Influence of hydrogen peroxide in the tribocorrosion behaviour of a CoCrMo biomedical alloy

This paper studies the influence of hydrogen peroxide (H2O2) in simulated body fluids on the wear and corrosion behaviour of a CoCrMo biomedical alloy. CoCrMo are passive materials commonly used in prosthesis and implants because of its high corrosion resistance and mechanical properties. Hydrogen peroxide is produced by bacteria and leukocytes as a consequence of an inflammatory reaction which may modify the tribo-electrochemical response of metals implanted in the human body. Indeed, the oxidizing environment generated by the presence of the peroxide increases the metal dissolution rate. Electrochemical and tribocorrosion tests were carried out in a PBS solution with different addition of H2O2 (0.5, 2, 4 and 12%).The authors acknowledge Generalitat Valencia for the Gerónimo Forteza financial support and to the Electron Microscopy Service of the UPV for the SEM images

Uncertainty Analysis in the Inverse of Equivalent Conductance Method for Dealing with Crosstalk in 2-D Resistive Sensor Arrays

2-D resistive sensor arrays (RSAs) appear in many applications to measure physical quantities in a surface. However, they suffer from a crosstalk problem when the simplest configuration is used to address a row-column. Thus, the value of a single cell cannot be measured directly. Several hardware solutions have been proposed to solve it totally or partially but all of them make the circuit more complex. In a previous paper we proposed an innovative numerical solution to eliminate crosstalk after a complete scan of the matrix, which is named in this paper as Inverse of Equivalent Conductance Method (IECM). In the current study, we have analyzed the implications of the method for the uncertainty of the calculated cell resistance by first deriving the sensitivity of the solution and then applying uncertainty propagation theory. The theoretical results have been tested in simulated arrays and in a real 6x6 RSA with known values of resistances with good agreement. The uncertainty analysis is able to predict which values are reliable. In general, the lowest resistances of the array are better solved by IECM as expected. In addition, it is also shown that IECM has the potential to be adapted to other hardware configurations that reduce crosstalk, helping to overcome some of its limitations. IEE

Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution

[EN] The tribo-electrochemical behavior of AISI 316L has been investigated under tribocorrosion conditions in a 3% NaCl solution and the material damage evolution with time has been analyzed. A numerical contact model based on a Boundary Element Method (BEM) has been developed in order to determine the contact pressure distribution and to quantify the worn material as a function of time. The time dependence of the tribological behavior of the material has been described. At the initial state, the high contact pressures generate a material flow causing an increase in the worn area. After around 300 cycles, the Archard wear model linearly describes the wear evolution with time. The proposed model describes the evolution with time of the wear profiles of the tested material and takes into account the plastic behavior of the material during the first cycles.This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Ref. MAT2014-53764-C3-3-R and the Generalitat Valenciana under the PROMETEO program Ref. 2016/040.Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2018). Wear model for describing the time dependence of the material degradation mechanisms of the AISI 316L in a NaCl solution. Wear. 394-395:166-175. https://doi.org/10.1016/j.wear.2017.10.015S166175394-39

Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva

[EN] In this paper, the degradation mechanisms of the ceramic and the metal in Titanium/Zirconia pairs for biomedical applications were analyzed. To do that, an experimental set-up with well-controlled mechanical and chemical conditions was used based on a unidirectional ball-on-disk tribometer coupled to a potentiostat. Tribocorrosion tests were carried out in artificial saliva at different applied potentials, this is, different chemical conditions of the surface. Wear damage of the titanium/zirconia pair was influenced by the properties and the behavior of wear debris in the contact. Under passive conditions metallic and oxidized titanium particles (formed by the cyclic removal of the passive film and subsequent repassivation) were smeared and mechanically mixed within the contact forming compacted wear debris through which the loading was carried out. Properties and amount of oxidized titanium lead to low wear at low passive conditions (OCP) and higher wear at high passive conditions. Zirconia did not suffer any damage under all the studied conditions and oxidized titanium was transferred to the ball at anodic applied potentials.Authors would like to acknowledge the Generalitat Valenciana for the financial support under the PROMETEO/2016/040 and GV/2017/042 projects. A. Dalmau acknowledges the Generalitat Valenciana for her contract (APOSTD/2017/051).Dalmau-Borrás, A.; Roda Buch, A.; Rovira, A.; Navarro-Laboulais, J.; Igual Muñoz, AN. (2019). Chemo-mechanical effects on the tribocorrosion behavior of titanium/ceramic dental implant pairs in artificial saliva. Wear. 426-427:162-170. https://doi.org/10.1016/j.wear.2018.12.052162170426-42

