Yazar "Budak, S." seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • Küçük Resim Yok
    Öğe
    Cell adhesion study of the titanium alloys exposed to glow discharge
    (Elsevier, 2007) Abidzina, V.; Deliloglu-Guerhan, I.; Ozdal-Kurt, F.; Sen, B. H.; Tereshko, I.; Elkin, I.; Budak, S.; Muntele, C.; Ila, D.
    Titanium for biomedical application stems mainly from its advantageous bulk mechanical properties in combination with a high degree of biocompatibility that is largely attributable to their surface properties. This work is focused on the investigation of surface properties of treated titanium and cell adhesion to titanium treated in glow-discharge plasma. Pure titanium samples (grade 4) were exposed to low-energy ion irradiation in a specially constructed plasma generator, where materials were irradiated by ions of residual gases in vacuum. The ion energy was 1-10 keV. The irradiation dose was maintained at 10(17) ions cm(-2). The irradiation time varied from 5 to 60 min. Rutherford backscattering spectrometry (RBS) was used for surface studies. RBS showed the presence of iron on the titanium surface that occurred from the cathode of plasma generator. In vitro biocompatibility test have been carried out with model cell lines (L929 mouse fibroblasts) to demonstrate that low-energy ion irradiation can favorably influence the surface of titanium for biomedical application. Scanning electron microscopy (SEM) was the main tool to demonstrate the cell attachment properties. (c) 2007 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Evaluation of Cases of Graft Nephrectomy After Graft Loss in Patients With Renal Transplantation
    (Elsevier Science Inc, 2018) Ustun, M.; Alci, E.; Budak, S.; Demir, H. B.; Yucel, C.; Sen, S.; Yilmaz, M.; Toz, H.
    Introduction. Renal transplantation is undoubtedly considered the best renal replacement therapy. Graft nephrectomy can be performed in patients with renal transplantation because of complications associated with the failed graft. We aimed to retrospectively investigate the characteristics of patients who underwent graft nephrectomy. Materials and Methods. Between January 2000 and November 2013, the records of 757 patients who had renal transplantation in Ege University Faculty of Medicine Hospital Nephrology-Transplantation outpatient clinic were examined. Sixty-four patients who underwent graft nephrectomy were included in the study. Patients were divided into 2 groups according to the timing of graft nephrectomy. The group of 30 patients who underwent graft nephrectomy in the first 56 days after the renal transplantation was referred to as the "early group" and the group of 34 patients who underwent graft nephrectomy after 56 days was referred to as "late group." Results. In our study, we found the body mass index to be significantly higher in those with early graft loss (P = .02). We found that there was a difference between the groups in terms of sex (P = .012). When the mortality and morbidity rates after graft nephrectomy were examined, mortality was observed in 3 of the 64 patients in the study and morbidity in 1 patient. Conclusion. According to our study, the body mass indices and ages of the subjects who need early graft nephrectomy are higher. However, male sex was significantly more prevalent in patients who underwent graft nephrectomy in the late period compared with the early period.
  • Küçük Resim Yok
    Öğe
    Nanoscale surface modification of UltraHigh Molecular Weight Polyethylene (UHMWPE) samples with the W plus C ion implantation
    (Materials Research Soc, 2007) Urkac, E. Sokullu; Oztarhan, A.; Tihminlioglu, F.; Kaya, N.; Budak, S.; Chhay, B.; Muntele, C.; Oks, E.; Nikolaev, A.; Ila, D.; Ila, D; Baglin, J; Kishimoto, N; Chu, PK
    In this work, Ultra High Molecular Weight Poly Ethylene (UHMWPE) samples Were implanted by W + C ions using Metal-Vapour Vacuum Arc (MEVVA) ion implantation system with a fluence of 10(17) ion/cm(2) and extraction voltage of 30 kV. Samples were characterized with Raman Spectra, ATR-FTIR, UV-VIS-NlR Spectrum and RBS. Surface morphology of implanted and unimplanted samples were examined in nanoscale with AFM.
  • Küçük Resim Yok
    Öğe
    Polymeric thermal analysis of C+H and C+H+Ar ion implanted UHMWPE samples
    (Elsevier Science Bv, 2007) Kaya, N.; Oztarhan, Ahmet M.; Urkac, E. S.; Ila, D.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tihminlioglu, F.; Tek, Z.; Cetiner, S.; Muntele, C.
    Chemical surface characterization of C + H hybrid ion implanted UHMWPE samples were carried out using DSC (differential scanning calorimeter) and TGA (thermal gravimetric analysis) techniques. Samples were implanted with a fluence of 10(17) ion/cm(2) and an extraction voltage of 30 kV. The study of TGA and DSC curves showed that: (1) Polymeric decomposition temperature increased, (2) T-m, Delta C-p and Delta H-m values changed while Delta C-p and Delta H-m increased. T-g value could not be measured, because of some experimental limitations. However, the increase in Delta H-m values showed that T-g values increased, (3) the branch density which indicated the increase in number of cross-link (M-c) decreased in ion implanted samples and (4) increase in Delta H-m values indicated increase in crystallinity of implanted surface of UHMWPE samples. Published by Elsevier B.V.
