Study of the Degradation of New Lubricant Oil Formulations with the Design and Demands of Current and Future Engines

[ES] El análisis de los aceites lubricantes de motor, englobado dentro de las tareas realizadas en el Oil Condition Monitoring (OCM), resulta ser una herramienta poderosa con la cual se es capaz de extraer información de utilidad. Por este motivo, en esta Tesis se decidió explotar este campo realizando un estudio en profundidad centrado en tres aspectos: mejorar las técnicas y protocolos ya existentes, desarrollar procedimientos propios acorde con las necesidades y requisitos del momento y, para terminar, poner en valor la información obtenida del análisis de los lubricantes mediante el uso de tratamientos estadísticos y quimiométricos. Bajo estas tres premisas, se ha desarrollado toda la tarea de investigación de esta Tesis. En primer lugar, en relación con el análisis de los aceites lubricantes, se realizó un estudio acerca de la degradación de cuatro formulaciones de aceites lubricantes. En este estudio se analizaron aspectos propios de los aceites como: su viscosidad cinemática, oxidación, nitración, caída de los aditivos antioxidantes, etc. así como parámetros de desgaste de motor (monitorizando la presencia de metales). Como resultado de este estudio fue posible encontrar limitaciones en las técnicas actuales, lo cual condujo a realizar mejoras y/o adaptaciones de estas técnicas para conseguir obtener la información deseada. El siguiente aspecto tratado en esta Tesis es una consecuencia de la necesidad de, en ciertas situaciones, disponer de información acerca de uno o varios parámetros de una determinada forma y con un grado de precisión elevado. El caso en cuestión analizado en la Tesis está relacionado con la cuantificación de hollín en el aceite lubricante. Respecto a la cuantificación del hollín se requirió encontrar una técnica que fuera capaz de aportar información de una forma rápida y, además, poder detectar pequeños cambios. Esta técnica fue la espectroscopia Ultravioleta-Visible, con la cual se diseñó un protocolo analítico que permitiera trabajar con muestras de aceites lubricante con muy poco uso y, por ende, poca cantidad de hollín disuelta, consiguiendo resultados muy satisfactorios en periodos de tiempo cortos. Por último, debido a la disponibilidad de una cantidad de datos considerable fruto del trabajo realizado durante todo el tiempo de duración de la Tesis, se decidió emplear toda ella para conseguir extraer la máxima información posible gracias al uso de tratamientos estadísticos y quimiométricos. Este trabajo, nuevo en la línea, se dividió en dos vertientes: la primera focalizada en el conjunto de datos de los aceites ya caracterizados (procedentes del estudio de la degradación de los aceites) y la otra parte en encontrar sinergias entre las técnicas espectroscópicas (FT-IR y NIR) y los ensayos de caracterización de los lubricantes. Como resultado de ello, se obtuvieron relaciones entre parámetros que anteriormente no se tenían presentes, así como modelos predictivos de propiedades de los lubricantes a partir del análisis de sus espectros. El presente documento de Tesis se encuentra redactado en dos idiomas: en español y en inglés. Principalmente el documento se encuentra redactado en inglés para hacer especial énfasis en aquellas labores de investigación desarrolladas en esta etapa, así como los resultados derivados de los diferentes estudios realzados. Mientras que, la parte confeccionada en español hace referencia a aquellos aspectos más descriptivos del documento de Tesis.[CA] L'anàlisi dels olis lubrificants de motor, englobat dins de les tasques realitzades en el Oil Condition Monitoring (OCM), resulta ser una eina poderosa amb la qual s'és capaç d'extraure informació d'utilitat. Per aquest motiu, en aquesta Tesi es va decidir explotar aquest camp realitzant un estudi en profunditat centrat en tres aspectes: millorar les tècniques i protocols ja existents, desenvolupar procediments propis d'acord amb les necessitats i requisits del moment i, per a acabar, posar en valor la informació obtinguda de l'anàlisi dels lubrificants mitjançant l'ús de tractaments estadístics i quimiomètrics. Sota aquestes tres premisses, s'ha desenvolupat tota la tasca d'investigació d'aquesta Tesi. En primer lloc, en relació a l'anàlisi dels olis lubrificants, es va realitzar un estudi sobre la degradació de quatre formulacions d'olis lubrificants. En aquest estudi es van analitzar aspectes propis dels olis com: la seua viscositat cinemàtica, oxidació, nitració, caiguda dels additius antioxidants, etc. així com paràmetres de desgast de motor (monitorant la presència de metalls). Com a resultat d'aquest estudi va ser possible trobar limitacions en les tècniques actuals, la qual cosa va conduir a realitzar millores i/o adaptacions d'aquestes tècniques per a aconseguir obtindre la informació desitjada. El següent aspecte tractat en aquesta Tesi és una conseqüència de la necessitat de, en unes certes situacions, disposar d'informació sobre un o diversos paràmetres d'una determinada forma i amb un grau de precisió elevat. El cas en qüestió analitzat en la Tesi està relacionat amb la quantificació de sutge (soot en anglès). Respecte a la quantificació del soot es va requerir trobar una tècnica que fora capaç d'aportar informació d'una forma ràpida i, a més, poder detectar xicotets canvis. Aquesta tècnica va ser l'espectroscòpia Ultravioleta-Visible, amb la qual es va dissenyar un protocol analític que permetera treballar amb mostres d'oli lubrificant amb molt poc ús i, per tant, poca quantitat de soot dissolta, aconseguint resultats molt satisfactoris en períodes de temps curts. Finalment, a causa de la disponibilitat d'una quantitat de dades considerable fruit del treball realitzat durant tot el temps de duració de la Tesi, es va decidir emprar tota ella per a aconseguir extraure la màxima informació possible gràcies a l'ús de tractaments estadístics i quimiomètrics. Aquest treball, nou en la línia, es va dividir en dos vessants: la primera focalitzada en el conjunt de dades dels olis ja caracteritzats (procedents de l'estudi de la degradació dels olis) i l'altra part a trobar sinergies entre les tècniques espectroscòpiques (FT-IR i NIR) i els assajos de caracterització dels lubrificants. Com a resultat d'això, es van obtindre relacions entre paràmetres que anteriorment no es tenien presents així com models predictius de propietats dels lubrificants a partir de l'anàlisi dels seus espectres. El present document de Tesi es troba redactat en dos idiomes: en espanyol i en anglès. Principalment el document es troba redactat en anglès per a fer especial èmfasi en aquelles labors d'investigació desenvolupades en aquesta etapa així com els resultats derivats dels diferents estudis realitzats. Mentre que, la part confeccionada en espanyol, fa referència a aquells aspectes més descriptius del document de Tesi.[EN] The analysis of engine lubricating oils, encompassed within the tasks carried out in Oil Condition Monitoring (OCM), is a powerful tool with which it is possible to extract useful information. For this reason, in this Thesis it has been decided to exploit this field by carrying out an in-depth study focusing on three aspects: improving existing techniques and protocols, developing our own procedures in accordance with current needs and requirements and finally, adding value to the information obtained from the analysis of lubricants through the use of statistical and chemometric treatments. All the research work in this Thesis has been carried out under these three premises. Firstly, in relation to the analysis of lubricating oils, a study was carried out on the degradation of four lubricating oil formulations. This study analysed aspects of the oils, such as their kinematic viscosity, oxidation, nitration, antioxidant additives depletion, etc. as well as engine wear parameters (monitoring the presence of metals). Using this study, it was possible to find limitations in the current techniques, which led to improvements and/or adaptations of these techniques in order to obtain the desired information. The next aspect dealt with in this Thesis is a consequence of the need, in certain situations, to have information about one or more parameters in a certain form and with a high degree of accuracy. The case in question analysed in the Thesis is related to the quantification of soot. With regard to soot quantification, it was necessary to find a technique that was capable of providing information quickly and, in addition, being able to detect small changes. This technique was Ultraviolet-Visible spectroscopy, with which an analytical protocol was designed to work with samples of lubricating oils with very little use and therefore, with a small amount of dissolved soot, achieving very satisfactory results in short periods of time. Finally, due to the availability of a considerable amount of information resulting from the work carried out throughout the duration of the Thesis, it was decided to use all of these data to extract as much information as possible, thanks to the use of statistical and chemometric treatments. This work, new in the research line, was divided into two parts: the first focused on the dataset of oils already characterised (from the study of oil degradation) and the other on finding synergies between spectroscopic techniques (FT-IR and NIR) and lubricant characterisation tests. As a result, relationships between previously unknown parameters were obtained, as well as predictive models of lubricant properties based on the analysis of their spectra. This Thesis document is written in two languages: Spanish and English. The document is mainly written in English in order to place special emphasis on the research work carried out at this stage, as well as the results derived from the different studies carried out. The part written in Spanish refers to the more descriptive aspects of the Thesis document.García Barberá, A. (2022). Study of the Degradation of New Lubricant Oil Formulations with the Design and Demands of Current and Future Engines [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/181668TESI

