Stanciuc, A.; Flamant, Q.; Sprecher, C.; Alini, M.; Anglada, M.; Peroglio, M. Journal of the european ceramic society Vol. 38, num. 3, p. 939-948 DOI: 10.1016/j.jeurceramsoc.2017.08.019 Fecha de publicación: 2018-03 Artículo de revista
Yttria-stabilised tetragonal zirconia polycrystals (3Y-TZP) bioinert ceramics combine excellent strength and toughness, good aesthetics, high resistance to corrosion and absence of allergic reaction. However, improved osseointegration is needed as higher marginal bone loss was sometimes reported. In the present work, 3Y-TZP multi-patterned samples for rapid screening of cell-surface interactions were fabricated by femtosecond laser micromachining. Pits with well-defined edges and micrometric precision in pit diameter, depth and spacing were produced, as determined by white light interferometry. Pits showed a nanometric granular texture on the sidewalls and ripples at pit bottom, as attested by scanning electron microscopy. Focused ion beam analyses indicated limited laser-induced damage. Micropatterns impacted human mesenchymal stem cell (hMSC) size and morphology. Cell area and aspect ratio were mainly influenced by pit diameter, while solidity and circularity were affected by both pit diameter and depth. The pattern 30. µm diameter/10. µm depth induced the strongest osteoblastic hMSC commitment.
Claverol, M.; García, A.; Garijo, D.; Seara, C.; Tejel, J. Computational geometry: theory and applications Vol. 68, p. 146-166 DOI: 10.1016/j.comgeo.2017.05.009 Fecha de publicación: 2018-03 Artículo de revista
We undertake a study on computing Hamiltonian alternating cycles and paths on bicolored point sets. This has been an intensively studied problem, not always with a solution, when the paths and cycles are also required to be plane. In this paper, we relax the constraint on the cycles and paths from being plane to being 1-plane, and deal with the same type of questions as those for the plane case, obtaining a remarkable variety of results. For point sets in general position, our main result is that it is always possible to obtain a 1-plane Hamiltonian alternating cycle. When the point set is in convex position, we prove that every Hamiltonian alternating cycle with minimum number of crossings is 1-plane, and provide O(n) and O(n2) time algorithms for computing, respectively, Hamiltonian alternating cycles and paths with minimum number of crossings.
Chicardi, E.; Bermejo, R.; Gotor, F.; Llanes, L.; Torres, Y. International journal of refractory metals and hard materials Vol. 71, p. 82-91 DOI: 10.1016/j.ijrmhm.2017.11.003 Fecha de publicación: 2018-02 Artículo de revista
The effect of the temperature on the mechanical strength of WC-Co cemented carbides with different microstructures (grain size and binder content) was evaluated. Biaxial flexural tests were performed on three cemented carbide grades at 600 °C using the ball-on-three-balls (B3B) method. Results were interpreted by Weibull statistics and compared to biaxial strength results at room temperature. A detailed fractographic analysis, supported by Linear Elastic Fracture Mechanics, was performed to differentiate the nature and size of critical defects and the mechanism responsible for the fracture. A significant decrease in the mechanical strength (around 30%) was observed at 600 °C for all grades of cemented carbides. This fact was ascribed to the change in the critical flaw population from sub-surface (at room temperature) to surface defects, associated with the selective oxidation of Co. Additionally, an estimation of the fracture toughness at 600 °C was attempted for the three cemented carbides, based upon the B3B strength results, the corresponding number of the tested specimens fragments and the macroscopic area of the B3B fracture surfaces. The fracture toughness was not affected by the temperature, at least up to 600 °C. In addition, the good agreement with the Single Edge Notch Beam toughness data suggests the possibility of employing this approach for fracture toughness evaluation of brittle materials under different testing conditions.
The contact of the coolant with the fuel pin during irradiation produces a gradient of temperature in the fuel pellet that segregates the radionuclides (RN) depending on its volatility and reactivity. This segregation determines the Instant Release Fraction (IRF), an important source of radiological risk in the performance assessment (PA) of a Deep Geologic Repository (DGR). RN segregation was studied radially in previous papers. In the present work, it was studied axially, taking into special consideration the cutting position of the solid sample to be studied. Iodine and caesium were the RN with the highest release, while the contribution of rubidium, strontium, molybdenum and technetium to the IRF depended on their chemical state. The interpellet presence (known also as dishing) effect was clearly observed for caesium, increasing its release by one order of magnitude. According to these results, one of the major contributions to the IRF comes from the RN trapped in the dishing and has to be considered in the sampling and data interpretation that will be performed for the PA of the DGR.
Tarrago, J.; Coureaux, D.; Torres, Y.; Jimenez-Pique, E.; Schneider, L.; Fair, J.; Llanes, L. International journal of refractory metals and hard materials Vol. 71, p. 221 DOI: 10.1016/j.ijrmhm.2017.11.031 Fecha de publicación: 2018-02 Artículo de revista
Strength and reliability of WC-Co cemented carbides (hardmetals) are dependent on effective fracture toughness as well as on nature, size and distribution of processing flaws. Regarding toughness, they exhibit a crack growth resistance (R-curve) behavior, derived from the development of a multiligament bridging zone at the crack wake. Accordingly, successful implementation of fracture mechanics requires consideration of tangency criterion, between applied stress intensity factor and R-curve, in addition to fractographic inspection. It is the aim of this study to evaluate the strength behavior of a series of experimental WC-Co grades on the basis of R-curve failure criteria. Results indicate that microstructural effects on the strength of hardmetals may be satisfactorily rationalized following the referred criterion. The analysis includes consideration of nature and distribution of fracture origins, found to be more diverse and wider, respectively, for the harder fine-grained grades. This experimental evidence, together with the fact that these hardmetals exhibit steeper rising R-curves than tougher coarse-grained ones, leads to lower reliability for the former. This investigation documents and validates the great relevance of R-curve behavior for optimizing the mechanical performance of WC-Co cemented carbides on the basis of microstructural design.
