600 research outputs found

    Collective Almost Synchronization in Complex Networks

    Get PDF
    This work introduces the phenomenon of Collective Almost Synchronization (CAS), which describes a universal way of how patterns can appear in complex networks even for small coupling strengths. The CAS phenomenon appears due to the existence of an approximately constant local mean field and is characterized by having nodes with trajectories evolving around periodic stable orbits. Common notion based on statistical knowledge would lead one to interpret the appearance of a local constant mean field as a consequence of the fact that the behavior of each node is not correlated to the behaviors of the others. Contrary to this common notion, we show that various well known weaker forms of synchronization (almost, time-lag, phase synchronization, and generalized synchronization) appear as a result of the onset of an almost constant local mean field. If the memory is formed in a brain by minimising the coupling strength among neurons and maximising the number of possible patterns, then the CAS phenomenon is a plausible explanation for it.Comment: 3 figure

    Coupled-PDMS grafted mesoporous γ-alumina membranes for solvent nanofiltration

    Get PDF
    In this paper grafting of mesoporous c-alumina membranes with hydride terminated polydimethylsiloxane is described. Vinyltriethoxysilane is used as linking agent and tetrakis(vinyldimethylsiloxy)silane as a coupling agent, to create a dense network structure that is grafted in the ceramic pores. Grafting performance of the organic moieties on c-alumina powders was analyzed by FTIR and TGA. The results indicate that grafting reactions were successfully carried out. Contact angle analysis on the grafted membranes showed that grafting occurs on the c-alumina layer and that the resulting membrane surface had a water contact angle of 108 . From permeability and rejection tests using Sudan Black in toluene, ethyl acetate or isopropanol, the use of a coupling agent was found to result in a more dense network structure grafted in the gamma alumina pores. This resulted in a higher rejection for nanofiltration of solvents but at the cost of a lower solvent permeability, when compared with PDMS-grafted alumina membranes where no coupling of PDMS was applied

    Creating advantages with Franchising in healthcare

    Get PDF
    Background Franchising is a promising and increasingly used organizational form to improve strategic, organizational, professional and client-related results in healthcare. However, evidence is scarce regarding how franchises should be operated to actualize such results. This paper aimed to explore the association between the results achieved by healthcare franchises and the working relationships among actors in these franchises. Methods A sequential mixed methods approach was used to obtain both in-depth and broader quantifiable insights into a little-investigated phenomenon. We first employed a qualitative multiple embedded case study. Data were collected through observations, document analyses, and 96 in-depth semi-structured interviews in three Dutch healthcare franchises. Withincase and cross-case comparative analyses were conducted. Subsequently, a crosssectional survey was developed based on the qualitative study and disseminated among 19 healthcare franchises. 40 franchisors and 346 unit actors filled in the questionnaire. Findings It seems important to have open, committed, cooperative franchise relationships in which professional franchisees and unit managers feel and trust that they have the opportunity to introduce ideas and articulate their needs to the franchisor. Such relationships help ensure satisfaction, survival, and quality of care, because they serve to foster synergy realization and local fit and prevent reinventing the wheel and professional resistance

    Direct Visualization of Single Nuclear Pore Complex Proteins Using Genetically-Encoded Probes for DNA-PAINT

    No full text
    The nuclear pore complex (NPC) is one of the largest and most complex protein assemblies in the cell and, among other functions, serves as the gatekeeper of nucleocytoplasmic transport. Unraveling its molecular architecture and functioning has been an active research topic for decades with recent cryogenic electron microscopy and super-resolution studies advancing our understanding of the architecture of the NPC complex. However, the specific and direct visualization of single copies of NPC proteins is thus far elusive. Herein, we combine genetically-encoded self-labeling enzymes such as SNAP-tag and HaloTag with DNA-PAINT microscopy. We resolve single copies of nucleoporins in the human Y-complex in three dimensions with a precision of circa 3 nm, enabling studies of multicomponent complexes on the level of single proteins in cells using optical fluorescence microscopy

    Doped microporous hybrid silica membranes for gas separation

    Get PDF
    Hybrid silica (i.e., bis-triethoxysilylethane: BTESE) membranes doped with B, Ta or Nb were made through a sol–gel process. Triethyl borate, tantalum (V) ethoxide (TPE) and niobium (V) ethoxide (NPE) were selected as doping precursors. The doping concentration was optimized to produce sols, suitable for membrane fabrication. Thermal stability, structural analysis, cross-sectional micrographs and single gas permeation experiments were performed on these membranes, and results are compared with an undoped BTESE membrane. It was observed that the synthesized doped BTESE materials and membranes resulted into a more open (and, in one occurrence, SF6 permeable) pore microstructure, showing high permeances of larger gas molecules, while having a cross-sectional thickness comparable to undoped BTESE membrane

    A reduced complexity numerical method for optimal gate synthesis

    Full text link
    Although quantum computers have the potential to efficiently solve certain problems considered difficult by known classical approaches, the design of a quantum circuit remains computationally difficult. It is known that the optimal gate design problem is equivalent to the solution of an associated optimal control problem, the solution to which is also computationally intensive. Hence, in this article, we introduce the application of a class of numerical methods (termed the max-plus curse of dimensionality free techniques) that determine the optimal control thereby synthesizing the desired unitary gate. The application of this technique to quantum systems has a growth in complexity that depends on the cardinality of the control set approximation rather than the much larger growth with respect to spatial dimensions in approaches based on gridding of the space, used in previous literature. This technique is demonstrated by obtaining an approximate solution for the gate synthesis on SU(4)SU(4)- a problem that is computationally intractable by grid based approaches.Comment: 8 pages, 4 figure

    Ferromagnetic phase transition in a Heisenberg fluid: Monte Carlo simulations and Fisher corrections to scaling

    Full text link
    The magnetic phase transition in a Heisenberg fluid is studied by means of the finite size scaling (FSS) technique. We find that even for larger systems, considered in an ensemble with fixed density, the critical exponents show deviations from the expected lattice values similar to those obtained previously. This puzzle is clarified by proving the importance of the leading correction to the scaling that appears due to Fisher renormalization with the critical exponent equal to the absolute value of the specific heat exponent α\alpha. The appearance of such new corrections to scaling is a general feature of systems with constraints.Comment: 12 pages, 2 figures; submitted to Phys. Rev. Let

    Auto-combustion synthesis of perovskite-type oxides SrTi1−xFexO3−δ

    Get PDF
    A versatile one-pot auto-combustion method for the synthesis of powders of iron-doped strontium titanate, SrTi1−xFexO3−δ, has been developed. The synthesis is optimized by the combined use of EDTA and citric acid as chelating agents, and an appropriate balance between fuel and oxidizing elements in the reaction mixture. The method produces immediately an almost phase-pure perovskite oxide powder, with an ultra-fine crystallite size of 20–40 nm, and with a low level of organic residues. Highly sinter-active powders are obtained after calcination and ball-milling of the powders
    corecore