171 research outputs found
Examining the impact of economy class flight satisfaction on brand loyalty in the light of falling aviation profitability after COVID-19: Case of Turkish Airlines
The aim of this study is to evaluate whether customer satisfaction for the most preferred economy class flight in airline businesses has a positive effect on brand loyalty. Turkish Airlines was chosen as the company that was discussed in the study. In the study, it was also aimed to investigate whether the perception of the effect of customer satisfaction on brand loyalty differs according to demographic characteristics. The study is also important because it provides up-to-date information about customer expectations that make the company preferable after the decline in airline profit rates after Covid-19. The first main hypothesis was created to measure whether customer satisfaction with economy class flight has a positive effect on brand loyalty. The second main hypothesis of the study was created to measure whether the perception of the effect of customer satisfaction on brand loyalty differs according to demographic characteristics. Questionnaire method was used methodologically in the collection of research data. 330 personnel responded to the questionnaire prepared according to a 5-point Likert scale. The SPSS-22 version was used in the analysis of the data, which includes the necessary complementary statistics and tests (frequency, percentage, mean, standard deviation, Cronbach's Alpha, factor analysis, correlation analysis, regression test, t-test, analysis of variance, Post-Hoc test, etc.). In the study, it was concluded that there is a positive and significant relationship between economy class customer satisfaction and brand loyalty. In addition, it was revealed that there were statistically significant differences between the groups according to gender, job position and educational status, but there was no significant difference according to age and travel purpose
2-piridinkarboksilik asit içeren bazı geçiş metal komplekslerinin sentezi, yapılarının analizi ve doğrusal olmayan optik özelliklerinin incelenmesi
06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu tez çalışmasında, pikolinik asit içeren yedi adet geçiş metal kompleksi {[Co(pic)2(H2O)2]•2H2O, [Zn(pic)2(H2O)2]•2H2O, [Ni(pic)2(H2O)2]•2H2O, [Mn(pic)2(H2O)2], [Cu(pic)2]•2H2O, [Cu(pic)2(phen)]•H2O ve [Mn(pic)2(phen)]•H2O} sentezlenerek, X-ışını kırınımı ve yoğunluk fonksiyonel teori (DFT) yöntemleri ile yapı tayini yapılmıştır. Sentezlenen pikolinat kompleslerinin hepsi bozulmuş oktahedral geometrili koordinasyon küresine sahiptirler. FT-IR ve Raman spektrumları kaydedilerek sentezlenen pikolinat komplekslerinin titreşim özellikleri incelenmiştir. Etanol çözücüsü içerisinde pikolinat komplekslerinin UV-Vis spektrumları kaydedilmiş ve elektronik soğurma bandları belirlenmiştir. Deneysel verileri desteklemek için DFT//B3LYP metodu ile birlikte C, N, O ve H atomları için 6-311++G(d,p) temel seti ve metal iyonları için LanL2DZ temel seti kullanılarak IR, Raman ve UV-Vis spektrumları hesaplanmıştır. Elde edilen kuramsal sonuçlar deneysel veriler ile karşılatırıldığında aralarında iyi bir uyum olduğu görülmüştür. Kuramsal hesaplamalar kısmında Gaussian 09 Revision D.01 paket programı kullanılmıştır. SWizard programı yardımıyla, elektronik geçişlere moleküler orbitalerden gelen önemli katkılar hesaplanmıştır. Kompleksler için HOMO, LUMO ve elektronik geçişlerde aktif olan diğer moleküler orbitaller hesaplanmıştır. Hesaplanan HOMO ve LUMO enerjileri kullanılarak elektronegativite, kimyasal potansiyel, kimyasal sertlik ve yumuşaklık gibi kuantum mekaniksel parametreler elde edilmiştir. Ayrıca, sentezlenen komplekslerin spin yoğunluğu dağılımları da incelenmiştir. DFT//B3LYP metodu ve 6-311++G(d,p)-LanL2DZ temel setleri kullanılarak, Doğal Bağ Orbital (NBO) analizi yapılmıştır. Pikolinat kompleksleri için Mulliken, NBO ve APT yükleri hesaplanarak birbirleri ile karşılaştırılmıştır. Son olarak, pikolinat kompleksleri için doğrusal olmayan optik özelliklerin birer göstergesi olan dipol moment (µ), ortalama kutuplanabilirlik (), yönelime bağlı kutuplanabilirlik (∆α) ve birinci mertebeden statik yüksek kutuplanabilirlik () parametreleri hesaplanmıştır.In this study, seven transition metal complexes which contain picolinic acid {[Co(pic)2(H2O)2]•2H2O, [Zn(pic)2(H2O)2]•2H2O, [Ni(pic)2(H2O)2]•2H2O, [Mn(pic)2(H2O)2], [Cu(pic)2]•2H2O, [Cu(pic)2(phen)]•H2O and [Mn(pic)2(phen)]•H2O} were synthesized and their structural characterizations were carried out by X-Ray diffraction and density functional theory (DFT) methods. The synthesized picolinate complexes have distorted octahedral geometry coordination sphere. The vibrational properties of synthesized picolinate complexes were investigated by recording FT-IR and Raman spectra. UV-Vis spectra for picolinate complexes were recorded in ethanol solvent, and the electronic absorption bands were determined. In order to support