2,089 research outputs found

    An assemblage of affective sounds: resistance and power through the Palestinian electronic music scene

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    This thesis is an exploratory, descriptive, conceptual research about the Palestinian electronic dance scene. First, it sets out to make sense of social relations and elements traversing and constituting this space, locating the scene chronologically, geographically and affectively through anecdotes, interviews and encounters in different dance floors and spaces. It explores how music, affect, class and space are bound together to produce a layered and mobile assemblage of people that relate in diverse ways to the practice of resistance. Second, this project focuses on the meanings and practices related to resistance within the scene. Departing from a critical standpoint on subcultural theory and traditional frameworks for resistance, I interrogate and amplify the meanings of resisting in this context. The idea of ‘generative resistance’ is articulated in this process and examined in terms of its production of new spaces, communities, affects, intimacies, alternatives and culture, disputing diverse power structures. This thesis uses a participant and feminist micro-ethnography. Developed between 2019- 2022, the methods employed are mainly participant and sensory observation, interviews and informal conversations, and online analysis. I conducted fieldwork in Ramallah (Palestine), Amman (Jordan), Berlin (Germany), Athens (Greece) and London (Britain). Through this process, I developed a critical ‘anti-research’ epistemology that questions my positionality and generates an ‘affective’ epistemology: a way of doing research and producing knowledge that is based on difference, discomfort, solidarity and transformation

    Transition from a mixed to a pure d-wave symmetry in superconducting optimally doped YBa2_2Cu3_3O7−x_{7-x} thin films under applied fields

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    We have probed the Landau levels of nodal quasi-particles by tunneling along a nodal direction of (110) oriented YBa2_2Cu3_3O7−x_{7-x} thin films with a magnetic field applied perpendicular to the CuO2CuO_2 planes, and parallel to the film's surface. In optimally doped films and at low temperature, finite energy nodal states are clearly observed in films thinner than the London penetration depth. Above a well defined temperature the order parameter reverts to a pure \emph{d}-wave symmetry.Comment: 4 pages, 4 figure

    Normal metal to ferromagnetic superconductor tunneling

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    We study the point-contact tunneling between normal metal and ferromagnetic superconductor. In the case of magnon-induced pairing the tunneling conductance is continuous and smooth function of the applied voltage. For small values of the applied voltage the Ohm law holds. We show that one can obtain the magnetization and the superconducting order parameter from the tunneling conduc- tance. In the case of paramagnon-induced superconductivity the tunneling does not depend on the magnetization. We argue that tunneling experiment can unambiguously determine the correct pairing mechanism in the ferromagnetic superconductors.Comment: 6 pages, 4 figur

    S-wave superconductivity near a surface

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    We study the superconducting order parameter near a surface with the Bogoliubov-de Gennes formalism. For definiteness we use the attractive Hubbard model. Near a surface, the order parameter and the density distribution exhibit ``Friedel-like'' oscillations. Although the local density of states is quite different from that in the bulk, the energy gap in the spectrum on a surface is almost the same as the bulk value. In the low-density limit, however, the energy gap tends to vanish on a surface.Comment: 9 pages, 13 figure

    Electronic transport in a series of multiple arbitrary tunnel junctions

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    Monte Carlo simulations and an analytical approach within the framework of a semiclassical model are presented which permit the determination of Coulomb blockade and single electron charging effects for multiple tunnel junctions coupled in series. The Coulomb gap in the I(V) curves can be expressed as a simple function of the capacitances in the series. Furthermore, the magnitude of the differential conductivity at current onset is calculated in terms of the model. The results are discussed with respect to the number of junctions.Comment: 3 figures, revte

    Fate of the Josephson effect in thin-film superconductors

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    The dc Josephson effect refers to the dissipationless electrical current -- the supercurrent -- that can be sustained across a weak link connecting two bulk superconductors. This effect is a probe of the fundamental nature of the superconducting state. Here, we analyze the case of two superconducting thin films connected by a point contact. Remarkably, the Josephson effect is absent at nonzero temperature, and the resistance across the contact is nonzero. Moreover, the point contact resistance is found to vary with temperature in a nearly activated fashion, with a UNIVERSAL energy barrier determined only by the superfluid stiffness characterizing the films, an angle characterizing the geometry, and whether or not the Coulomb interaction between Cooper pairs is screened. This behavior reflects the subtle nature of the superconductivity in two-dimensional thin films, and should be testable in detail by future experiments.Comment: 16 + 8 pages. 1 figure, 1 tabl

