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Documentos disponibles de esta editorial (389)
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Antoranz Canales, Pedro ; Vegas Azcárate, Ignacio ; Miranda Pantoja, José Miguel | Elsevier Science BV | 2010-08-11We present in this paper the design, fabrication and verification of a us-range pulse generator based on a Step Recovery Diode (SRD). This device needs only a 5 V DC power supply, delivers 1 ns pulses with peak amplitudes in excess of 4 V and fe[...]texto impreso
We show that the renormalized vacuum expectation value of he Wilson loop for topologically massive abelian gauge theory in R3 can be defined so that its large-mass limit is the renormalized vacuum expectation value of the Wilson loop for abelia[...]texto impreso
Rodriguez, A. ; Martín-Delgado Alcántara, Miguel Ángel ; Rodriguez-Laguna, J. ; Sierra, G. ; Malyshev, Andrey ; Domínguez-Adame Acosta, Francisco ; Lemaistre, I. J. | Elsevier Science BV | 2001-12The standard one-parameter scaling theory predicts that all eigenstates in two-dimensional random lattices are weakly localized. We show that this claim fails in two-dimensional dipolar Frenkel exciton systems. The linear energy dispersion at th[...]texto impreso
In this paper we study the adjacency structure of the order polytope of a poset. For a given poset, we determine whether two vertices in the corresponding order polytope are adjacent. This is done through filters in the original poset. We also p[...]texto impreso
Arqueros Martínez, Fernando ; Blanco Ramos, Francisco ; García Pinto, Diego ; Ortiz Ramis, Montserrat ; Rosado Vélez, Jaime ; Vázquez Peñas, José Ramón | Elsevier Science BV | 2011-04-11The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emissi[...]texto impreso
An axiomatic treatment of an aggregation problem when the aggregated group is defined as a fuzzy group, was proposed by the author in a previous paper. In the present paper, the fuzzy majority rule is characterized and an impossibility theorem f[...]texto impreso
Response surface methodology has been applied for modeling and optimization of air gap membrane distillation process used in desalination. Regression models have been developed to predict the performance index and the specific performance index [...]texto impreso
García Payo, María del Carmen ; Izquierdo Gil, María Amparo ; Fernández Pineda, Cristóbal | Elsevier Science BV | 2000-04-30Aqueous solutions of alcohol (ethanol, methanol or isopropanol) have been experimentally investigated in air gap membrane distillation (AGMD), for a wide range of operating conditions. The effects of the relevant process parameters on the permea[...]texto impreso
García Payo, María del Carmen ; Izquierdo Gil, María Amparo ; Fernández Pineda, Cristóbal | Elsevier Science BV | 1999-04-12In this paper results obtained with air gap membrane distillation (AGMD) using sucrose aqueous solutions are shown. The role of the relevant process parameters has been investigated experimentally (the flow rate through the cell, the feed initia[...]texto impreso
Quiroga Mellado, Juan Antonio ; Gómez Pedrero, José Antonio ; García Botella, Ángel | Elsevier Science BV | 2001-09-15In this work we present a new algorithm for fringe pattern normalization, that is. background suppression and modulation normalization. Normalization is necessary for several fringe pattern processing techniques. For example, this is the case of[...]texto impreso
Franco Peláez, Francisco Javier ; Palomar Trives, Carlos ; González Izquierdo, Jesús ; Agapito Serrano, Juan Andrés | Elsevier Science BV | 2015-01-11A reliable voltage reference is mandatory in mixed-signal systems. However, this family of components can undergo very long single event transients when operating in radiation environments such as space and nuclear facilities due to the impact o[...]texto impreso
Álvarez Galindo, Gabriel ; Martínez Alonso, Luis ; Medina Reus, Elena | Elsevier Science BV | 2011-07-11We present a method to compute the genus expansion of the free energy of Hermitian matrix models from the large N expansion of the recurrence coefficients of the associated family of orthogonal polynomials. The method is based on the Bleher-Its [...]texto impreso
