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Title: Friction coefficients and wear rates of different orthodontic archwires in artificial saliva
Authors: Alfonso, M.V.; Espinar, Eduardo; Llamas, José María; Rupérez de Gracia, Elisa; Manero Planella, José María; Barrera, J.M; Solano, E.; Gil Mur, Francisco Javier
Abstract: The aim of this paper is to analyze the influence
of the nature of the orthodontic archwires on the friction
coefficient and wear rate against materials used commonly as
brackets (Ti–6Al–4V and 316L Stainless Steel). The mate-
rials selected as orthodontic archwires were ASI304 stainless
steel, NiTi, Ti, TiMo and NiTiCu. The array archwire’s
materials selected presented very similar roughness but
different hardness. Materials were chosen from lower and
higher hardness degrees than that of the brackets. Wear tests
were carried out at in artificial saliva at 37
C. Results show a
linear relationship between the hardness of the materials and
the friction coefficients. The material that showed lower
wear rate was the ASI304 stainless steel. To prevent wear,
the wire and the brackets have high hardness values and in
the same order of magnitude.
Title: Los niveles de determinación como herramienta para analizar tareas de modelización matemática
Authors: Gómez Urgellés, Joan Vicenç
Abstract: Este trabajo se enmarca en las nuevas necesidades y expectativas de la educación matemática en el sistema educativo español: "preparar al alumno para su incorporación a estudios superiores y para su inserción laboral, y formado para el ejercicio de sus derechos y obligaciones en la vida como ciudadanas y ciudadanos"
Title: Multifunctional nanocomposite foams based on polypropylene with carbon nanofillers
Authors: Sousa Pais Antunes, Marcelo de; Gedler, Gabriel; Velasco Perero, José Ignacio
Abstract: This work considers the preparation and characterization of polypropylene foams with
variable concentrations of graphene and carbon nanofibres, focussing on the influence
of the foaming process and the nanofillers on the microstructural and dynamic-mechanical-
thermal properties of the foams. Great differences were found in terms of foam
morphology depending on the type of foaming process, with foams prepared by physical
foaming showing a vertically deformed cell structure, while chemical foams presented
an isotropic-like cellular structure. The addition of graphene resulted in foams with
higher cell densities and more uniform cellular structures when compared to the ones
with nanofibres. All these considerations are of extreme importance, as some of
the most promising applications of these polymer foams require a good electromagnetic
interference shielding efficiency, which greatly depends on the developed foam
Title: Small-scale characteristics and turbulent statistics of the flow in an external gear pump by time-resolved PIV
Authors: Ertürk, S.; Vernet, Anton; Pallarés, J.; Castilla López, Roberto; Raush Alviach, Gustavo Adolfo
Title: Valorization of pellets from municipal WWTP sludge in lightweight clay ceramics
Authors: Cusidó Fàbregas, Joan Antoni; Soriano Ortiz, Cecilia
Title: Scaling laws and the modern city
Authors: Isalgue Buxeda, Antonio; Coch Roura, Helena; Serra Florensa, Rafael
Title: Dynamic behaviour of a back-to-back five-level flying capacitor converter with reduced DC bus capacitance
Authors: Ghias, A.M.Y.M.; Ciobotaru, M.; Agelidis, Vassilios; Pou Félix, Josep
Abstract: Due to extensive research, advanced voltage source converter (VSC) such as multilevel and multi-module have been proposed for high power applications. These advanced VSCs must provide secure as well as, intelligent power management operation for the future electricity network under various grid events. The focus of this paper is to evaluate the dynamic performance of a back-to-back five-level flying capacitor (FC) converter system with reduced DC bus capacitance under different grid voltage disturbances. The system uses a classical synchronous reference frame control technique for active/reactive power control and DC voltage regulation, and is tested in terms of general grid events such as power flow reversal, voltage amplitude excursions, phase jumps and frequency variations using MATLAB/Simulink and PLECS blockset. The simulation results show that the back-to-back FC converter with reduced DC bus capacitance performs well during the mentioned grid events.
Title: Weak measurements with orbital-angular-momentum pointer states
Authors: Puentes, G.; Hermosa, N.; Pérez Torres, Juan
Abstract: Weak measurements are a unique tool for accessing information about weakly interacting quantum
systems with minimal back action. Joint weak measurements of single-particle operators with pointer
states characterized by a two-dimensional Gaussian distribution can provide, in turn, key information
about quantum correlations that can be relevant for quantum information applications. Here we
demonstrate that by employing two-dimensional pointer states endowed with orbital angular momentum
(OAM), it is possible to extract weak values of the higher order moments of single-particle operators, an
inaccessible quantity with Gaussian pointer states only. We provide a specific example that illustrates the
advantages of our method both in terms of signal enhancement and information retrieval.
Title: PARIS interferometric technique proof of concept: sea surface altimetry measurements
Authors: Rius, A.; Fabra Cervellera, Fran; Ribó, S.; Arco Fernandez, Juan Carlos; Oliveras, S.; Cardellach, Estel; Camps Carmona, Adriano José; Nogués Correig, O.; Kainulainen, J.; Rohue, E.; Martín Neira, Manuel
Abstract: We report preliminary results of an aircraft experiment aimed
to proof the PARIS Interferometric Technique. The experiment
was performed in the Gulf of Finland during a two hours
flight.We installed a PARIS Interferometric Receiver together
with a GOLD-RTR instrument to collect reflected C/A, P(Y)
and M-code GPS signals. The collected data has been analyzed
to produce altimetric observables with both techniques.
