Application of low-cost sensors for the development of a methodology to design front-end loaders for tractors

Tractor front-end loaders are an essential part of the equipment used on farms. At present, there are an important number of small- and medium-sized companies involved in the manufacturing of this equipment. These companies rely heavily on experience for innovative designs, as in the vast majority of cases they lack access to adequate methodology for the optimal design of new front-end loaders. The study conducted has developed a methodology to design tractor front-end loaders with a view of obtaining their accurate design during the bucket loading process. The methodology comprises two phases: the first phase involves a numerical analysis of the structural behaviour of the front-end loader components by means of the Finite Element Method; the second phase, the experimental phase, makes use of low-cost sensors, in particular, strain gauges, to analyse existing strains at selected points in the front-end loader structure. The experimental results obtained by means of low-cost sensors fitted onto the front-end loader allow analysing the existing strains at the points measured, as well as validate the numerical model developed. This methodology is validated by applying it to a commercial front-end loader, more specifically to model 430E2 of the company Maquinaria Agrícola El León S.A (Spain)

A theoretical analysis of Ballistic Electron Emission Microscopy: k-space distributions and spectroscopy

We analyze BEEM experiments. At low temperatures and low voltages, near the threshold value of the Schottky barrier, the BEEM current is dominated by the elastic component. Elastic scattering by the lattice results in the formation of focused beams and narrow lines in real space. To obtain the current injected in the semiconductor, we compute the current distribution in reciprocal space and, assuming energy and $k_{\parallel}$ conservation. Our results show an important focalization of the injected electron beam and explain the similarity between BEEM currents for Au/Si(111) and Au/Si(100).Comment: 17 pages, 5 figures (postscript), Latex, APS, http://www.icmm.csic.es/Pandres/pedro.htm. Appl. Surf. Sci. (in press

Applicability of Ammonia Sensors for Controlling Environmental Parameters in Accommodations for Lamb Fattening

Electrochemical ammonia sensors were used to analyse the existing relationship between the ammonia concentration and ambient levels of both temperature and relative humidity in commercial lamb fattening housing equipped with mechanical ventilation and straw-bedded pens. In the first stage of the experiment, sensors were placed over straw beds covered in lamb urine and analysed under laboratory conditions in order to determine ammonia emission evolution over time; three control temperatures (25, 35, and 50 degrees C) were used. A HOBO H8 temperature and relative humidity logger and a Drager NH3LC-6809680 electrochemical ammonia sensor placed in a Drager Polytron 7000 gas detector were utilized as sensors. A positive correlation was established between both ammonia emission time and emitted amount with temperature. Additionally, tests were performed in a commercial lamb housing to determine ammonia concentration variation with respect to height from the ground; three ammonia sensors placed at 50, 90, and 135 cm above the ground were used simultaneously. The ammonia concentration significantly decreased as height increased. A 90 cm height was selected, and three ammonia probes were placed in three different pens inside the livestock housing, along with temperature and relative humidity sensors; four different housing ventilation rates were then tested under real conditions over a time period of 4 months. An adjustment polynomial equation between the housing ambient temperature and the ammonia concentration was obtained with R-2 = 0.632. In conclusion, a relationship can be established between temperature and ammonia concentration in commercial lamb housing under certain handling conditions, which in turn allows for estimating the ammonia concentration adequately based on the ambient internal temperature

Plasmon-exciton-polariton lasing

Strong coupling of Frenkel excitons with surface plasmons leads to the formation of bosonic quasi-particles known as plasmon-exciton-polaritons (PEPs).Localized surface plasmons in nanoparticles are lossy due to radiative and nonradiative decays, which has hampered the realization of polariton lasing in a plasmonic system, i.e., PEP lasing. These losses can be reduced in collective plasmonic resonances supported by arrays of nanoparticles. Here we demonstrate PEP lasing in arrays of silver nanoparticles by showing the emergence of a threshold in the photoluminescence accompanied by both a superlinear increase of the emission and spectral narrowing. We also observe a reduction of the threshold by increasing the coupling between the molecular excitons and the resonances supported by the array despite the reduction of the quantum efficiency of the emitters. The coexistence of bright and dark collective modes in this plasmonic system allows for a 90?-change of polarization in the emission beyond the threshold

On the search for the electric dipole moment of strange and charm baryons at LHC

Permanent electric dipole moments (EDMs) of fundamental particles provide powerful probes for physics beyond the Standard Model. We propose to search for the EDM of strange and charm baryons at LHC, extending the ongoing experimental program on the neutron, muon, atoms, molecules and light nuclei. The EDM of strange \u39b baryons, selected from weak decays of charm baryons produced in pp collisions at LHC, can be determined by studying the spin precession in the magnetic field of the detector tracking system. A test of CPT symmetry can be performed by measuring the magnetic dipole moment of \u39b and \u39b\uaf baryons. For short-lived \u39bc+ and \u39ec+ baryons, to be produced in a fixed-target experiment using the 7 TeV LHC beam and channeled in a bent crystal, the spin precession is induced by the intense electromagnetic field between crystal atomic planes. The experimental layout based on the LHCb detector and the expected sensitivities in the coming years are discussed