Application assessment of UV-vis and NIR spectroscopy for the quantification of fuel dilution problems on used engine oils

[EN] Fuel dilution in engine oil is a frequent problem in internal combustion engines (ICE); its main consequence is the reduction of the oil viscosity, decreasing lubrication film strength, and causing a negative impact on friction and wear. The standard and more precise methods for assessing fuel content in oil are based on chromatographic analysis (e.g., ASTM D3524, ASTM D7593), requiring high-cost equipment and highly qualified personnel. This work performed a study to propose an alternative method for quantifying diesel fuel dilution in used engine oil by UV¿vis and NIR spectroscopy. The samples for the study were prepared from used oil from six different vehicles with various mileages. According to the results obtained in this study, NIR spectroscopy proved to be the most suitable method for the quantification of diesel fuel in used engine oils. Furthermore, the use of NIR spectroscopy combined with multivariate calibration methods could predict the fuel concentration of the samples used for validating the model. The best predictive model for the quantification was obtained by Partial Least Squares Regression, which achieved a Root Mean Squared Error of prediction of 0.436% and a coefficient of determination of 0.9435. In comparison, the parameters for Principal Component Regression were 1.049% and 0.8441, respectively.Acknowledgments This work has been partially supported by grant PID2020-119691RB-100 funded by MCIN/AEI/10.13039/501100011033.Macian Martinez, V.; Tormos, B.; García-Barberá, A.; Balaguer-Reyes, A. (2023). Application assessment of UV-vis and NIR spectroscopy for the quantification of fuel dilution problems on used engine oils. Fuel. 333. https://doi.org/10.1016/j.fuel.2022.12635033