We develop a systematic approach to G_(2) holonomy manifolds with an SU(2) × SU(2) isometry using maximal eight-dimensional gauged supergravity to describe D6-branes wrapped on deformed three-spheres. A quite general metric ansatz that generaliz[...]texto impreso
Piñuel Moreno, Luis ; Moreno-Vozmediano, Rafael ; Tirado Fernández, Francisco | Elsevier Science BV | 2001-05Value Prediction is one of the newest techniques used to break down ILP limits. Despite being under continuous study during the last few years, a few aspects related to this emerging technique remain unanalysed in depth. Exhaustively investigate[...]texto impreso
Ruiz Cembranos, José Alberto ; Cruz Dombriz, Álvaro de la ; Dunsby, Dunsby ; Méndez-Isla, Miguel | Elsevier Science BV | 2019-03-10In the context of brane-world extra-dimensional theories, we compute the positron production from branon dark matter annihilations and compare with the AMS-02 data. Three different scenarios have been considered; the first two assume that either[...]texto impreso
García Villaluenga, Juan Pedro ; Khayet Souhaimi, Mohamed ; Godino Gómez, María Paz ; Seoane Rodríguez, Benjamín ; Mengual Cabezón, Juan Ignacio | Elsevier Science BV | 2005-12The effect of the membrane thickness on the pervaporation separation of methanol and methyl tertiary butyl ether mixtures through membranes was studied. Membranes of a wide range of thicknesses were prepared from two different polymers: cellulos[...]texto impreso
Ballesteros, H. G. ; Carmona, J. M. ; Fernández Pérez, Luis Antonio ; Tarancón, A. | Elsevier Science BV | 1998-02-12We study the antiferromagnetic O(N). N model in the F_(4) lattice. Monte Carlo simulations are applied for investigating the behavior of the transition for N = 2,3. The numerical results show a first order nature but with a large correlation len[...]texto impreso
Antonelli, S. ; Bartoloni, A. ; Battista, C. ; Bellacci, M. ; Cabasino, S. ; Cabibbo, N. ; Fernández Pérez, Luis Antonio ; Panizzi, E. ; Paolucci, P. S. ; Muñoz Sudupe, Antonio ; Ruiz Lorenzo, J. J. ; Sarno, R. ; Tarancón, A. ; Todesco, G. M. ; Torelli, M. ; Vinici, P. | Elsevier Science BV | 1995-04We present numerical results obtained in full QCD with 2 flavors of Wilson fermions. We discuss the relation between the phase of Polyakov loops and the sea quarks boundary conditions. We report prefiminary results about the HMC autocorrelation [...]texto impreso
Al-Salmi, Moza ; Laqbaqbi, Mourad ; Al-Obaidani, Sulaiman ; Al-Maamari, Rashid S. ; Khayet Souhaimi, Mohamed ; Al-Abri, Mohammed | Elsevier Science BV | 2020-11-15Direct contact membrane distillation (DCMD) was investigated for the treatment of oil-field produced water using a hydrophobic polypropylene (PP) membrane with 0.2 mu m pore size. The DCMD performance was studied under different feed temperature[...]texto impreso
Rodrigo Martín-Romo, José Augusto ; Alieva, Tatiana Krasheninnikova ; Calvo Padilla, María Luisa | Elsevier Science BV | 2007-10-15Gyrator transform is a new tool for manipulation of two-dimensional signals such as images or laser beam profiles. Here we demonstrate various applications of the gyrator transform for image processing. Several aspects such as noise reduction, f[...]texto impreso
Beliakov, G. ; Gomez, D. ; Jameson, Simon S ; Montero, Javier ; Rodríguez, Juan Tinguaro | Elsevier Science BV | 2017The problem of missing data is common in real-world applications of supervised machine learning such as classification and regression. Such data often gives rise to the need for functions defined for varying dimension. Here we propose optimizati[...]texto impreso
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Sweeping gas membrane distillation process (SGMD) has been used for desalination and its performance index, defined as the product of the distillate flux and the salt rejection factor, has been modeled using artificial neural network (ANN) metho[...]texto impreso
