Collective Strong Coupling with Homogeneous Rabi Frequencies using a 3D Lumped Element Microwave Resonator

We design and implement 3D lumped element microwave cavities for the coherent and uniform coupling to electron spins hosted by nitrogen vacancy centers in diamond. Our design spatially focuses the magnetic field to a small mode volume. We achieve large homogeneous single spin coupling rates, with an enhancement of the single spin Rabi frequency of more than one order of magnitude compared to standard 3D cavities with a fundamental resonance at \SI{3}{GHz}. Finite element simulations confirm that the magnetic field component is homogeneous throughout the entire sample volume, with a RMS deviation of 1.54\%. With a sample containing $10^{17}$ nitrogen vacancy electron spins we achieve a collective coupling strength of \Omega=\SI{12}{MHz}, a cooperativity factor $C=27$ and clearly enter the strong coupling regime. This allows to interface a macroscopic spin ensemble with microwave circuits, and the homogeneous Rabi frequency paves the way to manipulate the full ensemble population in a coherent way.Comment: 3 figure

The marionette: embeddedness in a community of family-controlled firms

Purpose: Being embedded in family has proven to bring opportunities and facilitate resources for a firm. However, it has its dark side, where too much family involvement may hamper the entrepreneur’s ability to develop psychological ownership of the firm. By focusing on the role that family plays in entrepreneurship, this article aims to explore how embeddedness and agency interact during the entrepreneurial process. The research questions are: 1) how does family interact in the entrepreneurial process, and 2) how does embeddedness inform this process? Design/methodology/approach: The paper builds on a longitudinal case study of a small firm that is part of a local community of family-controlled firms. The narrative was created through in-depth interviews with the business owner covering a period of eight years from the opening to the closure of the firm. Departing from theories of family embeddedness, the family is viewed as part of the context. Findings: The findings show how agency operates in a community of family-controlled firms and how entrepreneurship is thus partly executed outside the firm’s legal boundaries. The metaphor of a marionette illustrates how family may tie up and restrain an entrepreneur. This hampers the entrepreneur in developing psychological ownership of the firm and thereby restrains the firm’s development. This shows a downside to having too much positive influence from embeddedness. Implications: The paper stresses the social role of family by emphasising the value that a family can bring to an entrepreneurial process and thereby to society at large. Practitioners need to reflect on the effects of embeddedness. By recognising the downsides of too much help from outsiders, they may instead strive for a balance. By introducing the theory of psychological ownership to the literature on embeddedness, this article opens the space for future developments of this cross-section. Originality/value: The article contributes to the entrepreneurship literature by unfolding the mechanisms of family embeddedness and illustrating how embeddedness informs the entrepreneurial process in different ways. Even though over-embeddedness has been investigated before, this has primarily focused on the negative control from outside the firm. This article employs the notion of psychological ownership to shed light on the previously hidden problem of too much positive influence from family

Exploring entrepreneurial processes in new markets : towards sustainable food systems

The aim of this thesis is to explore how entrepreneurial processes work in the creation and development of new markets. New markets are business environments in an early stage of formation and offer an opportunity to change patterns of consumption and production. This makes new markets an interesting subject in society’s quest towards more sustainable food systems. Therefore, we need to better understand the processes through which new markets are created and developed. This thesis studied the emergence of the Swedish meal-kit market, which was initiated to target sustainable values. The empirical material was gathered through a qualitative longitudinal study that was conducted between 2010 and 2018 and the main source of empirical material was interviews with the founders and managers of ten firms. The analysis was performed in a process that iterated between empirics and theory. The thesis contributes to an understanding of the micro-processes involved within and between founders, firms and markets, as new markets are created and developed. The processes are explained as embeddedness, identity work and branding, which all capture the interactions with context. It is argued that to better understand why and how entrepreneurship happens, we need to balance the myopic focus on economic values and also focus on other entrepreneurial outcomes than a firm’s success. Thus, the thesis call for more contextualized perspectives of entrepreneurship in order to understand sustainable change in new markets

