Fluxon-semifluxon interaction in an annular long Josephson 0-pi-junction

We investigate theoretically the interaction between integer and half-integer Josephson vortices (fluxons and semifluxons) in an annular Josephson junction. Semifluxons usually appear at the 0-$\pi$-boundary where there is a $\pi$-discontinuity of the Josephson phase. We study the simplest, but the most interesting case of one $\pi$-discontinuity in a loop, which can be created only artificially. We show that measuring the current-voltage characteristic after injection of an integer fluxon, one can determine the polarity of a semifluxon. Depending on the relative polarity of fluxon and semifluxon the static configuration may be stable or unstable, but in the dynamic state both configurations are stable. We also calculate the depinning current of $N$ fluxons pinned by an arbitrary fractional vortex.Comment: 8pages, 6 figures, submitted to PR

Resonant flux motion and I-V -characteristics in frustrated Josephson junctions

We describe the dynamics of fluxons moving in a frustrated Josephson junction with p, d, and f-wave symmetry and calculate the I-V characteristics. The behavior of fluxons is quite distinct in the long and short length junction limit. For long junctions the intrinsic flux is bound at the center and the moving integer fluxon or antifluxon interacts with it only when it approaches the junction's center. For small junctions the intrinsic flux can move as a bunched type fluxon introducing additional steps in the I-V characteristics. Possible realization in quantum computation is presented.Comment: 21 pages, 8 figure

Charge current in ferromagnet-superconductor junction with pairing state of broken time-reversal symmetry

We calculate the tunneling conductance spectra of a ferromagnetic metal/insulator/superconductor using the Blonder-Tinkham-Klapwijk (BTK) formulation. Two possible states for the superconductor are considered with the time reversal symmetry ($\cal{T}$) broken, i.e., $d_{x^2-y^2}+is$, or $d_{x^2-y^2}+id_{xy}$. In both cases the tunneling conductance within the gap is suppressed with the increase of the exchange interaction due to the suppression of the Andreev reflection. In the $(d_{x^2-y^2}+is)$-wave case the peaks that exist when the ferromagnet is a normal metal in the amplitude of the s-wave component due to the bound state formation are reduced symmetrically, with the increase of the exchange field, while in the $(d_{x^2-y^2}+id_{xy})$-wave case the residual density of states within the gap develops a dip around E=0 with the increase of the exchange field. These results would be useful to discriminate between $\cal{T}$-broken pairing states near the surface in high-$T_c$ superconductorsComment: 17 pages with 11 figure

A RESTFUL API FOR THE EXTENDED WHAT3WORDS ENCODING

Geocoding is a fundamental task of Geographic Information System (GIS) processing and analysis. It allows the transformation between a location reference (i.e., an address or an alphanumeric code) and coordinates, which is often an essential step when performing spatial analysis, mapping, and other geolocation related processes. Providing software functionality through RESTful APIs is a common practice in geospatial applications. Client programs are able to access or process geospatial data easily through a lightweight and scalable RESTful web service. Existing geocoding RESTful API providers include Google Maps Geocoding API, ArcGIS Geocoding REST API, MapQuest Open Geocoding API and what3words (w3w) Geocoding API. Extensions of what3words geocoding system have recently been proposed to overcome its limitation of fixed resolution and lack of consideration of the third dimension. This paper considers one of the extensions, the Quadtree Extension Model (QTEM) and introduces a RESTful API that provides operations for forward geocoding, reverse geocoding, single line and polygon encoding, and centre points encoding for a given area. The resources published by the web service could be implemented by software programs performing indoor and outdoor location referencing, location marking and path finding. This API could facilitate various geographic applications such as facility management, emergency evacuation, navigation and student survey data management in a university campus environment

Will oscillating wave surge converters survive tsunamis?

With an increasing emphasis on renewable energy resources, wave power technology is becoming one of the realistic solutions. However, the 2011 tsunami in Japan was a harsh reminder of the ferocity of the ocean. It is known that tsunamis are nearly undetectable in the open ocean but as the wave approaches the shore its energy is compressed, creating large destructive waves. The question posed here is whether an oscillating wave surge converter (OWSC) could withstand the force of an incoming tsunami. Several tools are used to provide an answer: an analytical 3D model developed within the framework of linear theory, a numerical model based on the non-linear shallow water equations and empirical formulas. Numerical results show that run-up and draw-down can be amplified under some circumstances, leading to an OWSC lying on dry ground

From the organic thin film transistor to the 3-D textile organic cylindrical transistors - perspectives, expectations and predictions

In this paper we examine the possibility to simulate and study the behaviour of a fiber-based Textile Transistor in a commercial TCAD system. We also examine the capability of such transistors to operate in sufficiently low voltages, aiming to the potential realization of low-voltage wearable textiles in the future. We have seen that it is potentially feasible to build transistors which can operate in low voltages by using typical materials. Even if some of the selected typical materials have to be replaced by others more suitable for practical use in the textile industry, the simulation is a good starting point for estimating the device typical operation and parameters

Sustainable intensification? Increased production diminishes omega-3 content of sheep milk

Intensifying agricultural production alters food composition, but this is often ignored when assessing system sustainability, yet it could compromise consumers’ health and the concept of ‘sustainable diets’. Here we consider milk composition from Mediterranean dairy sheep, finding inferior fatty acid (FA) profiles with respect to consumer health as a result of a more intensive system of production. Semi-intensive management did produce 57% more milk per ewe with 20% lower fat content, but inferior fat composition. Milk had a nutritionally poorer fatty acid (FA) profile, with 18% less omega-3 FA (n-3) (19% less long-chain n-3) and 7% less monounsaturated FA but 3% more saturated FA (9% higher in C14:0) concentrations compared with ewes under traditional, extensive management. Redundancy analysis identified close associations between fat composition and animal diets, particularly concentrate supplementation and grazing cultivated pasture - n-3 was associated with grazing diverse, native mountain pastures. The paper questions if identifying such key elements in traditional systems could be deployed for ‘sustainable intensification’ to maintain food quality whilst increasing output

Optimization of cylindrical textile organic field effect transistors using TCAD simulation tool

We used a commercial TCAD tool in order to simulate a cylindrical Textile Organic Field Effect Transistor (TOFET) and study the impact of different critical region sizes in its electrical characteristics. The simulation was based on models and parameters similar to those of previous simulations in Organic Thin Film Transistors. We have seen that it is potentially feasible to build transistors which can operate in low voltages by using typical materials. Even if some of the selected typical materials have to be replaced by others more suitable for practical use in the textile industry, the simulation is a good starting point for estimating the device typical operation and parameters. By optimizing critical region sizes of the device we conclude that the device should have an active layer thickness below 100 nm, channel length around 10 mu m and gate oxide thickness as small as possible (300 nm or less), in order to have optimum transistor performance