Frontal Chondrosarcoma in a Cat

F.Yildiz,A.Gurel,T.Yesildere,K.Ozer 대한수의학회 2003 Journal of Veterinary Science Vol.4 No.2

Chondrosarcoma in a CatF. Yildiz*, A. Gurel, T. Yesildere and K. Ozer1

Tungsten/Copper Functionally Graded Materials : Possible Applications and Processing through the Powder Metallurgy Route

Ozer O.,Missiaen J.M.,Pascal C.,Lay S.,Chaix J.M.,Mitteau R. 한국분말야금학회 2006 한국분말야금학회 학술대회논문집 Vol.2006 No.1

Processing of W-Cu graded materials from attritor-milled W-CuO mixtures is described. The powder reduction steps are investigated by TG and XRD analyses and by microstructural observations (SEM, TEM). Sintering of reduced powder with different compositions is analysed by dilatometry. Sintering behaviour of the graded component processed by co-compaction of a 10/20/30wt%Cu multi-layer material is briefly discussed. Liquid Cu migration is observed and smooths the composition gradient. Perspectives to control this migration are discussed.

Influence of Crown Margin Design on the Stress Distribution in Maxillary Canine Restored by All-Ceramic Crown: A Finite Element Analysis

Ozer, Zafer,Kurtoglu, Cem,Mamedov, Amirullah M.,Ozbay, Ekmel Korean Academy of Dental Science 2015 Journal of korean dental science Vol.8 No.1

Purpose: To investigate the influence of crown margin design on the stress distribution and to localize critical sites in maxillary canine under functional loading by using three dimensional finite element analysis. Materials and Methods: The bite force of 100 N, 150 N, and 200 N was applied with an angulation of $45^{\circ}$ to the longitudinal axis of tooth. Six models were restored with IPS e.max (Ivoclar Vivadent, Schaan, Liechtenstein) with a different margin design. With lingual ledge and various thicknesses, three different core ceramics were designed in each model. Result: In the core ceramic, the maximum tensile stresses were found at the labiocervical region. In the veneering ceramic the maximum tensile stresses were found at the area where the force was applied in all models. Conclusion: Shoulder and chamfer margin types are acceptable for all-ceramic rehabilitations. A ledge on the core ceramic at cervical region may affect the strength of all-ceramic crowns.

Management of the papillary microcarcinoma

Ozer Makay 대한외과학회 2014 대한외과학회 학술대회 초록집 Vol.2014 No.11

Method for the Rapid Evaluation of Vehicle Mobility on Unpaved Terrain

Ozer Cinicioglu,Caglar Cagbayir 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.5

In cases where the mobilization of vehicle convoys in off-road conditions are considered, the mechanism of soil-vehicle interaction emerges as the key parameter controlling the travel time along the chosen route. Therefore, this paper proposes a new simplistic method that would allow the rapid evaluation of vehicle mobility in off-road conditions based on soil topography and vehicle characteristics. This method considers the limit equilibrium of soil under the loading conditions imposed by an accelerating vehicle and by natural terrain geometry. The influence of surface topography on soil’s stress state is considered by modifying the dynamic fluidization theory. In this paper it is proven that the underlying assumptions of the fluidization theory are very well suited to define the nature of stress rotations in sloping ground and the resulting geometry of bearing capacity failure surfaces. Additionally, in order to consider the inertial effects and the effects of shear transfer between the vehicle and the soil, a Coulomb-type mechanism is adopted.

Cochlear Implant Failure in the Pediatric Population

Ozer Fulya,Yavuz Haluk,Yilmaz Ismail,Ozluoglu Levent N. 대한청각학회 2021 Journal of Audiology & Otology Vol.25 No.4

Background and Objectives: In cochlear implant (CI) surgery, the results and causes of revision and reimplantation may guide surgeons in establishing surgical protocols for revision surgery with safe audiological outcomes. The aim of this study was to review our experience in terms of etiology, surgical strategy, and hearing outcomes in pediatric patients who underwent CI removal and reimplantation.Subjects and Methods: All patients received implants of the same brand. Pre and postoperative Categories of Auditory Performance score and aided free-field pure tone audiometry thresholds were noted. In vivo integrity tests were performed for each patient and the results of ex vivo tests of each implant were obtained from manufacturer.Results: A total of 149 CIs were placed in 121 patients aged <18 years. The revision rate in children was 6.7% (10/121 children). Six patients had a history of head injury leading to a hard failure. The causes of reimplantation in others were soft failure (n=1), electrode migration (n=1), infection (n=1), and other (n=1). All patients showed better or similar postreimplantation audiological performance compared with pre-reimplantation results.Conclusions: It is very important to provide a safe school and home environment and educate the family for reducing reimplantation due to trauma. Especially for active children, psychiatric consultation should be continued postoperatively.