experimental data, IR, Raman and UV-Vis spectra were calculated by using DFT//B3LYP metod and 6-311++G(d,p) basis set for C, H, N and O atoms and LanL2DZ basis set for metal ions. When the obtained theoretical results were compared with experimental ones, it is seen that there is a good agreement between them. Gaussian 09 Revision D.01 package program was used in theoretical calculation part. The important contributions to electronic transitions from molecular orbitals were designated by using SWizard program. The HOMO, LUMO and other molecular orbitals, which are active in electronic transitions, have been calculated. The quantum mechanical parameters such as, electronegativity, chemical potential, chemical hardness and softness were obtained by using calculated HOMO and LUMO energies. Additionally, the spin density distributions of the synthesized complexes were also examined. Natural bonding orbital (NBO) analysis was performed by using DFT//B3LYP method and 6-311++G(d,p)-LanL2DZ basis set. Mulliken, NBO and APT charges for picolinate complexes were computed and compared with each other. Finally, dipole moment (μ), the average polarizability (), anisotropy of polarizability (Δα) and the first order static hyperpolarizability () parameters which are the indicators of the nonlinear optical (NLO) properties have been calculated
Yüzen Bir Yapının Düzenli Dalgalarda Hidroelastik Analizi
Konferans Bildirisi-- İstanbul Teknik Üniversitesi, Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2017Conference Paper -- İstanbul Technical University, Theoretical and Applied Mechanical Turkish National Committee, 2017Bu çalışmada, modal analiz prensiplerini temel alan lineer hidroelastisite teorisi konteyner tipi bir gemi için uygulanmıştır. Lineer hidroelastisite teorisinde, yapısal ve hidrodinamik problemler lineer davranış ve potansiyel akım kabulleri altında ilişkilendirilebilir. Modal süperpozisyon teknikleri serbest titreşim ve zorlamalı titreşim problemlerini verimli bir şekilde çözebilmemizi sağlar. Bu yöntem sayesinde yapısal tepki, asal titreşim şekillerindeki hareketlerin, şekil değiştirmelerin, vs. birleşimi olarak alınabilir. Bu çerçevede, öncelikle yapısal sönüm ve dış kuvvetlerin yokluğunda kuru yapının dinamik karakteristikleri yani doğal frekanslar ve karşılık gelen asal titreşim şekilleri standart sonlu elemanlar programı ile belirlenebilir. Problemin ikinci aşamasında, her bir asal titreşim şekline karşılık gelen akışkan kuvvetlerinin hareket denklemine dâhil edilmesi gerekir. Akışkanın yapıya uyguladığı hidrodinamik atalet, sönüm, geri getirme ve zorlayıcı kuvvetlerinin bulunabilmesi için sınır elemanları metodu kullanılabilir. Akışkanın ideal ve hareketinin döngüsüz olduğu kabul edilmesi halinde, potansiyel akımı tanımlayan Laplace denklemi, gerekli sınır koşullarını sağlayan bir sınır integral denklemine dönüştürülebilir. Böylelikle problem sadece geminin ıslak yüzeyi olan arayüzde tanımlı hale gelir.This study bases on modal analysis principles which means structural response considered as sum of motions and deformations at principal coordinates. Structural and hydrodynamic problems are coupled weakly by depending on linear hydroelasticity theory where structural and hydrodynamic problems regarded under the linear behavior and potential flow theory respectively. Finite element method is used for free vibration analysis of structure. Boundary element method is used to determine sea loads arise from coming and scattering waves around the floating structure as well as to determine wave loads arise from radiating waves due to ship motion. Excitation forces which effect the floating structure, can be determined by using distribution of velocity potential and radiation originated distributed velocity potential takes the effect of deep water. In this approach the structure response can be calculated under the condition of small wave steepness for regular waves
Retrospective evaluation of patients admitted to Karadeniz Technical University Pediatric Dentistry clinic due to trauma
Purpose Traumatic dental injuries are among the commonly observed problems in the primary and permanent teeth. The rate of prevalence of dental trauma varies globally. In this study, we investigated the type of dental trauma, related factors, and treatment procedures in children. Subjects and Methods During a 5-year period (January 2011–January 2016), 416 children aged in the range of 1–15 years were admitted to our clinic with dental trauma. The cause and type of the dental trauma in the primary and permanent teeth and their relation with gender and age were evaluated using the chi-square test, and their distribution by age was evaluated using regression analysis. Results Overall, girls and boys comprised 37% and 63% of the study population, respectively. The mean age was 8.5 years. Falls (61.1%) were the most common cause of traumatic dental injuries, and enamel–dentin fracture (26%) was the most common dental trauma type. Conclusions Traumatic dental injuries in children are common. A large proportion of patients without any clinical symptoms (15.8%) did not seek any treatment after the trauma. Teachers, parents, and children should be informed about the action to be taken when dental trauma occurs and about the importance of immediately taking the child to a dentist after the trauma to ensure an accurate diagnosis, an optimal treatment plan, and positive outcome