Title: Impact of the observation geometry on the GNSS-R direct descriptors used for sea state monitoring
Authors: Valencia Domenech, Enric; Camps Carmona, Adriano José; Hyuk, Park; Rodriguez Alvarez, N.; Ramos Pérez, Isaac
Abstract: In recent years GNSS-R has been proposed for ocean remote
sensing, both for altimetry and scatterometry. For the later,
two main approaches are available: fitting the measurements
with a model, or using some observable from the measurements
(either the waveform or the delay-Doppler Map) to be
directly linked to ocean surface’s roughness. For groundbased
and airborne experiments, several direct observables
have been proposed to describe ocean surface’s roughness,
and they have been used assuming that the observation geometry
had little impact on them. However, it may not be
true for a spaceborne scenario, since the dynamics are higher.
In this work an extensive simulation study is performed, and
the first results on how the observation geometry does impact
different GNSS-R direct observables is presented.
Title: Slew-rate and efficiency trade-off in slow envelope tracking power amplifiers
Authors: Gilabert Pinal, Pere Lluís; Montoro López, Gabriel; Vizarreta Paz, Pedro Pablo
Abstract: This paper presents a study on the trade-off between the envelope's slew-rate and the drain efficiency when slower envelopes are considered to dynamically supply the power amplifier (PA). This paper discusses a method to limit the slew-rate (and consequently the bandwidth) of the signal's envelope. Moreover, since the envelope tracking (ET) technique using a slower version of the original envelope introduces nonlinear distortion, slow envelope dependent predistortion has to be also incorporated in the design of ET PAs. Experimental results showed that it is possible to find a compromise between the bandwidth and slew-rate reduction (necessary to cope with the specific envelope amplifier requirements) and the amount of drain efficiency degradation suffered due to the use of a slower version of the original envelope.
Title: Towards a statistical mechanics of cell fate decisions
Authors: García Ojalvo, Jordi; Martinez Arias, Alfonso
Title: An integrated fuzzy-based trustworthiness system for P2P communications in JXTA-overlay
Authors: Umezaki, K.; Spaho, Evjola; Barolli, Leonard; Xhafa Xhafa, Fatos; Younas, Muhammad; Iwashige, J.
Title: Effects of the addition of simple and double decoys on the purchasing process of airline tickets
Authors: González Prieto, David; Sallán Leyes, José María; Simó Guzmán, Pep; Carrion, Raimon
Abstract: Air ticket purchases can be considered to be based on sequential decision-making processes with a limited number of alternatives with clearly identified product attributes. With this scenario, decoy contextual effects could potentially be useful in increasing the profitability of each choice set through driving the attention of the users to a particular alternative by changing their perceptions, such as the perceived attractiveness of particular options, to benefit one specific alternative. This study validates the efficiency of the addition of decoy options in increasing the proportion of users who select the target option in a choice set and introduces, theoretically and empirically, the use of double decoys. Three distinct hypothetical choice sets are configured using two different types of decoy.
Title: EMI performance comparison of two-level and three-level inverters in small dc-link capacitors based motor drives
Authors: Maheshwari, RamKrishan; Munk-Nielsen, Stig; Busquets Monge, Sergio
Abstract: The size of passive components in an adjustable speed drive can be reduced by using small dc-link capacitors. The EMI filter in the drive also consists of passive components. The size of the filter can be reduced by using a three-level inverter, which can have low output voltage distortion. However, the three-level inverter based on small dc-link capacitors requires a PWM strategy to maintain neutral-point voltage balance. In this paper, the common mode voltage, which is the determining factor for the EMI filter size, is analyzed for a virtual-vector-based PWM strategy. The common mode voltage, the shaft voltage, and the conducted emission for the small dc-link capacitor based three-level inverter are compared with that of the two-level inverter operated with space vector PWM strategy. Experimental results for the common mode voltage, the shaft voltage, and the conducted emission are presented. Results show that the conducted emission from the three-level inverter is lower than that of the two-level inverter. Thus, a three-level inverter requires a smaller EMI filter in motor drives with small dc-link capacitors.
Title: La construccio del territori
Authors: Pié Ninot, Ricard
Title: El detall estratègic
Authors: Tudó Galí, Roger; Ricart Ulldemolins, Josep; Aguiló Aran, Claudi; Claret Martí, Jordi
Title: Notas sobre la marginalidad urbanística
Authors: Solà-Morales Rubió, Manuel de; Busquets Grau, Juan; Font Arellano, Antonio; Domingo Clota, Miguel
Title: Curs d'introducció a l'Arquitectura
Authors: Salvadó, Ton; Usandizaga Calparsoro, Miguel M.
Title: Non-functional requirements in architectural decision-making
Authors: Ameller, David; Ayala Martínez, Claudia Patricia; Cabot, Jordi; Franch Gutiérrez, Javier
Abstract: A survey of software architects addressed how they face non-functional requirements from an engineering perspective and how these requirements influence decision making.