Fluid structure interaction of a submerged flexible circular cylinder mounted on an experimental rig

This study aims to develop a numerical tool for investigating the FSI and dynamic reactions of a scale model of a deeply submerged cylindrical flexible offshore structure mounted on an experimental rig that will be used for future studies. The flow around a finite cylinder with an aspect ratio of four causes smaller drag and lift forces compared to an infinite cylinder. However, for cylinders with flexible material properties these forces cause non-negligible deformations which require the investigation of FSI. For this purpose, a two-way coupled partitioned approach was used by coupling the FLUENT and Transient Structural modules in ANSYS with the help of dynamic meshing algorithms in order to communicate force and deformation data alternately between the solvers. Compared to two-way coupling, one-way coupling demands less effort and computational resources, however, it overestimates the deformations for the flexible cylinder. Two-way coupling requires more effort and computational resources, yet it is advantageous enough to justify extra work and computational resources

Total disc replacement for chronic back pain in the presence of disc degeneration

Scientific Assessment and Innovation in Neurosurgical Treatment Strategie

Volume CXIV, Number 4, November 7, 1996

Objective: Turner syndrome (TS) is a chromosomal disorder caused by complete or partial X chromosome monosomy that manifests various clinical features depending on the karyotype and on the genetic background of affected girls. This study aimed to systematically investigate the key clinical features of TS in relationship to karyotype in a large pediatric Turkish patient population.Methods: Our retrospective study included 842 karyotype-proven TS patients aged 0-18 years who were evaluated in 35 different centers in Turkey in the years 2013-2014.Results: The most common karyotype was 45,X (50.7%), followed by 45,X/46,XX (10.8%), 46,X,i(Xq) (10.1%) and 45,X/46,X,i(Xq) (9.5%). Mean age at diagnosis was 10.2±4.4 years. The most common presenting complaints were short stature and delayed puberty. Among patients diagnosed before age one year, the ratio of karyotype 45,X was significantly higher than that of other karyotype groups. Cardiac defects (bicuspid aortic valve, coarctation of the aorta and aortic stenosis) were the most common congenital anomalies, occurring in 25% of the TS cases. This was followed by urinary system anomalies (horseshoe kidney, double collector duct system and renal rotation) detected in 16.3%. Hashimoto's thyroiditis was found in 11.1% of patients, gastrointestinal abnormalities in 8.9%, ear nose and throat problems in 22.6%, dermatologic problems in 21.8% and osteoporosis in 15.3%. Learning difficulties and/or psychosocial problems were encountered in 39.1%. Insulin resistance and impaired fasting glucose were detected in 3.4% and 2.2%, respectively. Dyslipidemia prevalence was 11.4%.Conclusion: This comprehensive study systematically evaluated the largest group of karyotype-proven TS girls to date. The karyotype distribution, congenital anomaly and comorbidity profile closely parallel that from other countries and support the need for close medical surveillance of these complex patients throughout their lifespa

A numerical study of fluid structure interaction of a flexible submerged cylinder mounted on an experimental rig

The aim of the study is to investigate VIV effects, not only on a test cylinder but also on the experimental rig being towed under water at a prescribed depth and operating speeds. For this purpose, a numerical Multi-Physics model was created using one way coupled analysis simultaneously between the Mechanical and Fluent solvers of ANSYS software package. A system coupling was developed in order to communicate force data alternately between the solvers with the help of automatic mapping algorithms within millesimal time periods of a second. Numerical investigation into the dynamic characteristics of pressure and velocity fields for turbulent viscous fluid flow along with structural responses of the system, stressed the significance of time and space scales for convergence and accuracy of our Finite Volume (FV) CFD calculations.The article from: V. 7, Ocean EngineeringPeer reviewed: YesNRC publication: Ye

Evaluation of retinal ganglion cell-inner plexiform layer complex in healthy smokers

Smoking does not seem to have any effect on GC-IPL thickness, mean RNFL and CMT values. Further studies in larger groups are needed to reveal the effect of smoking on these parameters

Investigation of Muscle Fatigue by Processing EMG Signal

14th National Biomedical Engineering Meeting -- MAY 20-22, 2009 -- Izmir, TURKEYWOS: 000274345400107Surface EMG signals are taken from the human muscle and have some advantages over the needle electrode originated EMG's recordings. In this study, we have processed surface EMG's coming from the normal subject set (7 female and 7 male) to investigate the effects of the muscle fatigue on the 50% maximum voluntary contraction condition. We have observed great correlation between three features which are the slope of the changes of median frequency, number of zero crossing, and wavelet transform based entropy. We also found that the wavelet transform based entropy values have the great abrupt changes for some subjects

The Effect of Obesity Degree on Childhood Pulmonary Function Tests

Background: Childhood obesity has become a global epidemic. It is related to several chronic diseases such as essential hypertension, type 2 diabetes mellitus, and renal disease. The relationship between the degree of obesity and lung functions is well defined in adults, but limited information is available about the childhood period. Aims: This study aims to determine the impact of the degree of obesity on the pulmonary functions of school children and adolescents. Study Design: Cross sectional study. Methods: Included in the study were a total of 170 school children and adolescents (9-17 years old) referred to our paediatric outpatient clinic. Of these subjects, 42 were lean and non-obese (BMI % <85), 30 subjects were overweight (BMI % ˃85, <95), 34 subjects were obese (BMI % ˃95, <97), and 64 subjects were morbidly obese (BMI % ˃97). Anthropometric measurements were taken and spirometry was performed on all subjects. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), forced vital capacity 25-75 (FEV25-75) and peak expiratory flow (PEF) were used to measure the ventilatory functions for all the subjects. Results: The groups showed no significant differences in age or gender. Despite no statistically significant differences in FEV1, FVC, or FEV1/FVC, there were significant reductions in PEF (p<0.001) and FEV25-75 (p<0.001) in the overweight, obese and morbidly obese subjects, when compared with those who were non-obese. Conclusion: Overweight, obese and morbidly obese children have no obstructive abnormalities compared with healthy lean subjects