Proposal of an FTIR Methodology to Monitor Oxidation Level in Used Engine Oils: Effects of Thermal Degradation and Fuel Dilution

This article describes a procedure, based on ASTM standards D7214 and E2412, that has been defined to improve quantification of oil oxidation in used engine oils. Taking into account typical problems that can be found in this type of sample, including thermal oxidation and fuel dilution, Fourier transform infrared (FTIR) spectra were analyzed also considering the effect of the oil formulation. Two zones were considered inside the typical wave number range for quantification of oxidation, where those problems can be detected and assessed more easily: zone A between 1725 and 1650 cm-1, where the main oxidation products, such as aldehydes, carboxylic acids, and ketones, occur due to thermal degradation of the oil; and zone B between 1770 and 1725 cm-1, where esters due to potential biodiesel dilution problems are detected. Copyright © Society of Tribologists and Lubrication Engineers.The authors are grateful for Spanish Grant TRA2008-06508 (GLAUTO) from the Ministerio de Ciencia e Innovacion-Direccion General de Investigacion for supporting this work.Macian Martinez, V.; Tormos, B.; Gomez Estrada, YA.; Salavert Fernández, JM. (2012). Proposal of an FTIR Methodology to Monitor Oxidation Level in Used Engine Oils: Effects of Thermal Degradation and Fuel Dilution. Tribology Transactions. 55(6):872-882. https://doi.org/10.1080/10402004.2012.721921S87288255

Presencia de una especie del género Eretmocerus (Hymenoptera: Aphelinidae) sobre Bemisia tabaci (Hemiptera: Aleyrodidae) en el cultivo de pimiento en Tucumán, Argentina

Presence of a species of the genus Eretmocerus (Hymenoptera: Aphelinidae) on Bemisia tabaci (Hemiptera: Aleyrodidae) in the pepper crop from Tucumán, Argentina». The objective of this work was to identify the microhymenopterous parasitoid of B. tabaco in the pepper crop in Lules, Tucumán, Argentina. Sampling consisted in collect ing leaves with whitefly «pupae» with parasitoidism symptoms which were then taken to the Laboratory of Agricultural Zoology,National University of Tucumán (FAZ ? UNT), to obtain the adult parasitoids. Semipermanent microscopic preparations were made. Identification keys and taxonomical descriptions from different authors were used. It was identified to Eretmocerus sp., close to E. silvestrii Gerling. The silvestrii group is cited for the first time in South America and in Argentina on B. tabaci in the pepper crop.Fil: Paz, M. R.. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; ArgentinaFil: Maza, Noelia. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Tucumán; ArgentinaFil: Jaime, A. P.. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; ArgentinaFil: Macián, A. J.. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; ArgentinaFil: Ghiggia, L. I.. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; ArgentinaFil: Fernández, J. A.. Universidad Nacional de Tucuman. Facultad de Agronomia y Zootecnia. Catedra de Zoologia Agricola; Argentin