ANALYSIS OF PHYSICOCHEMICAL PROPERTIES AND TERRESTRIAL DYNAMICS OF MECHANICALLY FORMED MICRO-NANO SCALED PARTICLES FROM AGRICULTURAL PLASTIC MULCHES

Release of microplastics (MPs) and nanoplastics (NPs) into agricultural fields is of great concern due to their reported ecotoxicity to organisms that provide beneficial service to the soil such as earthworms, and the potential ability of MPs and NPs to enter the food chain. Most fundamental studies of the fate and transport of plastic particulates in terrestrial environments employ idealized MP materials as models, such as monodisperse polystyrene spheres. In contrast, plastics that reside in agricultural soils consist of polydisperse fragments resulting from degraded films employed in agriculture. There exists a need for more representative materials in fundamental studies of the fate, transport, and ecotoxicity of MPs and NPs in soil ecosystems. The objective of this study was therefore to develop a procedure to produce MPs and NPs from agricultural plastics (a mulch film prepared biodegradable polymer polybutyrate adipate-co-terephthalate (PBAT) and low-density PE [LDPE]), and to characterize the resultant materials. Soaking of PBAT films under cryogenic conditions promoted embrittlement, similar to what occurs through environmental weathering. LDPE and cryogenically treated PBAT underwent mechanical milling followed by sieve fractionation into MP fractions of 840 μm, 250 μm, 106 μm, and 45 μm. The 106 μm fraction was subjected to wet grinding to produce NPs of average particle size 366.0 nm and 389.4 nm for PBAT and LDPE, respectively. A two-parameter Weibull model described the MPs\u27 particle size distributions, while NPs possessed bimodal distributions. Size reduction did not produce any changes in the chemical properties of the plastics, except for slight depolymerization and an increase of crystallinity resulting from cryogenic treatment. This study suggests that MPs form from cutting and high-impact mechanical degradation as would occur during the tillage into soil, and that NPs form from the MP fragments in regions of relative weakness that possess lower molecular weight polymers and crystallinity

Identities at work in developing a new market

PurposeThe purpose of this paper is to explore the roles of identities in entrepreneurial processes during the development of a new market. Two research questions are used: How do the founder's identity, corporate identity and market identity interact as a new market is developing, and what are the functions of identity in the entrepreneurial process?Design/methodology/approachThis qualitative research is grounded in a study of multiple cases, from which five Swedish start-ups have been selected. Interviews were conducted with the founders at several points in time and accompanied by observations of websites, media performance, policy documents and commercial material. Analysis was conducted in an iterative process between empirics and theory.FindingsThe findings show how identities develop in entrepreneurs, firms and the market and how the interactions between these three levels of identity affect the development of each. The authors recognize and discuss three functions of identity: a constructing function, in which identity is used to create a new firm and market; a guiding function, which navigates between identities by imposing identity work on founders, firms and markets; and a configuring function, which takes part in shaping contexts.Research limitations/implicationsThis paper opens a space for future research on identities to advance understandings of how new firms and markets are developed. Investigating identity shows the importance of context to entrepreneurial processes. This points towards a need for researching different contexts, but also to the potential limited value of this study.Practical implicationsThe paper offers guidance to founders and managers in understanding and navigating different identities. Founders and managers are provided with a set of critical questions, which aim to assist when managing identity-related concerns.Originality/valueThere is a vast amount of literature on the development of companies and markets, yet start-ups in new markets operate in different contexts and face different challenges that we know less about. This paper targets the latter and proposes identity as a useful lens for understanding the dynamics between entrepreneurs, start-ups and the new market

Suicide inhibition of alpha-oxamine synthases:structures of the covalent adducts of 8-amino-7-oxononanoate synthase with trifluoroalanine

The suicide inhibition of the α-oxamine synthases by the substrate analog, L-trifluoroalanine was investigated. The inhibition resulted in the formation of a complex with loss of all three fluorine atoms. Decarboxylation and loss of fluoride occurred immediately after aldimine formation. The inherent flexibility could allow the difluorinated intermediate complex to adopt a suitable conformation. Decarboxylation in the normal mechanism occurs after formation of the ketoacid intermediate.link_to_subscribed_fulltex