Kodachrome (September 27-30, 2023)

Event program for Kodachrome (September 27-30, 2023)

ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS

Diesel fuel is composed of a complex mixture of hundreds of hydrocarbons that vary globally depending on crude oil sources, refining processes, legislative requirements and other factors. In order to simplify the study of this fuel, researchers create surrogate fuels with a much simpler composition, in an attempt to mimic and control the physical and chemical properties of Diesel fuel. The first surrogates were single-component fuels such as n-heptane and n-dodecane. Recent advancements have provided researchers the ability to develop multi-component surrogate fuels and apply them to both analytical and experimental studies. The systematic application of precisely controlled surrogate fuels promises to further enhance our understanding of Diesel combustion, efficiency, emissions and particulates and provide tools for investigating new and alternative engine combustion systems. This thesis employed analytical and experimental methods to develop, validate and study a library of multi-component surrogate Diesel fuels. The first step was to design a surrogate fuel to precisely match the physical and chemical properties of a full-range petroleum Diesel fuel with 50 cetane number and a typical threshold soot index value of 31. The next step was to create a Surrogate Fuel Library with 18 fuels that independently varied two key fuel properties: cetane number and threshold soot index. Within the fuel library cetane number ranged from 35 to 60 at three threshold soot index levels of 17, 31 and 48 (low, mid-range and high). Extensive ASTM fuel property tests showed that good agreement with important physical and chemical properties of petroleum Diesel fuel such as density, viscosity, heating value and distillation curve. An experimental investigation was conducted to evaluate the combustion, emissions, soot and exhaust particles from the petroleum Diesel fuel and the matching surrogate fuel. A fully-instrumented single-cylinder Diesel engine was operated with combustion strategies including Premixed Charge Compression Ignition (PCCI), Low-Temperature Combustion (LTC) and Conventional Diesel Combustion (CDC). For combustion, the ignition delay, low-temperature (first stage) and high temperature (second stage) heat-release matched very well. Gaseous emissions, soot and exhaust particles maintained good agreement as exhaust gas recirculation and combustion phasing were varied. This thesis demonstrated that fully representative Diesel surrogate fuels could be tailored with the proper blending of the following hydrocarbon components: n-hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, decahydronaphthalene and 1-methylnaphthalene. It was also established that the volumetric blending fractions of these four components could be varied to independently control the fuel cetane number and threshold soot index while retaining the combustion, physical and chemical properties of full-range petroleum Diesel fuel. The Surrogate Fuel Library provided by this thesis supplies Diesel engine researchers and designers the ability to analytically and experimentally vary fuel cetane number and threshold soot index. This new capability to independently vary two key fuel properties provides a means to further enhance the understanding of Diesel combustion and design future combustion systems that improve efficiency and emissions.El combustible diésel está compuesto por cientos de hidrocarburos cuya presencia y proporción varía dependiendo del origen del crudo, del proceso de refinado, de los requerimientos legislativos, y de muchos otros factores. Para evitar las dificultades que produce esta variabilidad y complejidad en su composición, en los estudios sistemáticos, los investigadores suelen trabajar con combustibles de sustitución, mucho más sencillos, pero que reproducen las propiedades químicas y físicas del gasóleo. Los primeros combustibles de sustitución estuvieron formados por un solo componente, como el n-heptano y el n-dodecano. Recientemente se han desarrollado combustibles de sustitución multi-componentes, que se aplican tanto a estudios experimentales como de modelado. La aplicación sistemática de combustibles de sustitución controlados con precisión es una vía prometedora para mejorar la comprensión de la combustión Diesel, su eficiencia, y sus emisiones y proporciona herramientas para la investigación de sistemas de combustión nuevos y alternativos. En esta tesis se han empleado métodos experimentales y de cálculo para desarrollar, estudiar y validar una librería de combustibles de sustitución multi-componentes. El primer combustible de sustitución se diseñó para reproducir con precisión las propiedades físicas y químicas de un gasóleo con número de cetano 50 y un índice de hollín umbral (TSI) de 31.El siguiente paso fue crear una biblioteca de combustibles de sustitución con 18 combustibles que pueden modificar independientemente dos propiedades clave del combustible: índice de cetano y TSI. En la biblioteca de combustibles el número de cetano osciló entre 35 y 60 con tres niveles de TSI iguales a 17, 31 