Evaluation of several Quality Criteria of Low Calorie Pumpkin Dessert
The aim of this study was to decrease the sugar concentration of the pumpkin dessert which is a Turkish traditional food using artificial sweeteners. Therefore, its energy content was reduced. As a result it was expected that this product can be consumed by diabetics and overweight people who do not prefer high calorie products. The design included constraints to permit sweetener addition according to the limits of Turkish food legislation. Physical and chemical properties of pumpkin desserts and the effects of sweeteners on sensory properties were investigated. According to the physical, chemical and sensory analyses it can be seen, by using aspartame and acesulfame K additives, low calorie pumpkin dessert could be produced
Frequency of the mdr‐1 C>T gene polymorphism in patients with COPD
BACKGROUND AND AIM: The multi-drug resistant-1 (MDR-1) gene is located on human chromosome 7 and encodes a glycosylated membrane protein that is a member of the ATP-binding cassette transporters superfamily. The aim of the study was to reveal the role of the C3435T MDR-1 gene polymorphism in chronic obstructive pulmonary disease. METHOD: DNA samples from 41 patients with chronic obstructive pulmonary disease and 50 healthy control participants were used to compare MDR-1 gene profiles. Genotyping assays were performed using the StripAssay technique that is based on reverse-hybridization. RESULTS: The T allele polymorphism in the MDR-1 gene located at position 3435 in exon 26 was shown to correlate with chronic obstructive pulmonary disease. CONCLUSION: These preliminary results suggest that the T allele polymorphism of the MDR-1 gene is associated with chronic obstructive pulmonary disease
Investigation of the usability of artificial neural networks (ANN) on 1/1000 scale cadastral map sheets transformation
Tapu ve Kadastro Genel Müdürlüğü tarafından Büyük Ölçekli Harita ve Harita Yapım Yönetmeliği (BÖHHBÜY) ne göre 1/1000 ölçekli kadastral paftalar üretilmektedir. Kadastral çalışmalarda altlık oluşturan 1/1000 ölçekli paftalar taranmaktadır. Taranmış görüntüler genellikle Afin ve Polinom yöntemleri kullanılılarak pafta dönüşümü yapılır. Afin ve İkinci Dereceden Polinom fonksiyonlarının matematiksel formüllerinin belirli olmasısebebiyle dönüşümün hassasiyeti dönüşümde kullanılan nokta sayısına ve kullanıcı hatasına bağlıdır. Dönüşümde elde edilen hassasiyet noktaların konum hatasına bağlı olarak parsellerde kenar ve alan hataları oluşturmaktadır. Yapay Sinir Ağlarında (YSA) dönüşüm işlemi, ağın eğitiminde belirli parametrelere ve fonksiyonlara bağlı kalınmadığından daha iyi sonuçlar vermektedir. Bu çalışmada mühendislik alanında sık kullanılan YSA’nın pafta dönüşümünde kullanılabilirliği incelenmiştir. 1/1000 ölçekli F42-d-24-d-4-b paftasından homojen olarak noktalar belirlenmiştir. Belirlenen 9 nokta Afin ve İkinci Dereceden Polinom dönüşümü Netcad programında hesaplanmıştır. Matlab programını kullanarak YSA ile 9 nokta Geri Yayılımlı Yapay Sinir Ağına(GYYSA)’na göre eğitilmiştir. 4 adet test noktasının karesel ortalama hatası üç yönteme göre de elde edilmiştir. YSA ile dönüştürülmüş test noktalarının koordinatları Afin ve İkinci Dereceden Polinom dönüşümlerinin sonucuna göre daha düşük çıkmıştır.1 \ 1000 scale cadastral map sheets are produced by General Directorate of Land Registry and Cadastre according to Large Scale Map and Mapping Regulation (LSMMIPR). In cadastral studies, that created based 1/1000 scale cadastral map sheets are scanned, and then Affine and Polynomial methods are generally used in the transformation of cadastral map sheets. Because of mathematical formulas of Affine and Second Degree Polynomial functions, it depends on the number of points used in the transformation and user error. Precision obtained in the transformation creates edge and area errors in the parcels depending on the position error of the points. Transformation processing in Artificial Neural Networks (ANN) gives better results because it does not depend on certain parameters and functions in network training. In this study, the applicability of ANN, which is frequently used in engineering field, to cadastral map sheetstransformation is examined. We chose homogeneously 9 grid points over a cadastral map sheets called F42-d-24-d-4-b with a scale of 1/1000. By selecting 9 grid points, and then Affine and second degree Polynomial transformation are applicated in Netcad program. Using Matlab program, trained according to ANN and 9 grid points Back Propagation Artificial Neural Network(BPANN). The quadratic mean error of 4 test points is calculated. The coordinates of the test points transformed with ANN are lower than those with Affine and Second Degree Polynomial transforms
