Orthodontic bonding to acid- or laser-etched prebleached enamel

Fulya Ozdemir,Umut Cakan,Nese Gonul,Derya Germec Cakan 대한치과교정학회 2013 대한치과교정학회지 Vol.43 No.3

Objective: Bonding forces of brackets to enamel surfaces may be affected by the procedures used for bleaching and enamel etching. The aim of this study was to investigate the bonding strength of orthodontic brackets to laser-etched surfaces of bleached teeth. Methods: In a nonbleached control group, acid etching (group A) or Er:YAG laser application (group B) was performed prior to bracket bonding (n = 13 in each group). Similar surface treatments were performed at 1 day (groups C and D; n = 13 in each subgroup) or at 3 weeks (groups E and F; n = 13 in each subgroup) after 38% hydrogen peroxide bleaching in another set of teeth. The specimens were debonded after thermocycling. Results: Laser etching of bleached teeth resulted in clinically unacceptable low bonding strength. In the case of acid-etched teeth, waiting for 3 weeks before attachment of brackets to the bleached surfaces resulted in similar, but not identical, bond strength values as those obtained with nonbleached surfaces. However, in the laser-etched groups, the bonding strength after 3 weeks was the same as that for the nonbleached group. Conclusions: When teeth bleached with 38% hydrogen peroxide are meant to be bonded immediately, acid etching is preferable.

Evaluation of 2,4-D removal via activated carbon from pomegranate husk/polymer composite hydrogel: Optimization of process parameters through face centered composite design

Fulya Taktak,Zeynep İlbay,Selin Şahin 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.9

A new type of polymer composite hydrogel was prepared by introducing activated carbons from pomegranate husk into poly ((2-dimethylamino) ethyl methacrylate) network. The removal of 2,4-dichlorophenoxyacetic acid (2,4-D) from aqueous solution was studied with respect to pH of the media, initial 2,4-D concentration and activated carbon content into the polymeric network. Face centered composite design (FCCD) through response surface methodology (RSM) was used for designing the experiments as well as for studying the effects of the process parameters. A quadratic model and a two factor interaction design model were developed for the removal of 2,4-D and adsorption capacity, respectively. The optimum pH of the pesticide solution, activated carbon content into the polymeric network and initial concentration of 2,4-D were found as 3, 2.5 wt% and 100mg/L. 63.245% and 68.805 (mg/g) for the removal of 2,4-D and adsorption capacity were obtained by using Simplex optimization method. Furthermore, the surface characteristics of the adsorbent prepared under optimized conditions were examined by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR).

Quantitative evaluation of alveolar cortical bone density in adults with different vertical facial typesusing cone-beam computed tomography

Fulya Ozdemir,Murat Tozlu,Derya Germec Cakan 대한치과교정학회 2014 대한치과교정학회지 Vol.44 No.1

Objective: The purpose of this study was to quantitatively evaluate the cortical bone densities of the maxillary and mandibular alveolar processes in adults with different vertical facial types using cone-beam computed tomography (CBCT) images. Methods: CBCT images (n = 142) of adult patients (20?45 years) were classified into hypodivergent, normodivergent, and hyperdivergent groups on the basis of linear and angular S-N/Go-Me measurements. The cortical bone densities (in Hounsfield units) at maxillary and mandibular interdental sites from the distal aspect of the canine to the mesial aspect of the second molar were measured on the images. Results: On the maxillary buccal side, female subjects in the hyperdivergent group showed significantly decreased bone density, while in the posterior region, male subjects in the hyperdivergent group displayed significantly decreased bone density when compared with corresponding subjects in the other groups (p<0.001). Furthermore, the subjects in the hyperdivergent group had significantly lower bone densities on the mandibular buccal side than hypodivergent subjects. The maxillary palatal bone density did not differ significantly among groups, but female subjects showed significantly denser palatal cortical bone. No significant difference in bone density was found between the palatal and buccal sides in the maxillary premolar region. Overall, the palatal cortical bone was denser anteriorly and buccal cortical bone was denser posteriorly. Conclusion: Adults with the hyperdivergent facial type tend to have less-dense buccal cortical bone in the maxillary and mandibular alveolar processes. Clinicians should be aware of the variability of cortical bone densities at mini-implant placement sites.