Effect of milk based fruit beverage enriched with plant sterols and/or galactooligosaccharides in a murine chronic colitis model

The potential anti-inflammatory effect of plant sterols (PS) enriched milk-based fruit beverages (PS, 1 g/100 mL) (MfB) with/without galactooligosaccharides (GOS, 2 g/100 mL) (MfB-G) in an experimental mice model of chronic ulcerative colitis was evaluated. Beverages were orally administered to mice every day by gavage to achieve PS and GOS doses of 35 and 90 mg/kg, respectively, and experimental colitis was induced by giving mice drinking water ad libitum containing 2% (w/v) dextran sulphate sodium (DSS) for 7 days, alternating with periods without DSS up to the end of the study (56 days). MfB beverage showed significant reduction of symptoms associated to ulcerative colitis and improved the colon shortening and mucosal colonic damage, but it was not able to reduce the increase of myeloperoxidase levels produced by DSS. MfB-G showed higher incidence of bloody feces and loss of stool consistency than MfB, as well as high levels of immune cells infiltration in colon tissue and myeloperoxidase. Therefore, PS-enriched milk-based fruit beverage could be an interesting healthy food to extend the remission periods of the diseases and the need to evaluate, in a pre-clinical model, the anti-inflammatory effect of the combination of bioactive compounds in the context of a whole food matrix

Study of the influence of emission control strategies on the soot content and fuel dilution in engine oil