  • Küçük Resim Yok
    Öğe
    Structural and electrical characterization of the nickel silicide films formed at 850 degrees C by rapid thermal annealing of the Ni/Si(100) films
    (Elsevier Science Bv, 2010) Utlu, G.; Artunc, N.; Budak, S.; Tari, S.
    Nickel di-silicide formation induced by RTA process at 850 degrees C for 60 s in the Ni/Si(1 0 0) systems are investigated as a function of the initial Ni film thickness of 7-89 nm using XRD, RBS, SEM, X-SEM and AFM. Based on the XRD and RBS data, in the silicide films of 400-105 nm, NiSi and NiSi(2) silicide phases co-exist, indicating that Ni overlayer is completely transformed to NiSi and NiSi(2) silicide phases. SEM reveals that these. lms consist of large grains for co-existence of NiSi(2) and NiSi phases, separated from one another by holes, reflecting that NiSi(2) grows as islands in NiSi matrix. These. lms have low sheet resistance, ranging from 1.89 to 5.44 Omega/square and good thermal stability. For thicknesses <= 80 nm RBS yields more Si-rich silicide phases compared to thicker. lms, whereas SEM reveals that Si-enriched silicide islands with visible holes grow in Si matrix. As the film thickness decreases from 400 to 35 nm, AFM reveals a ridge-like structure showing a general trend of decreasing average diameter and mean roughness values, while sheet resistance measurements exhibit a dramatic increase ranging from 1.89 to 53.73 Omega/square. This dramatic sheet resistance increase is generated by substantial grain boundary grooving, followed by island formation, resulting in a significant phase transformation from NiSi(2)-rich to Si-rich silicide phases. (C) 2010 Elsevier B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Structural and Thermal Characterization of Ti plus O Ion Implanted UltraHigh Molecular Weight Polyethylene (UHMWPE)
    (Amer Inst Physics, 2009) Oztarhan, A.; Urkac, E. Sokullu; Tihminlioglu, F.; Kaya, N.; Ila, D.; Budak, S.; Chhay, B.; Muntele, C.; Oks, E.; Nikolaev, A.; McDaniel, FD; Doyle, BL
    In this work, Metal-Gas Hybrid Ion Implantation technique was used as a tool for the surface modification of Ultra High Molecular Weight Polyethylene (UHMWPE). Samples were Ti + O ion implanted by using Metal-Vapour Vacuum Arc (MEVVA) ion implanter to a fluence of 5x10(16) ion/cm(2) for each species and extraction voltage of 30 kV. Untreated and surface treated samples were investigated by Rutherford Back Scattering (RBS) Spectrometry, Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) Spectroscopy, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). Results indicate that Ti + O ion implantation can be applied on UHMWPE surfaces successfully. ATR-FTIR spectra indicate that the C-H concentration on the surface decreased after Ti + O implantation. Thermal characterization with TGA and DSC shows that polymeric decomposition temperature is shifted after ion implantation.
  • Küçük Resim Yok
    Öğe
    Thermal Behaviour of W plus C Ion Implanted Ultra High Molecular Weight Polyethylene (UHMWPE)
    (Amer Inst Physics, 2009) Urkac, E. Sokullu; Oztarhan, A.; Tihminlioglu, F.; Ila, D.; Budak, S.; Chhay, B.; Muntele, C.; Oks, E.; Nikolaev, A.; McDaniel, FD; Doyle, BL
    The aim of this work was to examine thermal behavior of the surface modified Ultra High Molecular Weight Poly Ethylene (UHMWPE) in order to understand the effect of ion implantation on the properties of this polymer which is widely used especially for biomedical applications. UHMWPE samples were Tungsten and Carbon (W+C) hybrid ion implanted by using Metal Vapour Vacuum Arc (MEVVA) ion implantation technique with a fluence of 10 17 ions/cm2 and extraction voltage of 30kV. Untreated and surface-treated samples were investigated by Rutherford Back Scattering (RBS) Analysis, Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) Spectrometry, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). This study has shown that ion implantation represents a powerful tool on modifying thermal properties of UHMWPE surfaces. This combination of properties can make implanted UHMWPE a preferred material for biomedical applications.
  • Küçük Resim Yok
    Öğe
    Thermal characterization of Ag and Ag plus N ion implanted ultra-high molecular weight polyethylene (UHMWPE)
    (Elsevier Science Bv, 2007) Urkac, E. Sokullu; Oztarhan, A.; Tihminlioglu, F.; Kaya, N.; Ila, D.; Muntele, C.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tek, Z.
    Most of total hip joints are composed of ultra-high molecular weight polyethylene (UHMWPE). However, as ultra-high molecular weight polyethylene is too stable in a body, wear debris may accumulate and cause biological response such as bone absorption and loosening of prosthesis. In this study, ultra-high molecular weight polyethylene samples were Ag and Ag + N hybrid ion implanted by using MEVVA ion implantation technique to improve its surface properties. Samples were implanted with a fluence of 10(17) ion/cm(2) and extraction voltage of 30 kV. Implanted and unimplanted samples were investigated by thermo-gravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), optical microscopy (OM) and contact Angle measurement. Thermal characterization results showed that the ion bombardment induced an increase in the % crystallinity, onset and termination degradation temperatures of UHMWPE. (c) 2007 Elsevier B.V. All rights reserved.