Assessment of low-viscosity oil performance and degradation in a heavy duty engine real-world fleet test

Low viscosity engine oils (LVO) are considered one of the most interesting solutions for improving fuel economy in internal combustion engines (ICE). There are different studies involving LVO and ICE, but currently limited data are available regarding real-world performance of LVO in a real service fleet. Included in a broadest study related with fuel consumption saving effects and performance of LVO in a real service fleet, the aim of this work is to present the results obtained in terms of comparative oil performance. So, on this test, a comparative analysis using 39 buses was performed, based on a deep and extensive oil analysis program to assess those aspects above mentioned. Two engine technologies (Diesel and CNG) were considered and four different lubricants, two of them LVO and other two used as a reference baseline. The test duration comprised two oil drain intervals of 30000 km each one, totalizing more than 2 million of kilometers accumulated. Results have shown that LVO presented an excellent performance along the oil drain interval (ODI), even improving some characteristics of the baseline oils with higher viscosity values. Results have shown that oil degradation is more dependent on engine technology, but in any case presented a penalization in terms of ODI reduction, a key indicator for end-users related with maintenance costs. In the case of CNG engines, higher oil degradation in terms of oil oxidation and nitration was observed.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by the Spanish Ministerio de Ciencia e Innovacion (Project no. TRA2012-30907).Macian Martinez, V.; Tormos Martínez, BV.; Miró Mezquita, G.; Pérez, T. (2016). Assessment of low-viscosity oil performance and degradation in a heavy duty engine real-world fleet test. Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology. 230(6):729-743. doi:10.1177/1350650115619612S729743230

Reporting Model for Decision Support Based on the SAF-T Standard

The purpose of this paper is to summarize the results and conclusions obtained during an investigation aiming to reveal the usefulness and added value of the SAF-T when used to support decision making and the internal management of organizations. The research addresses the SAF-T standard as a source of knowledge for decision support and intelligent auditing. The research contextualizes the contribution of the SAF-T based model as a scalable way to make intelligent audits, implement new business processes and manage electronic control. The information quality of this report and digital model is also stressed. Upon automatic reporting based on SAF-T data one can draw financial conclusions and decide changes on a firm´s commercial scope. This article also highlights the advantages of decision making based on the proposed model and report. A set of hints and suggestions for further re-search work on this topic is also provided

Quaternary mixture designs applied to the development of multi-element oxygen electrocatalysts based on the Ln(0.58)Sr(0.4)Fe(0.8)Co(0.2)O(3-delta) system (Ln = La1-x-y-zPrxSmyBaz): Predictive modeling approaches

[EN] The experimental data generated through the optimization of oxygen electrocatalysts based on the perovskite Ln(0.58)Sr(0.4)Fe(0.8)Co(0.2)O(3-delta) system (Ln = La1-x-y-zPrxSmyBaz) have been modeled following different approaches. The main application of these catalysts is as fuel cell (SOFC) cathodes and activation layers on oxygen-transport membranes. Among the different La, Pr and Sm combinations, those containing at a time Sm-La-Ba or alternatively Pr-La-Ba show the lowest polarization resistance values. Within the same substitution degree, Pr-Ba-based compositions have lower electrode resistance than samarium-based ones. The experimental datasets available for the series of materials can be divided into: composition data, structural data (X-ray diffraction patterns), and electrochemical characterization data (electrochemical impedance spectra). Electrochemical characterization was performed for each electrode composition as a function of the operating temperature and oxygen partial pressure. Different ways of reducing the dimensionality of the spectral descriptors (XRD patterns and impedance spectroscopy) were applied based on knowledge-guided and unsupervised approaches. Different material descriptors were studied as input variables in the modeling of the electrochemical properties. (C) 2010 Elsevier B.V. All rights reserved.Funding from Universitat Politècnica de València (grant UPV2007-06), the Spanish Ministry for Science and Innovation (Project ENE-2008-06302), the Helmholtz Association of German Research Centers through the Helmholtz Alliance MEM-BRAIN (Initiative and Networking Fund) and EU through FP7 NASA-OTM Project (NMP3-SL-2009-228701) is kindly acknowledged.Serra Alfaro, JM.; Vert Belenguer, VB. (2011). Quaternary mixture designs applied to the development of multi-element oxygen electrocatalysts based on the Ln(0.58)Sr(0.4)Fe(0.8)Co(0.2)O(3-delta) system (Ln = La1-x-y-zPrxSmyBaz): Predictive modeling approaches. Catalysis Today. 159(1):47-54. https://doi.org/10.1016/j.cattod.2010.06.019S4754159