[EN] The engine oil contamination by both particulate matter (PM) and fuel is becoming an important problem since strategies to control pollutant emissions in internal combustion engines (ICE) significantly increase their presence in engine oil. As a consequence, the engine oil loses its tribological properties compromising engine lubrication and leading to potential problems in engine such as wear, corrosion, etc. For that reason, the study of the oil degradation and contamination due to these strategies have a special interest to the engine manufacturers and engine oil formulators. In this paper, the engine oil soot content and fuel dilution is analysed under real engine conditions. The study is addressed from two different but complementary points of views. First, on-line measurements at several engine operating conditions are performed in order to further understand how the soot generation correlates with the oil soot content and other derived problems on oil performance. Then, experimental data available after the experimental campaign is used to calibrate a numerical model, based on Computational Fluid Dynamics (CFD), that estimate the amount of soot particles settled in the engine oil. Results show that soot particles are more present in oil when operating high load-speed conditions and during the Diesel Particulate Filter (DPF) regeneration cycles. Regarding the fuel dilution, delayed post-injections are critical since they significantly increase the amount of fuel in the engine oil. Numerical results also show the relationships between the soot particles generated during combustion and the amount of soot in engine oil, giving an enhanced comprehension of soot-in-oil deposition mechanisms.A. Garcia-Barbera is partially supported through the Programa Nacional de Formation de Recursos Humanos de Investigacion of Spanish Ministerio de Ciencia e Innovation [grant number BES-2016-078073]. The authors also wish to thank Dr. José M. Pastor for his inestimable assistance in the CFD model implementation and data post-processing.Tormos, B.; Novella Rosa, R.; Gómez-Soriano, J.; García-Barberá, A.; Tsuji, N.; Uehara, I.; Alonso, M. (2019). Study of the influence of emission control strategies on the soot content and fuel dilution in engine oil. Tribology International. 136:285-298. https://doi.org/10.1016/j.triboint.2019.03.066285298136Lloyd, A. C., & Cackette, T. A. (2001). Diesel Engines: Environmental Impact and Control. Journal of the Air & Waste Management Association, 51(6), 809-847. doi:10.1080/10473289.2001.10464315Fiebig, M., Wiartalla, A., Holderbaum, B., & Kiesow, S. (2014). Particulate emissions from diesel engines: correlation between engine technology and emissions. Journal of Occupational Medicine and Toxicology, 9(1), 6. doi:10.1186/1745-6673-9-6C. Directive, 91/441/EEC of 26 June 1991 amending Directive 70/220, EEC on the approximation of the laws of the Member States relating to measures to be taken against air pollution by emissions from motor vehicles.E. Regulation, Regulation (EC) No 595/2009 of the European Parliament and of the Council of 18 June 2009 on type-approval of motor vehicles and engines with respect to emissions from heavy duty vehicles (Euro VI) and on access to vehicle repair and maintenance information and amending Regulation (EC) No 715/2007 and Directive 2007/46/EC and repealing Directives 80/1269/EEC, 2005/55/EC and 2005/78/EC, Off J Eur Communities - Legislation 188.Agarwal, D., Singh, S. K., & Agarwal, A. K. (2011). Effect of Exhaust Gas Recirculation (EGR) on performance, emissions, deposits and durability of a constant speed compression ignition engine. Applied Energy, 88(8), 2900-2907. doi:10.1016/j.apenergy.2011.01.066Divekar, P. S., Chen, X., Tjong, J., & Zheng, M. (2016). Energy efficiency impact of EGR on organizing clean combustion in diesel engines. Energy Conversion and Management, 112, 369-381. doi:10.1016/j.enconman.2016.01.042Lattimore, T., Wang, C., Xu, H., Wyszynski, M. L., & Shuai, S. (2016). Investigation of EGR Effect on Combustion and PM Emissions in a DISI Engine. Applied Energy, 161, 256-267. doi:10.1016/j.apenergy.2015.09.080Li, X., Xu, Z., Guan, C., & Huang, Z. (2014). Impact of exhaust gas recirculation (EGR) on soot reactivity from a diesel engine operating at high load. Applied Thermal Engineering, 68(1-2), 100-106. doi:10.1016/j.applthermaleng.2014.04.029Singh, S. K., Agarwal, A. K., & Sharma, M. (2006). Experimental investigations of heavy metal addition in lubricating oil and soot deposition in an EGR operated engine. Applied Thermal Engineering, 26(2-3), 259-266. doi:10.1016/j.applthermaleng.2005.05.004George, S., Balla, S., & Gautam, M. (2007). Effect of diesel soot contaminated oil on engine wear. Wear, 262(9-10), 1113-1122. doi:10.1016/j.wear.2006.11.002Fang, J., Meng, Z., Li, J., Pu, Y., Du, Y., Li, J., … G. Chase, G. (2017). The influence of ash on soot deposition and regeneration processes in diesel particular filter. Applied Thermal Engineering, 124, 633-640. doi:10.1016/j.applthermaleng.2017.06.076Behn, A., Feindt, M., Matz, G., Krause, S., & Gohl, M. (2015). Fuel Transport across the Piston Ring Pack: Measurement System Development and Experiments for Online Fuel Transport and Oil Dilution Measurements. SAE Technical Paper Series. doi:10.4271/2015-24-2535Aldajah, S., Ajayi, O. O., Fenske, G. R., & Goldblatt, I. L. (2007). Effect of exhaust gas recirculation (EGR) contamination of diesel engine oil on wear. Wear, 263(1-6), 93-98. doi:10.1016/j.wear.2006.12.055Dennis, A. J., Garner, C. P., & Taylor, D. H. C. (1999). The Effect of EGR on Diesel Engine Wear. SAE Technical Paper Series. doi:10.4271/1999-01-0839Heredia-Cancino, J. A., Ramezani, M., & Álvarez-Ramos, M. E. (2018). Effect of degradation on tribological performance of engine lubricants at elevated temperatures. Tribology International, 124, 230-237. doi:10.1016/j.triboint.2018.04.015Mc Geehan, J. A., Alexander, W., Ziemer, J. N., Roby, S. H., & Graham, J. P. (1999). The Pivotal Role of Crankcase Oil in Preventing Soot Wear and Extending Filter Life in Low Emission Diesel Engines. SAE Technical Paper Series. doi:10.4271/1999-01-1525Motamen Salehi, F., Morina, A., & Neville, A. (2017). The effect of soot and diesel contamination on wear and friction of engine oil pump. Tribology International, 115, 285-296. doi:10.1016/j.triboint.2017.05.041Lenk, J.