Interface properties of modified indium tin oxide based organic light emitting diodes withfunctional aromatic molecules

Thesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2011Includes bibliographical references (leaves: 89-96)xiii, 89 leavesThis thesis focused on modification and characterization of ITO substrates with carboxylic acid based self-assembled monolayers to improve OLED device performance. In this study, ITO was used as anode material in OLEDs. In order to modify ITO electrodes, MePIFA and DPIFA aromatic small molecules with double bound carboxylic acid have been used as self-assembly monolayer (SAM). Characterizations of modified ITO and unmodified ITO surfaces were performed via atomic force microscopy and scanning tunneling microscopy. In addition to surface characterization, I-V measurements of the modified and unmodified ITO were taken via spreading resistance microscopy and scanning tunneling microscopy. Moreover, in order to measure change in the surface potential after the modification of ITO surface with MePIFA and DPIFA SAM molecules, Kelvin Probe Force Microscopy was performed. Finally two different configurations of OLEDs devices were fabricated using thermal evaporator system in order to explore the effect of SAM modified ITO on electrical characterization of OLED devices. It was shown that OLED intensity, and turn on voltage were improved compared to OLED devices with unmodified ITO

Harmonik Tekil Yük Etkisindeki Boşluk İçeren Yarım Uzayın Titreşimleri

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2008Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2008Bu çalışmada, harmonik tekil kuvvet zorlaması için homogen, izotrop ve lineer elastik, silindirik boşluklu yarım uzayın davranışı incelenmiştir. Silindirik boşluğun ekseni boyunca geometri, malzeme özellikleri ve zorlamanın değişmemesi nedeni ile düzlem şekildeğiştirme hali göz önüne alınmıştır. Helmholtz yerdeğiştirme potansiyellerinin kullanılması ile yönetici denklem takımı kutupsal koordinatlarda iki adet ayrık dalga denklemine indirgenmiştir. İndirgenmiş dalga denklemleri Fourier-Bessel serileri ile analitik olarak çözülmüştür. Çözüm sonunda ortaya çıkan bilinmeyen sabitler delik yüzeyi ve serbest yüzey üzerinde yazılan sınır koşulları yardımıyla hesaplanmıştır. Oyuk yüzeyinde sınır koşullarının tam olarak sağlatılmasıyla bilinmeyen sabitlerin yarısı diğer yarısı cinsinden elde edilmiştir. Geri kalan bilinmeyenler, serbest yüzey üzerindeki gerilme bileşenlerinin sıfır olması koşulunun “En Küçük Kareler Yöntemi” kullanılarak yaklaşık olarak sağlatılması ile elde edilmiştir. Çözüm sonunda ω zorlama frekansı ve N terim sayısının çeşitli değerlerine göre yerdeğiştirme ve gerilme bileşenlerinin değişimleri grafikler yardımı ile verilmiştir.In this study, response of a homogeneous, isotropic and linear elastic semi-infinite medium, which includes a cylindrical cavity, is investigated when subjected to a harmonic point load. Because of the geometry, material properties of the medium and the forcing function have never changed through the axis of cylindrical cavity; the plane strain case is used. Coupled equation of motions is reduced into two wave equations by use of Helmholtz potentials in polar coordinates. Fourier-Bessel series are used to solve these reduced wave equations. Unknown coefficients are calculated by applying boundary conditions on the cavity and free surface. Boundary conditions on the cavity surface are satisfied exactly. Using these conditions, half of the unknown coefficients are calculated in terms of the others. The stress components on the free surface must be zero. Using the Least Square Technique, these conditions have been satisfied approximately. Graphical variation of displacement and stress components on cavity and free surface are evaluated with respect to ω circular frequency and N number of term

Düzlem Dışı Harmonik Yük Etkisinde İkili Silindirik Oyuk İçeren Yarım-Uzayın Davranışı

