Fluctuations of the correlation dimension at metal-insulator transitions

We investigate numerically the inverse participation ratio, $P_2$, of the 3D Anderson model and of the power-law random banded matrix (PRBM) model at criticality. We found that the variance of $\ln P_2$ scales with system size $L$ as $\sigma^2(L)=\sigma^2(\infty)-A L^{-D_2/2d}$, being $D_2$ the correlation dimension and $d$ the system dimension. Therefore the concept of a correlation dimension is well defined in the two models considered. The 3D Anderson transition and the PRBM transition for $b=0.3$ (see the text for the definition of $b$) are fairly similar with respect to all critical magnitudes studied.Comment: RevTex, 5 pages, 4 eps figures, to be published in Phys. Rev. Let

Optical sensor to determine plant spacing for precise application

Congreso Agroingeniería 2015. Orihuela (Alicante). 1 a 3 de junio de 2015La automatización en el manejo de la mala hierba de forma individualizada está siendo una realidad cada vez más cercana, tanto objetivos de eficiencia como de beneficio económico se están consiguiendo. En un futuro muy próximo la mecanización y su diseño tendrá que contemplar técnicas de monitorización o detección de precisión. El objetivo de este estudio fue evaluar la capacidad de un sensor óptico para determinar el espacio entre las plantas de una misma línea de cultivo en diferentes condiciones: laboratorio y campo. Este equipo de trabajo ha investigado la detección del cultivo con un sensor fotoeléctrico de infrarrojo (880 nm) en modo opuesto. La barrera fotoeléctrica de transmisión, usa un par de sensores y al paso de la planta por la cortina de luz interrumpe el haz. La señal de luz se recibe de forma simultánea en tiempo real mediante un sistema de control de alta velocidad. El sensor fotoeléctrico fue capaz de detectar la planta de tomate y por tanto de terminar la separación entre ellas de forma muy precisa. El uso de sistemas de detección como este puede dar lugar a una nueva era que permita el control en la línea de cultivo de la mala hierba de forma más económica y a la automatización de la operación. El control preciso de la mala hierba es un reto importante para este grupo, por ello tenemos previsto seguir trabajando en esta línea.Automation of individual crop plant care in commercial vegetable crop fields has increased practical feasibility and improved efficiency and economic benefit. Its systems approach is taken in the mechanization engineering design by the incorporation of precision sensing techniques. The objective of this study was design-sensing capabilities in an implement for measuring plant spacing under different test conditions: laboratory and field. For that proposal, a photoelectric transmission barrier, by using an optical light curtain transmitter and receiver, evaluated the interruption by the tomato stem of the light curtain, being recorded simultaneously in real-time by a high-speed embedded control system. The optical sensor provided tomato plant detection and therefore the spacing between tomato plants was determined with accuracy. The use of this detection system may result in a new era that allow for an online control of aggressive weeds and the automation of weeding tools, which we plan to pursue through future research.Junta de Andalucía P12-AGR-122

Determination by optical systems of the inter-plant real distance for precise weed control

La automatización en el manejo de las malas hierbas de forma individualizada está siendo una realidad cada vez más cercana, atendiendo a objetivos tanto de eficiencia como de beneficios económicos. En un futuro muy próximo la mecanización y su diseño tendrá que contemplar técnicas de monitorización o detección de precisión. El objetivo de este estudio fue evaluar la capacidad de un sensor óptico para determinar la distancia entre las plantas de una misma línea de cultivo en condiciones de laboratorio y campo. En concreto, se ha investigado la detección de plantas con un sensor fotoeléctrico de infrarrojo (880 nm) en modo opuesto. El sensor fotoeléctrico fue capaz de detectar la planta de tomate y por tanto permitir conocer la separación entre ellas de forma muy precisa. El uso de sistemas de detección como este puede dar lugar a una nueva era que permita el control en la línea de cultivo de la mala hierba de forma más económica y a la automatización de la operación.Automation of individual crop plant care in comercial vegetable crop fields has increased practical feasibility and improved efficiency and economic benefit. Its systems approach is taken in the mechanization engineering design by the incorporation of precision sensing techniques. The objective of this study was design-sensing capabilities in an implement for measuring plant spacing under different test conditions: laboratory and field. The optical sensor provided tomato plant detection and therefore the spacing between tomato plants was determined with accuracy. The use of this detection system may result in a new era that allow for an online control of aggressive weeds and the automation of weeding tools, which we plan to pursue through future research