-R., Meyer, L., & Provase, I. S. (2014). Oil Dilution Model for Combustion Engines - Detection of Fuel Accumulation and Evaporation. SAE Technical Paper Series. doi:10.4271/2014-36-0170Gautam, M., Chitoor, K., Durbha, M., & Summers, J. C. (1999). Effect of diesel soot contaminated oil on engine wear — investigation of novel oil formulations. Tribology International, 32(12), 687-699. doi:10.1016/s0301-679x(99)00081-xWattrus, M. (2013). Fuel Property Effects on Oil Dilution in Diesel Engines. SAE International Journal of Fuels and Lubricants, 6(3), 794-806. doi:10.4271/2013-01-2680Andreae, M., Fang, H., & Bhandary, K. (2007). Biodiesel and Fuel Dilution of Engine Oil. SAE Technical Paper Series. doi:10.4271/2007-01-4036Antusch, S., Dienwiebel, M., Nold, E., Albers, P., Spicher, U., & Scherge, M. (2010). On the tribochemical action of engine soot. Wear, 269(1-2), 1-12. doi:10.1016/j.wear.2010.02.028Sato, H., Tokuoka, N., Yamamoto, H., & Sasaki, M. (1999). Study on Wear Mechanism by Soot Contaminated in Engine Oil (First Report: Relation Between Characteristics of Used Oil and Wear). SAE Technical Paper Series. doi:10.4271/1999-01-3573Green, D. A., Lewis, R., & Dwyer-Joyce, R. S. (2006). Wear effects and mechanisms of soot-contaminated automotive lubricants. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 220(3), 159-169. doi:10.1243/13506501jet140Tang, Z., Feng, Z., Jin, P., Fu, X., & Chen, H. (2017). The soot handling ability requirements and how to solve soot related viscosity increases of heavy duty diesel engine oil. Industrial Lubrication and Tribology, 69(5), 683-689. doi:10.1108/ilt-02-2015-0024George, S., Balla, S., Gautam, V., & Gautam, M. (2007). Effect of diesel soot on lubricant oil viscosity. Tribology International, 40(5), 809-818. doi:10.1016/j.triboint.2006.08.002Ryason, P. R., Chan, I. Y., & Gilmore, J. T. (1990). Polishing wear by soot. Wear, 137(1), 15-24. doi:10.1016/0043-1648(90)90014-2Broatch, A., Olmeda, P., Margot, X., & Gomez-Soriano, J. (2019). Numerical simulations for evaluating the impact of advanced insulation coatings on H2 additivated gasoline lean combustion in a turbocharged spark-ignited engine. Applied Thermal Engineering, 148, 674-683. doi:10.1016/j.applthermaleng.2018.11.106Broatch, A., Novella, R., García-Tíscar, J., & Gomez-Soriano, J. (2019). On the shift of acoustic characteristics of compression-ignited engines when operating with gasoline partially premixed combustion. Applied Thermal Engineering, 146, 223-231. doi:10.1016/j.applthermaleng.2018.09.089Lapuerta, M., Armas, O., & Hernández, J. J. (1999). Diagnosis of DI Diesel combustion from in-cylinder pressure signal by estimation of mean thermodynamic properties of the gas. Applied Thermal Engineering, 19(5), 513-529. doi:10.1016/s1359-4311(98)00075-1Payri, F., Molina, S., Martín, J., & Armas, O. (2006). Influence of measurement errors and estimated parameters on combustion diagnosis. Applied Thermal Engineering, 26(2-3), 226-236. doi:10.1016/j.applthermaleng.2005.05.006Zhu, X., Zhong, C., & Zhe, J. (2017). Lubricating oil conditioning sensors for online machine health monitoring – A review. Tribology International, 109, 473-484. doi:10.1016/j.triboint.2017.01.015Bredin, A., Larcher, A. V., & Mullins, B. J. (2011). Thermogravimetric analysis of carbon black and engine soot—Towards a more robust oil analysis method. Tribology International, 44(12), 1642-1650. doi:10.1016/j.triboint.2011.06.002Broatch, A., Margot, X., Novella, R., & Gomez-Soriano, J. (2017). Impact of the injector design on the combustion noise of gasoline partially premixed combustion in a 2-stroke engine. Applied Thermal Engineering, 119, 530-540. doi:10.1016/j.applthermaleng.2017.03.081Broatch, A., Novella, R., García-Tíscar, J., & Gomez-Soriano, J. (2018). Potential of dual spray injectors for optimising the noise emission of gasoline partially premixed combustion in a 2-stroke HSDI CI engine. Applied Thermal Engineering, 134, 369-378. doi:10.1016/j.applthermaleng.2018.01.108Yakhot, V., & Orszag, S. A. (1986). Renormalization group analysis of turbulence. I. Basic theory. Journal of Scientific Computing, 1(1), 3-51. doi:10.1007/bf01061452Angelberger, C., Poinsot, T., & Delhay, B. (1997). Improving Near-Wall Combustion and Wall Heat Transfer Modeling in SI Engine Computations. SAE Technical Paper Series. doi:10.4271/972881Issa, R. . (1986). Solution of the implicitly discretised fluid flow equations by operator-splitting. Journal of Computational Physics, 62(1), 40-65. doi:10.1016/0021-9991(86)90099-9Colin, O., & Benkenida, A. (2004). The 3-Zones Extended Coherent Flame Model (Ecfm3z) for Computing Premixed/Diffusion Combustion. Oil & Gas Science and Technology, 59(6), 593-609. doi:10.2516/ogst:2004043K. Huh, A phenomenological model of diesel spray atomization, Proc. of the international conf. on multiphase flows' 91-tsukuba.Reitz, R. D., & Diwakar, R. (1987). Structure of High-Pressure Fuel Sprays. SAE Technical Paper Series. doi:10.4271/870598Habchi, C., Lafossas, F. A., Béard, P., & Broseta, D. (2004). Formulation of a One-Component Fuel Lumping Model to Assess the Effects of Fuel Thermodynamic Properties on Internal Combustion Engine Mixture Preparation and Combustion. SAE Technical Paper Series. doi:10.4271/2004-01-1996Karlsson, A., Magnusson, I., Balthasar, M., & Mauss, F. (1998). Simulation of Soot Formation Under Diesel Engine Conditions Using a Detailed Kinetic Soot Model. SAE Technical Paper Series. doi:10.4271/981022Hiroyasu, H., & Kadota, T. (1976). Models for Combustion and Formation of Nitric Oxide and Soot in Direct Injection Diesel Engines. SAE Technical Paper Series. doi:10.4271/760129Wiedenhoefer, J. F., & Reitz, R. D. (2003). Multidimensional Modeling of the Effects of Radiation and Soot Deposition in Heavy-duty Diesel Engines. SAE Technical Paper Series. doi:10.4271/2003-01-056