Low viscosity engine oils: Study of wear effects and oil key parameters in a heavy duty engine fleet test

Low viscosity engine oils (LVO) are considered key contributor for improving fuel economy in internal combustion engines (ICE). Attending that the use of LVO could imply a variation in tribological states found in ICE, this work's aim is to test LVO in real fleet, with emphasis on engine wear and oil key performance indicators. This test comprised 39 buses, two engine technologies and four different lubricants. For each sample, the elemental composition of the wear debris by ICP-AES and HTHS viscosity of the oil were measured among other properties. The results showed that, with a correct oil formulation, there is no significant difference when using LVO in terms of engine wear, HTHS viscosity variation and oil consumption. (C) 2015 Elsevier Ltd. All rights reserved.The authors would like to thank the Spanish Ministerio de Ciencia e Innovacion for its funding in this project (Project no. TRA2012-30907), and thank Repsol and EMT de Valencia for their collaboration. Additionally, the authors would like to thank Ruth Calatayud, Lorena Garzon, Leonardo Ramirez and Santiago Ballester for their help in this work.Macian Martinez, V.; Tormos Martínez, BV.; Ruiz Rosales, S.; Miró Mezquita, G. (2016). Low viscosity engine oils: Study of wear effects and oil key parameters in a heavy duty engine fleet test. Tribology International. 94:240-248. doi:10.1016/j.triboint.2015.08.028S2402489

Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load

Along the last years, engine researchers are more and more focusing their efforts on the advanced low temperature combustion (LTC) concepts with the aim of achieving the stringent limits of the current emission legislations. In this regard, several studies based on highly premixed combustion concepts such as HCCI has been confirmed as a promising way to decrease drastically the most relevant CI diesel engine-out emissions, NOx and soot. However, the major HCCI drawbacks are the narrow load range, bounded by either misfiring (low load, low speed) or hardware limitations (higher load, higher speeds) and the combustion control (cycle-to-cylce control and combustion phasing). Although several techniques have been widely investigated in order to overcome these drawbacks, the high chemical reactivity of the diesel fuel remains as the main limitation for the combustion control. The attempts of the researchers to overcome these disadvantages are shifting to the use of fuels with different reactivity. In this sense, gasoline PPC has been able to reduce emissions and improve efficiency simultaneously, but some drawbacks regarding controllability and stability at low load operating conditions still need solution. In this field, previous researches have been demonstrate the multiple injection strategy as an appropriate technique to enhance the combustion stability. However, PPC combustion has been found limited to engine loads higher than 5 bar BMEP when using fuels with octane number greater than 90. In this regard, previous work from the authors showed the capability of the spark plug to provide combustion control in engine loads below this limit even using 98 ON gasoline. The main objective of the present work is to couple the control capability of the spark assistance together with an appropriate mixture distribution by using double injection strategies with the aim of evaluating performance and engine-out emissions at low load PPC range using a high octane number gasoline. For this purpose the optical and metal version of a compression ignition single-cylinder engine, to allow high compression ratio, has been used during the research. A common rail injection system enabling high injection pressures has been utilized to supply the 98 octane number gasoline. An analysis of the in-cylinder pressure signal derived parameters, hydroxyl radical (OH*) and natural luminosity images acquired from the transparent engine as well as a detailed analysis of the air/fuel mixing process by means of a 1-D in-house developed spray model (DICOM) has been conducted. Results from both analysis methods, suggest the spark assistance as a proper technique to improve the spatial and temporal control over the low load gasoline PPC combustion process. A noticeable increase in the cycle to cycle repeatability (5% versus 15.1% CoV IMEP at 2 bar load) as well as a reduction in the knocking level (20.5 versus 33.6 MW/m2 at 7 bar load) is observed. In addition, the combination of the spark assistance with the use of the double injection strategy provides a great improvement in terms of combustion efficiency (93% versus 88% for a single injection strategy) with a benefit around 18% in the IMEPBenajes Calvo, JV.; Tormos Martínez, BV.; García Martínez, A.; Monsalve Serrano, J. (2014). Impact of Spark Assistance and Multiple Injections on Gasoline PPC Light Load. SAE International Journal of Engines. 7(4):1875-1887. doi:10.4271/2014-01-2669S187518877

