Aplicación del método SPH al estudio hidráulico de estructuras. Análisis hidrodinámico del aliviadero en pozo de la presa de Nagore (Navarra)

ResumenSon muchos los trabajos de calibración realizados que avalan la validez del método de hidrodinámica suavizada de partículas (SPH) para el análisis de flujos turbulentos en lámina libre. Sin embargo, sus altos requerimientos computacionales no permitían su empleo en trabajos reales. El desarrollo de las técnicas de supercomputación en unidades de procesamiento gráfico (GPU) ha modificado esta situación y está permitiendo su utilización como herramienta de diseño.CEDEX ha desarrollado el modelo SPHERIMENTAL basado en esta tecnología con el fin de apoyar los experimentos realizados con modelación física. Esto ha permitido calibrar el modelo y emplearlo en el estudio de fenómenos complejos.Se presentan los trabajos realizados para la comprobación hidrodinámica de flujos en lámina libre del aliviadero en pozo de la presa de Nagore (Navarra), describiendo tanto los trabajos de calibración previos como los resultados obtenidos.AbstractMany calibration works have been performed to support the validity of the smoothed particle hydrodynamics (SPH) method for studying turbulent-free surface flows. However, its high computational requirements made it difficult to use in real cases. The development of techniques for supercomputing graphics processing units (GPU) has changed this situation, and is allowing its use as a design tool.CEDEX has developed a model based on this technology, SPHERIMENTAL, in order to support studies on physical modelling. This has enabled the model to be calibrated in order to study complex phenomena.This paper shows the works done to check the hydrodynamics free surface flows in the Nagore dam morning glory spillway, describing both the previous calibration works and the results obtained

Synthesis, characterization and photo physical-theoretical analysis of D-π-A compounds. 2. Chain length effect through even-odd effect on the photophysical properties

In the continuous search for new compounds for solar devices, the family of dipolar D-π-A molecules, which have a donor (D) and an acceptor (A) charge joined by a conjugate bridge, have been the focus of attention in the recent years due their different properties. As we have shown before, there is a connection between the geometry of molecules based on tertiary asymmetric amines and their quantum yield. In the current work, four new compounds based on the same backbone molecule ((E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenylamino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid), but with different substituent, were synthesized. It is shown that the chain-size of the substituent group modifies the quantum yield. The news substituents introduced are a propyl (M8-3), butyl (M8-4), pentyl (M8-5) or hexyl (M8-6) group. In general, it was possible to see that the new substituents were able to increase their performances. Furthermore, an odd-even substituent effect, between propyl/pentyl and butyl/hexyl, was found and the theoretical geometrical data was able to follow the trend. However, theoretically, this substituent effect was inverted in the case of M8-3 and M8-4, which may be due to the disappearance in the emission patterns of an excited state close to 450 nm (at λ2), as it was shown in the experimental data. The most suitable behaviour belongs to [(E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenyl(propyl)amino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid] (M8-3). M8-3 has the highest quantum yields on average in all studied solvents; even higher than the last reported compounds with methyl (M8-1) and ethyl (M8-2) groups. Theoretically, the most likely explanation is that the dihedral angle formed between the carbonyl acceptor and nitrogen electron donor (Aryl-CO), should be as small as the molecule M8-3. This isolated compound has an average quantum yield including all solvents of 58.1% (average value), showing that a long group is not necessary to improve the performance

Relationship between photo-physical and electrochemical properties of D-π-A compounds regarding solar cell applications. 1. Substituent type effect in photovoltaic performance

Studying the electrochemical characteristics is an important step for determining interactions between molecules and the chemical environment. Moreover, the electrochemical evaluation of dyes is highly needed to establish the behavior of electro-active chemical species inside dye-sensitized solar cells (DSSCs). Four compounds, M8-1, M8-2, M8-O1, and M8-O2 (with a common organic structure (E)-2-cyano-3-(5-((E)-2-(9,9-diethyl-7-(phenylamino)-9H-fluoren-2-yl)vinyl)thiophen-2-yl)acrylic acid), are studied in two solvents, tetrahydrofuran (THF) and dimethylsulfoxide (DMSO). Among the studied compounds, M8-1 has highlighted characteristics compared with the others: its ground and excited states oxidation potential are the highest (1.14 and −1.22 V, respectively). Also, it shows the lowest energy gap between the excited state oxidation potential and the TiO2 conduction band. Relating to the substituent effect, the shorter the length, the higher the energetic difference in the electronic transition (M8-1 and 2). Comparing characteristics through quantum chemistry, the values obtained in DMSO are the most predictable. The injection energies signal that M8-1 is the best injector. The performances in solar cells are measured in three TiO2 materials: Degussa (D-TiO2), active opaque (A-TiO2), and transparent (T-TiO2). The IPCE results show the A > T > D average tendency, and the family of substituted alkyl has higher values than the alcoxyl one. Furthermore, in the first family the methyl substituent has a higher value than the ethyl one. M8-1 has the highest IPCE value, on average. In terms of efficiency, the alkyl substituted family again has higher values than the alcoxyl family. On average, the methyl substituent has a higher value than the ethyl one in both families. M8-1 has the highest efficiency value