Evaluation of the bioaccessibility of antioxidant bioactive compounds and minerals of four genotypes of Brassicaceae microgreens

Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Capacity) were determined before and after the standardized simulated gastrointestinal digestion process. All microgreens provided relevant amounts of vitamin C (31-56 mg/100 g fresh weight) and total carotenoids (162-224 mg β-carotene/100 g dry weight). Mineral content was comparable to that normally found in hydroponic microgreens and the low potassium levels observed would allow their dietetic recommendation for patients with impaired kidney function. Both total soluble polyphenols and total isothiocyanates were the greatest contributors to the total antioxidant capacity after digestion (43-70% and 31-63% bioaccessibility, respectively) while macroelements showed an important bioaccessibility (34-90%). In general, radish and mustard presented the highest bioaccessibility of bioactive compounds and minerals. Overall, the four hydroponic Brassicaceae microgreens present a wide array of antioxidant bioactive compounds

An Alternative Procedure to Quantify Soot in Engine Oil by Ultraviolet-Visible Spectroscopy

"This is an Accepted Manuscript of an article published by Taylor & Francis in Tribology Transactions on 02-11-2019, available online: https://www.tandfonline.com/doi/full/10.1080/10402004.2019.1645255."[EN] Due to new pollutant emissions standards, internal combustion engines need several emission control strategies (and related procedures) such as exhaust gas recirculation, diesel/gasoline particulate filters, and selective catalyst reduction that allow them to comply with complete requirements defined on those standards. These strategies result in faster degradation of engine oil, one of the most relevant consequences of which is an increase in soot contamination level. All of these strategies facilitate soot generation. Consequently, soot is one of the most important contaminants present in engine oil. The main technique to measure the content of soot in oil is thermogravimetric analysis (TGA), but this technique has certain limitations. TGA requires a long and specific procedure and has limitations in measuring small concentrations of soot in oil. Therefore, the design of an alternative technique to quantify soot in oil is relevant. One alternative is Fourier transform infrared (FTIR) spectroscopy, but it also has limitations related to low concentrations of soot in oil. This work presents an alternative technique based on ultraviolet-visible (UV-Vis) spectroscopy that allows quantification of small soot contents in used engine oil samples and avoids potential interference from other typical contaminants or those related to measurement processes, such as sample cuvette material.Antonio Garcia-Barbera was supported through the Programa Nacional de Formacion de Recursos Humanos de Investigacion of Spanish Ministerio de Ciencia e Innovacion (Grant Number BES-2016-078073).Macian Martinez, V.; Tormos, B.; Ruiz-Rosales, S.; García-Barberá, A. (2019). An Alternative Procedure to Quantify Soot in Engine Oil by Ultraviolet-Visible Spectroscopy. Tribology Transactions. 62(6):1063-1071. https://doi.org/10.1080/10402004.2019.1645255S10631071626Squaiella, L. L. F., Martins, C. A., & Lacava, P. T. (2013). Strategies for emission control in diesel engine to meet Euro VI. Fuel, 104, 183-193. doi:10.1016/j.fuel.2012.07.027Piock, W., Hoffmann, G., Berndorfer, A., Salemi, P., & Fusshoeller, B. (2011). Strategies Towards Meeting Future Particulate Matter Emission Requirements in Homogeneous Gasoline Direct Injection Engines. SAE International Journal of Engines, 4(1), 1455-1468. doi:10.4271/2011-01-1212Johnson, B. T. (2008). Diesel Engine Emissions and Their Control. Platinum Metals Review, 52(1), 23-37. doi:10.1595/147106708x248750Johnson, T. V. (2008). Diesel Emission Control in Review. SAE International Journal of Fuels and Lubricants, 1(1), 68-81. doi:10.4271/2008-01-0069Mohan, B., Yang, W., & Chou, S. kiang. (2013). Fuel injection strategies for performance improvement and emissions reduction in compression ignition engines—A review. Renewable and Sustainable Energy Reviews, 28, 664-676. doi:10.1016/j.rser.2013.08.051ALKEMADE, U., & SCHUMANN, B. (2006). Engines and exhaust after treatment systems for future automotive applications. Solid State Ionics, 177(26-32), 2291-2296. doi:10.1016/j.ssi.2006.05.051Bensaid, S., Caroca, C. J., Russo, N., & Fino, D. (2011). Detailed investigation of non-catalytic DPF regeneration. The Canadian Journal of Chemical Engineering, 89(2), 401-407. doi:10.1002/cjce.20408E, J., Xie, L., Zuo, Q., & Zhang, G. (2016). Effect analysis on regeneration speed of continuous regeneration-diesel particulate filter based on NO 2 -assisted regeneration. Atmospheric Pollution Research, 7(1), 9-17. doi:10.1016/j.apr.2015.06.012Tripathi, A., & Vinu, R. (2015). Characterization of Thermal Stability of Synthetic and Semi-Synthetic Engine Oils. Lubricants, 3(1), 54-79. doi:10.3390/lubricants3010054Karacan, Ö., Kök, M. V., & Karaaslan, U. (1999). Journal of Thermal Analysis and Calorimetry, 55(1), 109-114. doi:10.1023/a:1010136222719Heredia-Cancino, J. A., Ramezani, M., & Álvarez-Ramos, M. E. (2018). Effect of degradation on tribological performance of engine lubricants at elevated temperatures. Tribology International, 124, 230-237. doi:10.1016/j.triboint.2018.04.015Wattrus, M. (2013). Fuel Property Effects on Oil Dilution in Diesel Engines. SAE International Journal of Fuels and Lubricants, 6(3), 794-806. doi:10.4271/2013-01-2680Sharma, V., Uy, D., Gangopadhyay, A., O’Neill, A., Paxton, W. A., Sammut, A., … Aswath, P. B. (2016). Structure and chemistry of crankcase and exhaust soot extracted from diesel engines. Carbon, 103, 327-338. doi:10.1016/j.carbon.2016.03.024Pfau, S. A., La Rocca, A., Haffner-Staton, E., Rance, G. A., Fay, M. W., Brough, R. J., & Malizia, S. (2018). Comparative nanostructure analysis of gasoline turbocharged direct injection and diesel soot-in-oil with carbon black. Carbon, 139, 342-352. doi:10.1016/j.carbon.2018.06.050George, S., Balla, S., Gautam, V., & Gautam, M. (2007). Effect of diesel soot on lubricant oil viscosity. Tribology International, 40(5), 809-818. doi:10.1016/j.triboint.2006.08.002Antusch, S., Dienwiebel, M., Nold, E., Albers, P., Spicher, U., & Scherge, M. (2010). On the tribochemical action of engine soot. Wear, 269(1-2), 1-12. doi:10.1016/j.wear.2010.02.028Green, D. A., & Lewis, R. (2008). The effects of soot-contaminated engine oil on wear and friction: A review. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 222(9), 1669-1689. doi:10.1243/09544070jauto468Bredin, A., Larcher, A. V., & Mullins, B. J. (2011). Thermogravimetric analysis of carbon black and engine soot—Towards a more robust oil analysis method. Tribology International, 44(12), 1642-1650. doi:10.1016/j.triboint.2011.06.002VAN DE VOORT, F. R., SEDMAN, J., COCCIARDI, R. A., & PINCHUK, D. (2006). FTIR Condition Monitoring of In-Service Lubricants: Ongoing Developments and Future Perspectives. Tribology Transactions, 49(3), 410-418. doi:10.1080/10402000600781432Van de Voort, F. R., Ghetler, A., García-González, D. L., & Li, Y. D. (2008). Perspectives on Quantitative Mid-FTIR Spectroscopy in Relation to Edible Oil and Lubricant Analysis: Evolution and Integration of Analytical Methodologies. Food Analytical Methods, 1(3), 153-163. doi:10.1007/s12161-008-9031-6Ess, M. N., Ferry, D., Kireeva, E. D., Niessner, R., Ouf, F.-X., & Ivleva, N. P. (2016). In situ Raman microspectroscopic analysis of soot samples with different organic carbon content: Structural changes during heating. Carbon, 105, 572-585. doi:10.1016/j.carbon.2016.04.056Russo, C., Apicella, B., Lighty, J. S., Ciajolo, A., & Tregrossi, A. (2017). Optical properties of organic carbon and soot produced in an inverse diffusion flame. Carbon, 124, 372-379. doi:10.1016/j.carbon.2017.08.07