Evaluation of strain and structural style variations along the strike of the Fuegian thrust-fold belt front, Argentina

The Fuegian thrust-fold belt (TFB) forms the thin-skinned outer wedge of the Andes in Tierra del Fuego. Using subsurface and outcrop data from two areas (Western and Eastern) of the TFB front in Argentina we aimed to verify and characterize the apparent structural variations along the strike. Both areas reveal pro- and retro-vergent faultrelated folds detached at similar horizons, with a youngest early to middle (?) Miocene deformation age. However, the Western Area has gentle, large-wavelength folds whereas the Eastern Area is characterized by a very tight structural geometry, with closer fold geometries. This difference manifests itself in the shortening of analogous structures: below 5.5% in the west as against ~22% in the Eastern Area. Our findings verify structural style variations along the strike and suggest that the Eastern Area endured higher strain. We evaluate two possible causes of this strain gradient, assuming homogeneous regional shortening: (i) lateral rheological variations at the base of the thrust wedge, namely the occurrence of more competent beds which would have restrained the propagation of the detachment toward the east; and (ii) the effect of strong buttressing in the eastern TFB exerted by the Río Chico arch basement promontory during deformation. Published results, together with our current subsurface and outcrop data, rule out significant rheological gradients in a preferred direction along the TFB. On the other hand, we present evidence of the nucleation of frontal thrusts above basement steps at the Río Chico arch western margin, which comprise local buttresses. We speculate that this buttressing was mantained along the TFB front and is enhanced toward the east, where forward TFB propagation was hindered due to the southern projection of the Río Chico promontory. This would explain the higher strain and more complex structural style in the Eastern AreaEvaluación de variaciones en el grado de deformación y el estilo estructural a lo largo del frente de la faja corrida y plegada Fueguina, Argentina. La faja corrida y plegada Fueguina (FCP) comprende el cinturón de piel fina en el antepaís de los Andes en Tierra del Fuego. Con la finalidad de verificar y caracterizar posibles variaciones estructurales a lo largo del frente de la FCP en Argentina, hemos analizado datos de subsuelo y superficie en dos áreas (occidental y oriental). Ambas revelan pliegues relacionados con fallas, tanto provergentes como retrovergentes, que despegan en niveles similares, y tienen una edad mínima miocena temprana a media (?). Sin embargo, en el área occidental el plegamiento es suave y de alta longitud de onda mientras que en el área oriental la estructura es muy apretada, con pliegues más cerrados. Esta diferencia se manifiesta al comparar el acortamiento en estructuras análogas: menor a 5,5% en el oeste contra ~22% en el área oriental. Por lo tanto, queda verificada la existencia de variaciones en el estilo estructural a lo largo del rumbo, y se pone en evidencia que el área oriental fue sometida a mayor deformación. Evaluamos dos causas posibles para este gradiente de deformación, asumiendo una magnitud de acortamiento regional homogénea: (i) variaciones laterales en la reología de la base de la FCP, por ejemplo capas más competentes hacia el este que podrían haber dificultado la propagación del despegue en ese sector, y (ii) una fuerte obstaculización al avance de la FCP en el este, ejercida por el promontorio de basamento del Arco Río Chico. La información publicada previamente, así como los datos de este trabajo, descartan un gradiente reológico significativos en una dirección preferencial a lo largo de la FCP. Al contrario, nuestros datos evidencian localización de corrimientos frontales sobre escalones en el basamento del Arco Río Chico en el área occidental, que localmente obstaculizan el avance de la deformación. Especulamos con que este efecto obstaculizador se mantuvo a lo largo del frente de la FCP, con mayor intensidad hacia el este, donde el avance de la FCP fue restringido por la proyección austral del arco Río Chico. De esta manera se puede explicar la mayor deformación y el estilo estructural más complejo en el área oriental.Fil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina;Fil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - CONICET - Bahía Blanca. Instituto Geológico del Sur; Argentina;Fil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentina

Redox stability and electrochemical study of nickel doped chromites as anodes for H-2/CH4-fueled solid oxide fuel cells

[EN] The influence of nickel and strontium incorporation in LaCrO3 on the crystalline structure, redox behavior and electrochemical performance by impedance spectroscopy using symmetrical cells has been studied. Namely, the La1-xSrxCr1-yNiyO3-delta (x = 0, 0.15: y = 0.05, 0.1, 0.2) system was investigated. Structural and redox evolution has been monitored by X-ray diffraction in oxidized and reduced samples. Reduced samples kept the initial perovskite structure although metallic nickel nanoparticles were detected on the perovskite grain surface by TEM analysis. The re-oxidized surface did not present nickel particles, suggesting the nickel re-incorporation into perovskite lattice coupled with cation diffusion. The perovskites were tested as SOFC anodes and the polarization resistance depended on the nickel stoichiometry and the reduction temperature. La0.85Sr0.15Cr0.9Ni0.1O3-delta reduced at 800 degrees C showed the lowest polarization resistance, both in hydrogen and methane. In fact this composition showed a 20% methane conversion at 900 degrees C for the methane steam reforming in a fixed bed reactor. Tolerance to redox cycling was proved electrochemically by in situ treatments of La0.85Sr0.15Cr0.9Ni0.1O3-delta electrode. Materials were further analyzed by TPR and XPS (in oxidized and reduced state) in order to identify the possible species involved in the electrocatalytic processes. (C) 2011 Elsevier B.V. All rights reserved.Authors thank funding by the Universidad Politecnica de Valencia (Grant FPI-UPV-2007-06), the Spanish Ministry for Science and Innovation (Project ENE2008-06302) and Generalitat Valenciana (Grant ACOMP2010/223). P. Concepcion has contributed to this work with the XPS measurements. N. Morlanes, S. Climent and M. Algarra are kindly acknowledged for the catalytic experiments.Vert Belenguer, VB.; Melo Faus, FV.; Navarrete Algaba, L.; Serra Alfaro, JM. (2012). Redox stability and electrochemical study of nickel doped chromites as anodes for H-2/CH4-fueled solid oxide fuel cells. Applied Catalysis B Environmental. 115:346-356. https://doi.org/10.1016/j.apcatb.2011.12.03334635611

