Out-of-plane vibrations of planar curved beams having variable curvature and cross-section

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2012Includes bibliographical references (leaves: 33-34)Text in English; Abstract: Turkish and Englishx, 34 leavesIn this study, out of plane vibration characteristics of curved beams having variable curvatures and cross-sections are studied by FDM (Finite Difference Method). The effects of curvature and cross-section of the curved beam on natural frequencies are investigated for the curved beams having; variable curvature & constant cross-section and variable curvature & variable cross-section. Mathematical model of the present problem is based on the coupled differential eigenvalue problem with variable coefficients. Numerical solutions of the problem in this study are obtained by the computer program developed in Mathematica. The accuracy of the present results obtained from the developed program is evaluated by comparing with FEM (Finite Element Method) results found from solid model created in ANSYS. Good agreement is obtained in the comparisons of the present results with other results. All results are presented in tabular and graphical forms

Out-of-plane vibrations of planar curved beams having variable curvature and cross-section

Thesis (Master)--Izmir Institute of Technology, Mechanical Engineering, Izmir, 2012Includes bibliographical references (leaves: 33-34)Text in English; Abstract: Turkish and Englishx, 34 leavesIn this study, out of plane vibration characteristics of curved beams having variable curvatures and cross-sections are studied by FDM (Finite Difference Method). The effects of curvature and cross-section of the curved beam on natural frequencies are investigated for the curved beams having; variable curvature & constant cross-section and variable curvature & variable cross-section. Mathematical model of the present problem is based on the coupled differential eigenvalue problem with variable coefficients. Numerical solutions of the problem in this study are obtained by the computer program developed in Mathematica. The accuracy of the present results obtained from the developed program is evaluated by comparing with FEM (Finite Element Method) results found from solid model created in ANSYS. Good agreement is obtained in the comparisons of the present results with other results. All results are presented in tabular and graphical forms

Sınıf Öğretmenleri adaylarının öğretim perspektifleri

*Bu çalışma birinci yazarın yüksek lisans tezinden üretilmiştir.“Öğretim Perspektifi” kavramı Pratt (1998) tarafından geliştirilmiş olup eğitimcilerin öğretime nasıl baktıklarını tanımlayan bir kavramdır. Bu araştırmanın amacı sınıf öğretmeni adaylarının öğretim perspektiflerinin ne düzeyde olduğunu incelemek ve çeşitli değişkenlere göre anlamlı olarak farklılaşıp farklılaşmadığını görmektir. Sınıf öğretmeni adaylarının öğretim perspektiflerini incelemek amacıyla, Çanakkale Onsekiz Mart Üniversitesinde öğrenim görmekte olan 109 sınıf öğretmeni adayına ölçek uygulanmıştır. Sınıf öğretmeni adaylarının öğretim perspektifleri incelenirken cinsiyet değişkenine, eğitim fakültesi tercihini isteyerek yapma durumuna ve öğretmenlik mesleğine kendini hazır hissetme durumuna göre incelenmiştir. Araştırmada sınıf öğretmeni adaylarının öğretim perspektiflerinin cinsiyet değişkenlerine göre anlamlı olarak farklılaşmadığı ortaya çıkmıştır. Eğitim fakültesi tercihini isteyerek yapma değişkenine göre “Teşvik etme” hariç diğer perspektiflerde anlamlı farklılık görülmüştür. Öğretmenlik mesleğine kendini hazır hissetme değişkenine göre ise sadece “Aktarma” ve “Toplumsal reform” perspektiflerinde anlamlı farklılaşma olmuştur. 109 sınıf öğretmeni adayının sahip olduğu öğretim perspektifleri (Aktarma, Yetiştirme, Geliştirme, Teşvik Etme, Toplumsal Reform) incelendiğinde %42(46) oranında baskın perspektif “Teşvik etme” olurken bu oran “Toplumsal reform” perspektifinde sadece %2(2) oranında kendini göstermiştir

A New Natural Secondary Reference Material for Garnet U-Pb Dating by TIMS and LA-ICP-MS

Gem quality andradite-rich garnet (IUC-1), obtained from the Miocene trachyte dome near Ankara city (Turkey), has been identified as a potential natural secondary reference material for U-Pb dating. In this study, U-Pb dating was performed in five different laboratories using isotope dilution TIMS and laser ablation ICP-MS to determine the homogeneity of euhedral garnet crystals. The U-Pb ID-TIMS data for IUC-1 yielded 207Pb/235U and 206Pb/238U ages of 20.9 0.4 and 20.6 0.8 Ma respectively, and these values are consistent with U-Pb LA-ICP-MS analyses, in which different garnet crystals yielded ages of 20.8 0.1, 20.7 0.1, 20.7 0.2 and 20.2 0.1 Ma. An andradite (IUC-2) from the Serc eoren wollastonite skarn (Turkey) can be used as a secondary reference material provided detailed imaging of the € crystals is undertaken. ID-TIMS data yielded 207Pb/235U and 206Pb/238U ages of 20.4 0.4 and 20.9 1.0 Ma respectively, and yielded U-Pb ages on different grains of 20.5 0.1, 20.7 1.0, 20.8 1.7 and 20.9 1.6 Ma. The assigned weighted mean age of IUC-1 (20.4 0.5 Ma, 2s) is proposed as a 2023 reference value. IUC-1 garnet is expected to contribute significantly to rapidly developing garnet geochronology in the near future

Nation-wide analysis of the impact of Covid-19 pandemic on daily urology practice in Turkey

Ozkent, Mehmet Serkan/0000-0002-6613-0671; Mercimek, Mehmet Necmettin/0000-0002-0680-4451; karabay, emre/0000-0003-1654-8524; Sen, Volkan/0000-0003-2832-0682; Ceyhan, Erman/0000-0001-8223-6399; Irer, Bora/0000-0002-7719-9033; deger, dogan/0000-0002-5095-7770WOS: 000584084200001PubMed: 32996259Objective To present a nation-wide analysis of the workload of urology departments in Turkey week-by-week during Covid-19 pandemic. Methodology the centres participating in the study were divided into three groups as tertiary referral centres, state hospitals and private practice hospitals. the number of outpatients, inpatients, daily interventions and urological surgeries were recorded prospectively between 9-March-2020 and 31-May-2020. All these variables were recorded for the same time interval of 2019 as well. the weekly change of the workload of urology during pandemic period was evaluated, also the workload of urology and the distributions of certain urological surgeries were compared between the pandemic period and the same time interval of the year 2019. Results A total of 51 centres participated in the study. the number of outpatients, inpatients, urological surgeries and daily interventions were found to be dramatically decreased by the 3rd week of pandemics in state hospitals and tertiary referral centres; however, the daily urological practice were similar in private practice hospitals throughout the pandemic period. When the workload of urology in pandemic period and the same time interval of the year 2019 were compared, a huge decrease was observed in all variables during pandemic period. However, temporary measures like ureteral stenting, nephrostomy placement and percutaneous cystostomy have been found to increase during Covid-19 pandemic compared with normal life. Conclusions Covid-19 pandemic significantly affected the routine daily urological practice likewise other subspecialties and priority was given to emergent and non-deferrable surgeries by urologists in concordance with published clinical guidelines