Low-cost AUV based on Arduino Open Source Microcontroller Board for oceanographic research applications in a collaborative long term deployment missions and suitable for combining with an USV as autonomous automatic recharging platform

“©2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The challenge of extending the autonomy in AUV deployments is one of the most important issues in oceanographic research today. The possibility of maintaining a team of AUV under deployment in a defined area of interest for a long period could provide an additional source of information [8]. All this data in combination with the measures provided by buoys and sea gliders used for slow motion and long range operations will be very valuable. A group of low cost AUV's in alternative automatic switching system navigation-charging operation, could allow a kind of continuous surveying operation. This work is the continuation of the ideas that some of the authors previously presented in the AUV 2010 conference at MBARI [8]. At this conference was proposed the great interest for researching oceanic processes on two areas near Cartagena, Spain: cape Tiñoso and the Mar Menor a shallow coastal lagoon. Both areas require a different research structure configuration because of their opposite characteristics. The Mar Menor is a shallow salty lagoon 20 miles long with 7 m of maximum depth and particular features. This lagoon seems to present a sort of oceanic behavior and can be compared with the major oceans but a minor scale. The second area considered is cape Tiñoso, a very deep area in the Mediterranean Sea where the presence of a self-break provides an interesting potential for the research of the effect of upwelling currents.This work has been partly supported by the Spanish Ministry of Education under projects number TIN2011-28435-C03-01 and CTM2011-29691-C02-01.Busquets, J.; Busquets Mataix, JV.; Tudela, D.; Pérez, F.; Busquets-Carbonell, J.; Barberá, Á.; Rodríguez, C.... (2012). Low-cost AUV based on Arduino Open Source Microcontroller Board for oceanographic research applications in a collaborative long term deployment missions and suitable for combining with an USV as autonomous automatic recharging platform. IEEE. https://doi.org/10.1109/AUV.2012.6380720

