Analysis of ambient noise in Yalova, Turkey: discrimination between artificial and natural excitations

Ambient noise measurements acquired in Yalova, which was highly damaged during the 1999 Izmit earthquake, are analyzed to explore the site characteristics. The region of Yalova is governed by complex geological and geomorphological structures consisting of river beds extending from the mountains to the sea, ridges between them, plains in front of them with different size, and the sea coast. As a result of these shallow geological features, the H/V curves exhibit complex patterns. Clear peaks in the H/V curves, which can be interpreted as reliable site resonance frequency, are observed only at about half of the measurement sites. At the remaining sites industrial peaks, broad peaks, or flat responses dominate the spectral ratio graphs. We observed that man-made noises generated by marble cutting machines in Hersek delta mask the site resonance frequencies or can be misinterpreted as a resonance frequency. In total, we identified three anthropogenic noise sources at fundamental frequencies of 1.3, 1.5, and 1.7 Hz along with their two- and threefold harmonics. The parts of H/V curves showing unusual low scattering can be a clue to identify anthropogenic effects. In the assessment of H/V curves, the site location and the similarity of the near surface geology were taken into account. The Laledere plain with thick and soft sediment sequence surprisingly displays flat responses due to a possible low impedance contrast. The Ciftlikkoy and Hacimehmet plains exhibit clear resonance peaks at nearly 1 Hz possessing the largest amplitudes. These sites experienced the highest damage in Yalova during the Izmit earthquake. In contrast, the Cinarcik region which was also exposed to high damage, do not show any obvious amplifications on the H/V curves. Generally, the H/V curves for valley and ridge sites in Yalova reveals a resonance peak at approximately 1 Hz and almost flat curves, respectively. However, several sites on the ridges and valleys portray different patterns

Surgery for eventration of the diaphragm

Four patients were operated for unilateral left eventration of the diaphragm There were two male and two female patients with a mean age of 63.0+/-14.1 years. All of the patients had dyspnea for an average of 6.2+/-2.6 years. Chest X-ray, fluoroscopy, thorax computed tomography (CT) and in one patient magnetic resonance imaging (MRI) were used for diagnosis. Preoperative forced vital capacity (FVC) and arterial blood partial O-2 pressure (PaO2) values were 1.8+/-0.4 L and 73+/-1.4 mm Hg, respectively. Left thoracotomy via 7(th) intercostal space was applied and complete thinned diaphragmatic leaf was found in all patients. In three patients diaphragm was repaired by plication. In one patient after incision of the leaf, imbrication of one layer over the other was done. No morbidity and mortality were seen. Relief of dyspnea was achieved in all patients. Postoperative FVC and PaO2 values were increased to 2.3+/-0.4 L and 86.6+/-2.7 mm Hg, respectively. Surgery for eventration of the diaphragm in symptomatic patients increases FVC and PaO2 values, thus relieves dyspnea

Selecting the most suitable rupture model for the stochastic simulation of the 1999 Izmit earthquake and prediction of peak ground motions

In this study, we use a stochastic finite-fault technique based on a dynamic corner frequency to investigate how the fault and slip models affect the high frequency simulations of the 1999 Izmit (Turkey) earthquake. Seven different rupture models, one of them generated using common fault parameters and random slip distribution are tried to obtain the best matching with the observations. The synthetic seismograms computed in the frequency band 0.1-25 Hz are compared with the observations both in time and frequency domain. Six accelerometric stations located close to the observed surface rupture are chosen for the comparisons considering the fact that the slip contributions are visible at these station records better than the other stations. We also estimated average H/V spectral ratios using the available accelerometric recordings to take into account site amplification at each site. We also acquired ambient noise data at some stations that lack sufficient earthquake records. The results show that none of the rupture models fully simulate the observations at all the stations. Most of the rupture models underestimate the Fourier amplitudes at frequencies lower than 0.4 Hz, whereas overestimate them at higher frequencies. The underestimation may result from a directivity effect which likely causes higher amplitudes on the observed ground motions in low frequency band. While all the rupture models display similar average bias functions, the minimum average error for spectral amplitudes is obtained for the rupture model of Bouchon et al. (2002). The achievement of the random slip distribution model also yields satisfactory results. After we have optimized the rupture model, we have simulated the strong ground motions on a regular grid (0.2 degrees x 0.2 degrees) covering the study area for bedrock conditions. In total, we have estimated peak accelerations and peak velocities at 135 points. The results show that the maximum acceleration values during the lzmit earthquake reached 785 cm/s(2), and the largest velocity values were around 75 cm/s. The peak ground accelerations are still smaller than those predicted by the empirical relations but are well above the observed ones. The low accelerations might be attributed to the low stress drop that might be due to the large rupture length. (c) 2012 Elsevier Ltd. All rights reserved