Artificial neural network modeling and optimization of desalination by air gap membrane distillation
An experimental based artificial neural network (ANN) model is constructed to describe the performance of air gap membrane distillation process for different operating conditions. The air gap thickness, the condensation temperature, the feed inl[...]texto impreso
Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Elsevier Science BV | 2011-07Cathodoluminescence (CL) of Ga2O3 nanowires and planar microstructures has been studied in a scanning electron microscope, as a function of the orientation angle of the structures relative to the position of the light detection system in the mic[...]texto impreso
The angular momentum of non-uniformly totally polarized beams is investigated using methods from the beam characterization approach. The relationship between the elements of the beam matrix for the two components of the field and the angular mom[...]texto impreso
Piquero Sanz, Gemma María ; Martínez Herrero, Rosario ; Mejías Arias, Pedro Miguel | Elsevier Science BV | 2008-02-15In terms of the so-called irradiance moments of a light field, the beam quality change, ?Q, of radially and azimuthally polarized beams caused by propagation through a quartic phase plate (as occurs for example, in strongly pumped laser rods us[...]texto impreso
We obtain a supergravity solution arising when D6-branes are wrapped on coassociative four-cycles of constant curvature in seven manifolds of G_(2) holonomy. The solutions preserve two supercharges and thus represent supergravity duals of three [...]texto impreso
Monteiro, T. ; Pereira, E. ; Correia, M. R. ; Xavier, C. ; Hofmann, D. M. ; Meyer, B. K. ; Fischer, S. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Elsevier Science BV | 1997-06Mid-band-gap emissions in GaN epilayers grown on 6H-SiC and sapphire are studied by time-resolved spectroscopy (TRS). The yellow luminescence peaking at ca. 1.2 eV at low-temperature shifts to higher energies with increasing temperature. The pre[...]texto impreso
Elshorbagy, Mahmoud Hamdy Mohamed ; Abdel-Hady, Kamal ; Kamal, Hala ; Alda, Javier | Elsevier Science BV | 2017-01-07Absorption of amorphous-Si hydrogenated (aSi-H) solar cells can be enhanced by using dielectric nanostructures made of Si3N4 that work like antireflection coatings. The analysis focus on the short-circuit current delivered by the cell under sola[...]texto impreso
We prove that three-dimensional N=1 supersymmetric Yang Mills-Chem-Simons theory is finite to all loop orders, In general this leaves open the possibility that different regularization methods lead to different finite effective actions. We show [...]texto impreso
Dobado González, Antonio ; Llanes Estrada, Felipe José ; Torres Rincón, Juan M. | Elsevier Science BV | 2011-08-03We study the bulk viscosity of a pion gas in unitarized Chiral Perturbation Theory at low and moderate temperatures, below any phase transition to a quark-gluon plasma phase. We argue that inelastic processes are irrelevant and exponentially sup[...]texto impreso
Franco Peláez, Francisco Javier ; Zong, Yi ; Agapito Serrano, Juan Andrés | Elsevier Science BV | 2009-11-12Commercial-off-the-shelf (COTS) capacitor-based isolation amplifiers were irradiated at the Portuguese Research Reactor (PRR) in order to determine its tolerance to the displacement damage and total ionising dose (TID). The set of experimental d[...]texto impreso
Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Garcia, J. A. ; Remon, A. ; Opagiste, C. | Elsevier Science BV | 1997-05The capability of luminescence techniques to characterize BaCuO_2 and in particular to detect the presence of this compound as impurity phase in high-T-c superconductors (HTSC) has been investigated. Cathodoluminescence (CL) in the scanning elec[...]texto impreso
Cathodoluminescence (CL) microscopy and spectroscopy in the scanning electron microscope have been applied to the microcharacterization of superconducting Bi2Sr2CaCu2O8+x single crystals. CL spectra representative of the samples at macroscopic l[...]texto impreso
Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Opagiste, C. | Elsevier Science BV | 1996-03-01Luminescence properties of Tl_2Ba_2CuO_(6+ ?) samples with different superconducting transition temperatures have been studied by cathodoluminescence (CL) in the scanning electron microscope. Independent of the crystal structure, tetragonal or o[...]texto impreso
Palomar Trives, Carlos ; Franco Peláez, Francisco Javier ; González Izquierdo, Jesús ; López Calle, Isabel ; Agapito Serrano, Juan Andrés | Elsevier Science BV | 2014-02-11Shunt linear voltage regulators are still used in situations where other kinds of regulators are not advised. This paper explores a mechanism liable to induce long duration pulses ( ~ 100 ? s ) in these devices, which is eventually demonstrated [...]texto impreso
Fraile Prieto, Luis Mario ; Vedia Fernández, María Victoria ; otros, ... | Elsevier Science BV | 2018-12-01DTAS is a segmented total absorption y-ray spectrometer developed for the DESPEC experiment at FAIR. It is composed of up to eighteen NaI(Tl) crystals. In this work we study the performance of this detector with laboratory sources and also under[...]texto impreso
Superconducting Tl_2Ba_2Cu_1O(6+?) ceramics shows two broad luminescence bands centered at 430 nm (2.9 eV) and 530 nm (2.3 eV) wich can not be related to impurity phases. The intensity of the bands is inhomogeneously distributed in the sample an[...]texto impreso
We study quantum Chern-Simons theory as the large-mass limit of the limit D --> 3 of dimensionally regularized topologically massive Yang-Mills theory. This approach can also be interpreted as a BRS-invariant hybrid regularization of Chern-Simo[...]texto impreso
In the general framework of chiral lagrangians we compute the leading log contribution to the three boson coupling in the standard model coming from eventual new physics. We apply the results, together with a complete analysis of the background [...]texto impreso
We propose a method to derive the low-energy effective action of QCD assuming that the long-distance properties of strong interactions can be described by a string theory. We bypass the usual problems related to the existence of the tachyon and [...]texto impreso
An effective SU(2)L X U(1)Y invariant chiral lagrangian can accommodate any symmetry breaking scheme in the standard model. It is shown that all process-independent quantities relevant to LEP precision measurements (DELTA-rho, DELTA-K and DELTA-[...]texto impreso
Chronopotentiometric and swelling experiments have been conducted to characterize the behavior of a Nafion membrane in NaCl and KCl aqueous solutions without and with glucose. A mixture solution with similar composition to the cerebrospinal flui[...]texto impreso
Barragán García, Vicenta María ; García Villaluenga, Juan Pedro ; Izquierdo Gil, María Amparo ; Godino Gómez, María Paz ; Seoane Rodríguez, Benjamín ; Ruiz Bauzá, Carlos | Elsevier Science BV | 2008-10-15Liquid permeation and uptake measurements of pure water and methanol were carried out using three commercial cation-exchange membranes: Nafion-117 (perfluorinated polyethylene with pendant ether-linked side chains terminated with sulfonated grou[...]texto impreso
Galindo, R. ; Menendez, N. ; Crespo del Arco, Patricia ; Velasco, V. ; Bomati Miguel, O. ; Díaz Fernández, D. ; Herrasti, P. | Elsevier Science BV | 2014-06Nickel nanoferrites were obtained by means of four different synthetic wet-routes: co-precipitation (CP), sonochemistry (SC), sonoelectrochemistry (SE) and electrochemistry (E). The influence of the synthesis method on the structural and magneti[...]texto impreso
Fisher's method of maximum likelihood breaks down when applied to the problem of estimating the five parameters of a mixture of two normal densities from a continuous random sample of size n. Alternative methods based on minimum-distance estimat[...]texto impreso
UV-photografting using two different monomers, acrylic acid and N-vinylpyrrolidone, with different concentrations in an aqueous solution and various irradiation times were studied. Irreversible fouling of both the un-grafted polyethersulfone and[...]texto impreso