Roa, J.J.; Turon-Vinas, M.; Tovar-Vargas, D.; Ledesma, J.; Anglada, M. Ceramics international Vol. 44, num. 2, p. 2485-2490 DOI: 10.1016/j.ceramint.2017.10.226 Fecha de publicación: 2018-02-01 Artículo de revista
Tetragonal zirconia polycrystals doped with 3% mol of yttria (3Y-ZrO2) exhibit excellent mechanical properties and biocompatibility. However, under humid environments, their surface structural integrity is degraded by aging (low temperature degradation). Co-doping with Ceria by starting from mixtures of 3Y-ZrO2 and 12Ce-ZrO2 powders can increase the resistance to low temperature degradation. In this study, systematic chemical and nanomechanical measurements have been conducted in powder multilayers of the12Ce-ZrO2/3Y-ZrO2 system after sintering at different temperatures (from 1400 to 1600°C) during 2h in order to measure the distribution of diffusion of stabilizer solutes. The results indicate that the diffusion process zone at the 12Ce-ZrO2/3Y-ZrO2 interface increases with sintering temperature by following an Arrhenius equation. Measuring the hardness by nanoindentation through the diffusion zone gives similar activation energy at high sintering temperatures. At low sintering temperatures, nanoindentation has not enough resolution at low sintering temperatures for the sintering time used.
Phosphorus (P) is a vital macronutrient required to improve the agricultural yields but its excessive use as a fertilizer has resulted in pollution of water bodies leading to eutrophication. With no reserves of phosphorus source in Spain, increased dependence on phosphorus in agriculture have not only increased dependence on imports but also has raised concerns on its future availability as a resource. A Phosphorous Flow Analysis (PFA) was conducted for Spain for the year 2012 focusing on the food production and consumption systems. The results obtained were finally compared with PFA at both country level and continent level (EU-27). To quantify food and non-food flows systems, country specific data were considered. The sectors covered were crop production (CP), animal production (AP), food processing (FP), non-food production (NF) and consumption (HC). The findings reveal that a total of 325 kt P was imported by Spain in 2012; 66% of which was accumulated in markets stock of food and feed, fertilizers and non-food (91 kt P) while 33% was lost to the environment through land-fill, losses to water bodies, land accumulation and incineration. The largest proportion of losses is associated with water bodies (44.7 kt P) followed by agriculture and land accumulation (42.1 kt P). Wastewater treatment plants (WWTPs) received around 79.5 kt P within wastewater, with 60% being removed in sewage sludge. The 31.7 kt P discharged within final effluent represented the 71% of the total losses to water bodies. Around 69% of the sewage sludge was recycled to agriculture and 27% was sent directly to landfill including the ashes from incineration. Net accumulation was 1.84 kg P/cap which was similar to values reported for the EU-27 average (2.5 kg P/cap).
Guaya, D.; Valderrama, C.; Farran, A.; Sauras, T.; Cortina, J. Science of the total environment Vol. 612, p. 728-738 DOI: 10.1016/j.scitotenv.2017.08.248 Fecha de publicación: 2018-01-15 Artículo de revista
The removal of nutrients (nitrogen (N), phosphorous (P)) from waste water has become a resource recovery option in recent regulations worldwide, as observed in the European Union. Although both of these nutrients could be recovered from the sludge line, > 70–75% of the N and P is discharged into the water line. Efforts to improve the nutrient recovery ratios have focused on developing low-cost technologies that use sorption processes. In this study, a natural zeolite (clinoptilolite type) in its potassium (K) form was impregnated with hydrated metal oxides and used to prepare natural hybrid reactive sorbents (HRS) for the simultaneous recovery of ammonium (NH4 +) and phosphate (PO4 3 -) from treated urban waste water. Three unfertile soils (e.g., one acidic and two basic) amended with N-P-K charged HRS were leached with deionized water (e.g. to simulate infiltration in the field) at two- and three-day time intervals over 15 different leaching cycles (equivalent to 15 bed volumes). The N-P-K leaching profiles for the three charged hybrid sorbents exhibited continuous nutrient release, with their values dependent on the composition of minerals in the soils. In the basic soil that is rich in illite and calcite, the release of potassium (K+) and ammonium (NH4 +) is favoured by-ion exchange with calcium (Ca2 +) and accordingly diminishes the release of phosphate (PO4 3 -) due to its limited solubility in saturated calcite solutions (pH 8 to 9). The opposite is true for sandy soils that are rich in albite (both acidic and basic), whereas the release of NH4 + and K+ was limited and the values of both ions measured in the leaching solutions were below 1 mg/L. Their leaching solutions were poor in Ca2 +, and the release of PO4 3 - was higher (up to 12 mg P-PO4 3 -/L). The nutrient releases necessary for plant growth were provided continuously and were controlled primarily by the soil mineral dissolution rates fixing the soil aqueous solution composition (e.g. pH and ionic composition; in particular, the presence of calcite is a determinant for nutrient release, especially in alkaline soils). The N-P-K charged HRS sorbents that were used for soil amendment may be an alternative for avoiding nutrient leaching and reaching the goals of soil sustainability in agriculture and reducing the nutrient overloading of surface waters.
Buenestado, P.; Acho, L. Entropy: international and interdisciplinary journal of entropy and information studies Vol. 20, num. 46, p. 1-12 DOI: 10.3390/e20010046 Fecha de publicación: 2018-01-11 Artículo de revista
Image segmentation is defined as a partition realized to an image into homogeneous regions to modify it into something that is more meaningful and softer to examine. Although several segmentation approaches have been proposed recently, in this paper, we develop a new image segmentation method based on the statistical confidence interval tool along with the well-known Otsu algorithm. According to our numerical experiments, our method has a dissimilar performance in comparison to the standard Otsu algorithm to specially process images with speckle noise perturbation. Actually, the effect of the speckle noise entropy is almost filtered out by our algorithm. Furthermore, our approach is validated by employing some image samples.
In this paper a short introduction of human-computer interaction is presented taking into
account the relationship between interaction design and universal design. From the conference
Interaccion 2015, some selected papers in the field of interaction design for healthcare are presented,
Methods, tools, interface design, user evaluation are considered with the aim to improve the quality of
life of citizens using technology.
This paper investigates a three-dimensional finite-element (3D-FEA) thermal analysis based on an embedded cooling system with various number of ducts for the outer-rotor permanent magnet synchronous machines (PMSMs). The segmented stator core due to closed-slot topology is the reason of a high temperature-rise at this core. The application-oriented study is aimed to reduce temperature-rise of the conventional model at the stator core via radial and circumferential airflow ducts. A temperature distribution, and heat transfer comparison among all FE models such as conventional, two and four ducts in-core natural cooling systems will be comprehensively presented through freezing the electromagnetic performance. The alternative models using FEA, and computational fluid dynamic (CFD) are experimentally verified the innovative technique, in which the generator is operated by a vertical axis twisted savonius type wind turbine (VAWT).