y 48 (bajo, medio y alto rango). Los ensayos según la normativa ASTM demostraron una buena coincidencia con las propiedades del gasóleo como densidad, viscosidad, poder calorífico y curvas de destilación. Para comprobar la validez de la librería, se realizó un estudio experimental comparativo sobre el proceso de combustión, las emisiones gaseosas, hollín y partículas de un gasóleo y de su combustible de sustitución ajustado. El estudio se realizó con un motor monocilíndrico Diesel completamente instrumentado y operando con estrategias de combustión en premezcla parcial (PPCI) y de baja temperatura (LTC), además de la combustión Diesel convencional (CDC). Los parámetros de la combustión como el retraso al encendido y la liberación de calor tanto de baja como de alta temperatura se aproximaron muy bien. Las emisiones de gases, hollín y partículas también fueron similares al variar el nivel de EGR y la fase de la combustión. La tesis demuestra que se pueden encontrar combustibles de sustitución perfectamente representativos de un gasóleo corriente, en base a mezclas apropiadas de n-hexadecano, 2,2,4,4,6,8,8-heptamethylnonano, decahidronaftaleno y 1-metilnaftaleno. Asimismo, se concluye que variando la proporción de estos cuatro componentes se puede controlar independientemente el número de cetano y el índice de hollín umbral, a la vez que se mantienen las propiedades físico-químicas y de combustión del gasóleo. La librería de combustibles de sustitución definida en esta tesis es una herramienta a disposición de los investigadores para profundizar en el conocimiento de la combustión diésel y avanzar en el diseño de sistemas futuros de combustión con mejor rendimiento y menores emisiones.El combustible Diesel està compost per centenars d'hidrocarburs, la presència i proporció dels quals varia depenent de l'origen del cru, del procés de refinat, dels requeriments legislatius, i de molts altres factors. Per a evitar les dificultats que produeix aquesta variabilitat i complexitat en la seua composició, en els estudis sistemàtics, els investigadors solen treballar amb combustibles de substitució, molt més senzills, però que reprodueixen les propietats químiques i físiques del gasoil. Els primers combustibles de substitució van estar formats per un sol component, com el n-heptà i el n-dodecà. Recentment s'han desenvolupat combustibles de substitució multi-components, que s'apliquen tant a estudis experimentals com de modelatge. L'aplicació sistemàtica de combustibles de substitució controlats amb precisió és una via prometedora per a millorar la comprensió de la combustió Dièsel, la seua eficiència, i les seues emissions i proporciona eines per a la recerca de sistemes de combustió nous i alternatius. En aquesta tesi s'han emprat mètodes experimentals i de càlcul per a desenvolupar, estudiar i validar una llibreria de combustibles de substitució multi-components. El primer combustible de substitució es va dissenyar per a reproduir amb precisió les propietats físiques i químiques d'un gasoil amb índex de cetà 50 i un índex de sutge límit (TSI) de 31. El següent pas va ser crear una biblioteca de combustibles de substitució amb 18 combustibles que poden modificar independentment dues propietats clau del combustible: índex de cetà i TSI. En la biblioteca de combustibles l'índex de cetá va oscil·lar entre 35 i 60 amb tres nivells de TSI iguals a 17, 31 i 48 (baix, mitjà i alt rang). Els assajos segons la normativa ASTM van demostrar una bona coincidència amb les propietats del gasoil com a densitat, viscositat, poder calorífic i corbes de destil·lació. Per a comprovar la validesa de la llibreria, es va realitzar un estudi experimental comparatiu sobre el procés de combustió, les emissions gasoses, sutge i partícules d'un gasoil i del seu combustible de substitució ajustat. L'estudi es va realitzar amb un motor monocilíndric Dièsel completament instrumentat i operant amb estratègies de combustió en premescla parcial (PPCI) i de baixa temperatura (LTC), a més de la combustió Dièsel convencional (CDC). Els paràmetres de la combustió com el retard a l'encès i l'alliberament de calor tant de baixa com d'alta temperatura es van aproximar molt bé. Les emissions de gasos, sutge i partícules també van ser similars en variar el nivell d'EGR i la fase de la combustió. La tesi demostra que es poden trobar combustibles de substitució perfectament representatius d'un gasoil corrent, sobre la base de mescles apropiades de n-hexadecà, 2,2,4,4,6,8,8-heptamethylnonà, decahidronaftalé i 1-metilnaftaleno. Així mateix, es conclou que variant la proporció d'aquests quatre components es pot controlar independentment l'índex de cetà i l'índex de sutge límit, alhora que es mantenen les propietats físic-químiques i de combustió del gasoil. La llibreria de combustibles de substitució definida en aquesta tesi és una eina a la disposició dels investigadors per a aprofundir en el coneixement de la combustió Diesel i avançar en el disseny de sistemes futurs de combustió amb millor rendiment i menors emissions.Szymkowicz, P. (2017). ANALYTICAL AND EXPERIMENTAL INVESTIGATION OF MULTI-COMPONENT SURROGATE DIESEL FUELS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90406TESI