Physicochemical and sensorial properties of grapefruit jams as affected by processing

Jam is an effective and tasty way of preserving fruit. Jam processing procedures as well as storage conditions and duration are important factors for jam quality. Traditional jam processing involves the application of severe thermal treatments that imply undesirable changes in the product quality characteristics such as colour, texture, flavour and nutritional and functional value. In this work, osmotic dehydration (OD) and/or microwave energy (MW) was proven as adequate to obtain jam with the typical characteristics of water content, degree Brix, pH and water activity of jam obtained by conventional thermal heating. The sensory evaluation carried out to compare the product showed that samples submitted to more intense heating treatments (conventional or MW) had significantly higher scores in colour saturation, brightness, grapefruit taste and extensibility than OD or OD+MW ones. As deduced from the obtained results, OD treatment prevents grapefruit colour changes, and mild MW heating contributes to increase the consistency and decrease the extensibility of the obtained jam. In this way, OD+MW jam was preferred by assessors mainly due to its higher consistency. The sample obtained by this procedure was stable during storage.The authors would like to thank the Ministerio de Educacion y Ciencia for the financial support given throughout the Project AGL 2005-05994. The language revision of this paper was funded by the Universidad Politecnica de Valencia, Spain.Igual Ramo, M.; García Martínez, EM.; Camacho Vidal, MM.; Martínez Navarrete, N. (2013). Physicochemical and sensorial properties of grapefruit jams as affected by processing. Food and Bioprocess Technology. 6(1):177-185. https://doi.org/10.1007/s11947-011-0696-2S17718561AENOR (2009). Sensory analysis. Methodology. Paired comparison test. UNE-EN-ISO 5495.AOAC. (2000). Official methods of analysis of AOAC International (17th ed.). Gaithersburg: AOAC International.Baker, R.-A., Berry, N., Hui, Y.-H., & Barrett, D.-M. (2005). Fruit preserves and jams. In Processing fruits: science and technology (2nd ed., pp. 113–125). Boca Ratón: CRC Press.Bodart, M., de Peñaranda, R., Deneyer, A., & Flamant, G. (2008). Photometry and colorimetry characterisation of materials in daylighting evaluation tools. Building and Environment, 43, 2046–2058.BOE (1990). Real Decreto 670/1990, de 25 de mayo, por el que se aprueba la norma de calidad para confituras, jaleas y marmalade de frutas, crema de castañas y mermelada de frutas. BOE Nº 130 (31/5/1990), 15140–15144.Bourne, M. (1982). Food texture and viscosity—concept and measurement. New York: Academic.Cañumir, J.-A., Celis, J.-E., Brujin, J., & Vidal, L. (2002). Pasteurisation of apple juice by using microwaves. Lebensmittel-Wissenschaft und Technologie, 35, 389–392.Contreras, C., Martín-Esparza, M.-E., Martínez-Navarrete, N., & Chiralt, A. (2008). Influence of microwave application on convective drying: effects on drying kinetics, and optical and mechanical properties of apple and strawberry. Journal of Food Engineering, 88, 55–64.Dervisi, P., Lamb, J., & Zabetakis, I. (2001). High pressure processing in jam manufacture: effects on textural and color properties. Food Chemistry, 73, 85–91.Deyhim, F., Garica, K., Lopez, E., Gonzalez, J., Ino, S., Garcia, M., et al. (2006). Citrus juice modulates bone strength in male senescent rat model of osteoporosis. Nutrition, 22(5), 559–563.García-Martínez, E., Ruiz-Diaz, G., Martínez-Monzó, J., Camacho, M.-M., Martínez-Navarrete, N., & Chiralt, A. (2002). Jam manufacture with osmodehydrated fruit. Food Research International, 35, 301–306.Igual, M., García-Martínez, E., Camacho, M.-M., & Martínez-Navarrete, N. (2010a). Effect of thermal treatment and storage on the stability of organic acids and the functional value of grapefruit juice. Food Chemistry, 118, 291–299.Igual, M., Contreras, C., & Martínez-Navarrete, N. (2010b). Non-conventional techniques to obtain grapefruit jam. Innovative Food Science and Emerging Technologies, 11(2), 335–341.Meilgaard, M., Civille, G.-V., & Carr, B.-T. (1999). Attribute differences test. Pairwise ranking test: Friedman analysis. Sensory evaluation techniques (pp. 103–106). Boca Ratón: CRC Press.Moraga, M.-J., Moraga, G., Fito, P. J., & Martínez-Navarrete, N. (2009). Effect of vacuum impregnation with calcium lactate on the osmotic dehydration kinetics and quality of osmodehydrated grapefruit. Journal of Food Engineering, 90, 372–379.Nikdel, S., Chen, C., Parish, M., MacKellar, D., & Friedrich, L. (1993). Pasteurization of citrus juice with microwaves energy in a continuous-flow unit. Journal of Agricultural and Food Chemistry, 41, 2116–2119.Poulose, S.-M., Harris, E.-D., & Patil, B.-S. (2005). Citrus limonoids induce apoptosis in human neuroblastoma cells and have radical scavenging activity. Journal of Nutrition, 135, 870–877.Sanchez-Moreno, C., Plaza, L., De Ancos, B., & Cano, M.-P. (2003). Quantitative bioactive compounds assessment and their relative contribution to the antioxidant capacity of commercial orange juices. Journal of the Science of Food and Agriculture, 83, 430–439.Shi, X.-Q., Chiralt, A., Fito, P., Serra, J., Escoin, C., & Gasque, L. (1996). Application of osmotic dehydration technology on jam processing. Drying Technology, 14(3&4), 841–857.Tárrega, A., & Costell, E. (2007). Colour and consistency of semi-solid dairy desserts: instrumental and sensory measurements. Journal of Food Engineering, 78, 655–661.Vanamala, J., Reddivari, L., Yoo, K.-S., Pike, L.-M., & Patil, B.-S. (2006). Variation in the content of bioactive flavonoid in different brands of orange and grapefruit juices. Journal of Food Composition and Analysis, 19(2–3), 157–166.Wicklund, T., Rosenfeld, H.-J., Martinsen, B.-K., Sundførb, M.-W., Lea, P., Bruun, T., et al. (2005). Antioxidant capacity and colour of strawberry jam as influenced by cultivar and storage conditions. LWT-Food Science and Technology, 38(4), 387–391.Yu, L.-L., Zhou, K.-K., & Parry, J. (2005). Antioxidant properties of cold-pressed black caraway, carrot, cranberry, and hemp seed oils. Food Chemistry, 91, 723–729

