131 research outputs found
Fully Automated Electrically Controlled Tunable Broadband Interferometric Dielectric Spectroscopy for Aqueous Solutions
No full textsponsorship: Manuscript received May 16, 2021; accepted June 22, 2021. This work was supported in part by KU Leuven Internal Funding (C2 project mu 2BIO) and in part by the Flemish Hercules. The work of Meng Zhang was supported by the Scholarship provided by the Chinese Scholarship Council. (Corresponding author: Xiue Bao.) (KU Leuven Internal Fund, Flemish Hercules, Chinese Scholarship Council)status: Publishe
Local rigidity of infinite-dimensional Teichmüller spaces
No full textThis paper presents a rigidity theorem for infinite-dimensional Bergman spaces of hyperbolic Riemann surfaces, which states that the Bergman space , for such a Riemann surface , is isomorphic to the Banach space of summable sequence, . This implies that whenever and are Riemann surfaces that are not analytically finite, and in particular are not necessarily homeomorphic, then is isomorphic to . It is known from V. Markovic that if there is a linear isometry between and , for two Riemann surfaces and of non-exceptional type, then this isometry is induced by a conformal mapping between and . As a corollary to this rigidity theorem presented here, taking the Banach duals of and shows that the space of holomorphic quadratic differentials on , is isomorphic to the Banach space of bounded sequences, . As a consequence of this theorem and the Bers embedding, the Teichmüller spaces of such Riemann surfaces are locally bi-Lipschitz equivalent
Il concerto delle Muse nella Città Ideale : indagini sul programma iconografico del Tempietto del Palazzo Ducale di Urbino con un'ipotesi di ricostruzione virtuale
No full textThe pictorial cycle originally housed in the so-called Tempietto delle Muse in Federico da Montefeltro’s Ducal Palace in Urbino (the oldest attestation of the iconographic representation of the Muses as musicians within a courtly context), visualizes the celebratory theme of music as a mirror of the harmony realized by the Duke during his reign, representing, at the same time, the praise of the ducal "musicality" and that of his favorite musical instruments and repertories.
There is no doubt that this sophisticated iconographic project was elaborated within an humanistic neoplatonic celebratory program, but its reconstruction is complicated by the lack of documents concerning its sources and the original number and disposition of the paintings, partly lost.
On the basis of an in-depth analysis of the pictorial cycle’s 'iconographic genealogy’, the Author proposes an original global interpretation of the decorative programme and a new hypothesis to identify the iconographic sources of the lost paintings and their possible disposition.
To support these hypotheses, the essay includes also a virtual reconstruction of the pictorial cycle, "relocating” inside the Tempietto both the surviving and the missing paintings
One vote in favour of Franjo Marković
No full textIn the event of 70‘h anniversary of the death of the Croatian romantic
writer Franjo Markovic (1845—1914) the author tries to incite the interest for the researching and interpreting of the works of this poet, epic writer, playwright, critic, essayist and philosopher. The author tries to stimulate the new attitude towards Croatian literary work of the past century and point out Markovid’s importance and stimulative function which is unduly being forgotten
High-performance hybrid-fibre concrete: Development and utilisation