Mass Spectrometry Methods for Enhanced Characterization of Biological Systems

As the pharmaceutical industry moves towards larger protein-based therapeutics over chemically synthesized small molecules, there are increasing demands for parallel advancement in the technologies used for quality control of these biologically-derived products (biopharmaceuticals). This work describes the implementation of mass spectrometry (MS)-based methods in three areas where MS is well-positioned to fulfill unmet analytical needs. First, time-resolved electrospray ionization hydrogen-deuterium exchange (TRESI-HDX) and ion mobility spectroscopy (IMS)-MS were used to study conformational dynamics in transient Cytochrome c-lipid interactions. MS was also implemented for proteomic characterization of in-process and purified samples from acellular Pertussis vaccines. Further development of a targeted MS method is described for quantitation of two residual protein toxins, adenylase cyclase toxin (ACT) and dermoneucrotic toxin (DNT), and a glycopeptide, tracheal cytotoxin (TCT), from Bordetella pertussis. Collectively, the results highlight advancement in the application of structural and quantitative proteomics for more effective characterization of next generation biopharmaceuticals

The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels

[EN] The influence of internal nozzle flow characteristics over ignition delay, and flame lift-off of reacting direct-injection sprays is studied experimentally for three fuels using two different nozzle geometries. This is a continuation of previous work by the authors, where, evaporative and non-evaporative, isothermal spray developments were studied experimentally for the same nozzle geometries and fuels. Current study reports the ignition delay through Schlieren technique, and flame lift-off length through OH* chemiluminescence visualization. The nozzle geometries consist of a conical nozzle and a cylindrical nozzle with 8.6% larger outlet diameter when compared to the conical nozzle. The three fuels considered are n-heptane, n-dodecane and a three-component surrogate to better represent the physical and chemical properties of diesel fuel. Reacting spray is found to penetrate faster than non-reacting spray due to combustion induced acceleration after ignition. Higher oxygen concentration, and ambient temperature enhance the reactivity leading to higher spray tip penetration. Injection pressure does not affect the reactivity significantly and hence, influences spray penetration through momentum-similar to a non-reacting spray. Both ignition delay and lift-off length are found to be shortest and longest for n-dodecane and n-heptane, respectively, while the surrogate fuel falls in-between the two pure component fuels. Both ignition delay and lift-off length are found to decrease with increase in oxygen concentration, ambient temperature, and density. The cylindrical nozzle, in spite of shorter lift-off length is found to have longer ignition delay, when compared to the conical nozzle. This could be due to better atomization leading to larger spread angle and evaporative cooling from the cylindrical nozzle compared to a conical nozzle. The longer ignition delay also leads to leaner equivalence ratios at the time of ignition. (C) 2017 Elsevier Ltd. All rights reserved.This work was sponsored by Ministerio de Economia y Competitividad of the Spanish Government in the frame of the Project "Estudio de la interaccion chorro-pared en condiciones realistas de motor", Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and Diesel surrogate were provided and defined by GM R&D.Payri, R.; Viera-Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, P. (2017). The effect of nozzle geometry over ignition delay and flame lift-off of reacting direct-injection sprays for three different fuels. Fuel. 199:76-90. https://doi.org/10.1016/j.fuel.2017.02.075S769019

The effect of nozzle geometry over the evaporative spray formation for three different fuels