Maximum likelihood soft-output detection through Sphere Decoding combined with box optimization

This is the author’s version of a work that was accepted for publication in Signal Processing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Signal Processing 125 (2016) 249–260. DOI 10.1016/j.sigpro.2016.02.006.This paper focuses on the improvement of known algorithms for maximum likelihood soft-output detection. These algorithms usually have large computational complexity, that can be reduced by using clipping. Taking two well-known soft-output maximum likelihood algorithms (Repeated Tree Search and Single Tree Search) as a starting point, a number of modifications (based mainly on box optimization techniques) are proposed to improve the efficiency of the search. As a result, two new algorithms are proposed for soft-output maximum likelihood detection. One of them is based on Repeated Tree Search (which can be applied with and without clipping). The other one is based on Single Tree Search, which can only be applied to the case with clipping. The proposed algorithms are compared with the Single Tree Search algorithm, and their efficiency is evaluated in standard detection problems (4 4 16-QAM and 4 4 64-QAM) with and without clipping. The results show that the efficiency of the proposed algorithms is similar to that of the Single Tree Search algorithm in the case 4 4 16-QAM; however, in the case 4 4 64- QAM, the new algorithms are far more efficient than the Single Tree Search algorithm. & 2016 Elsevier B.V. All rights reserved.This work has been partially funded by Generalitat Valenciana through the projects ISIC/2012/006 and PROMETEO II/2014/003, and by Ministerio Espanol de Economia y Competitividad through the project TEC2012-38142-C04 and through the Grant RACHEL TEC2013-47141-C4-4-R.García Mollá, VM.; Simarro Haro, MDLA.; Martínez Zaldívar, FJ.; González Salvador, A.; Vidal Maciá, AM. (2016). Maximum likelihood soft-output detection through Sphere Decoding combined with box optimization. Signal Processing. 125:249-260. https://doi.org/10.1016/j.sigpro.2016.02.006S24926012

Plasmon exciton-polariton lasing

Strong light-matter interaction leads to the appearance of new states, i.e. exciton-polaritons, with photophysical properties rather distinct from their constituents. Recent developments in fabrication techniques allow us to make metallic structures with strong electric field confinement in nanoscale mode volumes, allowing for a facile assembly of strongly coupled systems at room temperature based on a hybrid organic-plasmonic architecture. In this research, a planar array of metallic nano-antennas is covered by a polymer layer doped with organic molecules, achieving strong coupling of organic excitons with collective plasmonic resonances in the array. We use photoluminescence spectroscopy to measure an onset in nonlinear emission and polariton lasing in this system. At increasing molecular doping levels we observe an increase of the Rabi splitting caused by strong coupling and a concomitant decrease in the lasing threshold. This behavior is observed in spite of a strong reduction in the photoluminescence lifetime and the quantum yield of the dye. Using angular resolved photoluminescence spectroscopy, we measure the thermalization and condensation of plasmon-exciton-polaritons (PEPs) into a mode which is dark in the linear regime. These measurements can be interpreted in terms of stimulated scattering of PEPs at room temperature in the open cavity defined by the nano-antenna array [1, 2]. The lowest threshold that we measure is lower than previous values reported at room temperature in organic materials using microcavities. These results illustrate the potential of metamaterials and plasmonic systems for polariton lasing in spite of the inherent losses of metals

Adaptive step ODE algorithms for the 3D simulation of electric heart activity with graphics processing units

In this paper we studied the implementation and performance of adaptive step methods for large systems of ordinary differential equations systems in graphics processing units, focusing on the simulation of three-dimensional electric cardiac activity. The Rush-Larsen method was applied in all the implemented solvers to improve efficiency. We compared the adaptive methods with the fixed step methods, and we found that the fixed step methods can be faster while the adaptive step methods are better in terms of accuracy and robustness. (c) 2013 Elsevier Ltd. All rights reserved.This work has been partially funded by Universitat Politecnica de Valencia through Programa de Apoyo a la InvestigaciOn y Desarrollo (PAID-06-11) and (PAID-05-12), by Generalitat Valenciana through projects PROMETEO/2009/013 and Ayudas para la realizacion de proyectos de I+D para grupos de investigacion emergentes GV/2012/039, and by Ministerio Espafiol de Economia y Competitividad through project TEC2012-38142-004.García Mollá, VM.; Liberos Mascarell, A.; Vidal Maciá, AM.; Guillem Sánchez, MS.; Millet Roig, J.; González Salvador, A.; Martínez Zaldívar, FJ.... (2014). Adaptive step ODE algorithms for the 3D simulation of electric heart activity with graphics processing units. Computers in Biology and Medicine. 44:15-26. https://doi.org/10.1016/j.compbiomed.2013.10.023S15264