Simulation study of resistor networks applied to an array of 256 SiPMs

[EN] In this work we describe a procedure to reduce the number of signals detected by an array of 256 Silicon Photo-multipliers (SiPMs) using a resistor network to divide the signal charge into few readout channels. Several configurations were modeled, and the pulsed signal at the readout contacts were simulated. These simulation results were experimentally tested on a specifically designed and manufactured set of printed circuit boards. Three network configurations were modeled. The modeling provided encouraging results for all three configurations. The measurements on the prototypes constructed for this study, however, provided useful position-sensitivity for only one of the network configurations. The lack of input signal amplification into the networks, the SiPM dark current, as well as the complexity of an eight layers board with parasitic capacitances, could have caused the degradation of resolving the impact photon position. This is hard to overcome with external printed circuit boards and components.This work was supported by the Spanish Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica (I+D+I) under Grant FIS2010-21216-CO2-01, the Valencian Local Government under Grant PROMETEO 2008/114 and through the JAE-Predoc grant from CSIC (BOE 29/01/2010).Gonzalez, A. J., Moreno, M., Barbera, J., Conde, P., Hernandez, L., Moliner, L., . . . Benlloch, J. M. (2013). Simulation study of resistor networks applied to an array of 256 SiPMs. IEEE Transactions on Nuclear Science, 60(2), 592-598. doi:10.1109/TNS.2012.2226051S59259860

SilvAdapt.Net: A Site-Based Network of Adaptive Forest Management Related to Climate Change in Spain

[EN] Adaptive forest management (AFM) is an urgent need because of the uncertainty regarding how changes in the climate will affect the structure, composition and function of forests during the next decades. Current research initiatives for the long-term monitoring of impacts of silviculture are scattered and not integrated into research networks, with the consequent losses of opportunities and capacity for action. To increase the scientific and practical impacts of these experiences, it is necessary to establish logical frameworks that harmonize the information and help us to define the most appropriate treatments. In this context, a number of research groups in Spain have produced research achievements and know-how during the last decades that can allow for the improvement in AFM. These groups address the issue of AFM from different fields, such as ecophysiology, ecohydrology and forest ecology, thus resulting in valuable but dispersed expertise. The main objective of this work is to introduce a comprehensive strategy aimed to study the implementation of AFM in Spain. As a first step, a network of 34 experimental sites managed by 14 different research groups is proposed and justified. As a second step, the most important AFM impacts on Mediterranean pines, as one of the most extended natural and planted forest types in Spain, are presented. Finally, open questions dealing with key aspects when attempting to implement an AFM framework are discussed. This study is expected to contribute to better outlining the procedures and steps needed to implement regional frameworks for AFM.A.J. Molina is beneficiary of an "APOSTD" fellowship (APOSTD/2019/111) funded by the Generalitat Valenciana. M. Moreno-de las Heras is beneficiary of a Serra Hunter fellowship (UB-LE-9055) funded by the Generalitat de Catalunya. F.J. Ruiz-Gomez is supported by a postdoctoral fellowship of the Junta de Andalucia (Sevilla, Spain), and the European Social Fund 2014-2020 Program (DOC_0055). The authors received national and international funding through the following projects: SILVADAPT.NET (RED2018-102719-T), ESPECTRAMED (CGL2017-86161-R), Life-FOREST CO2 (LIFE14 CCM/ES/001271), ALTERACLIM (CGL2015-69773-C2-1-P), INERTIA (PID2019-111332RB-C22-BDV), CEHYRFO-MED (CGL2017-86839-C3-2-R), DEHESACLIM (IB16185), RESILIENTFORESTS (LIFE17 CCA/ES/000063), Rhysotto (PID2019-106583RB-I00), AGL2017-83828C2-2-R, RTI2018-096884-B-C31, ESPAS (CGL2015-65569-R), and caRRRascal (RTI2018-095037-B-I00).Molina Herrera, A.; Navarro Cerrillo, R.; Pérez-Romero, J.; Alejano, R.; Bellot, JF.; Blanco, JA.; Camarero, JJ.... (2021). SilvAdapt.Net: A Site-Based Network of Adaptive Forest Management Related to Climate Change in Spain. Forests. 12(12):1-27. https://doi.org/10.3390/f12121807127121

Investigación en la enseñanza y aprendizaje de las Ciencias Experimentales en el Grado de Maestro en Educación Primaria

Tras analizar en un trabajo anterior las concepciones alternativas de los estudiantes del Grado de Maestro en Educación Primaria sobre el tema de las propiedades de la materia (el cual forma parte del curriculo de primaria), en el presente trabajo desarrollamos una propuesta didáctica para mejorar la enseñanza de la densidad en dicho grado, con lo que se pretende no sólo que el alumnado mejore su formación sobre el tema en cuestión, sino que además dicha propuesta didáctica les sirva para ponerla en práctica con sus futuros discentes. Para ello, se ha llevado a cabo un estudio en tres grupos de la asignatura ‘Enseñanza y Aprendizaje de las Ciencias Experimentales II’, de tercer curso del Grado, con un total de 124 personas. Los instrumentos empleados han sido: un cuestionario pre-test y post-test, y el programa guía de la unidad didáctica sobre densidad. Los resultados del pre-test de este estudio mostraron que a pesar de que casi el 60% del alumnado supo identificar correctamente cuándo un objeto es más denso que otro, apenas el 38% sabe explicar el porqué. Tras realizar la intervención didáctica en el aula, los resultados mejoraron considerablemente respondiendo correctamente el 80% de los participantes