Influence of substrate on strawberry plug plant production

[EN] The plug plant technique for the commercial propagation of strawberries is increasing in importance. Several factors, including the properties of the substrate, can affect plug plant quality. Tests on nine substrates containing different proportions of perlite [from 0 ¿ 75%, (v/v)], and dark and light peat [both from 0 ¿ 80% (v/v)], were performed using a simplex-lattice design in order to establish a model for strawberry plug plant production based not only on the single component composition of the substrate, but also on the influences of the chemical and physical properties of the substrate on plug plant quality. Notable differences in physical and chemical properties were found among the nine different substrates tested, as a consequence of the broad range of their component compositions. Substrate mixes containing medium-to-high proportions [from 60 ¿ 70% (v/v)] of light peat and low proportions of dark peat and perlite are recommended, as these resulted in a low nutrient content, a high organic matter content, a low pH, and a low ¿coarseness¿ index, which led to high-grade plug plants with greater root and crown dry weights.Funding was provided by the Spanish Ministry for Science and Technology-FEDER through Research Project No. AGL2004-04365/AGR. The authors are grateful to Dr. J.L. Guardiola and Dr. Manual Abad for comments on this manuscript. The authors are also grateful to Ms. Debra Westall for revising the grammar of the manuscript.López Galarza, SV.; San Bautista Primo, A.; Pascual España, B.; Maroto Borrego, JV. (2010). Influence of substrate on strawberry plug plant production. Journal of Horticultural Science. 85(5):415-420. doi:10.1080/14620316.2010.11512690S41542085

Compact Combline Filter Embedded in a Bed of Nails

[EN] In this paper, we propose a compact topology for high-frequency bandpass filters using coaxial cavities embedded in a bed of nails, including a complete design procedure combining equivalent circuit models and full-wave simulators. The resonance generated around a shortened cylindrical nail of the bed hosting structure is used as the basic element of the proposed filter, which is fed through groove gap waveguides. For design purposes, an equivalent circuit model of the considered resonance is first obtained, and then the coupling levels between resonators are recovered with the distance between adjacent shortened nails. In order to validate the proposed structure and its design procedure, a filter prototype with a bandpass response (centered at 30 GHz and with relative bandwidth of 1.7%) has been designed, manufactured, and measured. Good experimental results, in terms of insertion losses (with a minimum value of 1.6 dB) and return losses (greater than 16.6 dB in the whole passband), have been achieved.This work was supported in part by the Spanish Government, Ministry of Economy, National Program of Research, Development and Innovation through the project SATCOM-KA "New antennas for mobile satellite communications in Ka-band" under Project TEC2016-79700-C2-1-R and in part by the "Demostradores tecnologicos de filtros y multiplexores con respuestas selectivas y sintonizables en nuevas guias compactas para aplicaciones espaciales" under Project TEC2016-75934-C4-1-R.Baquero Escudero, M.; Valero-Nogueira, A.; Ferrando-Rocher, M.; Bernardo Clemente, B.; Boria Esbert, VE. (2019). Compact Combline Filter Embedded in a Bed of Nails. IEEE Transactions on Microwave Theory and Techniques. 67(4):1461-1471. https://doi.org/10.1109/TMTT.2019.2895576S1461147167

Thrust-fold belt kinematics and orogenic growth in Tierra del Fuego, Argentina: implications of backthrusting for critical Coulomb wedge development

Analysis of balanced cross-sections and of the chronostratigraphy of the deformed foreland basin successions allows to solve the structural kinematics of the eastern Fuegian thrust-fold belt. Based on the Coulomb wedge theory, we propose a chronologically and geometrically well-constrained growth history for the frontal Fuegian Andes orogen. The mountain front behaved in a critical manner during the Early Eocene, characterized by forward thrusting. The wedge became subcritical after that, until renewed forward propagation of the thrust front in the Early Miocene. The long period as a subcritical wedge enhanced retrodeformation, recorded by out-of-sequence thrusting and backthrusting. We suggest that backthrusts should be considered an important mechanism for accommodating shortening in subcritical orogenic wedges.Fil: Torres Carbonell, Pablo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Dimieri, Luis Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Geológico del Sur. Universidad Nacional del Sur. Departamento de Geología. Instituto Geológico del Sur; ArgentinaFil: Olivero, Eduardo Bernardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; Argentin