Gomez, J.; Sanchez-Soto, M.; Maspoch, M. Composites. Part A, applied science and manufacturing Vol. 104, p. 1-13 DOI: 10.1016/j.compositesa.2017.10.014 Fecha de publicación: 2018-01-01 Artículo de revista
The aim of the present work is to analyze the morphology, mechanical properties and fracture behaviour of solid and foamed plates made of glass fiber-reinforced PP. The morphology exhibited a solid skin/foamed core structure, dependent on the foaming ratio. Simulation of the microcellular injection molding process with Moldex 3DR software provided a good approach to the experimental results. The flexural properties and impact resistance showed lower values as the apparent density decreased, but constant specific properties. The fracture characterization was carried out by determining the Crack Tip Opening Displacement (CTOD) at low strain rate, as well as the fracture toughness (KIc) at impact loading. Foamed specimens presented higher values of CTOD than the solid ones and higher as the foaming ratio increases, due to cells acting as crack arrestors by blunting the crack tip. However, the fracture toughness KIc decreased with decreasing the apparent density. Anisotropy due to fiber orientation was also observed. Fibers were aligned in the filling direction in the surface layers, while they were oriented in the transverse direction in the core. According to the amount of fibers oriented in one direction or another, different properties were obtained
Asef, P.; Bargallo, R.; Barzegaran, M.; lapthorn, A.; Mewes, D. Electric power systems research Vol. 154, p. 484-492 DOI: 10.1016/j.epsr.2017.08.041 Fecha de publicación: 2018-01-01 Artículo de revista
In this paper, the influence of gap consideration on load identification under various Halbach-array-based topologies (HABOs) is investigated while the system is on-duty. The load characteristics of a radial flux generator with closed-slots and the exterior rotor topology is discussed, where the effect of eddy-currents are observed. This comparative study deals with the consideration of the combined moment of inertia calculation that demonstrates how electromagnetic-based post processing calculations are estimated without the aid of nominal machine parameter values. The analysis was performed using a 2-D finite-element simulation of different HABOs with the gap consideration between the segments. Additionally, a comprehensive comparison with no gap is considered. Also, the dynamic analysis using an uncontrolled conventional rectifier model is used to derive effected key output parameters such as torque, output power, power factor, and line-to-line voltage. The major objective of the study is to determine corresponding load results in order to employ the most suitable and capable magnetization topology from the load perspective in the PM synchronous generator (PMSGs). Accordingly, the maximum power (MP) point was carried out to maximize the output DC power. With respect to the combined moment of inertia estimation, the load parameter estimation is verified experimentally on a surface-mounted PMSG using different magnetization topologies. Furthermore, commercial and environmental issues of the project are considered to reduce CO2 emissions as part of green power generation development.
Borroto-Ramírez, A.; Bruyère, S.; Thurieau, N.; Gendarme, C.; Jimenez-Pique, E.; Roa, J.J.; Pierson, J.F.; Mücklich, F.; Horwat, D. Journal of alloys and compounds Vol. 729, p. 137-143 DOI: 10.1016/j.jallcom.2017.09.153 Fecha de publicación: 2017-12-30 Artículo de revista
Zr1-xMox thin films were synthesized on glass substrates by co-sputtering molybdenum and zirconium targets in the presence of argon with x in the 0.32–0.95 range. From X-ray diffraction analyses and transmission electron microscopy images it was possible to observe an evolution of the samples structure from a nano-crystalline solid solution of Zr in the bcc lattice of Mo to clusters of Zr(Mo) nano-crystalline in an amorphous matrix. The coherence length deduced from X-ray diffractograms was around 1 nm–8 nm depending on the composition. Mechanical measurements show that the films exhibited high hardness H, low Young's modulus E and therefore high H/E ratio compared with the bulk of Zr and Mo. We also found a low friction coefficient values for all the samples. Finally, an inverse Hall-Petch effect was observed for coherence length lower than 6 nm.
En aquesta tesis, nous homooligopèptids derivats de fenilalanina ha estat sintetitzats per tal d'estudiar la seva capacitat d'autoorganització i examinar la influencia de l'estructura química i les condicions externes. Encara que les interaccions NH3+···-OOC cap-a-cua en els homopèptids desprotegits mostren estabilitzar les estructures peptídiques, s'han introduït funcionalitzacions químiques a través de la incorporació de proteccions a N- i C-, com per exemple, grups bloquejadors aromàtics, grups d'acoblament azida-alquí, l'anió trifluoroacetat o un bloc de polilàctide.Diferents capítols estan dedicats a mostrar que la llargada del bloc d'homopèptid també juga un paper rellevant en l'organització supramolecular dels derivats de fenilalanina.Els resultats publicats evidencien no només el control que exerceixen les característiques de l'ambient sinó també del substrat. Les interaccions pèptid··· pèptid, pèptid···superfície i la rugositat superficial han estat assenyalades com a factors clau que defineixen la forma, les dimensions i l'estabilitat de les estructures jerarquitzades.
This paper presents results to assure the almost sure
stability of switching stochastic nonlinear systems. The switching
rule governing the parameters of the system is driven by
independent and identically distributed random variables. In this
scenario, we prove that the switching nonlinear system is almost
surely stable when appropriate matrices have spectral radius
less than one. The result is particularly useful for applications,
as shown in the paper by the application for an automotive
electronic throttle device. The stability result was used to design
a real-time controller for the automotive throttle device, and the
experimental data confirm the usefulness of our approach.
Karabencheva, T.; Torras, J.; Mulholland, A.; Lodola, A.; Christov, C. Scientific reports Vol. 7, num. 17395, p. 1-15 DOI: 10.1038/s41598-017-17789-x Fecha de publicación: 2017-12-12 Artículo de revista
Tryptophan 7-halogenase catalyzes chlorination of free tryptophan to 7-chlorotryptophan, which is the first step in the antibiotic pyrrolnitrin biosynthesis. Many biologically and pharmaceutically active natural products contain chlorine and thus, an understanding of the mechanism of its introduction into organic molecules is important. Whilst enzyme-catalyzed chlorination is accomplished with ease, it remains a difficult task for the chemists. Therefore, utilizing enzymes in the synthesis of chlorinated organic compounds is important, and providing atomistic mechanistic insights about the reaction mechanism of tryptophan 7-halogenase is vital and timely. In this work, we examined a mechanism for the reaction of tryptophan chlorination, performed by tryptophan 7-halogenase, by calculating potential energy and free energy surfaces using two different Combined Quantum Mechanical/Molecular Mechanical (QM/MM) methods both employing Density Functional Theory (DFT) for the QM region. Both computational strategies agree on the nature of the rate-limiting step and provided close results for the reaction barriers of the two reaction steps. The calculations for both the potential energy and the free energy profiles showed very similar geometric features and hydrogen bonding interactions for the characterized stationary points.