Influence of thermo-light curing on the microhardness and fluoride release of glass-Ionomer cements
Glass ionomer cements (GICs) are important restorative materials that are frequently preferred in both primary and permanent teeth. The aim of this study was to investigate the effect of thermo-light curing on the surface microhardness and fluoride ion (F-) release of the materials during the curing reactions of high-viscosity GICs. In our study, Equia Fil (EQ-GC), Fuji IX GP Extra (FGP-GC), and Fuji IX Capsule (FC-GC) were prepared in accordance with the manufacturer's instructions, and for 60 and 90 seconds during curing Woodpecker LED-C (WL), GC D-Light Pro (GLC) and BlueLuxcer M-855 Halogen Curing Light (HALO) light instruments formed the experimental groups, and self-curing glass ionomer cement samples formed the control groups. VHN and F- release values of both groups were evaluated on 1st day, 1st week, 1st, 3rd, and 6th months. The Jamovi (Version 1.0.4) program was used for statistical analysis. Significant difference was analyzed by the Tukey's post hoc-test (a = 0.05). In the 1st month, EQ exhibited significantly higher microhardness than FC (p0.05). All materials exhibited higher microhardness during 1st day than in other periods (p0.05). Within the limitations of this study, it can be concluded that thermo-light application does not cause unacceptable long-term changes in the physical and chemical properties of materials
Procalcitonin and other acute phase reactants in patients with chronic obstructive pulmonary disease exacerbation
The aim of this study was to investigate the correlation between procalcitonin and other acute phase reactants, and also analyze their relationship with clinical situation in chronic obstructive pulmonary disease (COPD) acute exacerbations.Materials and methods: The study was made with 122 acute COPD exacerbated patients, who were admitted to emergency service. Patients with below 0.25 ng/ml PCT value included Group 1, and the patients with PCT values ≥ 0.25 ng/ml Group 2. Serum procalcitonin levels, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) values and white blood cell (WBC) counts were measured. Also, patients hospitalization time and mortality rates were recorded and compared with PCT.Results: Patients were divided in 3 groups according to their clinical diagnosis; Pneumonia (n=27), Mycoplasma-Chlamydia pneumonia (n=11) and the patients with only COPD exacerbation(n=84). Mean PCT values according to the groups were 9.47 ± 8.1 ng/ml, 0.41 ± 0.2 ng/ml, and 0.21 ± 0.05 ng/ml respectively. The relationship between PCT with CRP and white blood cell has been found between significiant (p=0.001, p=0.005 respectively), whereas the relationship between PCT and ESR was nonsignificant (p=0.55). Procalcitonin and CRP had a positive correlation with the hospitalization time (p=0.034, p=0.022 respectively). The mean ± standard error of PCT for the patients who died was 28.3 ± 27.5 ng/ml, and the difference between patients who died or were discharged was statistically significant (p= 0.012).Conclusion: PCT can be a useful indicator for morbidity and prognosis in COPD patients
Examination of the Relationship between Umbilical Cord Blood Gas Values and Hearing Function in Neonates
Objective: The aim of the present study was to examine the relationship between the results of the transient otoacoustic emission (TEOAE) test used in neonatal hearing screening and the results of the umbilical cord blood (UCB) analysis in neonates.Methods: This retrospective study included 209 neonates born in the obstetric unit at the 37th gestational week. Based on the results of the TEOAE test, the neonates included in the study were divided into two groups as the study group composed of those “REFER” (n=141) and the control group consisting those “PASS” (n=68) the test. The UCB sampling procedure was performed on all neonates. In the blood samples, the pH parameters were evaluated by using glass electrodes, and the pCO2 and pO2 parameters were evaluated directly by using sensitive electrodes.Results: When the additional maternal diseases were compared with the TEOAE results, the ratio of hypothyroidism was found to be statistically higher in the study group (p0.05).Conclusion: The results of the present study showed that there was no statistically significant difference between the results of UCB analysis and the TEOAE test. However, we believe that conducting a larger study evaluating other parameters and employing UCB analysis would be useful, and UCB evaluation, which is an inexpensive, easy and effective method in determining hypoxia in neonates, might be a significant marker in cases at risk of hearing loss
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