Synthesis, Characterization, Morphology and Photovoltaic Properties of Aniline-Tiophene Based Polymers

Monomers composed of thiophene and aniline rings, 4-(2-thiophen)aniline and 4-(3-thiophen)aniline, were successfully synthetized through the Suzuki-Miyaura cross coupling reaction and then polymerized. The polymers poly 4-(2-tiophen)aniline and poly 4-(3-tiophen)aniline (P4,2TA and P4,3TA) were characterized via spectroscopycal NMR, optical and electrochemical methodologies. Subsequently the morphology of deposits were characterized using atomic force microscopy (AFM) and X-ray diffraction (XRD). The photovoltaic devices were constructed under the same conditions, observing differences in the photovoltaic yield of each polymer. P4,2TA exhibited higher photovoltaic yield in comparison with P4,3TA, indicating that the molecular geometry affects the crystallinity and surface morphology of the polymeric deposits, and the photovoltaic propertie

Oligo(benzo[c]thiophene-2-oxide) a poly(isothianaphthene) derivative with good photovoltaic properties

To improve the performances of organic solar cells, many efforts have been devoted to the synthesis of new compounds whose absorption spectra allow a better matching with that of the solar spectrum. To that respect, a new poly(isothianaphthene) derivative, with a low band gap, called, poly(benzo[c]thiophene-2-oxide), was synthesized and characterized by elemental analysis, UV–vis, FT-IR, 1H NMR and XPS spectroscopy. The polymer synthesis was performed from 1,3-dihydrobenzo[c]thiophene-2-oxide by oxidative coupling using sulphuric acid in methanol as oxidizing agent in the presence of air. Oligomers have an optical band gap of 1.8 eV. The oligomeric film prepared under high vacuum was probed in photovoltaic devices as an electron donor. Photovoltaic devices based on Glass/ITO/MoO3(3 nm)/poly(benzo[c]thiophene-2-oxide) (15 nm)/fullerene-C60(40 nm)/Bathocuproine (BCP) (9 nm)/Aluminium have been probed. The active area of the cells was 0.16 cm2. These cells showed a power conversion efficiency of 1.24% under the illumination of AM 1.5 at 100 mW/cm2, which shows that this family of poly(isothianaphthene) oligomers have promising properties for photovoltaic applications

Electropolymerization and Morphologic Characterization of α-Tetrathiophene

In this research, poly(α-tetrathiophene), poly(α-TTP), was potentiostatic and potentiodynamically electrosynthesized on Pt and F-doped SnO2 electrodes. The solvent effect (CH2Cl2 and CH3CN) on the nucleation and growth mechanism, NGM, and morphology of the respective deposit was established by potentiostatic method and scanning electron microscopy (SEM), respectively. Potentiodynamic electropolymerization at low sweep rates proved to favor the obtention of a polymer with a more uniform morphology and, in addition, its capacitance as capacitor increased and the p-doping/undoping relationship is close to one (reversible doping). On the other hand, when potentiostatic electropolymerization was realized, deconvolution of the obtained j/t transients revealed that under all conditions, the main contribution to electrolysis at high times (greater than 20 s) was instantaneous nucleation with 3D growth. Nevertheless, the contribution of instantaneous nucleation with 2D growth is always more important in the early stages of the process. However, regardless of the conditions employed in the electropolymerization, the use of an oligomer as starting unit, such as α-TTF, affords deposits with more homogeneous morphology than when the respective monomer is used. Therefore, the information gathered in the current work constitutes a significant contribution that validates the proposed model for the electropolymerization mechanism

Thiophene and Pyrrole Derivative Polymers Electro-Synthesized on Stainles Steel. Doping and Morphology Characterization