Evaluating seawater quality objectives: Application to the Andalusian littoral

The University of Cadiz (southern Spain) and the Andalusian Environmental Agency (AMA) have signed an agreement to draw up a proposal of quality objectives for Andalusian littoral waters in accordance with the classification of zones approved in the Andalusian Littoral Waters Quality Objectives Regulations (Decree 14/1996, 01-16-1996, BOJA no. 19, 02-08-1996). The present paper reviews different regulations (European Union, Spain and the United States) concerning seawater quality criteria and presents the quality criteria proposed by the University of Cadiz.La Universidad de Cádiz y la Agencia de Medio Ambiente Andaluza (AMA) han desarrollado un convenio cuya finalidad es la realización de una propuesta de objetivos de calidad para las aguas litorales andaluzas según la clasificación de zonas establecida en el Decreto 14/1996, por el que se aprueba el Reglamento de Calidad de las Aguas Litorales Andaluzas (BOJA n.° 19 de 8 de febrero de 1996). En este trabajo se hace una revisión de la normativa referente a los objetivos de calidad de las aguas marinas en la Unión Europea, España y Estados Unidos. Además, se recoge la propuesta de objetivos de calidad de aguas litorales realizada por la Universidad de Cádiz.Instituto Español de Oceanografí

Simulations of Two-Dimensional Melting on the Surface of a Sphere

We have simulated a system of classical particles confined on the surface of a sphere interacting with a repulsive $r^{-12}$ potential. The same system simulated on a plane with periodic boundary conditions has van der Waals loops in pressure-density plots which are usually interpreted as evidence for a first order melting transition, but on the sphere such loops are absent. We also investigated the structure factor and from the width of the first peak as a function of density we can show that the growth of the correlation length is consistent with KTHNY theory. This suggests that simulations of two dimensional melting phenomena are best performed on the surface of a sphere.Comment: 4 eps figure

Assessing inter-limb asymmetries in soccer players: magnitude, direction and association with performance

In this study, we aimed to analyze the magnitude and direction of interlimb asymmetries in ankle dorsiflexion range of motion (ROM), power (using iso-inertial devices), and a neuromuscular skill (change of direction). Secondarily, we aimed to determine the relationship between interlimb asymmetry scores for each test and also between these scores and the scores for the different performance tests. Sixteen semiprofessional male soccer players (age: 25.38 6.08 years; body height: 1.78 0.64 m; body mass: 79.5 14.9 kg) participated in this study. We calculated interlimb asymmetries using five tests: ankle dorsiflexion ROM, change of direction (COD 180º), and iso-inertial resistance tasks in the open (leg extension strength (LE), leg curl strength (LC)) and closed (crossover step (CRO)) kinetic chain. Our results showed that asymmetry magnitudes differed between all tests with highest interlimb asymmetries displayed during iso-inertial overloading. In addition, we observed that the direction of asymmetries varied depending on the test-specificity, and that the CRO asymmetries had a negative association with LE and CRO performance. These findings highlight the independent nature of asymmetries and that CRO could be an appropriate test to detect asymmetries related with the performance of soccer-specific actions (such as changes of direction). Practitioners are encouraged to use multiple tests to detect existing interlimb differences according to the specific characteristics of each sport

Hydrodynamic identification of NAUTILUS FOWT platform from small scale tests

A small-scale tank test campaign of the NAUTILUS offshore wind floating semisub-mersible platform was held at the Ifremer Deep Water Basin within the framework of the MaRINET 2 project. The support structure consists in four stabilized columns on a square pontoon supporting a generic 8-MW wind turbine. The tests were carried out at 1:36 Froude scale in parked conditions, and the mooring system was modelled as a set of aerial mooring springs providing a nonlinear stiffness. The hydrodynamic characterization of the floater from experimental data was tackled by using traditional techniques in naval architecture), as well as approaches derived from operational modal analysis in the frequency domain, such as the Sub Space Identification—Covariance (SSI-COV) method. The validity of this approach and its potential application to the identification of such kind of structures is discussed against the results of a more traditional technique based on the fitting of decay tests

High spatial resolution optical imaging of the multiple T Tauri system LkH{\alpha} 262/LkH{\alpha} 263

We report high spatial resolution i' band imaging of the multiple T Tauri system LkH$\alpha$ 262/LkH$\alpha$ 263 obtained during the first commissioning period of the Adaptive Optics Lucky Imager (AOLI) at the 4.2 m William Herschel Telescope, using its Lucky Imaging mode. AOLI images have provided photometry for each of the two components LkH$\alpha$ 263 A and B (0.41 arcsec separation) and marginal evidence for an unresolved binary or a disc in LkH$\alpha$ 262. The AOLI data combined with previously available and newly obtained optical and infrared imaging show that the three components of LkH$\alpha$ 263 are co-moving, that there is orbital motion in the AB pair, and, remarkably, that LkH$\alpha$ 262-263 is a common proper motion system with less than 1 mas/yr relative motion. We argue that this is a likely five-component gravitationally bounded system. According to BT-settl models the mass of each of the five components is close to 0.4 M$_{\odot}$ and the age is in the range 1-2 Myr. The presence of discs in some of the components offers an interesting opportunity to investigate the formation and evolution of discs in the early stages of multiple very low-mass systems. In particular, we provide tentative evidence that the disc in 263C could be coplanar with the orbit of 263AB.Comment: 11 pages, 7 figures, Accepted 2016 May