Aerodynamic Design Optimization of a Micro Radial Compressor of a Turbocharger

This study presents an aerodynamic design optimization of a micro radial compressor impeller on a turbocharger used in a 0.8 L two-cylinder gasoline engine. In the conventional design optimization of the impeller, the hub and shroud curve of the main blade is commonly parameterized with a beta distribution, and splitter blades are generally considered short versions of the full blade. However, geometrical parameterizations in our study mainly focus on the beta distribution of a full blade, and it is parameterized differently from the conventional way. Eight parameters are selected as design variables for the beta distribution. To maximize the isentropic efficiency, design points that are created by Design of Experiment (DOE) are evaluated through single-objective optimization coupled with a non-parametric regression surrogate model. Furthermore, the splitter leading edge location on the meridional plane is investigated to enhance the performance of the impeller after the optimization process. The results show that total efficiency enhancement of approximately 2.2% is achieved. Furthermore, the findings show that a full blade beta distribution and the splitter leading edge location are sufficient parameters to optimize the impeller, and, with the proposed optimization, splitter blades are no longer copies of the full blade for each application

Good versus poor prescribers: the comparison of prescribing competencies in primary care

Aim: To compare the competencies of primary care physicians (PCPs) with poor and good prescribing performance in frequently encountered indications. Background: Primary care centers are one of the mostly visited health facilities by the population for different health issues. Methods: In this cross-sectional study, we analyzed 6 125 487 prescriptions generated by 1431 PCPs which were selected by systematic sampling in 2016 in Istanbul. We defined PCPs as poor prescriber (n = 227) or good prescriber (n = 210) in terms of their prescribing performance per WHO/INRUD criteria. We compared solo diagnosis prescriptions of these two groups in 'percentage of prescriptions in compliance with clinical guidelines' and also rational prescribing indicators. Findings: Poor prescribers and good prescribers significantly differed in each of the prescribing indicators for their all solo diagnosis prescriptions. Hypertension had the highest difference of the average cost per encounter (Delta = 284.2%) between poor prescribers (US$43.99 +/- 63.05) and good prescribers (US$11.45 +/- 45.0), whereas headache had the highest difference between the groups in the percentage encounters with an antibiotic (14.9% vs. 1.5%). Detailed analysis of the prescribing performances showed significantly higher values of each WHO/INRUD indicators for all examined diagnoses. We found significantly higher percentages of guideline-compliant drugs in good prescribers compared to that in poor prescribers in hypertension (40.8% vs 34.8%), tonsillopharyngitis (57.9% vs 50.7%), and acute sinusitis (46.4% vs 43.6%). Conclusion: This study shows that the prescribing performances of PCPs are not rational enough in terms of drug selection and prescription content. Furthermore, even the physicians who have good prescribing practice appear as not satisfactorily rational in compliance with current pharmacotherapy competencies

Propuesta de reducción del retraso de productos terminados en el área de producción de una empresa metalmecánica mediante la Teoría de las Restricciones y herramientas Lean

La siguiente tesis está conformada por cuatro capítulos, donde el primero presenta el marco teórico investigado en fuentes académicas respaldadas por autores especializados en metodologías de administración de producción y manufactura. En el segundo capítulo se muestra el análisis y diagnóstico realizado a una empresa metalmecánica nacional donde explica su entorno, sus procesos y el problema que enfrenta. En el capítulo 3 se muestra la propuesta de solución en función al diagnóstico realizado y el marco teórico investigado, se aterrizará al entorno de la empresa las diferentes metodologías explicadas en el capítulo 1, además se presentará una análisis económico justificando la rentabilidad de la implementación de la solución. Para finalizar en el capítulo 4 brinda las principales conclusiones a partir de la propuesta de solución y recomendaciones futuras para la empresa en estudio.Tesi

alpha-olefin selectivity of Fe-Cu-K catalysts in Fischer-Tropsch synthesis: Effects of catalyst composition and process conditions

Fischer-Tropsch (FT) synthesis has been studied over a series of precipitated Fe catalysts promoted to investigate the effect of K and Cu promoters on the carbon number distribution of FT product. The main intention is to maximize the alpha-olefin selectivity by controlling the secondary reactions of alpha-olefin as a function of potassium and copper loadings. The results showed that impregnation of different loadings of Cu and K promoters to precipitated iron-based catalyst was found to have significant influences on the crystallographic structure, morphological and physical properties of iron-based catalysts, as well as catalytic activity, stability and selectivity performances during FT synthesis. 100Fe7Cu3K sample exhibited the highest catalytic activity and stability in TOS tests. The catalyst is capable of working under a variety of temperatures and space velocities at a same activity level with no significant activity loss. Proper control of Cu and K contents is essential to obtain maximum C-5+ yield since the changes in the relative loadings of both Cu and K promoters affect hydrocarbon product distribution. 100Fe7Cu3K sample has high secondary alpha-olefin hydrogenation activity as olefin/paraffin ratio decreases with increasing carbon number while C-19+ selectivity is relatively low compared to other samples. The effects of space velocity and temperature on alpha-olefin selectivity are strongly dependent on the amounts of Cu and K promoters and chain length. The maximum alpha-olefin/n-paraffin ratio has been obtained over 100Fe3Cu1K sample at 543 K with a space velocity of 3 NL/h/g-cat. (C) 2011 Elsevier B.V. All rights reserved

<b>Patterns and Trends in Continuous Glucose Monitoring Utilization Among Commercially Insured Individuals With Type 1 Diabetes: 2010–2013 to 2016–2019</b>

Prior studies suggest that only ~30% of patients with type 1 diabetes use continuous glucose monitoring (CGM), but most studies to date focused on children and young adults seen by endocrinologists or in academic centers. This study examined national trends in CGM utilization among commercially insured children and adults with type 1 diabetes. Overall, CGM utilization was 20.12% in 2010–2013 and 49.78% in 2016–2019, reflecting a 2.5-fold increase in utilization within a period of <10 years. Identifying populations with low CGM use is a necessary first step in developing targeted interventions to increase CGM uptake. Key Points · Roughly half (49.78%) of the individuals in our sample of commercially insured individuals with type 1 diabetes used continuous glucose monitoring from 2016 to 2019. · This represents a 2.5-fold increase in utilization within <10 years. · Utilization was highest in those who were aged 0–12 years, were female, had health maintenance organization insurance, and were living in urban areas.</p