On the combination of high-pressure and low-pressure exhaust gas recirculation loops for improved fuel economy and reduced emissions in high-speed direct-injection engines

In this paper, an experimental study of the combination of low-pressure and high-pressure exhaust gas recirculation architectures has been carried out. In the first part of the paper, the effects of both high-pressure and low-pressure exhaust gas recirculation architectures on engine behaviour and performance are analysed by means of a series of steady tests. In the second part, the effects of the combination of both architectures are addressed. The results show that the low-pressure configuration improves high-pressure exhaust gas recirculation results in brake-specific fuel consumption, nitrogen oxides and exhaust gas opacity; nevertheless, hydrocarbon emissions are increased, especially during the engine warm up. In addition, the exhaust gas recirculation rate achieved with low-pressure systems is limited by the pressure difference between diesel particulate matter outlet and compressor inlet; therefore, the high-pressure system can be used to achieve the required exhaust gas recirculation levels without increasing pumping losses. In this sense, the combination of both exhaust gas recirculation layouts offers significant advantages to reduce emissions and fuel consumption to meet future emission requirements.This work was supported by the Ministry of Science and Innovation (Spanish Government) [grant number IPT-370000-2010-022].Desantes Fernández, JM.; Luján, JM.; Plá Moreno, B.; Soler Muniesa, JA. (2013). On the combination of high-pressure and low-pressure exhaust gas recirculation loops for improved fuel economy and reduced emissions in high-speed direct-injection engines. International Journal of Engine Research. 14(1):3-11. https://doi.org/10.1177/1468087412437623S311141Taylor, A. M. K. P. (2008). Science review of internal combustion engines. Energy Policy, 36(12), 4657-4667. doi:10.1016/j.enpol.2008.09.001Lü, X.-C., Chen, W., & Huang, Z. (2005). A fundamental study on the control of the HCCI combustion and emissions by fuel design concept combined with controllable EGR. Part 2. Effect of operating conditions and EGR on HCCI combustion. Fuel, 84(9), 1084-1092. doi:10.1016/j.fuel.2004.12.015Nakano, M., Mandokoro, Y., Kubo, S., & Yamazaki, S. (2000). Effects of exhaust gas recirculation in homogeneous charge compression ignition engines. International Journal of Engine Research, 1(3), 269-279. doi:10.1243/1468087001545173Zheng, M., Reader, G. T., & Hawley, J. G. (2004). Diesel engine exhaust gas recirculation––a review on advanced and novel concepts. Energy Conversion and Management, 45(6), 883-900. doi:10.1016/s0196-8904(03)00194-8Hountalas, D. T., Mavropoulos, G. C., & Binder, K. B. (2008). Effect of exhaust gas recirculation (EGR) temperature for various EGR rates on heavy duty DI diesel engine performance and emissions. Energy, 33(2), 272-283. doi:10.1016/j.energy.2007.07.002Luján, J. M., Galindo, J., Serrano, J. R., & Pla, B. (2008). A methodology to identify the intake charge cylinder-to-cylinder distribution in turbocharged direct injection Diesel engines. Measurement Science and Technology, 19(6), 065401. doi:10.1088/0957-0233/19/6/065401Ladommatos, N., Abdelhalim, S., & Zhao, H. (2000). The effects of exhaust gas recirculation on diesel combustion and emissions. International Journal of Engine Research, 1(1), 107-126. doi:10.1243/1468087001545290Maiboom, A., Tauzia, X., & Hétet, J.-F. (2008). Influence of high rates of supplemental cooled EGR on NOxand PM emissions of an automotive HSDI diesel engine using an LP EGR loop. International Journal of Energy Research, 32(15), 1383-1398. doi:10.1002/er.1455Gautier, P., Albrecht, A., Chasse, A., Moulin, P., Pagot, A., Fontvieille, L., & Issartel, D. (2009). A Simulation Study of the Impact of LP EGR on a Two-Stage Turbocharged Diesel Engine. Oil & Gas Science and Technology - Revue de l’IFP, 64(3), 361-379. doi:10.2516/ogst/2009019Torregrosa, A. J., Olmeda, P., Martín, J., & Degraeuwe, B. (2006). Experiments on the influence of inlet charge and coolant temperature on performance and emissions of a DI Diesel engine. Experimental Thermal and Fluid Science, 30(7), 633-641. doi:10.1016/j.expthermflusci.2006.01.00

KSU Brass Faculty Recital

Enjoy a performance by the KSU brass faculty: Doug Lindsey, Mike Tiscione, Richard Williams, J.D. Handshoe, and Ryan Moser, all accompanied pianists Judith Cole and Eric Jenkins.https://digitalcommons.kennesaw.edu/musicprograms/2377/thumbnail.jp

