Therefore, employing literature review and feedback received from experts, 16 important barriers were identified to CSC adoption in India. These barriers were analysed using integrated Interpretive Structural Modelling ? MICMAC approach. The findings will contribute in transforming supply chains thereby bringing economic prosperity, addressing global warming and generating employment opportunities. Finally, crucial policy measures and recommendations are proposed to assist managers and government bodies.

Detta arbete är en fortsättning på projektet Framtidens kvarter och har som mål att ta reda på hur ett cirkulärt gatuplan kan genomföras. För att ta reda på detta genomfördes en intervjustudie och en litteraturstudie. Intervjuerna var semistrukturerade och genomfördes med sex respondenter från både fastighetsägarsidan och den kommersiella sidan. Intervjuerna analyserades med en deduktiv metod och sorterades i olika teman. Litteraturstudien genomfördes i Google scholar och Scopus för att kunna söka både brett och detaljerat. Resultatet analyserades sedan efter dem teman som valts ut, dessa var cirkulär fastighetsutveckling, cirkulär affärsmodell samt cirkulär profilering. Cirkulär fastighetsutveckling anses av respondenterna innebära att bygga med återvunnet återbrukat material. Det ansågs av fastighetsägarna vara möjligt att hyra ut till cirkulära aktörer men att det kanske idag inte finns tillräckligt många aktörer för att det ska bära sig. Hållbarhetsgalleriorna å andra sidan hade inga problem med att attrahera cirkulära aktörer till sina verksamheter. I diskussionen talas det om att ekonomin är en stor faktor för fastighetsägarna när det kommer till uthyrning av lokalerna. Därför ställer de sig också frågande kring huruvida det finns tillräckligt många cirkulära aktörer idag för att bara hyra ut till denna grupp utan att riskera vakanser. Det diskuteras också kring vad cirkulär fastighetsutveckling innebär och att synen idag kan behöva breddas för att inkludera också verksamheternas miljöpåverkan. Något som inte är lika utforskat i den forskning som finns på området. / This work is a continuation of the project “Framtidens kvarter” and its goal is to find out how a circular street level can be done. To find this out an interview study and a literature study was performed. The interviews were semi structured and done with six respondents from both the real estate owner sector and the commercial sector. The interviews were analyzed with a deductive method and sorted into different themes. The literature study was performed in Google Scholar and in Scopus to be able to search both wide and detailed. The result was analyzed after the themes that had been chosen, these were circular real estate development, circular business models and circular profiling. Circular real estate development was seen by the respondents in a way where you build with recycled and reused materials. The real estate owners considered it a possibility to rent out to circular actors but that it today not might be enough actors for it to carry. The sustainability malls on the other hand didn’t have any problems with attracting circular actors to their businesses. In the discussion it´s talked about that the economy is a big factor for the real estate owners when it comes to the renting of the premises. Therefore, they wonder about whether there are enough circular actors today that it´s possible to rent out to this group without risking vacancies. It was also discussed about what circular real estate development is and that the view today might need to be widened to also include the environmental impact of the operations. Something that is not as explored in the research that exits in the area.

Global consumption levels currently extend far beyond what planet Earth in terms of natural resources can regenerate in a sustainable manor and will by 2050 reach levels corresponding to what it would require three Earths to sustain. This overexploitation and unsustainable management of the Earth’s resources in combination with the necessity of mitigating climate change and reaching net zero CO2 emissions by 2050 require action across all sectors, not least the manufacturing industry. This thesis covers how large manufacturing enterprises can implement and utilize strategic targets and Key Performance Indicators (KPIs) to align with the principles of a Circular Economy (CE), and as a result, improve sustainability and business performance. Based on a case study conducted at Siemens Energy (SE) involving a literature study, interview study, and focus groups, a carefully selected set of strategic circularity targets and KPIs are presented to measure, evaluate, and drive circularity performance within large manufacturing enterprises. Since the thesis’ ambition was to provide valuable insights beyond SE, strategic circularity targets and KPIs specifically directed at SE were further generalized to be universally relevant for academia and other large manufacturing enterprises. Enterprises within the given sector share several key characteristics such as extensive material resource flows and complex value chains, hence strategic targets and KPIs emphasize material efficiency through decreasing virgin material dependency, increasing recirculation rates, and transitioning towards circular business models. While suggested targets and KPIs are universally directed at large manufacturing enterprises, individual organizations are recommended to conduct internal investigations and analyzes to further tailor and adapt strategic targets and KPIs towards the specific enterprise. In addition to strategic targets and KPIs, the thesis also presents an overview of opportunities, benefits, risks, and potential impacts for large manufacturing enterprises aspiring to increase circular initiatives, highlighting key principles to manage risk and capitalize on opportunities. The findings conclude that the main opportunity enabled by CE is to leverage synergies which align environmental, economic, and strategic corporate incentives, with key benefits including aspects such as decarbonization and reduced environmental impact, increased revenues and cost savings, risk management, and new business opportunities. Risks associated with CE include rebound effects, organizational insufficiencies, lack of material quality and safety, as well as a low product performance, which further can lead to potential impacts mitigating the positive effects of CE, or at worst setbacks causing a net negative output from implemented circular measures. In summary, the opportunities and benefits associated with CE are many, but implemented circular measures require risk awareness and continuous management to ensure efficiency.

This thesis discusses colouring, circular list colouring and adapted game colouring of graphs. For colouring, this thesis obtains a sufficient condition for a planar graph to be 3-colourable. Suppose G is a planar graph. Let H_G be the graph with vertex set V (H_G) = {C : C is a cycle of G with |C| ∈ {4, 6, 7}} and edge set E(H_G) = {CiCj : Ci and Cj have edges in common}. We prove that if any 3-cycles and 5-cycles are not adjacent to i-cycles for 3 ≤ i ≤ 7, and H_G is a forest, then G is 3-colourable. For circular consecutive choosability, this thesis obtains a basic relation among chcc(G), X(G) and Xc(G) for any finite graph G. We show that for any finite graph G, X(G) − 1 ≤ chcc(G) < 2 Xc(G). We also determine the value of chcc(G) for complete graphs, trees, cycles, balanced complete bipartite graphs and some complete multi-partite graphs. Upper and lower bounds for chcc(G) are given for some other classes of graphs. For adapted game chromatic number, this thesis studies the adapted game chromatic number of various classes of graphs. We prove that the maximum adapted game chromatic number of trees is 3; the maximum adapted game chromatic number of outerplanar graphs is 5; the maximum adapted game chromatic number of partial k-trees is between k + 2 and 2k + 1; and the maximum adapted game chromatic number of planar graphs is between 6 and 11. We also give upper bounds for the Cartesian product of special classes of graphs, such as the Cartesian product of partial k-trees and outerplanar graphs, or planar graphs.