We provide the explicit solution of a general second order linear difference equation via the computation of its associated Green function. This Green function is completely characterized and we obtain a closed expression for it using functions of two–variables, that we have called Chebyshev functions due to its intimate relation with the usual one–variable Chebyshev polynomials. In fact, we show that Chebyshev functions become Chebyshev polynomials if constant coefficients are considered.
Roitero, E.; Lasserre, F.; Roa, J.J.; Anglada, M.; Mücklich, F.; Jimenez-Pique, E. Journal of the european ceramic society Vol. 37, num. 15, p. 4876-4887 DOI: 10.1016/j.jeurceramsoc.2017.05.052 Fecha de publicación: 2017-12 Artículo de revista
The aim of this study is to characterize in detail the microstructural changes and collateral damage induced by direct laser patterning on the surface of dental-grade zirconia (3Y-TZP) employing an interference setup with the 532 and 355. nm harmonics of a Nd:YAG laser (pulse duration of 10. ns).Laser-material interaction mainly results in thermal effects for both wavelengths studied. Upon laser irradiation the material locally melts producing pattern and establishing a steep thermal gradient on the surface. This generates a. ~. 1. µm thick heat affected zone where microcracking, directional recrystallization, phase transformation (from tetragonal to monoclinic, t ¿. m) and texturization (ferroelastic domain switching) take place. In addition, surface coloration results from the activation of F-centers as a consequence of high energy radiation exposure. No chemical segregation or diffusion was detected. All these microstructural changes should be taken into account to ensure integrity and long-term reliability of the zirconia components.
Romanini, M.; Del Barrio, M.; Macovez, R.; Ruiz, M.; Capaccioli, S.; Tamarit, J. Ll. Scientific reports Vol. 7, num. 1346, p. 1-11 DOI: 10.1038/s41598-017-01464-2 Fecha de publicación: 2017-12-01 Artículo de revista
We probe the temperature- and pressure-dependent specific volume (v) and dipolar dynamics of the amorphous phase (in both the supercooled liquid and glass states) of the ternidazole drug (TDZ). Three molecular dynamic processes are identified by means of dielectric spectroscopy, namely the a relaxation, which vitrifies at the glass transition, a Johari-Goldstein ßJG relaxation, and an intramolecular process associated with the relaxation motion of the propanol chain of the TDZ molecule. The lineshapes of dielectric spectra characterized by the same relaxation time (isochronal spectra) are virtually identical, within the studied temperature and pressure ranges, so that the time-temperature-pressure superposition principle holds for TDZ. The a and ßJG relaxation times fulfil the density-dependent thermodynamic scaling: master curves result when they are plotted against the thermodynamic quantity Tv¿, with thermodynamic exponent ¿ approximately equal to 2. These results show that the dynamics of TDZ, a system characterized by strong hydrogen bonding, is characterized by an isomorphism similar to that of van-der-Waals systems. The low value of ¿ can be rationalized in terms of the relatively weak density-dependence of the dynamics of hydrogen-bonded systems.
Yang, J.; Roa, J.J.; Schwind, M.; Odén , M.; Johansonn Joesaar, M.; Llanes, L. Materials characterization Vol. 134, p. 302-310 DOI: 10.1016/j.matchar.2017.11.004 Fecha de publicación: 2017-12 Artículo de revista
The metallic binder phase dictates the toughening behavior of WC-Co cemented carbides (hardmetals), even though it occupies a relative small fraction of the composite. Studies on deformation and phase transformation of the binder constituent are scarce. Grinding represents a key manufacturing step in machining of hardmetal tools, and is well-recognized to induce surface integrity alterations. In this work, metallurgical alterations of the binder phase in ground WC-Co cemented carbides have been assessed by a combination of electron back scattered diffraction and transmission electron microscopy techniques. The Co-base binder experiences a martensitic phase transformation from fcc to hcp crystal structure, predominantly in the first 5 µm below the surface. The hcp fraction decreases gradually along a depth of 10 µm. Surface Co displays severe plastic deformation under the highest strain, resulting in formation of nanocrystalline grains in the first micrometer below the surface. Microstructural refinement within the binder phase is observed even at greater depth. Stacking faults were detected in most of the refined grains. The metallurgical alterations of the binder phase modify the local stress distribution during grinding, which affects the discerned subsurface microcracking. The resulting residual stress profile is the sum of multiple subsurface changes, such as phase transformation, severe plastic deformation and grain refinement, where it is discerned that the depth profile of the transformed hcp-Co fraction coincides with the grinding-induced residual stress profile.
López, P.; Pérez-Rodríguez, I.; Estrany, F.; Devesa, R. Journal of water supply research and technology (AQUA) Vol. 66, num. 8, p. 598-605 DOI: 10.2166/aqua.2017.183 Fecha de publicación: 2017-12-01 Artículo de revista
The role of sulfate and nitrate in the taste of drinking water is not entirely clear. Taste threshold concentrations (TTCs) were estimated for these two species by the 3-AFC method by a trained panel, as sodium and calcium salts. In both cases TTCs for nitrate were about 100 mg NO3/L, twice the usual reference value of international recommendations. TTCs for sulfate were about 160 mg SO4/L (sodium salt) and 80 mg SO4/L (calcium); 75% detection values were also estimated for both anions. An experiment with a series of duo-trio tests plus preference showed that sulfate at low concentrations tended to improve the taste of water. However, at high concentrations it was perceived negatively: salty and bitter were the main descriptors used. The reversion concentration took place between 176 and 259 mg SO4/L. These results indicate that nitrate has to be considered an important issue for health, but with no relevant role in the taste of water. Sulfate shows a positive influence at moderate concentrations but becomes negative at high levels. The usual aesthetic-based level of 250 mg/L established by international regulations appears to be reasonable. The findings of this study with trained panellists are preliminary. Future research with consumer panels is recommended.