Since transitivity is quite often violated even by decision makers that accept transitivity in their preferences as a condition for consistency, a standard approach to deal with intransitive preference elicitations is the search for a close enou[...]texto impreso
El-Abbassi, A. ; Hafidi, A. ; García Payo, María del Carmen ; Khayet Souhaimi, Mohamed | Elsevier Science BV | 2009-09-15The possibility of olive mill wastewaters (OMW) treatment and concentration by membrane distillation has been investigated. The objective is to obtain pure water and a concentrate containing high amounts of polyphenols, which can be extracted la[...]texto impreso
Scigaj, Mateusz ; Gázquez, Jaume ; Varela del Arco, María ; Fontcuberta Griñó, Josep ; Herranz Casabona, Gervasi ; Sánchez Barrera, Florencio | Elsevier Science BV | 2015-11-15Interfaces between (110) and (111)SrTiO_3 (STO) single crystalline substrates and amorphous oxide layers, LaAlO_3 (a-LAO), Y:ZrO_2 (a-YSZ), and SrTiO_3 (a-STO) become conducting above a critical thickness tc. Here we show that t_c for a-LAO is n[...]texto impreso
Menéndez Calleja, María Luisa ; Pardo Llorente, Leandro ; Pardo Llorente, María del Carmen | Elsevier Science BV | 2009-02-01In this paper we present recentered confidence sets for the parameters of a logistic regression model based on preliminary minimum phi-divergence estimators. Asymptotic coverage probabilities are given as well as a simulation study in order to a[...]texto impreso
We study in this paper a modification of continued fractions defined by the author, such that its lexicographic order coincides with the linear order of real numbers. This fact has beautiful consequences in Topology. Indeed, it gives the possibi[...]texto impreso
We report a relativistic many-body calculation for the hybrid meson spectrum utilizing a QCD inspired Coulomb gauge Hamiltonian. Our approach is comprehensive and unifies the quark and gluon sectors. The vacuum and quasiparticle properties are g[...]texto impreso
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Darboux transformation is reconsidered for the supersymmetric KdV system. By iterating the Darboux transformation, a supersymmetric extension of the Crum transformation is obtained for the Manin-Radul SKdV equation, in doing so one gets Wronskia[...]texto impreso
A combined scanning electron microscope-scanning tunneling microscope (SEM-STM) system has been used to investigate surface topographic and electronic properties of YBa2Cu3O7-x (YBCO) and Bi2Sr2Ca-Cu2O8+x (Bi-2212) single crystals. Current imagi[...]texto impreso
In this paper we present a vectorial Darboux transformation, in terms of ordinary determinants, for the supersymmetric extension of the Korteweg-de Vries equation proposed by Manin and Radul. It is shown how this transformation reduces to the Ko[...]texto impreso
We construct Darboux transformations for the super-symmetric KP hierarchies of Manin-Radul and Jacobian types. We also consider the binary Darboux transformation for the hierarchies. The iterations of both type of Darboux transformations are bri[...]texto impreso
Quiroga Mellado, Juan Antonio ; Servín Guirado, Manuel ; Cuevas de la Rosa, Francisco Javier | Elsevier Science BV | 2001-12-15First- and second-order recursive Digital Phase Locked Loops (DPLLs) have been used recently in fringe data processing because it is the fastest way to obtain the unwrapped phase of a carrier frequency fringe pattern due to its minimal computati[...]texto impreso
Arganda, E. ; Arqueros Martínez, Fernando ; García Pinto, Diego ; Minaya Flores, Ignacio Andrés ; Ortiz Ramis, Montserrat ; Rosado Vélez, Jaime | Elsevier Science BV | 2012-04Atmospheric conditions at the site of a cosmic ray observatory must be known for reconstructing observed extensive air showers. The Global Data Assimilation System (GDAS) is a global atmospheric model predicated on meteorological measurements an[...]texto impreso