No full textAlthough concrete is the most utilised building material nowdays, this material has a large shortcoming: it has a good resistance against compressive stresses, but a very low resistance against tensile stresses. Usual way to solve this problem is the application of steel reinforcement in concrete structures. Other possibility is the application of different types of fibres in concrete, for example steel or synthetic fibres: this material is then called "fibre concrete". In the past, many types of fibre concrete were developed. For many of them, the added value of fibres was rather low: almost no improvement of tensile strength could be achieved. In this research project, an innovative type of fibre concrete is developed, with improved both the tensile strength and the ductility: the Hybrid-Fibre Concrete (HFC). The expression "Hybrid" is here applied to point out to the hybridisation of fibres: short and long steel fibres were combined together in one concrete mixture. This is opposite to the conventional steel fibre concretes, which contain only one type of fibre. Within this research project, all important aspects needed for successful development and applications of Hybrid-Fibre Concrete have been considered. In total 15 mixtures, with different types and amounts of steel fibres were developed and tested in the fresh state (workability, with the self-compactability as a main goal) as well as in the hardened state (uniaxial tensile tests, flexural tests, pullout tests on single fibres and compressive tests). A new analytical model for bridging of cracks by fibres was developed and successfully implemented for tensile softening response of HFC. At the end, the utilisation of HFC in the engineering practice was discussed, including a case-study on light precast prestressed beams made of HFC, without conventional reinforcement. There many other possibilities for the applications of this material in building engineering, civil infrastructure, geotechnical and tunnelling engineering. It is also expected that the durability of the Hybrid-Fibre Concrete is better compared to conventional concrete, which could be its another big advantage.Civil Engineering and Geoscience
Influence of reaction-induced convection on quorum sensing in enzyme-loaded agarose beads
No full text© 2019 Author(s). In theory, groups of enzyme-loaded particles producing an acid or base may show complex behavior including dynamical quorum sensing, the appearance of synchronized oscillations above a critical number or density of particles. Here, experiments were performed with the enzyme urease loaded into mm-sized agarose beads and placed in a solution of urea, resulting in an increase in pH. This behavior was found to be dependent upon the number of beads present in the array; however, reaction-induced convection occurred and plumes of high pH developed that extended to the walls of the reactor. The convection resulted in the motion of the mm-sized particles and conversion of the solution to high pH. Simulations in a simple model of the beads demonstrated the suppression of dynamical quorum sensing in the presence of flow
Neuropsychological constraints to human data production on a global scale
No full textWhich are the factors underlying human information production on a global level? In order to gain an insight into this question we study a corpus of 252–633 mil. publicly available data files on the Internet corresponding to an overall storage volume of 284–675 Terabytes. Analyzing the file size distribution for several distinct data types we find indications that the neuropsychological capacity of the human brain to process and record information may constitute the dominant limiting factor for the overall growth of globally stored information, with real-world economic constraints having only a negligible influence. This supposition draws support from the observation that the files size distributions follow a power law for data without a time component, like images, and a log-normal distribution for multimedia files, for which time is a defining qualia.
Author summary: The generation of new information is limited by two key factors, by the incurring economic costs and by the capacity of the human brain to process and store data and information; the controlling agent needs to retain an overall understanding even when data is generated by semiautomatic processes. These processes are reflected in the statistical properties of the data files publicly available on the Internet. Collecting a corpus of 252–633 mil. files we find that the statistics of the file size distribution are consistent with the supposition that data production on a global level is shaped and limited by the neuropsychological information processing capacity of the brain, with economic and hardware constraints having a negligible influence