Properties related with the charge storage capacity have been evaluated for three-layered films made with two sheets of poly(3,4-ethylenedioxythiophene) separated by a sheet of poly(N-methylpyrrole) or poly(3,4-ethylenedioxythiophene-co-N-methylpyrrole) (3l-PEDOT/PNMPy or 3l-PEDOT/P(EDOT-co-NMPy), respectively). The most distinctive trend of the copolymer, which shows electrochemical properties intermediate between those of the two homopolymers, is the formation of a biphasic structure, EDOT- and NMPy-rich blocks organizing separately. The ability to exchange charge reversibly is higher for 3l-PEDOT/P(EDOT-co-NMPy) than for 3l-PEDOT/PNMPy, the electroactivity and electrostability of such two 3-layered films being significantly better than that of single-layered PEDOT. Advantages of 3l-PEDOT/P(EDOT-co-NMPy) are mainly based on the nanophase-segregated structure of the copolymer. Thus, the intermediate layer can be considered as random disposition of ultrathin dielectrics having nanometric length and width. In terms of charge storage, the intermediate layer of 3l-PEDOT/P(EDOT-co-NMPy) can be viewed as a thin reservoir filled of heterogeneously distributed nanometric supercapacitors that are connected in series among them and in parallel to the PEDOT layers. The superiority of 3l-PEDOT/P(EDOT-co-NMPy) as organic electrochemical supercapacitor compared to other 3-layered systems, has been proved by powering a red LED bulb.
Lähde, A.; Chimentao, R.; Karhunen, T.; Alvarez , M.; Llorca, J.; Medina, F.; Jokiniemi, J.; Modesto, L. Advanced powder technology Vol. 28, num. 12, p. 3296-3306 DOI: 10.1016/j.apt.2017.10.009 Fecha de publicación: 2017-12 Artículo de revista
The catalytic properties of Co-Al spinel nanoparticles prepared by liquid-feed flame spray pyrolysis (L-F FSP) were investigated in the glycerol conversion in gas phase in an atmosphere of hydrogen. Reduction at 1123¿K of the as-synthesized spinel nanoparticles induced the formation a new phase containing metallic cobalt species. Although, the reducibility of cobalt oxides is greatly decreased due to interaction with aluminium species, this strong interaction may prevent the aggregation of Co particles under the harsh reduction conditions. X-ray photoelectron spectroscopy (XPS) of the reduced spinel nanoparticles at 1123¿K revealed that the Co/Al atomic ratio has decreased to Co/Al¿=¿0.11, which may indicate a redistribution of the aluminum and cobalt species at the surface of the sample submitted to the reduction in a flow of hydrogen at 1123¿K. X-ray diffraction (XRD) and high resolution electron microscopy (HRTEM) also reinforced the formation of metallic cobalt species after reduction of cobalt from the spinel nanoparticles at 1123¿K. The main products obtained from the conversion of glycerol in the gas phase were hydroxyacetone, pyruvaldehyde, lactic acid and lactide. FSP ensured uniform dispersion of the active metal on a support material.
González, N.; Custal, M.A.; Tomara, G.; Psarras, G.; Riba, J.; Armelin, E. European polymer journal Vol. 97, p. 57-67 DOI: 10.1016/j.eurpolymj.2017.10.001 Fecha de publicación: 2017-12 Artículo de revista
Natural rubber (NR) nanocomposites have been prepared with hydroxylated barium titanate filler (BaTiO3-OH), employing emulsion polymerization followed by vulcanization process. The addition of barium titanate, a compound with high dielectric permittivity, was envisaged to increase the insulating properties of NR films, thereby reducing the electrical stress and the possibility of undesired arcing on their surfaces. The content of perovskite particles greatly affected both, the mechanical and the electrical properties, of the vulcanized films. It was observed that the optimum functionalized nanoparticle concentration is around 0.25–0.50 phr, range in which the elongation of break was maintained between 874–935% and the tensile strength was between 4.40–4.80 MPa; whereas the dielectric permittivity (¿') is slightly lower than the pristine NR or the NR compounded with high content of BaTiO3 nanoparticles. The dielectric study revealed the presence of two dielectric relaxation modes: (i) glass to rubber transition (a-relaxation) and (ii) interfacial polarization (IP), known as Maxwell-Wagner-Sillars (MWS) polarization. The comparison between small concentrations of non-functionalized and functionalized BaTiO3 inside NR polymeric films lead to the conclusion that the dielectric breakdown strength is high for non-functionalized fillers, supposedly due to less IP polarization phenomena.
Brizuela, A.; Pérez, E.; Jiménez, A.; Gil, J.; Manero, J.; Punset, M.; Chávarri, D.; Diéguez, M.; Monticelli, F. Biomed Research International Vol. 2017, p. 1-10 DOI: 10.1155/2017/2785863 Fecha de publicación: 2017-11-29 Artículo de revista
Aznar, A.; LLoveras, P.; Romanini, M.; Del Barrio, M.; Tamarit, J. Ll.; Cazorla, C.; Errandonea, D.; Mathur, N.; Planes, A.; Moya, X.; Mañosa Carrera, Lluis Nature communications num. 8, p. 1-6 DOI: 10.1038/s41467-017-01898-2 Fecha de publicación: 2017-11-29 Artículo de revista
Current interest in barocaloric effects has been stimulated by the discovery that these pressure-driven thermal changes can be giant near ferroic phase transitions in materials that display magnetic or electrical order. Here we demonstrate giant inverse barocaloric effects in the solid electrolyte AgI, near its superionic phase transition at ~420 K. Over a wide range of temperatures, hydrostatic pressure changes of 2.5 kbar yield large and reversible barocaloric effects, resulting in large values of refrigerant capacity. Moreover, the peak values of isothermal entropy change (60 J K-1 kg-1 or 0.34 J K-1 cm-3) and adiabatic temperature changes (18 K), which we identify for a starting temperature of 390 K, exceed all values previously recorded for barocaloric materials. Our work should therefore inspire the study of barocaloric effects in a wide range of solid electrolytes, as well as the parallel development of cooling devices.
