Implementation of Engine Control and Measurement Strategies for Biofuel Research in Compression-Ignition Engines

The global petroleum fuel supply is a limited resource that is understood to have negative influences on the environment because of its usage. In order address this issue, researchers are investigating sources of sustainable energy to offset this finite energy supply. One promising option for the transportation sector is biodiesel derived from various feedstocks. In order to perform viable research in the area of sustainable biodiesel, a multi-disciplinary effort to study the entire biodiesel spectrum from production to tailpipe emissions is underway at the University of Kansas. A critical aspect of this research includes investigating the effects of biodiesel combustion on engine operation. This includes observing engine power output, fuel consumption, and mechanical wear. In order to detect these characteristics effectively, full instrumentation of a single-cylinder compression-ignition engine is necessary. This engine serves as a test apparatus for experimental fuels and as a student-training tool. Of particular interest is the upgrade of this engine's fuel system to include electronically controlled fuel injection using an engine control unit. To aid in future research and to serve as a training reference, a detailed description of the construction, maintenance, and troubleshooting of the engine, dynamometer, auxiliary systems, and data acquisition equipment is included. Furthermore, this dissertation contains findings from biodiesel studies illustrating how fuel properties, such as fuel viscosity, play a role in injection and combustion behavior. The completed engine testing system provides the opportunity to continue into more sophisticated research venues, such as low temperature combustion and multiple injection events

Design, Construction, and Validation of an In-Cylinder Pressure Recording System for Internal Combustion Engine Analysis

Due to an increased global interest in sustainable energy sources, it is imperative that the transportation sector find substitutes for the limited petroleum supply, such as biodiesel. This thesis contains three sections detailing the construction of a biodiesel engine testing system intended for biodiesel and engine technology research. Chapter one details the initial construction of the biodiesel test cell. In addition, the limitations of the system are individually pointed out, with solutions to these limitations discussed. Finally, the focus of this thesis is included to set the scope of the work discussed in chapters two and three. In chapter two, a biodiesel study was completed in order to investigate changes in engine performance because of the differences in fuel properties derived from various feedstock oils. The goal of this investigation was to determine which biodiesel fuel properties impact engine emissions and fuel consumption in comparison to petroleum-based diesel. The findings indicate good agreement with published works and resulted in correlations for fuel properties that were not discussed in literature. In chapter three, the design, construction, and validation of an engine cylinder pressure recording system are covered. In particular, the discussion includes the equipment selection, machining of the engine head and encoder adapter, writing of a LabVIEW program to record pressure and crank angle data, and the validation of this system. Validation was accomplished by testing three different fuels with very different combustion characteristics and directly comparing the results to literature trends and fundamental engine performance characteristics

Influence of Fuel Injection System and Engine-Timing Adjustments on Regulated Emissions from Four Biodiesel Fuels

The use of biofuels for transportation has grown substantially in the past decade in response to federal mandates and increased concern about the use of petroleum fuels. As biofuels become more common, it is imperative to assess their influence on mobile source emissions of regulated and hazardous pollutants. This assessment cannot be done without first obtaining a basic understanding of how biofuels affect the relationship between fuel properties, engine design, and combustion conditions. Combustion studies were conducted on biodiesel fuels from four feedstocks (palm oil, soybean oil, canola oil, and coconut oil) with two injection systems, mechanical and electronic. For the electronic system, fuel injection timing was adjusted to compensate for physical changes caused by different fuels. The emissions of nitrogen oxides (NOx) and partial combustion products were compared across both engine injection systems. The analysis showed differences in NOx emissions based on hydrocarbon chain length and degree of fuel unsaturation, with little to no NOx increase compared with ultra-low sulfur diesel fuel for most conditions. Adjusting the fuel injection timing provided some improvement in biodiesel emissions for NOx and particulate matter, particularly at lower engine loads. The results indicated that the introduction of biodiesel and biodiesel blends could have widely dissimilar effects in different types of vehicle fleets, depending on typical engine design, age, and the feedstock used for biofuel production

