Person: ÖZTÜRK, MURAT
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
ÖZTÜRK
First Name
MURAT
Name
3 results
Search Results
Now showing 1 - 3 of 3
Publication Prevention of wave propagation via circular arrangement of seismic metamaterials formed with concrete piles(MDPI, 2023-08-01) Kaçın, Selçuk; Öztürk, Murat; Sevim, Umur Korkut; Karaaslan, Muharrem; Akgöl, Oğuzhan; Özer, Zafer; Demirci, Mustafa; Ünal, Emin; Mert, Bayram Ali; Alkurt, Maide Erdoğan; Alkurt, Fatih Özkan; Başar, Mustafa Tunahan; Kaya, Seyda Gülsüm; ÖZTÜRK, MURAT; Mühendislik Fakültesi; İnşaat Mühendisliği Bölümü; AAE-1138-2020It is known that the low frequencies of seismic surface waves have a destructive effect. The main purpose of seismic metamaterials is to protect structures from seismic waves at low frequencies, especially in a wide band. In this study, the effects of seismic metamaterials formed using circular array concrete piles on surface waves were investigated. Each concrete pile has been selected due to symmetric properties to investigate the band diagram. Therefore, the direction independence can also be determined with respect to frequency. This study was conducted both numerically and experimentally in the low-frequency range of 5-15 Hz. Two fields, with and without metamaterials, have been designed and compared. In numerical analysis, transmission loss graphs were drawn using the finite element method (FEM), and wave propagation at frequencies where the loss happened was simulated. In numerical analysis, optimum dimensions such as radius and depth were determined, and these dimensions were applied exactly in the experimental field. The results obtained from the experiment using a harmonic vibration device are mapped. In this numerical and experimental study, it has been revealed that the proposed structure prevents the propagation of seismic surface waves.Publication Capacitive self tension sensing properties of steel beam: Electrode configuration and stress regime(IOP Publishing, 2023-11-01) Öztürk, Murat; ÖZTÜRK, MURAT; Mühendislik Fakültesi; İnşaat Fakültesi; 0000-0002-5202-8246; AAE-1138-2020A structural material is called self-sensing when it is able to reveal its own state without the need for any external sensors. Self-sensing for steel is valuable for the control and safety of steel structures such as buildings and bridges. The changes in the capacitance of steel in response to cyclic tensile stresses applied in low, medium and high stress regimes are measured by using a Inductnce-Capacitance-Resistance (LCR) meter. Coplanar and parallel plate electrode configuration is used for capacitance measurements. Aluminum foil is used as electrode. A steel beam of 100 mm in length, 30 mm in width and 2.5 mm in thickness is tensioned by holding it at both ends to produce direct tensile stresses in the material. The maximum stresses applied for low, medium and high stress regimes are 6.7 MPa, 33.3 MPa and 66.7 MPa. The capacitance value of the sample with coplanar and parallel plate electrode configurations measured without applying load are 203.42 pF and 196.00 pf, respectively. The fractional changes in capacitance are 0.059%, 0.192% and 0.275% when 6.7 MPa, 33.3 MPa and 66.7 MPa direct tensile stress is created in the steel beam. These values are 0.12%, 0.20% and 0.29% for parallel plate electrode configuration. Test results demonstrates that there is a relation between stress and fractional change in capacitance. In other words, measuring fractional change in capacitance gives information about the stress variations in the material. From the experimental results, parallel plate electrode configuration is found to be more effective in tensile stress self-sensing. In addition, the relationship between stress and fractional change in capacitance is more linear for both electrode configurations in the low stress regime. This paper aims to reveal the tensile stresses occurring in steel by means of capacitance-based sensing. Sensing capability in larger scale structures and factors effecting sensing sensitivity are to be addressed in future work.Publication Laparoscopic extraperitoneal radical prostatectomy: Our first experiences(Aves, 2005-09-01) Oktay, Bülent; Vuruskan, Hakan; VURUŞKAN, HAKAN; Yavasçaoğlu, İsmet; YAVAŞCAOĞLU, İSMET; Kordan, Yakup; Çalışkan, Zülküf; Öztürk, Murat; ÖZTÜRK, MURAT; Tıp Fakültesi; Üroloji Ana Bilim Dalı; 0000-0002-9947-848X; 0000-0002-0668-8075Introduction: Laparoscopic radical prostatectomy is a relatively new and contemporary approach in the surgical management of localized prostate cancer. We report our preliminary results after 6 procedures.Materials and Methods: We performed laparoscopic extraperitoneal radical prostatectomy (LERP) in 6 patients between January and June in 2004. Clinical stage, serum PSA, Gleason score, operating time, surgical and medical complications, estimated blood loss, transfusion rate, hospital stay and catheterization times were recorded. The pathologic stage (1997 TNM classification), status of surgical margins and continence were noted.Results: There was no conversion and reintervention. The mean operation time was 320 minutes. The mean blood loss was 178.3 ml. The mean hospital stay was 4.5 days. There were no major complications. Subileus occurred in one patient and resolved spontaneously. The mean catheterization time was 13.3 days. 2 of 6 patients had positive surgical margins at the urethra. 4 of 6 patients were continent after a median followup period of 3 months.Conclusion: LERP as a minimally invasive procedure seems to offer the same early oncological and surgical results as conventional open radical prostatectomy. Long and gradual learning curve of this procedure is its main disadvantage.