Para uma era das plataformas : estratégias de abertura e controlo nas plataformas digitais

Digital platforms and the underlying platform business models have become increasingly important for business and innovation in the past years. The world9s most valuable companies (e.g., Apple, Meta, Google and Amazon) are primarily digital platforms facilitating interactions and transactions among various user groups. While comprehensive research exists on platform strategies and their impact, the balance between platform openness and control to leverage network effects remeins an underexplored. This study utilizes a qualitative research approach including 11 expert interviews to analyze the effects of platform openness and control. The research finds key strategies for platforms to manage the tension between openness and control. The key themes that emerged from the analysis relate to leveraging platform architecture through APIs, aligning openness with business models, implementing adaptive competitive strategies, enforcing quality assurance policies, optimizing network effects, pursuing innovative monetization approaches, and managing strategic risks. The study provides valuable insights into the strategic decisions that digital platforms must make to balance openness and control. Furthermore, it provides a strategic framework for managing openness in digital platforms, significantly contributing to the existing literature.Nos últimos anos, as plataformas digitais e os modelos de negócio subjacentes tornaram-se cada vez mais importantes para empresas e inovação. As empresas mais valiosas do mundo (Apple, Meta, Google, Amazon) são essencialmente plataformas digitais que facilitam interações e transações entre vários grupos de utilizadores. Embora exista investigação exaustiva sobre as estratégias das plataformas e o seu impacto, o equilíbrio entre a abertura e o controlo das plataformas para potenciar os efeitos de rede continua pouco explorado. Este estudo utiliza uma abordagem qualitativa com 11 entrevistas a peritos para analisar os efeitos da abertura e do controlo das plataformas. A investigação revela estratégias-chave para as plataformas gerirem a tensão entre abertura e controlo. Os principais temas que emergiram incluem o aproveitamento da arquitetura da plataforma através de API, o alinhamento da abertura com os modelos de negócio, a implementação de estratégias competitivas adaptáveis, a aplicação de políticas de garantia de qualidade, a otimização dos efeitos de rede, a procura de abordagens inovadoras de monetização e a gestão de riscos estratégicos. O estudo fornece informações valiosas sobre as decisões estratégicas que as plataformas digitais devem tomar para equilibrar a abertura e o controlo. Além disso, oferece um quadro estratégico para gerir a abertura nas plataformas digitais, contribuindo significativamente para a literatura existente

In-situ x-ray scattering study of the cubic to hexagonal transformation of AlN in Ti1-xAlxN

In the present work, we have studied the decomposition of arc evaporated Ti0.55Al0.45N and Ti0.36Al0.64N during heat treatment in vacuum by in-situ synchrotron wide angle x-ray scattering primarily to characterize the kinetics of the phase transformation of AlN from the cubic NaCl-structure to the hexagonal wurtzite-structure. In addition, in-situ small angle x-ray scattering measurements were conducted to explore details of the wavelength evolution of the spinodal decomposition, thus providing information about the critical size of the c-AlN rich domains prior to the onset of the h-AlN transformation. We report the fractional cubic to hexagonal transformation of AlN in Ti1-xAlxN as a function of time and extract activation energies between 320 and 350 kJ/mol dependent on alloy composition. The onset of the hexagonal transformation occurs at about 50 K lower temperature in Ti0.36Al0.64N compared to Ti0.55Al0.45N where the high Al content alloy also has a significantly higher transformation rate. A critical wavelength for the cubic domains of about 13 nm was observed for both alloys. Scanning transmission electron microscopy shows a c-TiN/h-AlN microstructure with a striking morphology resemblance to the c-TiN/c-AlN microstructure present prior to the hexagonal transformation.On the day of the defence date of the thesis the status of this article was Manuscript.</p

Exchange biased surface acoustic wave magnetic field sensors

Abstract Magnetoelastic composites which use surface acoustic waves show great potential as sensors of low frequency and very low amplitude magnetic fields. While these sensors already provide adequate frequency bandwidth for most applications, their detectability has found its limitation in the low frequency noise generated by the magnetoelastic film. Amongst other contributions, this noise is closely connected to domain wall activity evoked by the strain from the acoustic waves propagating through the film. A successful method to reduce the presence of domain walls is to couple the ferromagnetic material with an antiferromagnetic material across their interface and therefore induce an exchange bias. In this work we demonstrate the application of a top pinning exchange bias stack consisting of ferromagnetic layers of (Fe90Co10)78Si12B10 and Ni81Fe19 coupled to an antiferromagnetic Mn80Ir20 layer. Stray field closure and hence prevention of magnetic edge domain formation is achieved by an antiparallel biasing of two consecutive exchange bias stacks. The set antiparallel alignment of magnetization provides single domain states over the complete films. This results in a reduction of magnetic phase noise and therefore provides limits of detection as low as 28 pT/Hz1/2 at 10 Hz and 10 pT/Hz1/2 at 100 Hz