Molecular Composition of Staufen2-Containing Ribonucleoproteins in Embryonic Rat Brain

Messenger ribonucleoprotein particles (mRNPs) are used to transport mRNAs along neuronal dendrites to their site of translation. Numerous mRNA-binding and regulatory proteins within mRNPs finely regulate the fate of bound-mRNAs. Their specific combination defines different types of mRNPs that in turn are related to specific synaptic functions. One of these mRNA-binding proteins, Staufen2 (Stau2), was shown to transport dendritic mRNAs along microtubules. Its knockdown expression in neurons was shown to change spine morphology and synaptic functions. To further understand the molecular mechanisms by which Stau2 modulates synaptic function in neurons, it is important to identify and characterize protein co-factors that regulate the fate of Stau2-containing mRNPs. To this end, a proteomic approach was used to identify co-immunoprecipitated proteins in Staufen2-containing mRNPs isolated from embryonic rat brains. The proteomic approach identified mRNA-binding proteins (PABPC1, hnRNP H1, YB1 and hsc70), proteins of the cytoskeleton (α- and β-tubulin) and RUFY3 a poorly characterized protein. While PABPC1 and YB1 associate with Stau2-containing mRNPs through RNAs, hsc70 is directly bound to Stau2 and this interaction is regulated by ATP. PABPC1 and YB1 proteins formed puncta in dendrites of embryonic rat hippocampal neurons. However, they poorly co-localized with Stau2 in the large dendritic complexes suggesting that they are rather components of Stau2-containing mRNA particles. All together, these results represent a further step in the characterization of Stau2-containing mRNPs in neurons and provide new tools to study and understand how Stau2-containing mRNPs are transported, translationally silenced during transport and/or locally expressed according to cell needs

Use of the aspartate aminotransferase to platelet ratio index to follow liver fibrosis progression in infants with short gut

Infants with parenteral nutrition dependence may develop liver dysfunction and progress to liver failure requiring transplantation. The aspartate aminotransferase–to-platelet ratio index (APRI) has good correlation with liver fibrosis progression in adults. This study applies APRI scoring to parenteral nutrition-dependant, short-gut infants to determine hepatic fibrosis progression. Laboratory values and biopsies were collected from initial intestinal resection (time 0) up to transplantation (end). Fibrosis scoring ranged from F0 (normal) to F4 (cirrhosis). Children were divided into 3 groups: (1) isolated intestine; and combined liver/intestine with gestational age (2) 34 weeks or greater and (3) 30 weeks or less. Liver function values over time, including calculated APRI, were analyzed as predictors of fibrosis. Fifteen children who had 33 biopsies were included. Median APRI by fibrosis grade was F ≤ 2: 1.88, F3: 3.23, and F4: 14.16 ( P < .01). Median APRI at transplant by study group was (1) isolated intestine: 2.47, (2) liver/intestine 35 weeks or longer EGA: 14.16, and (3) liver/intestine 30 weeks or less EGA: 14.74 ( P = .04). Progression of APRI up to 60 days initially demonstrates similar values among study groups, but over time the score distinguishes those children with impending liver cirrhosis and differentiates fibrosis grade and study group

FEDSM2003-45579 FLOW SEPARATION WITHIN THE ENGINE INLET OF AN UNINHABITED COMBAT AIR VEHICLE (UCAV)

ABSTRACT This paper discusses the structure of the flow within the engine inlet of an uninhabited combat air vehicle (UCAV). The UCAV features a top-mounted, serpentine inlet leading to an engine buried within the fuselage. The performance of the inlet is found to depend strongly on a flow separation that occurs within the inlet. Both the time-averaged and the unsteady structure of this separation is studied, and an argument relating the inlet performance to the behaviour of this separation is suggested. The results presented in this paper also suggest that there are considerable aerodynamic limitations to further shortening or narrowing of the inlet. Since there are substantial, system level benefits from using a smaller inlet, the case for separated flow control therefore appears clear