Instrumentation-related uncertainty of reflectance and transmittance measurements with a two-channel spectrophotometer

Spectrophotometers are operated in numerous fields of science and industry for a variety of applications. In order to provide confidence for the measured data, analyzing the associated uncertainty is valuable. However, the uncertainty of the measurement results is often unknown or reduced to sample-related contributions. In this paper, we describe our approach for the systematic determination of the measurement uncertainty of the commercially available two-channel spectrophotometer Agilent Cary 5000 in accordance with the Guide to the expression of uncertainty in measurements. We focus on the instrumentation-related uncertainty contributions rather than the specific application and thus outline a general procedure which can be adapted for other instruments. Moreover, we discover a systematic signal deviation due to the inertia of the measurement amplifier and develop and apply a correction procedure. Thereby we increase the usable dynamic range of the instrument by more than one order of magnitude. We present methods for the quantification of the uncertainty contributions and combine them into an uncertainty budget for the device. © 2017 Author(s)

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

Über die IR-Spektren ungesättigter N-heterocyclischer Verbindungen: I. Mitt.: Chinoxalin und Derivate

Auf Chinoxalin und 17 Derivate dieser Verbindung werden die Regelmäßigkeiten, die im Bereich der nicht-ebenen C-H-Deformations-Schwingungen in Abhängigkeit von der Zahl der Substituenten am Benzolkern aufgestellt worden sind, angewandt. Es zeigt sich, daß auch diese Verbindungsklasse diesem Schema eingefügt werden kann

PA-SPECTROSCOPIC INVESTIGATION ON FLOWER PETALS

Les spectres photoacoustiques en amplitude et en phase de pétales de fleur intacts sont comparés aux spectres correspondants obtenus par des techniques de réflexion et de transmission diffuses et aux spectres des pigments en solution.PA amplitude and phase spectra of intact flower petals are compared with the corresponding scattered transmittance, diffuse reflectance spectra and the solution spectra of pigments