Meconio y exposición prenatal a neurotóxicos

6 pages, 1 figures, 2 tables.[ESP] Introducción. La ubicuidad con la que se encuentran la mayoría de las substancias neurotóxicas en el medio ambiente implica a los pediatras en la necesidad de desarrollar métodos para medir la magnitud de la exposición durante los periodos vulnerables del desarrollo. Una forma útil de abordar este problema consiste en analizar muestras biológicas que acumulen las substancias neurotóxicas o sus metabolitos durante el periodo fetal.Método. Revisión bibliográfica sistemática de los últimos 20 años obtenida principalmente de Medline; Science Citation Index y Embase sobre los estudios con meconio como matriz de exposición prenatal a substancias neurotóxicas. El perfil de búsqueda utilizado fue: meconium, prenatal exposure, biological markers, matrices, environmental pollutants, nervous system poisonings, neurotoxicity sindromes. Hemos seleccionado los trabajos más importantes y de sus referencias se han obtenido los más relevantes de los años previos a la búsqueda.Resultados. Tradicionalmente, los esfuerzos para determinar la exposición fetal se han centrado en el análisis de sangre de cordón u orina de la madre o el neonato. El meconio es fácilmente disponible, es inerte, acumula los neurotóxicos y/o sus metabolitos desde la semana 12 de gestación donde quedan “fosilizados” hasta el nacimiento. Puede constituir un instrumento muy importante para investigar la exposición fetal a los distintos contaminantes ambientales y en particular a neurotóxicos.Conclusiones. Las exposiciones fetales a los distintos neurotóxicos estudiados a través de sangre materna, de cordón, pelo, uña, placenta y orina parecen ser menos predictivas sobre los efectos neurológicos que las mediciones de los mismos realizadas en meconio. Son necesarios más estudios en este campo.Implementar y desarrollar la medida en meconio de una amplia gama de sustancias neurotóxicas ayudará en la práctica pediátrica a una intervención e identificación temprana mostrando las exposiciones que puedan provocar daño y facilitando el desarrollo de medidas preventivas y rehabilitadoras.[ENG] Brackground. The environmental ubiquity of most neurotoxicants implies the pediatricians in the development of methods for exposure measurement during the vulnerable periods of development. The analysis of biological samples able to accumulate the neurotoxicant substances or its metabolites during the fetal period is a useful approach to fulfil this objective.Material and methods. A systematic literature review of the last 20 years in Medline, Science Citation Index and Embase on the studies with meconium like womb of prenatal exposure to neurotoxicants has been undertaken. The search profile was: “meconium”, “prenatal exposure”, “biological markers”, “matrices”, “environmental pollutants”, “nervous system poisonings”, “neurotoxicity sindromes”. We selected the most relevant articles and retrieved more from their references.Results. Traditionally, the efforts to determine the fetal exposure have been centered in the analysis of cord blood, urinates of the mother or of the neonato. Meconium is easily available, inert, accumulates the neurotoxicants and/or its metabolitos from week 12 of gestation where they are "fossilized" until the birth. It can constitute a very important instrument for the investigation of the fetal exposure to the different environmental pollutants and in particular to neurotoxicants.Conclusions. Foetal exposure to different neurotoxicants monitored from maternal blood, cord blood, hair, fingernail, placenta and urinates seem to be less predictive for neurological effects than meconium. However, more studies are needed to confirm this hypothesis.Implementation and measurement in meconium of a wide range of neurotoxic substances will be of help in the pediatric practice for intervention and early identification as it will reveal harmful exposures and facilitate the implementation of preventive measures.Los autores quieren expresar su agradecimiento a los miembros de la red de Investigación Colaborativa INMA, y en especial a Amparo Quiles Latorre, Elena Romero Aliaga y Sandra Pérez Aliaga, por su apoyo y colaboración en la realización del trabajo de campo; al equipo de enfermería de la 7ª, 8ª y 9ª de la maternidad del Hospital Materno-Infantil Universitario La Fe y a los recién nacidos y sus felices padres que con su colaboración y entusiasmo hacen posible llevar a término estos estudios.Peer reviewe

Identificación y cría de microhimenópteros parasitoides de Bemisia tabaci (Gennadius) presentes en una plantación comercial de pimiento (Capsicum annuum L.) bajo carpa plástica y en la vegetación asociada al mismo

La mosca blanca Bemisia tabaci (Gennadius) se encuentra entre los insectos plaga de mayor importancia económica que afectan al cultivo de pimiento bajo carpa plástica. El daño provocado por las mismas en la planta hospedera se debe a la succión de la savia y a la producción de sustancias azucaradas que favorecen el desarrollo de hongos (fumagina) sobre la superficie de las hojas, lo que afecta la capacidad fotosintética y la evapotranspiración, mancha hojas y frutos, disminuyendo el valor estético y la calidad comercial del cultivo. Otro daño indirecto y más grave aún que el anterior, es la transmisión de enfermedades virales a las especies en las que se hospeda (Byrne y Bellows, 1991; Hilje, 2001; González Bez et al., 2002). Se caracteriza por ser un insecto polífago, con un amplio rango de plantas hospederas que incluye ornamentales, malezas y cultivos hortícolas (Polack, 2005).Fil: Figueroa, M. F.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Ghiggia, L. I.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Paz, M. R.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Macián, A. J.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Maza, Noelia. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, J. A.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Jaime, A. P.. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentin

Advances in the understanding of phytoseiid mites genera (Acari: Phytoseiidae) present in citrus plantations Tucuman, Argentina