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2013Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2013Bu çalışmada, düzlem dışı harmonik yük etkisinde ikili silindirik oyuk içeren türdeş, eş yönlü ve doğrusal esnek yarım-uzayın davranışı incelenmiştir. Oyuklar farklı yarıçaplarda olup, aralarındaki mesafe değişkendir. Her iki oyuk merkezinin de serbest yüzeye olan uzaklığı eşittir. Birinci oyuk iç yüzeyi düzlem dışı harmonik yük etkisinde iken ikinci oyuğun iç yüzeyi serbesttir. Dalga fonksiyonu açılım tekniği kullanılarak yer değiştirme alanları Fourier-Bessel serileri ile ifade edilmiştir. Kutupsal koordinat takımlarının kullanılması ile oyuk yüzeyindeki sınır koşulları doğrudan sağlatılmıştır. Serbest yüzeydeki sınır koşulu da yansıma tekniği kullanılarak sağlatılmıştır. Sayısal sonuç kısmında ikinci oyuk yarıçapının ve oyuklar arasındaki mesafenin, birinci oyuk yüzeyindeki dairesel gerilmeye olan etkileri gösterilmiştir. Anahtar kelimeler: Yarım uzay, ikili oyuk, Fourier-Bessel serisi, yansıma tekniğiIn this study, response of a homogeneous, isotropic and linear elastic half-space, which includes twin circular cavities, is investigated when subjected to out-of-plane harmonic force. Cavities have different radius and the distance between centers of the cavities varies. Cavity centers are at the same depth. First cavities inner surfaces is subjected to out-of-plane harmonic force whereas second cavities inner surface is stress-free. By using wave function expansion method, displacement fields are expressed in terms of Fourier-Bessel series. Boundary conditions at cavity surfaces are satisfied directly when polar coordinates are used. Boundary condition at flat surface is satisfied by imaging technique. In numerical results, the effect of second cavities radius and the distance between cavity centers on circumferential stress at first cavities surface is demonstrated. Key words: Half-space, twin cavities, Fourier-Bessel series, imaging techniqu

Perceptions of Higher Education Faculty Members on Bilingual Education in Turkey

In recent years, bilingual education has been a crucial phenomenon in the educational community in Turkey. This study aims to investigate whether academics have positive perceptions towards bilingual education or not. Regarding this issue, it is important to get the opinions of academics that are responsible for training future teachers. An online scale was emailed to the academics in 74 universities in Turkey. The study utilized quantitative research methods. A total of 208 academics completed the Bilingual Education Percept"ion Scale. Their responses were graded and these grades were used in generating various analyses. Cronbach Alpha reliability analysis was implemented and the reliability coefficient of the scale was determined to be .96. The mean of academics’ scores indicates that they have shown highly positive perceptions about bilingual education. Moreover, demographic data was used as independent variable and regression analysis was performed. The findings of this study showed that academics have shown higher positive perception towards bilingual education

Estimation of broad-sense heritability for grain yield and some agronomic and quality traits of bread wheat (Triticum aestivum L.)

Twenty-five wheat genotypes (Triticum aestivum L.) were grown at three locations (Samsun, Amasya and Tokat) in the Middle Black Sea Region of Turkey in order to estimate the broad-sense heritability for grain yield and some agronomic and quality traits. Estimation of the heritability will help to identify selection parameters in our breeding programs for target environments. The heritability for grain yield, test weight, 1000-kernel weight, Zeleny sedimentation, protein content and plant height were 46.05%, 86.88%, 81.82%, 89.13%, 87.45% and 43.69%, respectively. It was found that Zeleny sedimentation was the least affected trait over environments and followed protein content, test weight and 1000-kernel weight. On the other hand, grain yield and plant height were the most affected traits across environmental conditions

Simultaneous endovascular stent and renal stent placement for acute type B aortic dissection with malperfusion of kidney

AbstractAcute aortic dissection frequently causes life-threatening organ ischemia. The optimal therapy for acute type-B aortic dissection is still controversial. Surgery for acute dissection with organ malperfusion is known to carry a high morbidity and mortality; however endovascular treatment is becoming an alternative form of treatment. We report a clinical case of emergency percutaneous thoracal aorta endovascular stenting and renal artery stenting in a patient who had renal malperfusion and acute renal failure due to acute type-B dissection. The present case is a fundamental examples of collaboration between the cardiologist and cardiovascular surgeon in a hybrid procedure