Optimized Fundamental Signal Processing Operations for Energy Minimization on Heterogeneous Mobile Devices

[EN] Numerous signal processing applications are emerging on both mobile and high-performance computing systems. These applications are subject to responsiveness constraints for user interactivity and, at the same time, must be optimized for energy efficiency. The increasingly heterogeneous power-versus-performance profile of modern hardware introduces new opportunities for energy savings as well as challenges. In this line, recent systems-on-chip (SoC) composed of low-power multicore processors, combined with a small graphics accelerator (or GPU), yield a notable increment of the computational capacity while partially retaining the appealing low power consumption of embedded systems. This paper analyzes the potential of these new hardware systems to accelerate applications that involve a large number of floating-point arithmetic operations mainly in the form of convolutions. To assess the performance, a headphone-based spatial audio application for mobile devices based on a Samsung Exynos 5422 SoC has been developed. We discuss different implementations and analyze the tradeoffs between performance and energy efficiency for different scenarios and configurations. Our experimental results reveal that we can extend the battery lifetime of a device featuring such an architecture by a 238% by properly configuring and leveraging the computational resources.This work was supported by the Spanish Ministerio de Economia y Competitividad projects under Grant TIN2014-53495-R and Grant TEC2015-67387-C4-1-R, in part by the University Project UJI-B2016-20, in part by the Project PROMETEOII/2014/003. The work of J. A. Belloch was supported by the GVA Post-Doctoral Contract under Grant APOSTD/2016/069. This paper was recommended by Associate Editor Y. Ha.Belloch Rodríguez, JA.; Badia Contelles, JM.; Igual Peña, FD.; Gonzalez, A.; Quintana Ortí, ES. (2017). Optimized Fundamental Signal Processing Operations for Energy Minimization on Heterogeneous Mobile Devices. IEEE Transactions on Circuits and Systems I Regular Papers. 65(5):1614-1627. https://doi.org/10.1109/TCSI.2017.2761909S1614162765

Epidemiology of congenital Chagas disease 6 years after implementation of a public health surveillance system, Catalonia, 2010 to 2015