3,4-ethylenedioxythiophene (EDOT), 3,4-propylenedioxythiophene (PRODOT), 3,4-ethylenedioxypyrrole (PEDOP) and 3,4 propylenedioxypyrrole (PRODOP), thiophene and pyrrole derivatives, were electro-polymerized by potentiodynamic and potentiostatic methods on stainless steel AISI 316 electrodes, using lithium perchlorate as support electrolyte in acetonitrile. In all cases electrodes modified with the respective polymeric deposit (PEDOT, PPRODOT, PPEDOP and PPRODOP) were obtained. One of the most relevant features of these polymers is that their voltammetric responses revealed that all presented p- and n-doping/undoping processes, being both processes reversible. Moreover, nucleation and growth mechanism (NGM) of the polymers was established by deconvolution of the experimental j/t transients recorded during it electropolymerization. PEDOT and PPRODOP showed a single contribution to the overall process, corresponding to instant nucleation with three-dimensional growth, controlled by charge transfer, whereas pyrrole derivatives (PEDOP and PPRODOP) are controlled by the same contribution, but there is also a second one corresponding to progressive nucleation with diffusion-controlled three-dimensional growth. Nuclei shape predicted from these NGM is consistent with the respective morphologies determined by SEM and AFM that, once more, validated the proposed electropolymerization model and the morphology prediction from the NGM of the respective polymers. To sum up, a correlation between the structure of the starting unit, doping, and morphology of the electro-deposited polymers was established

Improved performance of organic solar cells by growth optimization of MoO3/CuI double-anode buffer

We investigated the effect of a CuI anode buffer layer (ABL) on the molecular orientation of the copper phthalocyanine (CuPc) in organic photovoltaic cells (OPV cells), and we compare it to the effect of MoO3 buffer layer. While, in the presence of CuI, the CuPc molecules lie down parallel to the substrate, they stand up perpendicular in the case of MoO3. We show that the optical absorption, the morphology, and the JV characteristics of the OPV cells depends strongly on the orientation of the CuPc molecules. The improvement of the OPV cells performance is related to the property modifications induced by the change in molecule orientation. We show that the improvement of the OPV cell performance through the templating effect of CuI depends strongly on the deposition rate of the CuI, because the CuI thin-film morphology depends on this deposition rate. In this context, we show that the use of a double-ABL MoO3/CuI leads to a significant improvement of the cell performance. These results are discussed on the basis of the dual function of MoO3 and CuI. While both of them reduce the hole-injection barrier, CuI improves the CuPc film absorbance through specific molecular order and MoO3 prevents the OPV cells from leakage-path formation

Effect of Perylene as Electron Acceptor and poly(tetrabromo-p-phenylene Diselenide) as ‘‘Buffer Layer’’ on Heterojunction Solar Cells Performances

Perylene derivatives, that behave as liquid crystal and might be used as electron acceptors, and poly(tetrabromo-p-phenylenediselenide) (PTBrPDSe) were synthesized with the purpose of using the polymer as buffer layer in solar cells. It was demonstrated that perylene compounds of N,N0-diheptyl-3,4,9,10-perylentetracarboxyldiimide (PTCDI-C7) and N,N0-diundecyl-3,4,9,10-perylentetracarboxyldiimide (PTCDI-C11) enabled obtaining photovoltaic effect when coupled with copper phthalocyanine (CuPc). The power conversion efficiency of the cells prepared from these perylenes is similar, whatever the x value. However this efficiency is smaller than the one achieved when the couple CuPc/C60 (fullerene) is used. More precisely, the best efficiency was obtained when a PTBrPDSe/Au buffer layer is introduced between the ITO anode and the CuPc. It was established that the presence of the thin PTBrPDSe layer allows improving the shunt resistance and consequently the cells performance

Adipose-derived stem cells combined with Neuregulin-1 delivery systems for heart tissue engineering

Myocardial infarction (MI) is the leading cause of death worldwide and extensive research has therefore been performed to find a cure. Neuregulin-1 (NRG) is a growth factor involved in cardiac repair after MI. We previously described how biocompatible and biodegradable microparticles, which are able to release NRG in a sustained manner, represent a valuable approach to avoid problems related to the short half-life after systemic administration of proteins. The effectiveness of this strategy could be improved by combining NRG with several cytokines involved in cardiac regeneration. The present study investigates the potential feasibility of using NRG-releasing particle scaffold combined with adipose derived stem cells (ADSC) as a multiple growth factor delivery-based tissue engineering strategy for implantation in the infarcted myocardium. NRG-releasing particle scaffolds with a suitable size for intramyocardial implantation were prepared by TROMS. Next, ADSC were adhered to particle scaffolds and their potential for heart administration was assessed in a MI rat model. NRG was successfully encapsulated reaching encapsulation efficiencies of 92.58 ± 3.84 %. NRG maintained its biological activity after the microencapsulation process. ADSC cells adhered efficiently to particle scaffolds within a few hours. The ADSC-cytokine delivery system developed proved to be compatible with intramyocardial administration in terms of injectability through a 23-gauge needle and tissue response. Interestingly, ADSC-scaffolds were present in the peri-infarted tissue two weeks after implantation. This proof of concept study provides important evidence required for future effectiveness studies and for the translation of this approach