Decoding neighbour volatiles in preparation for future competition and implications for tritrophic interactions
No full textPlant volatile signals can provide important information about the physiological status and genetic identity of the emitter, and nearby plants can use this information to detect competitive neighbours. The novelty of these signals is that plants eavesdropping to volatiles of undamaged neighbours respond with typical competition responses, even before competition takes place, initiating specific growth responses that can increase their competitive capacity. This preparing for future competition mechanism affects the behaviour and abundance of herbivore pests and their natural enemies. Previously, such responses were only known to occur in response to volatiles released by damaged plants. However, volatile interactions occur only in specific combination of species/genotypes, indicating that plants use volatile signals in the detection and adaption only to substantial competitive neighbours. (C) 2016 The Author(s). Published by Elsevier GmbH
Electrocatalytic activity at surface-modified Pt nanoparticles assembled in polyelectrolyte
No full textAssemblies of polyacrylate-capped Pt nanoparticles (〈d〉 =2.5±0.6 nm) in poly(diallyldimethylammonium chloride) are reported to be electrocatalytically active for key charge-transfer reactions, viz., hydrogen evolution, hydrogen oxidation, and oxygen reduction and can thus serve as model nanostructured electrodes for studying electrocatalysis at well-characterized solution-prepared Pt and other metal nanoparticles. These results indicate that catalytic adsorption sites for the O2 reduction and H2 oxidation reactions are not blocked at the surface-modified nanoparticles, and that charge and mass transport supporting these electrochemical reactions are feasible in the films. Comparison is made with an electrochemically activated polycrystalline Pt electrode. © 2006 The Electrochemical Society. All rights reserved.Ahmadi TS, 1996, SCIENCE, V272, P1924, DOI 10.1126-science.272.5270.1924; Ahmadi TS, 1996, CHEM MATER, V8, P1161, DOI 10.1021-cm9601190; Bard A. J., 2001, ELECTROCHEMICAL METH; CLAVILIER J, 1988, ACS SYM SER, V378, P202; Climent V, 2000, J PHYS CHEM B, V104, P3116, DOI 10.1021-jp993480t; CONWAY BE, 1957, J CHEM PHYS, V26, P532, DOI 10.1063-1.1743339; Ghannoum S, 2003, LANGMUIR, V19, P4804, DOI 10.1021-la0209839; KABBABI A, 1994, J ELECTROANAL CHEM, V373, P251, DOI 10.1016-0022-0728(94)03503-2; KONISHITA K, 1990, J ELECTROCHEM SOC, V137, P845; Li Y, 2002, LANGMUIR, V18, P4921, DOI 10.1021-la011469q; Li Y, 2000, ORG LETT, V2, P2385, DOI 10.1021-ol0061687; Markarian MZ, 2005, J PHYS CHEM B, V109, P11616, DOI 10.1021-jp044267m; Markovic N. M., 2003, CATALYSIS ELECTROCAT; Markovic NM, 1996, J PHYS CHEM-US, V100, P6715; Markovic NM, 1997, J PHYS CHEM B, V101, P5405, DOI 10.1021-jp970930d; MARKOVIC NM, 1995, J PHYS CHEM-US, V99, P3411, DOI 10.1021-j100011a001; Markovic NM, 2001, FUEL CELLS, V1, P105, DOI 10.1002-1615-6854(200107)1:2105::AID-FUCE1053.0.CO;2-9; Markovic NM, 1996, J CHEM SOC FARADAY T, V92, P3719, DOI 10.1039-ft9969203719; PARSONS R, 1958, T FARADAY SOC, V54, P1053, DOI 10.1039-tf9585401053; Petroski JM, 1998, J PHYS CHEM B, V102, P3316, DOI 10.1021-jp981030f; Schmidt TJ, 2002, J ELECTROANAL CHEM, V524, P252, DOI 10.1016-S0022-0728(02)00683-6; Schmidt TJ, 2002, ELECTROCHIM ACTA, V47, P3765, DOI 10.1016-S0013-4686(02)00347-X; Takasu Y, 1996, ELECTROCHIM ACTA, V41, P2595, DOI 10.1016-0013-4686(96)00081-3; Toda T, 1999, J ELECTROCHEM SOC, V146, P3750, DOI 10.1149-1.1392544; Toda T, 1998, J ELECTROCHEM SOC, V145, P4185, DOI 10.1149-1.1838934; Toda T, 1999, J ELECTROANAL CHEM, V460, P258, DOI 10.1016-S0022-0728(98)00361-1; TOSHIMA N, 1993, J CHEM SOC FARADAY T, V89, P2537, DOI 10.1039-ft9938902537; WATANABE M, J ELECTROANAL CHEM I; Yang MH, 2006, BIOMATERIALS, V27, P246, DOI 10.1016-j.biomaterials.2005.05.077; Ye HC, 2005, J AM CHEM SOC, V127, P4930, DOI 10.1021-ja0435900; Zhao MQ, 1999, ADV MATER, V11, P21764
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