16 research outputs found
Phase-induced atomic permutations in icosahedral quasicrystals : a model for self-diffusion
The process of phase-induced self-diffusion has been investigated for the three-dimensional Ammann-Kramer-Penrose tiling. This happens along the lines of Kalugin and Katz (1993) for the octagonal planar tiling. It is found that for any permutation within two subsets of the ten vertices in a triacontahedral cage there is a corresponding loop in phase space. There are other loops by which vertices are exchanged between interlocked triacontahedral cages. Along chains of such triacontahedral cages, percolative diffusion is possible. This self-diffusion, however, occurs along two separated sublattices. Thus it is a two-component diffusion
Analytical Results for Multifractal Properties of Spectra of Quasiperiodic Hamiltonians near the Periodic Chain
The multifractal properties of the electronic spectrum of a general
quasiperiodic chain are studied in first order in the quasiperiodic potential
strength. Analytical expressions for the generalized dimensions are found and
are in good agreement with numerical simulations. These first order results do
not depend on the irrational incommensurability.Comment: 10 Pages in RevTeX, 2 Postscript figure
In-situ microscopy and 2D fluorescence spectroscopy as online methods for monitoring CHO cells during cultivation
Typical methods for monitoring cultivation processes are offline analyses like cell counting, measurement of various substrates and products (e. g. glucose or lactate) as well as the online monitoring of several physical process parameters (temperature, pH-value or the concentration of dissolved oxygen). To improve cell cultivations detailed information about important analytes should be available online. Therefore new monitoring methods need to be established, preferably as in-situ methods to minimize the risk of contamination. Two different in-situ online-methods were used to monitor cultivations: In-situ microscopy and 2D fluorescence spectroscopy. Therefore CHO-K1 cells (provided by University of Bielefeld) were cultivated in a complex culture medium (TC 42, TeutoCell, Bielefeld, Germany) using a 2.5 L stainless steel reactor with a work volume of 2 L. A total of three cultivation runs were conducted
Between crises and decarbonisation : realigning EU climate and energy policy for the new ‘state of the world'
The Russian invasion of Ukraine in February 2022 compounded an already difficult policy landscape characterised by rising energy prices, international supply chains’ disruptions, growing greenhouse gas emissions and exacerbating geopolitical tensions. This combination of crises ushers in a new ‘state of the world’, where energy security is a much more pressing concern, and calls for an intervention in the short term to address the social and economic consequences of the surge in the cost of energy. In this context, support must be targeted and mute efficient price signals in energy markets to the minimum possible extent. In the medium and longer term, the transition towards a low-carbon economy must be accelerated, duly considering the significant efforts needed for a major reorganisation of the energy supply to European citizens and firms. The scale of the acceleration required questions the ability of the EU and its Member States to make it happen. Ensuring the feasibility of the investments in new infrastructures, the procurement of sufficient raw materials and manufactured components, and the deployment of a skilled and abundant workforce is fundamental. The acceleration of the transition questions the adequacy of the existing European electricity market design as well, which must be carefully assessed and possibly amended in order to be future-proof. It questions, finally, the existing European governance for energy, which must evolve to support a long-term collaborative decision-making process and deal with a multi-vector and highly integrated energy system at multiple levels. This policy paper, which summaries a joint research initiative between the FSR and the European Climate Foundation, addresses these issues in three sections: 1) what are the key characteristics of the new state of the world? 2) what are the policy priorities in the near and longer term? 3) what are the process and governance to make it work
Analytical results for random walk persistence
In this paper, we present the detailed calculation of the persistence
exponent for a nearly-Markovian Gaussian process , a problem
initially introduced in [Phys. Rev. Lett. 77, 1420 (1996)], describing the
probability that the walker never crosses the origin. New resummed perturbative
and non-perturbative expressions for are obtained, which suggest a
connection with the result of the alternative independent interval
approximation (IIA). The perturbation theory is extended to the calculation of
for non-Gaussian processes, by making a strong connection between the
problem of persistence and the calculation of the energy eigenfunctions of a
quantum mechanical problem. Finally, we give perturbative and non-perturbative
expressions for the persistence exponent , describing the
probability that the process remains bigger than .Comment: 23 pages; accepted for publication to Phys. Rev. E (Dec. 98
Discursus quartus Ad Aureae Bullae Caroli Quarti Rom. Imp. Leges Imperii Fundamentales : Authoritate Maiorum Publico disputantium examini, & omnium publici iuris Indagatorum censurae Expositus
Quem Praesidente ... Dn. Dominico Arumaeo ... In auditorio Ictorum propugnabit Andreas Rudingerus Rudersdorfo-Thur. 30. August. horis consuetisAlternativfingerprint mit Bindevariante Corollarium am Schluß: n&b. osa. i-e- ilvo C 1617AHauptteil auch in: Arumäus, Dominicus: Discursus Academici Ad Auream Bullam Caroli Quarti Romanorum Imperatoris &c
The impact of systemic factors on the deployment of cooperative projects within renewable electricity production - An international comparison
While cooperative organizations created with the aim to initiate, develop, and operate renewable electricity (RE) projects have received attention for their roles in the transition to a sustainable energy system, the disparities in the number of RE cooperative projects among countries suggest that institutional contexts may have an impact on their deployment. In order to systematically identify the systemic factors that impact their deployment, we use an established framework, considering the strengths and weaknesses in market structure, infrastructures, institutions, interactions, and capabilities. We compare the deployment context in Germany, France, and Sweden in order to understand which systemic factors have an impact and how they affect RE cooperative projects. Based on a review of the literature and qualitative interviews with experts in RE cooperatives, it appears that, although RE cooperative projects share some obstacles with most new entrants of RE, they are particularly exposed to a lack of financial insfrastructure, a lack of knowledge and interactions, and problems related to a lack of regulatory frameworks facilitating their deployment. Results also show that systemic factors are complementary and dependent on each other; lowering one barrier lowers other barriers, and some obstacles strengthen other obstacles. Drawing on the comparison among Germany, France, and Sweden, we highlight some interesting practices that could be used in the coordination and alignment of systemic conditions for the deployment of RE cooperative projects.Funding agencies: Swedish Energy Agency [40642-1]</p
Oxide ceramic matrix composites - manufacturing, machining, properties and industrial applications
Oxide ceramic matrix composites (O-CMC) combine high temperature stability, low density, high strength and good corrosion resistance with a damage-tolerant quasi-ductile fracture behaviour enabling a variety of applications with demanding thermal and mechanical requirements