Complex-Distance Potential Theory and Hyperbolic Equations

An extension of potential theory in R^n is obtained by continuing the Euclidean distance function holomorphically to C^n. The resulting Newtonian potential is generated by an extended source distribution D(z) in C^n whose restriction to R^n is the delta function. This provides a natural model for extended particles in physics. In C^n, interpreted as complex spacetime, D(z) acts as a propagator generating solutions of the wave equation from their initial values. This gives a new connection between elliptic and hyperbolic equations that does not assume analyticity of the Cauchy data. Generalized to Clifford analysis, it induces a similar connection between solutions of elliptic and hyperbolic Dirac equations. There is a natural application to the time-dependent, inhomogeneous Dirac and Maxwell equations, and the `electromagnetic wavelets' introduced previously are an example.Comment: 25 pages, submited to Proceedings of 5th Intern. Conf. on Clifford Algebras, Ixtapa, June 24 - July 4, 199

Fibrosis assessment in patients with chronic hepatitis B virus (HBV) infection

Chronic hepatitis B virus (HBV) infection is a major cause of liver morbidity and mortality worldwide. While a proportion of the 250 million individuals chronically infected with HBV will not come to significant harm or require therapy, many others risk developing complications of the end-stage liver disease such as decompensated cirrhosis and hepatocellular carcinoma (HCC), without intervention. Due to the complex natural history of HBV infection, patients require an expert assessment to interpret biochemistry, viral serology and appropriately stage the disease, and to initiate monitoring and/or therapy where indicated. The detection and quantification of liver fibrosis is a key factor for disease management and prognostication for an individual with HBV. The reliance on invasive liver biopsy to stage disease is diminishing with the advent of robust non-invasive blood- and imaging-based algorithms which can reliably stage disease in many cases. These tests are now incorporated into International guidelines for HBV management and relied upon daily to inform clinical judgement. Both blood- and imaging-based approaches have advantages over liver biopsy, including minimal risks, lower cost, better patient acceptance and speed of results, while disadvantages include lower diagnostic accuracy in intermediate disease stages and variability with co-existing hepatic inflammation or steatosis. This review outlines the methods of fibrosis assessment in chronic HBV infection and focuses on the most commonly used blood- and imaging-based non-invasive tests, reviewing their diagnostic performance and applicability to patient care

Genetic testing in dementia — utility and clinical strategies

Techniques for clinical genetic testing in dementia disorders have advanced rapidly but remain to be more widely implemented in practice. A positive genetic test offers a precise molecular diagnosis, can help members of an affected family to determine personal risk, provides a basis for reproductive choices and can offer options for clinical trials. The likelihood of identifying a specific genetic cause of dementia depends on the clinical condition, the age at onset and family history. Attempts to match phenotypes to single genes are mostly inadvisable owing to clinical overlap between the dementias, genetic heterogeneity, pleiotropy and concurrent mutations. Currently, the appropriate genetic test in most cases of dementia is a next-generation sequencing gene panel, though some conditions necessitate specific types of test such as repeat expansion testing. Whole-exome and whole-genome sequencing are becoming financially feasible but raise or exacerbate complex issues such as variants of uncertain significance, secondary findings and the potential for re-analysis in light of new information. However, the capacity for data analysis and counselling is already restricting the provision of genetic testing. Patients and their relatives need to be given reliable information to enable them to make informed choices about tests, treatments and data sharing; the ability of patients with dementia to make decisions must be considered when providing this information

Nucleotide sequence analyses of the MRP1 gene in four populations suggest negative selection on its coding region

BACKGROUND: The MRP1 gene encodes the 190 kDa multidrug resistance-associated protein 1 (MRP1/ABCC1) and effluxes diverse drugs and xenobiotics. Sequence variations within this gene might account for differences in drug response in different individuals. To facilitate association studies of this gene with diseases and/or drug response, exons and flanking introns of MRP1 were screened for polymorphisms in 142 DNA samples from four different populations. RESULTS: Seventy-one polymorphisms, including 60 biallelic single nucleotide polymorphisms (SNPs), ten insertions/deletions (indel) and one short tandem repeat (STR) were identified. Thirty-four of these polymorphisms have not been previously reported. Interestingly, the STR polymorphism at the 5' untranslated region (5'UTR) occurs at high but different frequencies in the different populations. Frequencies of common polymorphisms in our populations were comparable to those of similar populations in HAPMAP or Perlegen. Nucleotide diversity indices indicated that the coding region of MRP1 may have undergone negative selection or recent population expansion. SNPs E10/1299 G>T (R433S) and E16/2012 G>T (G671V) which occur at low frequency in only one or two of four populations examined were predicted to be functionally deleterious and hence are likely to be under negative selection. CONCLUSION: Through in silico approaches, we identified two rare SNPs that are potentially negatively selected. These SNPs may be useful for studies associating this gene with rare events including adverse drug reactions

Improving Patient Postpartum Show Rates Through Increased Education and Scheduling

Maternal health and patient outcomes post-pregnancy have been in the news during COVID-19 as the pandemic has underscored disparities in care and access. But the issues of access to care, and the difficulties faced by patients and providers in organizing care post-partum, have been studied by many over decades. The post-partum period is critical to women and infants not only to follow-up on pregnancy and birthing but also as the window to taking care of women’s health for a lifetime. Join us to hear about ideas for promoting follow-up care in the post-partum period implemented during a study conducted in center city Philadelphia and tested for sustainability during COVID-19. Presentation: 59:4