Vegas Azcárate, Ignacio ; Antoranz Canales, Pedro ; Miranda Pantoja, José Miguel ; Franco Peláez, Francisco Javier | Elsevier Science BV | 2017-01-01A variable width pulse generator featuring more than 4-V peak amplitude and less than 10-ns FWHM is described. In this design the width of the pulses is controlled by means of the control signal slope. Thus, a variable transition time control ci[...]texto impreso
Two types of bisphenol monomers, Bisphenol A (BPA) and Tetramethyl Bisphenol A (TMBPA), with different concentrations of bisphenol aqueous solution (0.5% to 2.%w/v) and various interfacial polymerisation times (10 s, 30 s and 60 s) in the fixed [...]texto impreso
A system of an array of side-coupled quantum dots attached to a quantum wire is studied theoretically. Transport through the quantum wire is investigated by means of a noninteracting Anderson tunneling Hamiltonian. Analytical expressions of the [...]texto impreso
Carrasco, J. A. ; Nebreda Manjón, Jenifer ; Peláez Sagredo, José Ramón | Elsevier Science BV | 2015-10-07We apply a recently developed dispersive formalism to calculate the Regge trajectories of the f_2(1270), f´_ 2(1525) and K^?(892) mesons. Trajectories are calculated, not fitted to a family of resonances. Assuming that these resonances can be tr[...]texto impreso
The intrinsic helix conformation of the DNA strands is known to be the key ingredient of control of the electric current through the molecule by the perpendicular (gate) electric field. We show theoretically that Bloch oscillations in periodic s[...]texto impreso
We study the beta functions of the quartic and Yukawa couplings of General Relativity and Unimodular Gravity coupled to the ??4 and Yukawa theories with masses. We show that the General Relativity corrections to those beta functions as obtained [...]texto impreso
This overview demonstrates the potential of historical documents from Ecuador, Peru, Bolivia, Chile and Argentina, for developing continuous and precise reconstructions of past climatic variations in South America, during past centuries. We prov[...]texto impreso
Iglesias Freire, O. ; Jaafar, M. ; Pérez García, Lucas ; Abril, Abril, de ; Vázquez, M. ; Asenjo, A. | Elsevier Science BV | 2014-04The proximity effect in the collective behavior of arrays of magnetic nanostripes is currently a subject of intensive research. The imperative of reducing the size and distances between elements in order to achieve higher storage capacity, faste[...]texto impreso
Torcal Milla, Francisco José ; Sánchez Brea, Luis Miguel ; Bernabeu Martínez, Eusebio | Elsevier Science BV | 2008-12-01Steel tape gratings are used in different metrology applications. As the period of these gratings was large (around 100?m,), its analytical study has been performed, up to date, using a geometrical approach. Nowadays, steel tape gratings can be [...]texto impreso
Carmona, J. M. ; Cruz, A. ; Fernández Pérez, Luis Antonio ; Jiménez, S. ; Martín Mayor, Víctor ; Muñoz Sudupe, Antonio ; Pech, J. ; Ruiz Lorenzo, J. J. ; Tarancón, A. ; Téllez, P. | Elsevier Science BV | 2003-05-08It is shown that a bosonic formulation of the double-exchange model, one of the classical models for magnetism, generates dynamically a gauge-invariant phase in a finite region of the phase diagram. We use analytical methods, Monte Carlo simulat[...]texto impreso
We summarise results on the infrared behaviour of Landau gauge QCD from the Green's functions approach and lattice calculations. Approximate, nonperturbative solutions for the ghost, gluon and quark propagators as well as first results for the q[...]texto impreso
Manzanares Ituarte, Ana ; Calvo Padilla, María Luisa ; Chevalier dl Río, Margarita ; Lakshminarayanan, Vasudevan | Elsevier Science BV | 1998-12We discuss a formalism to characterize degraded edge images formed in a diffraction limited system (with circular pupil of unit radius) under conditions of incoherent illumination. We introduce a novel definition of degraded edges and consider t[...]texto impreso