Chagas disease; Trypanosoma cruzi; CongenitalMalaltia de Chagas; Trypanosoma cruzi; CongènitEnfermedad de Chagas; Trypanosoma cruzi; CongénitoBackgroundChagas disease is endemic in Latin America and affects 8 million people worldwide. In 2010, Catalonia introduced systematic public health surveillance to detect and treat congenital Chagas disease.AimThe objective was to evaluate the health outcomes of the congenital Chagas disease screening programme during the first 6 years (2010-2015) after its introduction in Catalonia.MethodsIn a surveillance system, we screened pregnant women and newborns and other children of positive mothers, and treated Chagas-positive newborns and children. Diagnosis was confirmed for pregnant women and children with two positive serological tests and for newborns with microhaematocrit and/or PCR at birth or serology at age 9 months.ResultsFrom 2010 to 2015, the estimated screening coverage rate increased from 68.4% to 88.6%. In this period, 33,469 pregnant women were tested for Trypanosoma cruzi and 937 positive cases were diagnosed. The overall prevalence was 2.8 cases per 100 pregnancies per year (15.8 in Bolivian women). We followed 82.8% of newborns until serological testing at age 9-12 months and 28 were diagnosed with Chagas disease (congenital transmission rate: 4.17%). Of 518 siblings, 178 (34.3%) were tested and 14 (7.8%) were positive for T. cruzi. Having other children with Chagas disease and the heart clinical form of Chagas disease were maternal risk factors associated with congenital T. cruzi infection (p < 0.05).ConclusionThe increased screening coverage rate indicates consolidation of the programme in Catalonia. The rate of Chagas disease congenital transmission in Catalonia is in accordance with the range in non-endemic countries

Highly Photoluminescent Blue Ionic Platinum-Based Emitters

New cycloplatinated N-heterocyclic carbene (NHC) compounds with chelate diphosphines (P^P) as ancillary ligands: [Pt(R-C^C*)(P^P)]PF6 (R = H, P^P = dppm (1A), dppe (2A), dppbz (3A); R = CN, P^P = dppm (1B), dppe (2B), dppbz (3B)) have been prepared from the corresponding starting material [{Pt(R-C^C*)(μ-Cl)}2] (R = H, A, R = CN, B) and fully characterized. The new compound A has been prepared by a stepwise protocol. The photophysical properties of 1A-3A and 1B-3B have been widely studied and supported by the time-dependent-density functional theory. These compounds show an efficient blue (dppe, dppbz) or cyan (dppm) emission in PMMA films (5 wt %), with photoluminescence quantum yield (PLQY) ranging from 30% to 87% under an argon atmosphere. This emission has been assigned mainly to transitions from 3ILCT [π(NHC) → π*(NHC)] excited states with some 3LL'CT [π(NHC) → π*(P^P)] character. The electroluminescence of these materials in proof-of-concept solution-processed organic light-emitting diodes containing 3A and 3B as dopants was investigated. The CIE coordinates for devices based on 3A (0.22, 0.41) and 3B (0.24, 0.44) fit within the sky blue region

Room temperature vacuum-deposition of CsPbI2Br perovskite films from multiple-sources and mixed halide precursors

Fully inorganic cesium lead halide perovskites, such as CsPbI2Br, show enhanced thermal stability compared to hybrid ones and are being widely investigated as wide bandgap absorbers for tandem applications. Despite their simple stoichiometry, the preparation of highly crystalline and stable cesium lead halide thin films is not trivial. In general, high-efficiency solar cells based on solution-processed CsPbI2Br thin films are prepared by hightemperature annealing or the use of chemical additives. In this work, we use solvent-free synthesis to investigate the formation of CsPbI2Br in bulk or in thin films via mechanochemical synthesis and multiple-source vacuum deposition, respectively. We demonstrate the importance of fostering halide alloying in the vacuum processing of inorganic lead halide perovskites, which can be attained either by using mixed halide precursors or by increasing the number of precursors (and hence deposition sources). These strategies lead to highly oriented perovskite films even at room temperature, with improved optoelectronic properties. We obtained promising power conversion efficiencies of 8.3% for solar cells employing asdeposited perovskites (without any annealing) and 10.0% for devices based on CsPbI2Br annealed at low temperatures (150 °C). This study allowed us to highlight the most promising processes and strategies to further optimize the material deposition as well as the solar cell architecture