Laparoscopic versus open cholecystectomy: effect on pulmonary function tests

To compare the changes in pulmonary function tests (PFT) after open and laparoscopic cholecystectomy, two groups of 25 patients were set up. Each patient had 3 PFTs performed and 2 PA grid chest roentgenograms taken. After taken into consideration the difference between PFT values were not significant (p less than or equal to 0.05). All PFT values decreased significantly on the first postoperative day (p less than or equal to 0.05). When PA chess roentgenograms were compared no clinically evident atelectasis except 1 lineary was seen in laparoscopic cholecystectomy group whereas 3 lineary, 4 focal, and 1 segmentary atelectasia were encountered in open cholecystectomy group (p less than or equal to 0.05). We believe that laparoscopic cholecystectomy has more advantages when speaking of postoperative PFT and atelectasia

A Micromechanics Based Numerical Investigation of Dual Phase Steels

1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials, IWPDF (2019 ; Ankara, Turkey)The aim of this paper is to investigate the effects of microstructural parameters such as the volume fraction, morphology and spatial distribution of the martensite phase and the grain size of the ferrite phase on the plasticity and localized deformation of dual-phase (DP) steels. For this purpose, Voronoi based representative volume elements (RVEs) are subjected to proportional loading with constant stress triaxility. Two alternative approaches are employed in a comparative way to model the plastic response of the ferrite phase, namely, micromechanically motivated crystal plasticity and phenomenological J2 flow theory. The plastic response of the martensite phase, however, is modeled by the J2 flow theory in all the calculations. The predictions of both approaches closely agree with each other in terms of the overall macroscopic response of the DP steels, while clear differences are observed in the localized deformation patterns. The results of the present study are also compared with experimental and computational findings from the literature. (C) 2019 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review line: Peer-review under responsibility of the 1st International Workshop on Plasticity, Damage and Fracture of Engineering Materials organizers

Intracoronary Shunt Versus Bulldog Clamp in Off-Pump Bypass Surgery. Endothelial Trauma: Shunt Versus Clamp

Background. During off-pump coronary bypass grafting, local vascular control of the target vessel and a bloodless field are crucial. The aim of this study is to asses the histopathological outcomes of intracoronary shunts and bulldog clamping on the beating heart in a canine model

Effects of Metabolic Syndrome on Early Mortality and Morbidity in Coronary Artery Bypass Graft Patients

Metabolic syndrome is a well-known cardiovascular risk factor closely related to increased insulin resistance. This study assessed the effects of metabolic syndrome on early post-operative mortality and morbidity in 100 coronary artery bypass graft (CABG) patients: 50 patients with and 50 without metabolic syndrome. A total of 17 patients were excluded from the analysis as they did not attend follow-up, leaving 51 males (61.4%) and 32 (38.6%) females of mean +/- SD age 60.02 +/- 9.76 years for analysis. Diabetes, hypertension and a high body mass index were significantly more common in patients with metabolic syndrome. A statistically significant relationship was found between metabolic syndrome and surgical wound infection. Non-significant positive correlations were found between metabolic syndrome and post-operative atrial fibrillation, surgical revision due to haemorrhage, ventricular tachycardia and ventricular fibrillation, and prolonged intubation. In conclusion, metabolic syndrome did not affect mortality, but did increase the risk of postoperative surgical wound infection

Aortic perforation following chest tube insertion: an unusual complication

Tube thoracostomy is a routine intervention which is used in cardiovascular surgery clinics. Although it is a life-saving intervention in most cases, it has serious complications leading to mortality. We encountered an ascending aortic perforation, an unusual complication following apical chest tube insertion, in a 71-year-old male patient who underwent coronary artery bypass graft (CABG) surgery in our clinic. This complication was managed successfully and the patient was discharged with a complete recovery. This rare but fatal complication should be considered for the patients undergoing tube thoracostomy, particularly with a toracar. It should also be noticed whether the patients have mediastinal shift in postoperative period

Cavitary lung cancer presenting as subcutaneous emphysema on the contralateral side

Bronchocutaneous fistula is an extremely rare complication of lung cancer and is frequently seen following biopsy or radiotherapy. A 67-year old male patient was administered to our hospital due to sudden onset of shortness of breath and subcutaneous emphysema on the right side. Chest computed tomography revealed a cavitary lesion in the left upper lobe in connection with the subcutaneous emphysema on the right side through sternum and anterior chest wall. The pathological examination of the biopsy performed during tube insertion revealed a well-differentiated squamous cell carcinoma of the lung. The patient was referred for adjuvant therapy to local oncology hospital. He passed away 9 months following diagnosis