CFD Simulations and External Shape Optimization of Missile with Wing and Tailfin Configuration to Improve Aerodynamic Performance

The wing of missile can be considered as an effective factor for determination of lift to drag ratio. However, there are few studies that investigate wing effect on missile aerodynamics. Therefore, the purpose of this study is to indicate wing effect on the missile aerodynamics and optimize wing geometry for enhancement of aerodynamic efficiency. The missile designed tail-fin configuration is selected from a previous study which contains experimental data. In the beginning of study, Computational Fluid Dynamics (CFD) simulations of selected missile are performed and compared with experimental data. Wing is then mounted to the selected missile and CFD solution is repeated for modified missile at 6o angle of attach (AoA) and subsonic and supersonic speeds. The modified missile shows good performance in point of aerodynamics when compared with baseline missile model. In addition, wing geometry is optimized to improve aerodynamic performance using Multi-Objective Genetic Algorithm (MOGA). Objective functions are determined as lift and drag coefficients. Wing geometry parameters are determined as design variables for optimization. After the optimization process, the results are showed that the aerodynamic coefficients are improved when compared with baseline geometry. In addition, response surface analysis is presented to show which design parameters are more effective on drag and lift forces. The findings of study show that optimum results are more efficient in terms of performance. CFD solution method and the optimization procedure can be applied to design or optimize for different geometry

Is Pentraxin-3 Stronger Than C-Reactive Protein to Determine Inflammation in Peritoneal Dialysis Patients?

Pentraxin-3 (PTX-3) is the prototype of long pentraxins and is produced by many tissues and organs including vascular endothelial cells in response to pro-inflammatory signals. It is thought to be an independent indicator of disease activity. We analyzed the correlation of PTX-3 with other markers of inflammation in peritoneal dialysis (PD) patients. Non-diabetic patients on chronic PD program who meet the dialysis adequacy criteria and who had no active infectious/inflammatory disease were included. Demographic and clinical parameters were recorded as well as hsCRP, fibrinogen, interleukin-6 (IL-6) and PTX-3 levels; and the correlation between them were studied. Twenty-five patients (mean age: 45.7±12.5 years; female/male ratio: 16/9) were included. Mean PTX-3 level was 2.16±2.76ng/ml. PTX-3 was found to be correlated positively with only IL-6 among inflammatory markers (r=0.827; p<0.001) but not with hsCRP. With linear regression model, IL-6 was the only independent determinant of PTX-3 levels. PTX-3 may be a more valuable marker of inflammation than CRP in patients on PD

The Relationship between Plasma Soluble Tnf-like Weak Inducer of Apoptosis Level and Inflammatory Markers in Patients with Type 2 Diabetes Mellitus

Soluble TNF-like weak inducer of apoptosis (sTWEAK) is a member of the TNF super family with many biological activities. There is a limited number of studies on the role of sTWEAK in chronic kidney disease. We aimed in this study to examine the relation of sTWEAK with albuminuria and inflammatory markers in patients with type 2 diabetes mellitus (DM). One hundred and eighteen diabetic patients with varying levels of albuminuria were included. Group 1 comprised patients with albuminuria less than 30 mg/day, while Group 2 and Group 3 were composed of patients with albuminuria between 30–300 mg/day or more than 300 mg/day, respectively. Groups were compared for sTWEAK levels besides demographic, clinical and biochemical data. There was no difference between groups regarding sTWEAK and TNF-α levels. IL-1 levels in Group 1 were higher than in Group 3. hsCRP levels were significantly higher in Group 3 compared to other groups. Use of a renin angiotensin system blocker did not have any effect on sTWEAK, TNF-α and hsCRP levels, while IL-1 level was significantly lower in patients using a renin angiotensin blocker. A statistically significant positive correlation was detected between sTWEAK and IL-1 levels (r=0.245; p=0.008). The groups were found to be similar regarding sTWEAK and TNF-α level. This finding may be interpreted as there being no effect of proteinuria on sTWEAK levels. But the close correlation between proteinuria and IL-1, and between IL-1 and sTWEAK may be a clue for an indirect relationship. Lack of difference between groups regarding sTWEAK levels may be due to involvement of patients with GFR more than 60 ml/minute only

Endothelial constitutive nitric oxide synthase, angiotensin converting enzyme, angiotensin II type 1 receptor gene polymorphisms and endothelial functions in healthy individuals

INTRODUCTION: Endothelial dysfunction is recognized as an early and initiating event in the pathogenesis of coronary artery disease. Gene polymorphisms of endothelial constitutive nitric oxide synthase (ecNOS), angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (AT1R) have been found to be associated with atherosclerosis. We aimed to investigate the possible effects of ecNOS, ACE and AT1R gene polymorphisms on endothelial functions in healthy population

The Relationship between Soluble Tumor Necrosis Factor-like Weak Inducer of Apoptosis Levels and Cardiac Functions in Peritoneal Dialysis Patients

Tumor necrosis factor (TNF)-like weak inducer of apoptosis (sTWEAK) levels has been reported to be decreased in patients on hemodialysis (HD) and patients with heart failure. We aimed to study the relationship between sTWEAK levels and cardiac functions in peritoneal dialysis (PD) patients. This cross-sectional study was carried out on patients on chronic PD programs for more than three months. Patients aged under 18 or over 80 years, patients with overt cardiac disease, overt hypervolemia, active systemic infection, malignancy, peritonitis within the last month were excluded. The patient group was compared with the control group including healthy adults aged 24–61 years. Fifty-two PD patients were included in the study (mean age: 52.7±15.4 years; female/male ratio: 30/22). The corresponding data of the control group were 41.3±10.7 years and 17/14. There was no statistically significant difference between demographic parameters of the groups except age. The mean sTWEAK level of the patient and the control groups were similar (564±17 pcg/ml vs 535±126 pcg/ml, p=0.419). No correlation was detected between any of the demographic variables and sTWEAK levels. Among the echocardiographic parameters, only ejection fraction was found to be correlated negatively with sTWEAK levels. Patients with ischemic heart disease (IHD) and heart failure had significantly higher sTWEAK levels compared with the patients without these diseases. With linear regression analysis, only age and the presence of heart failure were found to be the independent determinants of sTWEAK levels. Level of sTWEAK is significantly high in PD patients with heart failure and IHD. sTWEAK may be a marker of cardiac functions in PD patients