Barragán García, Vicenta María ; Ruiz Bauzá, Carlos ; Imaña Pascual, José Luis | Elsevier Science BV | 2002-03-01The influence of an alternating (AC) sinusoidal perturbation, of known frequency and small amplitude, superimposed to the usual applied continuous (DC) signal in a desalination electrodialysis process has been studied. The experiments were carri[...]texto impreso
Melle Hernández, Sonia ; Gómez Calderón, Óscar ; Carreño Sánchez, Fernando ; Cabrera Granado, Eduardo ; Antón Revilla, Miguel Ángel ; Jarabo Lallana, Sebastián | Elsevier Science BV | 2007-11-01The effect of ion density on slow light propagation enabled by coherent population oscillations has been experimentally investigated for highly doped erbium fibers at room temperature. We found that fractional delay increases with ion density. A[...]texto impreso
The thermal membrane potential through a cation-exchange membrane has been determined under different experimental situations. In all cases, a good linear dependence between the thermal membrane potential, Delta psi, and the temperature differen[...]texto impreso
Pérez García, Lucas ; de Abril, O. ; Sánchez Tujillo, M. C. ; Aroca, C. ; López, E. ; Sánchez, P. | Elsevier Science BV | 2000-06Multilayer films composed of Co_(x)P_(1-x) ferromagnetic layers with different composition (0.74texto impreso
We present recent results on finite temperature electromagnetic form factors and the electrical conductivity in a pion gas. The standard Chiral Perturbation Theory power counting needs to be modified for transport coefficients. We pay special at[...]texto impreso
Gómez, I. ; Díez, E. ; Domínguez-Adame Acosta, Francisco ; Orellana, P. | Elsevier Science BV | 2003-06We present a novel model to calculate vertical transport properties such as conductance and current in unintentionally disordered double-barrier GaAs-AlxGa1-xAs heterostructures. The source of disorder comes from interface roughness at the heter[...]texto impreso
Domínguez-Adame Acosta, Francisco ; Maciá Barber, Enrique Alfonso ; Méndez Martín, Bianchi | Elsevier Science BV | 1994-10-31We study the electronic structure of a new type of Fibonacci superlattice based on Si delta-doped GaAs. Assuming that delta-doped layers are equally spaced, quasiperiodicity is introduced by selecting two different donor concentrations and arran[...]texto impreso
Enhanced time response of 1-in. LaBr_3(Ce) crystals by leading edge and constant fraction techniques
Vedia Fernandez, Victoria ; Mach Henryk, Andrzej ; Fraile Prieto, Luis Mario ; Udías Moinelo, José Manuel ; Lalkovski, S. | Elsevier Science BV | 2015-09-21We have characterized in depth the time response of three detectors equipped with cylindrical LaBr_3(Ce) crystals with dimensions of 1-in. in height and 1-in. in diameter, and having nominal Ce doping concentration of 5%, 8% and 10%. Measurement[...]texto impreso
An axiomatic basis for fuzzy rationality measures has already been introduced by the authors in a previous paper [5], formalizing the fact that there exist degrees of consistency when preferences over a fixed set of alternatives are expressed in[...]texto impreso
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Direct methanol fuel cells (DMFCs) are attractive for several applications, however, at present, methanol crossover from the anode to the cathode appears to be a major limitation. For this reason, as one of the alternatives, membrane technology [...]texto impreso
We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface det[...]texto impreso
An exact solution for the Schwinger model at finite temperature is given. Path integral methods and thermo field dynamics are used. The explicit dependence of the complete propagators with temperature is foundtexto impreso
A class of exact solutions of the dispersionless Toda hierarchy constrained by a string equation is obtained. These solutions represent deformations of analytic curves with a finite number of nonzero harmonic moments. The corresponding tau-funct[...]texto impreso
Gómez-Ullate Otaiza, David ; González López, Artemio ; Rodríguez González, Miguel Ángel | Elsevier Science BV | 2001-05-28A quantum Hamiltonian describing N particles on a line interacting pairwise via an elliptic function potential in the presence of an external field is introduced. For a discrete set of values of the strength of the external potential, it is show[...]texto impreso