Fraioli, R.; Tsimbouri, P.; Fisher, L.; Nobbs, A.; Su, B.; Neubauer, S.; Rechenmacher, F.; Kessler, H.; Ginebra, M.P.; Dalby, M.; Manero, J.; Mas-Moruno, C. Scientific reports Vol. 7, p. 1-13 DOI: 10.1038/s41598-017-16385-3 Fecha de publicación: 2017-11-27 Artículo de revista
Engineering the interface between biomaterials and tissues is important to increase implant lifetime and avoid failures and revision surgeries. Permanent devices should enhance attachment and differentiation of stem cells, responsible for injured tissue repair, and simultaneously discourage bacterial colonization; this represents a major challenge. To take first steps towards such a multifunctional surface we propose merging topographical and biochemical cues on the surface of a clinically relevant material such as titanium. In detail, our strategy combines antibacterial nanotopographical features with integrin selective synthetic ligands that can rescue the adhesive capacity of the surfaces and instruct mesenchymal stem cell (MSC) response. To this end, a smooth substrate and two different high aspect ratio topographies have been produced and coated either with an avß3-selective peptidomimetic, an a5ß1-selective peptidomimetic, or an RGD/PHSRN peptidic molecule. Results showed that antibacterial effects of the substrates could be maintained when tested on pathogenic Pseudomonas aeruginosa. Further, functionalization increased MSC adhesion to the surfaces and the avß3-selective peptidomimetic-coated nanotopographies promoted osteogenesis. Such a dual physicochemical approach to achieve multifunctional surfaces represents a first step in the design of novel cell-instructive biomaterial surfaces.
Gebbia, J.; Ramos , M.; Szewczyk, D.; Jezowski, A.; Krivchikov, A.; Horbatenko, Y.; Guidi, T.; Bermejo, F. J.; Tamarit, J. Ll. Physical review letters Vol. 119, num. 21, p. 215506-1-215506-6 DOI: 10.1103/PhysRevLett.119.215506 Fecha de publicación: 2017-11-21 Artículo de revista
The low-temperature thermal and transport properties of an unusual kind of crystal exhibiting minimal molecular positional and tilting disorder have been measured. The material, namely, low-dimensional, highly anisotropic pentachloronitrobenzene has a layered structure of rhombohedral parallel planes in which the molecules execute large-amplitude in-plane as well as concurrent out-of-plane librational motions. Our study reveals that low-temperature glassy anomalies can be found in a system with minimal disorder due to the freezing of (mostly in-plane) reorientational jumps of molecules between equivalent crystallographic positions with partial site occupation. Our findings will pave the way to a deeper understanding of the origin of the above-mentioned universal glassy properties at low temperature.
The family of compounds CBrnCl4-n has been proven helpful in unraveling microscopic mechanisms responsible for glassy behavior. Some of the family members show translational ordered phases with minimal disorder which appears to reveal glassy features, thus deserving special attention in the search for universal glass anomalies. In this work, we studied CBrCl3 dynamics by performing extensive molecular dynamics simulations. Molecules of this compound perform reorientational discrete jumps, where the atoms exchange equivalent positions among each other revealing a cage-orientational jump motion fully comparable to the cage-rototranslational jump motion in supercooled liquids. Correlation times were calculated from rotational autocorrelation functions showing good agreement with previous reported dielectric results. From mean waiting and persistence times calculated directly from trajectory results, we are able to explain which microscopic mechanisms lead to characteristic times associated with a- and ß-relaxation times measured experimentally. We found that two nonequivalent groups of molecules have a longer characteristic time than the other two nonequivalent groups, both of them belonging to the asymmetric unit of the monoclinic (C2/c) lattice.
The global trend on energy integration and building efficiency is making both researchers
and building developers look for technical solutions to use facade surfaces for energy harvesting.
In this work, the assessment of the thermal performance of a double-skin facade (DSF) with a venetian
blind-type of structure used as a solar thermal collector by means of computational fluid dynamics
(CFD) is presented. A Venetian blind collector would allow for heat rejection/energy harvesting and
exterior views simultaneously and can be easily integrated into the DSF aesthetical design. For the
purposes of this study, the modeled facades (south, west, and east-oriented) were set to be located in
Barcelona (Spain), where large solar gains are a constant condition throughout the year, and such
large semi-transparent envelopes lead to interior over-heating in buildings, even during the winter.
For the studied facades, both the reductions in radiative heat gains entering the building and the heat
recovery in the Venetian blind collector were evaluated for a yearlong operation.
Khelfa, T.; Rekik, M.; Muñoz, J.; Cabrera, J.; Khitouni, M. International journal of advanced manufacturing technology p. 1-13 DOI: 10.1007/s00170-017-1310-1 Fecha de publicación: 2017-11-08 Artículo de revista
The microstructure, mechanical properties, and strengthening mechanisms of an Al-Mg-Si alloy (AA6060) subjected to severe plastic deformation using equal channel angular pressing (ECAP) were investigated. Samples were passed through a die with an inner angle of F = 90° and outer arc of curvature of ¿ = 37° at room temperature up to 12 passes via route Bc. Electron backscatter diffraction (EBSD) was used to evaluate the microstructure and misorientation boundaries. The microstructure showed a large fraction of low-angle boundaries associated with subgrain formation in the first ECAP pass, while after eight and 12 passes, a heterogeneous ultrafine grain structure with an average grain size around 0.57 and 0.47 µm, respectively, was obtained. In order to characterize the mechanical properties, microhardness and tensile tests were carried out. Results of mechanical property tests show that microhardness, yield stress, and ultimate tensile strength increase as ECAP pass number increases up to a maximum value of 120 HV, 344 MPa, and 355 MPa, respectively, after five passes. The Hall–Petch effect, dislocation, solid solution, and precipitation strengthening were evaluated to determine the dependence of the yield stress on the ECAP pass number. The results show that the strength effect arises from the subgrain microstructure rather than from the high-angle grain boundaries developed.
The conversion of infrared light to visible-light which allows a larger fraction of sun-light to be used is needed to improve light-harvesting. In this work a tri-functional material composed of an up-converter (NaYF4–Yb–Tm), plasmonic gold nanorods and CdS was made photocatalytically active using 980 nm wavelength light for the reduction of H+ to H2.
Eduardo Prieto-Araujo; Junyent, A.; Collados, C.; Clariana, G.; Gomis-Bellmunt, O. Electric power systems research Vol. 152, p. 424-437 DOI: 10.1016/j.epsr.2017.06.020 Fecha de publicación: 2017-11 Artículo de revista
This paper describes a control design strategy of Modular Multilevel Converters (MMC) for High Voltage Direct Current (HVDC) applications to operate during normal and AC fault conditions. First, a steady state analysis of the converter is performed to identify the uses of the current components within the control strategy. Based on the initial stationary study, a complete converter control structure is proposed, which enables full control of the MMC internal energy during normal and AC fault conditions. A detailed design procedure is included for the current and energy regulators, in order to be able to ensure a dynamic response under any grid condition. Finally, theoretical developments are validated through simulation results by means of a detailed model in normal operation and during an AC voltage sag.
