Browsing by Author "Balci S."

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    A retrospective evaluation of the epithelial changes/lesions and neoplasms of the Gallbladder in Turkey and a review of the existing sampling methods: A multicentre study
    (Federation of Turkish Pathology Societies, 2018) Esendağli G.; Akarca F.G.; Balci S.; Argon A.; Şengiz Erhan S.; Turhan N.; İnce Zengin N.; Hallaç Keser S.; Çelik B.; Bulut T.; Abdullazade S.; Erden E.; Savaş B.; Bostan T.; Sağol Ö.; Aysal Ağalar A.; Kepil N.; Karslioğlu Y.; Günal A.; Markoç F.; Saka B.; Özgün G.; Özdamar Ş.O.; Bahadır B.; Kaymaz E.; Işık E.; Ayhan S.; Tunçel D.; Özgüven Yılmaz B.; Çelik S.; Karabacak T.; Erbarut Seven İ.; Ataizi Çelikel Ç.; Gücin Z.; Ekinci Ö.; Akyol G.
    Objective: As there is continuing disagreement among the observers on the differential diagnosis between the epithelial changes/lesions and neoplasms of the gallbladder, this multicentre study was planned in order to assess the rate of the epithelial gallbladder lesions in Turkey and to propose microscopy and macroscopy protocols. Material and Method: With the participation of 22 institutions around Turkey that were included in the Hepato-Pancreato-Biliary Study Group, 89,324 cholecystectomy specimens sampled from 2003 to 2016 were retrospectively evaluated. The numbers of adenocarcinomas, dysplasias, intracholecystic neoplasms/adenomas, intestinal metaplasias and reactive atypia were identified with the review of pathology reports and the regional and countrywide incidence rates were presented in percentages. Results: Epithelial changes/lesions were reported in 6% of cholecystectomy materials. Of these epithelial lesions, 7% were reported as adenocarcinoma, 0.9% as high-grade dysplasia, 4% as low-grade dysplasia, 7.8% as reactive/regenerative atypia, 1.7% as neoplastic polyp, and 15.6% as intestinal metaplasia. The remaining lesions (63%) primarily included non-neoplastic polypoids/hyperplastic lesions and antral/pyloric metaplasia. There were also differences between pathology laboratories. Conclusion: The major causes of the difference in reporting these epithelial changes/lesions and neoplasms include the differences related to the institute’s oncological surgery frequency, sampling protocols, geographical dissimilarities, and differences in the diagnoses/interpretations of the pathologists. It seems that the diagnosis may change if new sections are taken from the specimen when any epithelial abnormality is seen during microscopic examination of the cholecystectomy materials. © 2018, Federation of Turkish Pathology Societies. All rights reserved.
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    Reduction of the core size and power losses by using soft magnetic material for a single-phase induction motor
    (Elsevier B.V., 2022) Balci S.; Akkaya M.
    Induction motors are widely used in our daily life and industrial machines. Single-phase induction motors with small power, manufactured with few horsepowers (HP), are preferred as compressor motors for household refrigerators and air conditioners. This inevitably leads to the lower energy consumption of compressor systems and requirements for a more compact design. In this study, a single-phase induction motor manufactured with classical core material for a certain power value is modeled using finite element analysis (FEA) software and the power losses are investigated. Later, this electric motor is designed with 6.5% SiFe jfe super core material, one of the soft magnetic core materials, for the same power value and comparative performance studies are performed. In these comparisons, mechanical volume and weight for the motor dimensions, electrical power losses and electromagnetic parameters are studied. It is therefore recommended that the jfe super core material, which has become popular in recent years, be used for the manufacture of single-phase induction motors, which are often used in household appliances. © 2022 Elsevier Ltd
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    Numerical and experimental analysis of refrigerating performance for hybrid nanolubricants with sepiolite additives
    (Elsevier Ltd, 2023) Akkaya M.; Sarilmaz A.; Balci S.; Ozel F.
    The use of nanomaterials in various forms and compositions provides the basis for the creation of high-performance structures in their application in many heating and cooling systems. In this study, the lubrication properties of rod-shaped Sepiolite (SP) and its various carbon composites Carbon Black (CB), Multi-Walled Carbon Nanotubes (MWCNT), and reduced Graphene Oxide (rGO) were investigated for the first time in a vapor compression cooling system. The cooling heat transfer performance was compared by analyzing the rheological and thermal behaviors using nanolubricants. The best improvement in cooling Coefficient of Performance (COP) was obtained by using SP-rGO nanoparticles. Compared to Polyol Ester (POE), the cooling performance COP increased by 23.6 % with the addition of SP-rGO. The strategy proposed here is simple and has great potential for producing high-efficiency cooling systems. In addition, the single-phase compressor motor was modeled with Finite Element Analysis (FEA) simulation in the experimental studies, and the simulation results were reported. According to the power loss data obtained from FEA simulation results, a total power loss of 119 W is determined as core losses of 44 W, winding losses of 65 W and frictional losses of 10 W for a 1 HP single-phase compressor motor. Thus, the electrical energy efficiency of the motor is approximately 86 %. © 2022 Elsevier Ltd