[EN] The influence of internal nozzle flow characteristics over the evaporative spray development is studied experimentally for two different nozzle geome-tries and three different fuels. This is a continuation of previous work by the authors where non-evaporative isothermal spray development was stud-ied experimentally for the same nozzle geometries and fuels. Current study reports macroscopic spray characteristics by imaging the liquid and vapor phases of the spray simultaneously using independent cameras and optical techniques. The liquid phase is captured by a fast-pulsed diffused back illumination setup, while the vapor phase is captured by a single-pass Schlieren setup with diaphragm. The nozzle geometries consist of a conical nozzle and a cylindrical nozzle with 8.6 % larger outlet diameter when compared to the conical nozzle. Among the three fuels, two are pure components n-heptane and n-dodecane while the third consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. For a fixed ambient density, the liquid penetration is controlled by ambient temperature while the vapor penetration is controlled by injection pressure. The cylindrical nozzle, in spite of higher mass flow rate and momentum flux,shows slower vapor spray tip penetration when compared to the conical noz-zle. Also, the cylindrical nozzle consistently produced shorter liquid lengths. The vapor spray spreading angle is found to be inversely proportional to the spray tip penetration, largely influenced by the nozzle geometry and the am-bient density. n-Heptane spray shows the shortest liquid lengths, followed by n-dodecane and finally the Surrogate. No significant difference in vapor penetration rates was found between fuels, confirming that the vapor spray is controlled by momentum, which is independent of fuel. This was not the case for the non-evaporative isothermal sprays previously studied by the au-thors. Liquid lengths show the expected responses to parametric variations of ambient temperature and density. Two empirical predictive models are presented and utilized to analyze the influence of fuel properties on the liq-uid length. The primary factor controlling the liquid length between fuels is found to be their volatility. Finally, the cylindrical nozzle exhibits larger line-of-sight contour fluctuations in both the liquid and vapor phases, which in turn contributes to the shorter liquid lengths and slower vapor penetration.This work was sponsored by Ministerio de Economía y Competitividad of the Spanish Government in the frame of the Project “Estudio de la interaccin chorro-pared en condiciones realistas de motor”, Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and Diesel surrogate were provided and defined by GM R&D. The authors would like to thank José Enrique Del Rey and María del Carmen Tomás for their collaboration in the setup of the experiments and laboratory work, and Guillermo Miró for his help measuring fuel properties.Payri, R.; Viera-Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, P. (2017). The effect of nozzle geometry over the evaporative spray formation for three different fuels. Fuel. 188:645-660. https://doi.org/10.1016/j.fuel.2016.10.064S64566018

The effect of nozzle geometry over internal flow and spray formation for three different fuels

The influence of internal nozzle flow characteristics over macroscopic spray development is studied experimentally for two different nozzle geometries and three fuels. The measurements include a complete hydraulic characterization consisting of instantaneous injection rate and spray momentum flux measurements, followed by a high-speed visualization of isothermal liquid spray in combination with cylindrical and conical nozzle configurations. Two of the fuels are pure components n-heptane and n-dodecane while the third fuel consists of a three-component surrogate to better represent the physical and chemical properties of diesel fuel. The cylindrical nozzle with 8.6 % larger diameter, in spite of higher mass flow rate and momentum flux, shows slower spray tip penetration when compared to the conical nozzle. The spreading angle is found to be inversely proportional to the spray tip penetration. The spreading angle is largely influenced by the nozzle geometry and the ambient density. Rail pressure was found to have weak influence on the near-field spreading angle and no influence on the standard deviation of the spreading angle. n-Heptane spray shows slowest penetration rates while n-dodecane and the surrogate fuel mixture show very similar spray behavior for variations in injection pressure and back pressure. However, the surrogate fuel mixture shows higher penetration than n-dodecane when using the conical nozzle and lower penetration than n-dodecane when using cylindrical nozzle.This work was sponsored by Ministerio de Economia y Competitividad of the Spanish Government in the frame of the Project "Estudio de la interaccin chorro-pared en condiciones realistas de motor", Reference TRA2015-67679-c2-1-R. Additionally, the employed nozzles and diesel surrogate were provided and defined by GM R&D.Payri Marín, R.; Viera Sotillo, JP.; Gopalakrishnan, V.; Szymkowicz, PG. (2016). The effect of nozzle geometry over internal flow and spray formation for three different fuels. Fuel. 183:20-33. doi:10.1016/j.fuel.2016.06.041S203318