Atout, H.; Alvarez , M.; Chebli, D.; Bouguettoucha, A.; Tichit, D.; Medina Cabello, Francisco; Llorca, J. Materials research bulletin Vol. 95, p. 578-587 DOI: 10.1016/j.materresbull.2017.08.029 Fecha de publicación: 2017-11 Artículo de revista
In this study, two different preparation methods of titanium dioxide nanoparticles/reduced graphene oxide nanocomposites were investigated using direct sol-gel method followed by hydrothermal treatment or simple hydrothermal route. A different amount of graphene (1- 20%) was mixed with TiO2 for both series of samples in order to improve the photocatalytic activity. The influence of the preparation method on the physico-chemical properties was established by different characterization methods and the photocatalytic degradation of methylene blue (MB) under UV light irradiation was used as test reaction. The highest photocatalytic activity was observed for the nanocomposites containing 10 wt% of graphene. The elimination of MB can reach 93% and 82% for the nanocomposites with 10 wt% graphene prepared by the sol-gel and hydrothermal methods, respectively. These photocatalysts are promising for practical application in nanotechnology.
Millan, O.; Salazar, J.; Chavez-Dominguez, J. A.; Turo, A.; Garcia, M. IEEE transactions on instrumentation and measurement Vol. 66, num. 11, p. 2845-2851 DOI: 10.1109/TIM.2017.2731018 Fecha de publicación: 2017-11 Artículo de revista
The objective of this paper is to measure the zero-flow offset variation in ultrasonic Clamp-on flowmeters produced by using pipes made of materials with a nonhomogeneous and nonlinear behavior. The evaluation of this phenomenon has been tested by the experimental measurement, the experiments consist of measuring the variation in the flow measurement when in ``no-flow condition,'' the transducers are moved along the pipe. Experimental results reveal that the reciprocity criterion is not fulfilled when nonhomogeneous and nonlinear pipe materials are used. Consequently, in these types of pipes materials, it is necessary to calibrate the offset when transducers are installed, and probably will need recalibration if the transducers are displaced to another position on the pipe. However, in installations, where it is not possible to stop flow in order to calibrate, the flowmeter will have an error in the measured value and this error will depend on the acoustic characteristics of the pipe material.
Schönleber, K.; Eduardo Prieto-Araujo; Ratés, S.; Gomis-Bellmunt, O. Electric power systems research Vol. 152, p. 148-159 DOI: 10.1016/j.epsr.2017.06.026 Fecha de publicación: 2017-11 Artículo de revista
High-voltage DC (HVDC) connections enable integration of wind power plants located very far from shore. The decoupled AC offshore grid comprises multiple WT converters, and the voltage magnitude and frequency is primarily controlled by the offshore high-voltage DC voltage-source converter (VSC-HVDC). Faults in the offshore grid challenge the connected converters to provide an adequate response improving the overall fault behavior. Of special interest are asymmetrical faults due to the resulting unbalanced voltage conditions. This article addresses such conditions in the offshore grid and analyzes the impact on the offshore grid behavior for different converter contributions. Four fault ride-through strategies are studied for the WT converters. The effect of over-modulation of the converter voltages during such voltage conditions is highlighted. A test system is defined to analyze the fault and post-fault behavior. It is found that voltage support from the WT converters in both positive and negative sequence shows the best performance compared to controlled negative sequence current suppression. This scheme helps additionally the VSC-HVDC AC voltage control to return quickly to normal operation. To validate this statement simulations are performed for line-to-line (LL) and single line-to-ground (SLG) faults in immediate vicinity of the VSC-HVDC.
Gallinetti, S.; Mestres, G.; Canal, C.; Persson, C.; Ginebra, M.P. Journal of the mechanical behavior of biomedical materials Vol. 75, p. 495-503 DOI: 10.1016/j.jmbbm.2017.08.017 Fecha de publicación: 2017-11-01 Artículo de revista
Calcium phosphate cements (CPCs) are extensively used as synthetic bone grafts, but their poor toughness limits their use to non-load-bearing applications. Reinforcement through introduction of fibers and yarns has been evaluated in various studies but always resulted in a decrease in elastic modulus or bending strength when compared to the CPC matrix. The aim of the present work was to improve the interfacial adhesion between fibers and matrix to obtain tougher biocompatible fiber-reinforced calcium phosphate cements (FRCPCs). This was done by adding a polymer solution to the matrix, with chemical affinity to the reinforcing chitosan fibers, namely trimethyl chitosan (TMC). The improved wettability and chemical affinity of the chitosan fibers with the TMC in the liquid phase led to an enhancement of the interfacial adhesion. This resulted in an increase of the work of fracture (several hundred-fold increase), while the elastic modulus and bending strength were maintained similar to the materials without additives. Additionally the TMC-modified CPCs showed suitable biocompatibility with an osteoblastic cell line.