Phytoseiidae es dentro de los ácaros depredadores, la familia más estudiada y muchas de sus especies se utilizan como agentes de control biológico de insectos y ácaros plagas. Estudios previos reportan la presencia de Amblyseius hibisci (Ch.), Thyphloseiopsis arboreus (Ch.), Phytoseiulus macropilis (B.) y Euseius concordis (Ch.) en cítricos de las regiones del noroeste (NOA) y noreste (NEA) de Argentina. Sin embargo, no existe información reciente sobre las especies presentes en plantaciones cítricas del NOA. Este trabajo se propuso actualizar la diversidad de ácaros fitoseidos en plantaciones de pomelo, naranja, mandarina, limón y la vegetación espontánea asociada en la provincia de Tucumán, noroeste de Argentina. Se identificaron especies de los siguientes géneros: en pomelo, Euseius W., Amblyseius B. y Galendromus M.; en naranja, Euseius W.; en mandarina, Euseius W., Amblyseius B. y Tryphlodromalus M.; en limón, Euseius W., Amblyseius B. y Phytoseiulus E. mientras que en la vegetación espontánea se encontraron los géneros Neoseiulus H., Euseius W., Amblyseius B., Typhlodromalus M. y Graminaseius Ch. y Mc M. El género que se presentó en mayor porcentaje y que estuvo representado en todas las especies muestreadas fue Euseius W. Los resultados obtenidos muestran un incremento en la diversidad de géneros de Phytoseiidae presentes en el agroecosistema cítrico de Tucumán respecto a lo reportado por otros autores. Esta información es de relevancia para el desarrollo de programas de control biológico de ácaros fitófagos en los cultivos cítricos de la de la región.The Phytoseiidae is within predatory mites the family most studied and many of its species are used as biological control agents of insect and mite pests. Previous studies report the presence of Amblyseius hibisci (Ch.), Thyphloseiopsis arboreus (Ch.), Phytoseiulus macropilis (B.) and Euseius concordis (Ch.) in citrus regions of the Northwest (NOA) and Northeastern (NEA) of Argentina. However, there is no recent information on the species present in citrus plantations from NOA. The aim of this study was to update the diversity of phytoseiid mites in plantations of grapefruit, orange, tangerine, lemon and the spontaneous vegetation associated to them in the province of Tucuman, Northwest Argentina. The following genera were identified: in grapefruit, Euseius W., Amblyseius B. and Galendromus M.; orange, Euseius W.; in Mandarin, Euseius W., Amblyseius B. and Tryphlodromalus M.; in lemon, Euseius W., Amblyseius B. and Phytoseiulus E. while in the spontaneous vegetation the genera Neoseiulus H., Euseius W., Amblyseius B., Typhlodromalus M. and Graminaseius Ch. y Mc M. were found. The most representative genus in all citrus species sampled was Euseius. Results show an increase in the diversity of the Phytoseiidae family genera present in the citrus agricultural system of the province of Tucuman compared to what has been reported by other authors. This information is relevant for the development of biological control programs of phytophagous mites in citrus crops in the region.Centro de Estudios Parasitológicos y de Vectore

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

Relationship between olive oil consumption and ankle-brachial pressure index in a population at high cardiovascular risk

The aim of this study was to ascertain the association between the consumption of different categories of edible olive oils (virgin olive oils and olive oil) and olive pomace oil and ankle-brachial pressure index (ABI) in participants in the PREDIMED-Plus study, a trial of lifestyle modification for weight and cardiovascular event reduction in individuals with overweight/obesity harboring the metabolic syndrome. Methods: We performed a cross-sectional analysis of the PREDIMED-Plus trial. Consumption of any category of olive oil and olive pomace oil was assessed through a validated food-frequency questionnaire. Multivariable linear regression models were fitted to assess associations between olive oil consumption and ABI. Additionally, ABI ≤1 was considered as the outcome in logistic models with different categories of olive oil and olive pomace oil as exposure. Results: Among 4330 participants, the highest quintile of total olive oil consumption (sum of all categories of olive oil and olive pomace oil) was associated with higher mean values of ABI (beta coefficient: 0.014, 95% confidence interval [CI]: 0.002, 0.027) (p for trend = 0.010). Logistic models comparing the consumption of different categories of olive oils, olive pomace oil and ABI ≤1 values revealed an inverse association between virgin olive oils consumption and the likelihood of a low ABI (odds ratio [OR] 0.73, 95% CI [0.56, 0.97]), while consumption of olive pomace oil was positively associated with a low ABI (OR 1.22 95% CI [1.00, 1.48]). Conclusions: In a Mediterranean population at high cardiovascular risk, total olive oil consumption was associated with a higher mean ABI. These results suggest that olive oil consumption may be beneficial for peripheral artery disease prevention, but longitudinal studies are needed

Drinking Water Library: nuevo recurso para identificar cepas bacterianas en aguas de consumo

De acuerdo con el RD 140/2003, el agua apta para el consumo humano no debe mostrar presencia de los indicadores bacterianos Escherichia coli, Clostridium perfringens y Enterococcus sp. Pero, aunque no se detecten estos indicadores, el agua del grifo no es estéril y puede tener cierta cantidad de microrganismos que muchas veces puede generar colonias en las placas de cultivo. Lejos de representar un peligro para la salud humana, si se dispone de un método rápido, sencillo, robusto y fiable para la identificación de estas colonias, se puede avanzar mucho en el conocimiento de la microbiología del agua potable. El proyecto Drinking Water Library ha permitido desarrollar la primera base de datos para MALDI-TOF MS específica para bacterias presentes en aguas de consumo