    BCS Model in Tsallis' Statistical Framework

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    We show that there is an effect of nonextensivity acting upon the BCS model for superconductors in the ground state that motivates its study in the Tsallis' statistical framework. We show that the weak-coupling limit superconductors are well described by q∼1q \sim 1, where q is a real parameter which characterizes the degree of nonextensivity of the Tsallis' entropy. Nevertheless, small deviations with respect to q = 1 provide better agreement when compared with experimental results. To illustrate this point, making use of an approximated Fermi function, we show that measurements of the specific heat, ultrasonic attenuation and tunneling experiments for tin (Sn) are better described with q = 0.99.Comment: 13 pages, amssym

    Mesoscopic proximity effect in double barrier Superconductor/Normal Metal junctions

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    We report transport measurements down to T=60mK of SININ and SNIN structures in the diffusive limit. We fabricated Al-AlOx/Cu/AlOx/Cu (SININ) and Al/Cu/AlOx/Cu (SNIN) vertical junctions. For the first time, a zero bias anomaly was observed in a metallic SININ structure. We attribute this peak of conductance to coherent multi-reflections of electrons between the two tunnel barriers. This conductance maximum is quantitatively fitted by the relevant theory of mesoscopic SININ structures. When the barrier at the SN interface is removed (SNIN structure), we observe a peak of conductance at finite voltage accompagnied by an excess of sub-gap conductance.Comment: 4 pages, 4 figures, editorially approved for publication in Phys. Rev. B Rapid Com

    Developing a real time sensing system to monitor bacteria in wound dressings

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    Infection control is a key aspect of wound management strategies. Infection results in chemical imbalances and inflammation in the wound and may lead to prolonged healing times and degradation of the wound surface. Frequent changing of wound dressings may result in damage to healing tissues and an increased risk of infection. This paper presents the first results from a monitoring system that is being developed to detect presence and growth of bacteria in real time. It is based on impedance sensors that could be placed at the wound-dressing interface and potentially monitor bacterial growth in real time. As wounds can produce large volumes of exudate, the initial system reported here was developed to test for the presence of bacteria in suspension. Impedance was measured using disposable silver-silver chloride electrodes. The bacteria Staphylococcus aureus were chosen for the study as a species commonly isolated from wounds. The growth of bacteria was confirmed by plate counting methods and the impedance data were analysed for discernible differences in the impedance profiles to distinguish the absence and/or presence of bacteria. The main findings were that the impedance profiles obtained by silver-silver chloride sensors in bacterial suspensions could detect the presence of high cell densities. However, the presence of the silver-silver chloride electrodes tended to inhibit the growth of bacteria. These results indicate that there is potential to create a real time infection monitor for wounds based upon impedance sensing

    A comparative analysis of DNA barcode microarray feature size

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    <p>Abstract</p> <p>Background</p> <p>Microarrays are an invaluable tool in many modern genomic studies. It is generally perceived that decreasing the size of microarray features leads to arrays with higher resolution (due to greater feature density), but this increase in resolution can compromise sensitivity.</p> <p>Results</p> <p>We demonstrate that barcode microarrays with smaller features are equally capable of detecting variation in DNA barcode intensity when compared to larger feature sizes within a specific microarray platform. The barcodes used in this study are the well-characterized set derived from the Yeast KnockOut (YKO) collection used for screens of pooled yeast (<it>Saccharomyces cerevisiae</it>) deletion mutants. We treated these pools with the glycosylation inhibitor tunicamycin as a test compound. Three generations of barcode microarrays at 30, 8 and 5 μm features sizes independently identified the primary target of tunicamycin to be <it>ALG7</it>.</p> <p>Conclusion</p> <p>We show that the data obtained with 5 μm feature size is of comparable quality to the 30 μm size and propose that further shrinking of features could yield barcode microarrays with equal or greater resolving power and, more importantly, higher density.</p
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