This paper reports experimental results regarding the scaling properties of wetting fronts during the hydration of repacked bentonite clay with a wide range of pore sizes (over five decades). The process of hydration in this swelling, heterogene[...]texto impreso
We find a new exact vacuum solution in the framework of the Poincaré Gauge field theory with massive torsion. In this model, torsion operates as an independent field and introduces corrections to the vacuum structure present in General Relativit[...]texto impreso
The so called Li&Ma formula is still the most frequently used method for estimating the significance of observations carried out by Imaging Atmospheric Cherenkov Telescopes. In this work a straightforward extension of the method for point source[...]texto impreso
In the same way as 'comprehensive fuzziness' deals with o-fields of labels, 'extensive fuzziness' deals with objects. In this paper, the concept of 'extensive mapping' is defined in order to justify the notion of 'measurable fuzzy function'. Thi[...]texto impreso
Paris, J.L. ; Lafuente-Gómez, Nuria ; Cabañas Criado, Victoria ; Román, Jesús ; Peña, Juan ; Vallet Regí, María | Elsevier Science BV | 2019-03-013D porous scaffolds based on agarose and nanocrystalline apatite, two structural components that act as a temporary mineralized extracellular matrix, were prepared by the GELPOR3D method. This shaping technology allows the introduction of therma[...]texto impreso
Membrane distillation (MD) has a great potential as a concentration process for temperature labile liquids such as fruit juices, etc. Besides water, also aroma compounds will permeate through the membrane depending on their volatility and how th[...]texto impreso
Antoranz Canales, Pedro ; Barrio Uña, Juan Abel ; Contreras González, José Luis ; Fonseca González, Mª Victoria ; López Moya, Marcos ; Miranda Pantoja, José Miguel ; Nieto, Daniel | Elsevier Science BV | 2008-09-11Until April 2007 the Major Atmospheric Gamma ray Imaging Cherenkov (MAGIC) telescope used a 300 MSamples/s flash analog-to-digital converter (FADC) system to sample the shaped photomultiplier tube (PMT) signals produced by the captured Cherenkov[...]texto impreso
It is shown that thermo-field dynamics permits the extension of the path integral methods used to solve the Thirring model at zero temperature to the finite temperature case. A family of exact solutions for the propagator and their dependence wi[...]texto impreso
Piquero Sanz, Gemma María ; Borghi, Riccardo ; Mondello, A. ; Santarsiero, Massimo | Elsevier Science BV | 2001-08-15We analyze the polarization features of the beam, generated by a class of partially polarized quasi-homogeneous sources, which propagates through a polarization grating. Analytical expressions in the far zone for the beam coherence polarization [...]texto impreso
This paper presents a fibre-optic sensor to measure weight in motion based on a multiple fibre-optic interferometer. The differential phase between the arms of the interferometer produced by the pressure is compensated by a feedback system, thus[...]texto impreso
Ballesteros, H. G. ; Fernández Pérez, Luis Antonio ; Martín Mayor, Víctor ; Muñoz Sudupe, Antonio | Elsevier Science BV | 1996-10-10We study the critical properties of three-dimensional O(N) models, for N = 2,3,4. Parameterizing the leading correctionsto-scaling for the r] exponent, we obtain a reliable infinite volume extrapolation, incompatible with previous Monte Carlo va[...]texto impreso
Ballesteros, H.G. ; Fernández Pérez, Luis Antonio ; Martín Mayor, Víctor ; Muñoz Sudupe, Antonio ; Parisi, G. ; Ruiz-Lorenzo, J. J. | Elsevier Science BV | 1998-04We study the four dimensional site-diluted Ising model using finite-size scaling techniques. We explore the whole parameter space (density-coupling) in order to determine the Universality Class of the transition line. Our data are compatible wit[...]