Dombayci, C.; Espuña, A. International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management p. 147-154 DOI: 10.5220/0006485201470154 Fecha de presentación: 2017-11 Presentación de trabajo en congreso
Las secuencias ricas en AT le confieren al ADN propiedades únicas como un alto polimorfismo y flexibilidad. Su abundancia en el genoma de varios patógenos y la selectividad de unión a secuencias AT que presentan ciertas moléculas, han llevado al estudio de ligandos que interactúan con el surco estrecho de DNA con alto contenido en AT. De especial interés son los parásitos kinetoplástidos, como el Trypanosoma brucei, agente causante de la enfermedad del sueño, los cuales se distinguen por la presencia de una estructura de ADN mitocondrial muy rica en AT llamada kinetoplasto.Los ligandos de unión al surco estrecho han ofrecido información primordial sobre el reconocimiento molecular del ADN, proporcionando estrategias terapéuticas útiles. Por ello, se ha elegido como objeto de estudio complejos de ADN ricos en AT con diferentes ligandos, específicamente con proteínas HMG y compuestos bisimidazolinio.Las HMG son una familia de proteínas arquitectónicas que se unen al ADN e influyen en numerosos procesos celulares esenciales. En este trabajo se han estudiado dos subfamilias de las HMG: HMGA y HMGB. Ambas se unen al surco estrecho del ADN mediante diferentes motivos de unión: AT-hook (HMGA) y HMG-box (HMGB). Se han expresado y purificado las formas HMGA1a(50-91), HMGB1 box B y HMGB1 box AB. Mediante SPR, ambas proteínas presentaron una afinidad de unión alta y similar hacia un ADN conteniendo la secuencia [AATAAT_ATTATT]. Se cristalizó el complejo d[CCAATAATCGCGATTATTGG]2- HMGB1 box B. La difracción a una resolución de 2.68 Å presentó reflexiones bien definidas que indicaban dos orientaciones preferenciales.Una serie de derivados del compuesto FR60 [4-((4,5-dihidro-1H-imidazol-2-il)amino)-N-(4-((4,5-dihidro-1H-imidazol-2-il)amino)fenil)benzamida] han demostrado ser ligandos de alta afinidad por secuencias AT con respecto a GC, mostrando cierta preferencia hacia secuencias con [AATT] comparado con [(AT)4] o [AATAAT_ATTATT]. Además, se ha demostrado que el JNI18 compite con la HMGA1a y la HMGB1 en su unión al ADN y es capaz de desplazar a dichas proteínas de sus sitios de unión al ADN. Este hecho es de especial relevancia, ya que se han encontrado proteínas relacionadas que son esenciales en parásitos kinetoplástidos.La estructura del compuesto de bis(2-aminoimidazolinio) CDIV32 con el oligonucleótido d[AAATTT]2 ha sido parcialmente resuelta a una resolución de 3.10 Å. Se encontraron columnas de oligonucleótidos apilados formando una hélice pseudo-continua, empaquetada en una configuración de columnas cruzadas perpendicularmente. La presencia del fármaco CDIV32 modula la organización de las hélices de ADN.Se ha resuelto la estructura cristalográfica del complejo d[AAATTT]2-FR60 a resolución atómica de 1.25 Å (PDB-ID: 5LIT). Se encontraron los oligonucleótidos apilados organizados en columnas infinitas y paralelas en una configuración pseudo-tetragonal. El fármaco interacciona con la región central [AATT], ocupa el surco estrecho del ADN, desplaza las moléculas de agua presentes e interactúa con moléculas de ADN vecinas como un agente entrecruzador.Finalmente, se ha realizado un análisis funcional del efecto de diferentes compuestos bis(2-aminoimidazolinio) en T. brucei (con >70% de AT en su kDNA) para evaluar si el ADN del parásito es una diana para estos compuestos. Se ha estudiado su efecto in vitro mediante una combinación decitometría de flujo y técnicas como microscopía de fluorescencia y TEM. Los resultados permitieron demostrar que estos compuestos tienen un efecto claro sobre la fase S del ciclo celular de T. brucei al dañar específicamente el kinetoplasto. Se ha podido concluir que los compuestos FR60 y JNI18 son potentes tripanocidas que actúan directamente sobre el ADN del kinetoplasto. Ya que los compuestos muestran una actividad curativa del 100% en un modelo de ratón infectado por T. b. rhodesiense, representan un agente quimioterapéutico potencialmente eficaz para el tratamiento de la enfermedad del sueño.
Canal, C.; Khurana, K.; Labay, C.; Gallinetti, S.; Ginebra, M.P. Symposium and Annual Meeting of the International Society for Ceramics in Medicine p. 64 Fecha de presentación: 2017-10-25 Presentación de trabajo en congreso
Molina, B.; Bendrea, A.; Cianga, L.; Armelin, E.; del Valle, LJ.; Cianga, Ioan; Aleman, C. Polymer chemistry Vol. 8, num. 39, p. 6112-6122 DOI: 10.1039/c7py01326d Fecha de publicación: 2017-10-21 Artículo de revista
Amphiphilic copolymers consisting of an all conjugated polythiophene backbone and sparsely attached oligo-¿-caprolactone side chains have been prepared by anodic electropolymerization of hydroxymethyl-3,4-ethylenedioxythiophene (HMeEDOT) with a thiophene-ended oligo-¿-caprolactone macromonomer (Th-PCL), obtained by ring opening polymerization of ¿-caprolactone with thiophene methanol. The random copolymers, obtained starting from two different molar ratios of the co-monomers in the feed (HMeEDOT :&Th-PCL of 80&:&20 and 60&:&40), and the homopolymer (PHMeEDOT) were synthesized by using three different working electrodes. After structural characterization by FTIR, the electrochemical, morphological and surface properties of the obtained copolymers were examined, and the results evidenced a dependence on both the working electrode and the composition in the feed. In order to evaluate the opportunities in the copolymers's further bioapplications, biodegradability, cytotoxicity and cell proliferation investigations were carried out. By combining the results of electrochemical characterization with those of biocompatibility and dopamine sensing capability tests, it was concluded that a co-monomer feed ratio of 80&:&20 could be the optimal choice for the potential use of these amphiphilic copolymers in sensing devices. All in all, this study shows the benefit of a designed "hairy-rod" conjugated polymeric architecture which, via their side chain nature (biocompatible/biodegradable, hydrophobic, oligomeric) and their grafting density, enabled the synthesis of a material for targeted application.
Amphiphilic copolymers consisting of an all conjugated polythiophene backbone and sparsely attached oligo-¿-caprolactone side chains have been prepared by anodic electropolymerization of hydroxymethyl-3,4-ethylenedioxythiophene (HMeEDOT) with a thiophene-ended oligo-¿-caprolactone macromonomer (Th-PCL), obtained by ring opening polymerization of ¿-caprolactone with thiophene methanol. The random copolymers, obtained starting from two different molar ratios of the co-monomers in the feed (HMeEDOT :&Th-PCL of 80&:&20 and 60&:&40), and the homopolymer (PHMeEDOT) were synthesized by using three different working electrodes. After structural characterization by FTIR, the electrochemical, morphological and surface properties of the obtained copolymers were examined, and the results evidenced a dependence on both the working electrode and the composition in the feed. In order to evaluate the opportunities in the copolymers's further bioapplications, biodegradability, cytotoxicity and cell proliferation investigations were carried out. By combining the results of electrochemical characterization with those of biocompatibility and dopamine sensing capability tests, it was concluded that a co-monomer feed ratio of 80&:&20 could be the optimal choice for the potential use of these amphiphilic copolymers in sensing devices. All in all, this study shows the benefit of a designed
This paper presents a vibration control design to
the string-tip-mass system by using a non-symmetric peakdetector
mechanism. Previously, this peak-detector system was
used as an easy algorithm to mitigate vibration on a real flexible
structure. Moreover, its mathematical representation is simple
and it just has two parameters to tune. Following this former
experience, we adequate this strategy to the vibration control
of the string-tip-mass system. Finally, and according to our
numerical experiments, our control performance is better than
the boundary damper control here programmed for comparison