Metacognitive Performance, the Tip-of-Tongue Experience, Is Not Disrupted in Parkinsonian Patients

The present study investigated whether a form of metamemory, the tip-of-tongue phenomenon (TOT), was affected in patients with Parkinson's disease (PD). The PD patient (n = 22), age-matched elderly control (n = 22), and college student control (n = 46) groups were compared on a motor timing task and TOT measures. Motor timing was assessed using a cued hand-clapping task, whereas TOT was assessed using general knowledge questions. The results indicated that motor timing was significantly impaired in the PD group relative to both control groups. However, all of the TOT metacognitive measures: frequency, strength, and accuracy were statistically equivalent between the PD patients and elderly control groups, both of whom showed significantly better memory performance than college controls. These findings demonstrate that TOT metamemory is not compromised in PD patients, and that further insight into TOT mechanisms in PD may prove helpful in developing novel intervention strategies to enhance memory and general cognitive functions in these patients

Development of a Diesel Surrogate Fuel Library

[EN] Diesel fuel is composed of a complex mixture of hundreds of hydrocarbons that vary globally depending on crude oil sources, refining processes, legislative requirements and other factors. In order to simplify the study of this fuel, researchers create surrogate fuels to mimic the physical and chemical properties of Diesel fuels. This work employed the commercial software Reaction Workbench - Surrogate Blend Optimizer (SBO) to develop a Surrogate Fuel Library containing 18 fuels. Within the fuel library, the cetane number ranges from 35 to 60 (in increments of 5) at threshold soot index (TSI) levels representative of low, baseline and high sooting tendency fuels (TSI = 17, 31 and 48, respectively). The Surrogate Fuel Library provides the component blend ratios and predicted properties for cetane number, threshold soot index, lower heating value, density, kinematic viscosity, molar hydrogen-to-carbon ratio and distillation curve temperatures from T-10 to T-90. A market petroleum Diesel fuel with a cetane number of 50 and a threshold soot index of 31 was selected as the Baseline Diesel Fuel. The combustion, physical and chemical properties of the Baseline Diesel Fuel were precisely matched by the Baseline Surrogate Fuel. To validate the SBO predicted fuel properties, a set of five surrogate fuels, deviating in cetane number and threshold soot index, were blended and examined with ASTM tests. Good agreement was obtained between the SBO predicted and ASTM measured fuel properties. To further validate the Surrogate Fuel Library, key properties that were effected by altering the component blend ratios to control cetane number and TSI were compared to a set of five market Diesel fuels with good results. These properties included density, viscosity, energy density and the T-10 and T-90 distillation temperatures. The Surrogate Fuel Library provided by this work supplies Diesel engine researchers and designers the ability to analytically and experimentally vary fuel cetane number and threshold soot index with fully-representative surrogate fuels. This new capability to independently vary cetane number and threshold soot index provides a means to further enhance the understanding of Diesel combustion and design future combustion systems that improve efficiency and emissions.Szymkowicz, P.; Benajes, J. (2018). Development of a Diesel Surrogate Fuel Library. Fuel. 222:21-34. https://doi.org/10.1016/j.fuel.2018.01.112S213422

Assessment and management of pain/nociception in patients with disorders of consciousness or locked-in syndrome: A narrative review

The assessment and management of pain and nociception is very challenging in patients unable to communicate functionally such as patients with disorders of consciousness (DoC) or in locked-in syndrome (LIS). In a clinical setting, the detection of signs of pain and nociception by the medical staff is therefore essential for the wellbeing and management of these patients. However, there is still a lot unknown and a lack of clear guidelines regarding the assessment, management and treatment of pain and nociception in these populations. The purpose of this narrative review is to examine the current knowledge regarding this issue by covering different topics such as: the neurophysiology of pain and nociception (in healthy subjects and patients), the source and impact of nociception and pain in DoC and LIS and, finally, the assessment and treatment of pain and nociception in these populations. In this review we will also give possible research directions that could help to improve the management of this specific population of severely brain damaged patients