1,721,049 research outputs found
Magnetic Force Microscopy of Brain Microtubules
No full textBeing biological object, microtubules attract significant attention in physics, since it is believed that they are responsible for quantum processing of information in the brain. There were, however, no direct experiments checking such a statement. Recently, strong advancement in quantum computing took place utilizing properties of superconductors at low temperatures. Following this progress, it was proposed that brain microtubules are superconducting at room temperature allowing quantum processing of information. Moreover, the evidence of room-temperature superconductivity in brain slices containing microtubules was obtained by electrical transport measurements, and even specific scenario of quantum processing in the microtubules has been suggested. These results, however, are not yet accepted by the scientific community as there are no known attempts to reproduce them. Another step in proving superconductivity would be confirming ideal diamagnetism of microtubules, since ideal diamagnetism is more fundamental property of superconductivity than perfect conductivity, some features of which were seen indirectly, or the existence of energy gap, which was already confirmed by the transport measurements. Here brain microtubules are examined by the magnetic force microscopy. The evidence of strong diamagnetism and its sensitivity to the water content in the microtubules is obtained. This gives another strong argument in favor of the concept suggesting superconductivity-based quantum processing of information in living organisms
Nanomaterials for renewable energy economy
No full textRenewal energy economy relies on a range of novel materials for efficient production, distribution and consumption of energy. Nano science is playing increasingly important role in design and production of these materials. Examples of nano applications in energy sector are given following original research on materials for energy economy with focus on transmission of energy. The research is focused on nano-modified superconductors and novel thermo-insulators. A forecast for future activity is given, which is expected to lead to better materials, for example, superconductors with higher critical temperature and/or higher critical current density. The processes and equipment to process nano-materials are also discussed.
© 2017 Institute of Electrical and Electronics Engineers (IEEE
Possible Superconductivity in the Brain
No full textThe unprecedented power of the brain suggests that it may process information quantum-mechanically. Since quantum processing is already achieved in superconducting quantum computers, it may imply that superconductivity is the basis of quantum computation in the brain too. Superconductivity could also be responsible for long-term memory. Following these ideas, the paper reviews the progress in the search for superconductors with high critical temperature and tries to answer the question about the superconductivity in brain. It focuses on recent electrical measurements of brain slices, in which graphene was used as a room-temperature quantum mediator, and argues that these measurements could be interpreted as providing evidence of superconductivity in the neural network of mammalian brains. The estimated critical temperature of superconducting network in the brain is rather high, 2022 ± 157 K. A similar critical temperature was predicted in the Little’s model for one-dimensional organic chains linked to certain molecular complexes. A reasonable suggestion is that superconductivity develops in microtubules inside the neurons of the brain
Excitation of Vortex-antivortex Pairs in Thin Superconducting Films
No full textDirect imaging of the accumulation of magnetic flux and antiflux resulted from the excitation of vortex-antivortex pairs inside thin superconducting films is reported. Thin-film superconductors, like YBa2Cu3O7PrBa2Cu3O7 superlattices or NbN films grown by pulsed laser deposition were used in experiments. The superlattices provide enhanced pinning for vortices, facilitating imaging of accumulated flux, and feature nanoscale fractures ideal for excitation of vortex-antivortex pairs. The idea of experiment is to record images using specific magneto-optical mode that allows distinguishing between positive and negative magnetic field in the sample. Two types of fluxantiflux patterns are observed. In one type, flux and antiflux are entering on permanent defects, like nano-fractures formed in the process of film deposition. In another type, flux and antiflux patterns are formed by application of strong localized magnetic field and not are linked to permanent defects. In first type, the amount of flux and antiflux entering superconductor from defect is strongly affected by external magnetic field. In the second type, the permanent frozen pattern is hardly influenced by the field. An unusual and dramatic effect of the excitation of flux-antiflux dendritic avalanches is also reported
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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