Structural and optical characteristics of antimony selenosulfide thin films prepared by two-step method

Turkoglu Fulya,Ekren Memduh Emirhan,Cantas Ayten,Yakinci Kubra,Gundogan Hazal,Koseoglu Hasan,Aygun Gulnur,Ozyuzer Lutfi 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.81 No.3

Antimony triselenide (Sb2Se3) is one of the most promising absorber material choices among the inorganic semiconductors that has attracted much attention today. However, highest recorded efciencies for Sb2Se3 solar cells are still lower than ideal. Exploring antimony selenosulfde (Sb2(SxSe1−x)3) to increase device performance is one option because some features of alloyed Sb2(SxSe1−x)3 depend on composition such as bandgap and band position. In this study, two-step process was used to grow Sb2(SxSe1−x)3 thin flms. In the frst stage, Sb2Se3 thin flms were deposited on soda lime glass substrates using direct current magnetron sputtering technique. In the second stage, Sb2Se3 thin flms were exposed to sulfurization process in a quartz ampoule to obtain Sb2(SxSe1−x)3 thin flms. Characterization results showed that morphological, optical, and structural properties of Sb2(SxSe1−x)3 thin flms grown by presented method were highly dependent on amount of sulfur in the flms. By the adjustment of the S/S+Se atomic ratio, Sb2(SxSe1−x)3 absorber materials with suitable bandgap, favorable orientation and compact morphology can be obtained for photovoltaic applications.

Generalized crossed modules over generalized group-groupoids

H. Fulya Akız 강원경기수학회 2024 한국수학논문집 Vol.32 No.1

In this paper we define generalized double group-groupoids and crossed modules over generalized group-groupoids. Also we prove that these algebraic structures are categorically equivalent.

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.

Orthodontic bonding to acid- or laser-etched prebleached enamel

Ozdemir, Fulya,Cakan, Umut,Gonul, Nese,Cakan, Derya Germec The Korean Association Of Orthodontists 2013 대한치과교정학회지 Vol.43 No.3

Objective: Bonding forces of brackets to enamel surfaces may be affected by the procedures used for bleaching and enamel etching. The aim of this study was to investigate the bonding strength of orthodontic brackets to laser-etched surfaces of bleached teeth. Methods: In a nonbleached control group, acid etching (group A) or Er:YAG laser application (group B) was performed prior to bracket bonding (n = 13 in each group). Similar surface treatments were performed at 1 day (groups C and D; n = 13 in each subgroup) or at 3 weeks (groups E and F; n = 13 in each subgroup) after 38% hydrogen peroxide bleaching in another set of teeth. The specimens were debonded after thermocycling. Results: Laser etching of bleached teeth resulted in clinically unacceptable low bonding strength. In the case of acid-etched teeth, waiting for 3 weeks before attachment of brackets to the bleached surfaces resulted in similar, but not identical, bond strength values as those obtained with nonbleached surfaces. However, in the laser-etched groups, the bonding strength after 3 weeks was the same as that for the nonbleached group. Conclusions: When teeth bleached with 38% hydrogen peroxide are meant to be bonded immediately, acid etching is preferable.

MONODROMY GROUPOID OF A LOCAL TOPOLOGICAL GROUP-GROUPOID

Akiz, H. Fulya The Kangwon-Kyungki Mathematical Society 2019 한국수학논문집 Vol.27 No.2

In this paper, we define a local topological group-groupoid and prove that if G is a local topological group-groupoid, then the monodromy groupoid Mon(G) of G is a local group-groupoid.

Dr. Mitsuo Gen, Editor-in-Chief, Ranked as Top Productive Authors in POM

Runwei Cheng,Fulya Altiparmak 대한산업공학회 2010 Industrial Engineeering & Management Systems Vol.9 No.4

Publishing a new research paper in academic and professional journals is very important to facilitate knowledge sharing among scientists and engineers, researchers and practitioners. Variouse measures and citation scores have been developed to evaluate and rank scientific publications in order to foster the progress of research and real world applications. Recently, Hsieh and Chang reported "An assessment of world-wide research productivity in production and operations management" in International Journal of Production Economics[1]. This report explores the global production and operations management (POM) research performance on papers published in 20 core POM journals in the past half century, which is based on the data of 1959-2008 from Thomson Reuters" Web of Science/Knowledge databases.

A Hybrid Genetic Algorithm for the Location-Routing Problem with Simultaneous Pickup and Delivery

Ismail Karaoglan,Fulya Altiparmak 대한산업공학회 2011 Industrial Engineeering & Management Systems Vol.10 No.1

In this paper, we consider the Location-Routing Problem with simultaneous pickup and delivery (LRPSPD) which is a general case of the location-routing problem. The LRPSPD is defined as finding locations of the depots and designing vehicle routes in such a way that pickup and delivery demands of each customer must be performed with same vehicle and the overall cost is minimized. Since the LRPSPD is an NP-hard problem, we propose a hybrid heuristic approach based on genetic algorithms (GA) and simulated annealing (SA) to solve the problem. To evaluate the performance of the proposed approach, we conduct an experimental study and compare its results with those obtained by a branch-and-cut algorithm on a set of instances derived from the literature. Computational results indicate that the proposed hybrid algorithm is able to find optimal or very good quality solutions in a reasonable computation time.