A New Fe (III)-Selective Membrane Electrode Based on Fe (II) Phthalocyanine

Ozer, Tugba,Isildak, Ibrahim The Korean Electrochemical Society 2019 Journal of electrochemical science and technology Vol.10 No.3

A new miniaturized all solid-state contact Fe (III)-selective PVC membrane electrode based on Fe (II) phthalocyanine as a neutral carrier was described. The effects of the membrane composition and foreign ions on the electrode performance was investigated. The best performance was obtained with a membrane containing 32% poly (vinyl chloride), 64% dioctylsebacate, 3% Fe (II) phthalocyanine, and 1% potassium tetrakis (p-chlorophenyl) borate. The electrode showed near Nernstian response of $26.04{\pm}0.95mV/decade$ over the wide linear concentration range $1.0{\times}10^{-6}$ to $1.0{\times}10^{-1}M$, and a very low limit of detection $1.8{\pm}0.5{\times}10^{-7}M$. The potentiometric response of the developed electrode was independent at pH 3.5-5.7. The lifetime of the electrode was approximately 3 months and the response time was very short (< 7 s). It exhibited excellent selectivity towards Fe (III) over various cations. The miniaturized all solid-state contact Fe (III)-selective membrane electrode was successfully applied as an indicator electrode for the potentiometric titration of $1.0{\times}10^{-3}M$ Fe (III) ions with a $1.0{\times}10^{-2}M$ EDTA and the direct determination of Fe (III) ions in real water samples.

Diabetes is an Important Risk Factor for Metastasis in Non-Muscle-Invasive Bladder Cancer

Ozer, Kutan,Horsanali, Mustafa Ozan,Gorgel, Sacit Nuri,Ozbek, Emin Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.1

Background: Epidemiological evidence indicates that individuals with diabetes mellitus (DM) may have a modestly increased risk of bladder cancer. In the present study, we aimed to show any association between DM and risk of metastasis in patients with non-muscle-invasive bladder cancer (NMIBC). Materials and Methods: We retrospectively analyzed 698 patients between January 2007 and December 2014 who were diagnosed with and underwent transurethral resection of bladder tumors (TUR-BT). Comparisons of means was conducted by independent samples t test, and relations between categorical variables were investigated by non-parametric chi-square test. A p value of 0.05 was accepted as statistically significant in comparisons. Results: We analyzed 418 patients with non muscle invasive bladder cancer. 123 of whom were diabetic and 295 non-diabetic. In diabetic patients, 13 were N1 stage and 11 M1 stage. When compared with non diabetic patients that was statistically significant (p<0.001). TNM stages were more advanced in diabetic patients (p<0.001), but concurrent CIS (p=0.1) and squamous metaplasia did not significantly differ between diabetic and non-diabetic cases (p=1). Conclusions: Diabetic patients with non-muscle-invasive bladder cancer may suffer metastases earlier than expected although they are non invasive. Therefore such patients must be followed-up carefully and early cystectomy decision may be necessary. Further prospective studies with more patients are needed to confirm these findings.

Shear bond strength of luting cements to fixed superstructure metal surfaces under various seating forces

Fusun Ozer,Elif Pak-Tunc,Nesrin Esen Dagli,Deepika Ramachandran,Deniz Sen,Markus Bernhard Blatz 대한치과보철학회 2018 The Journal of Advanced Prosthodontics Vol.10 No.5

PURPOSE. In this study, the shear bond strengths (SBS) of luting cements to fixed superstructure metal surfaces under various seating forces were investigated. MATERIALS AND METHODS. Seven different cements [Polycarboxylate (PCC), Glass-Ionomer (GIC), Zinc phospahate (ZPC), Self-adhesive resin (RXU), Resin (C&B), and Temporary cements ((RXT) and (TCS))] were bonded to a total number of 224 square blocks (5×5×3 mm) made of one pure metal [Titanium (CP Ti) and two metal alloys [Gold-Platinum (Au-Pt) and Cobalt-Chrome (Co-Cr)] under 10 N and 50 N seating forces. SBS values were determined and data were analyzed with 3-way ANOVA. Pairwise comparisons and interactions among groups were analyzed with Tukey’s simultaneous confidence intervals. RESULTS. Overall mean scores indicated that Co-Cr showed the highest SBS values (1.96±0.4) (P<.00), while Au-Pt showed the lowest among all metals tested (1.57±0.4) (P<.00). Except for PCC/CP Ti, RXU/CP Ti, and GIC/Au-Pt factor level combinations (P<.00), the cements tested under 10 N seating force showed no significantly higher SBS values when compared to the values of those tested under 50 N seating force (P>.05). The PCC cement showed the highest mean SBS score (3.59±0.07) among all cements tested (P<.00), while the resin-based temporary luting cement RXT showed the lowest (0.39±0.07) (P<.00). CONCLUSION. Polycarboxylate cement provides reliable bonding performance to metal surfaces. Resin-based temporary luting cements can be used when retrievability is needed. GIC is not suitable for permanent cementation of fixed dental prostheses consisting of CP Ti or Au-Pt substructures.

Robotic Metal Spinning- Experiments with Cascaded Position-Velocity Control with an add-on Vibration Suppressor for Enhanced Trajectory Tracking

Abdullah Ozer,Hirohiko Arai 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In order to increase the adaptability of industrial robots to broader application areas, it is required toimprove the fundamental control strategies with supplementary methods to a more sophisticated level. Machiningprocesses are one of the areas that need more advanced and robust control approaches due to the steady forcerequirements and inevitable feedback between the task forces and dynamics of the system. With this research, it isaimed to introduce industrial robots, as a highly versatile automation tool, to the metal spinning process and expand its application areas. An industrial robot has been used to implement robotic metal spinning process and to conductexperiments. Preliminary experimental results for an enhanced trajectory tracking algorithms are presented in this paper to provide a foundation for the expansion of robotic applications. The results show that it is feasible to performthe metal spinning process by using an industrial robot with cascaded trajectory tracking algorithms. Furtherimprovements can be observed with the proposed cascaded control technique together with an add-on vibration suppressor, in an attempt to enhance the process and attenuate the robot’s joint oscillations.