Analyzing hospital high length of stay outliers in Turkey

Purpose: The study aims to examine the length of stay (LOS) outliers by analyzing the hospital administrative database.Material and Methods: The Turkish Ministry of Health DRG grouper database was utilized to obtain hospital administrative data on discharges for 15 training and research hospitals in 2012. For each diagnosis-related group (DRG), the geometric mean plus two standard deviations were calculated to identify the outliers. According to the recent data, demographic, clinical, and DRG-specific characteristics influence LOS outliers. Analyses were conducted using descriptive statistics and logistic regression using generalized estimating equations (GEE).Results: High LOS outliers were found to be 4.4 % of the cases. Even though they made up only 4.4 percent of the patients, outliers accounted for 24.50 percent of all discharge days. The top three specific DRGs with the highest LOS outliers were neonatal cases. According to the multivariate model, alcohol, drug use disorders, burns, and ear, nose, mouth, and throat diseases influenced high LOS outliers the most. Furthermore, DRG weight, DRG type, discharge type, and age groups were other significant factors related to high LOS outliers.Conclusion: A quarter of all inpatient days are made up of LOS outliers. Burns, neonate cases, and alcohol/drug use cases should be carefully evaluated. To improve clinical quality and effectively manage hospital resources, hospital administrators and health policymakers should consider the length of stay outliers

Elastik Zemine Oturan Fonksiyonel Derecelendirilmiş Kare Bir Plağın Statik Yükler Altında Davranışı

Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Bu çalışmada, elastik zemine oturan fonksiyonel derecelendirilmiş (FD) kare bir plağın statik davranışı Ritz yöntemi ile Kirchhoff-Love plak teorisi çerçevesinde incelenmiştir. Ritz yönteminin uygulanması için plak yer değiştirme fonksiyonu kuvvet serisine açılmıştır. Sınır koşulları yer değiştirme fonksiyonuna yardımcı bir fonksiyon ilave edilmesiyle sağlatılmıştır. Çalışmada, farklı malzeme kompozisyonları, farklı sınır koşulları ve elastik zemin parametresinin plağın yer değiştirmeleri ve eksenel normal gerilmeler üzerindeki etkisi incelenmiştir.In this study, the static behavior of a functionally graded (FG) square plate resting on the elastic foundation is investigated via Ritz method within the framework of Kirchhoff-Love plate theory. In order to apply Ritz method, the trial function for the deflection of the plate is expressed in the polynomial form. Boundary conditions are satisfied by adding an auxiliary function to the trial function. The effects of various material compositions, boundary conditions and the parameter of elastic foundation on the deflection and axial normal stress of the plate are examined

Um Estudo de Campo para Determinar o Compromisso Organizacional e a Satisfação no Trabalho em Hotéis

For organizations to shape their future of Tourism industry, it is essential for them to hire and retain top talent. Therefore, in this research, the relationship between organizational commitment and job satisfaction was examined. A quantitative research method was applied to test between the variables. The questionnaire technique has been used. The data were collected from 218 employees working in five-star and four-star hotels in the city of Ankara, capital of Turkey. First, the correlation coefficients between variables were calculated. Then, T test and One Way Anova analysis were conducted to determine whether there was a difference between variables and demographic characteristics. Finally, it was found that there was a positive and significant relationship between emotional commitment, a sub dimension of organizational commitment and job satisfaction. Further results indicated there is a negative and significant relationship between job satisfaction and other sub dimensions of organizational commitment, normative commitment and continuation commitment. Key words: Organizational Commitment, Job Satisfaction, Hotel Employees, Tourism Establishments, Human Resources, Tourism.Para que las organizaciones den forma a su futuro en la industria del turismo, es esencial que contraten y retengan a los mejores talentos. Por lo tanto, en esta investigación se examinó la relación entre el compromiso organizacional y la satisfacción laboral. Se aplicó un método de investigación cuantitativa para probar entre las variables. Se utilizó la técnica del cuestionario. Los datos fueron recopilados de 218 empleados que trabajan en hoteles de cinco y cuatro estrellas en la ciudad de Ankara, capital de Turquía. Primero, se calcularon los coeficientes de correlación entre variables. Luego, se realizó la prueba T y el análisis One Way Anova para determinar si había una diferencia entre las variables y las características demográficas.  Finalmente, se encontró que existía una relación positiva y significativa entre el compromiso emocional, una subdimensión del compromiso organizacional y la satisfacción laboral. Otros resultados indicaron que existe una relación negativa y significativa entre la satisfacción laboral y otras subdimensiones del compromiso organizacional, el compromiso normativo y el compromiso de continuación.  Palabras clave: Compromiso Organizacional, Satisfacción Laboral, Empleados Hoteleros, Empresas Turísticas, Recursos Humanos, Turismo.Para que as organizações moldam seu futuro na indústria do turismo, é  essencial que contratem e retenham os melhores talentos. Portanto, nesta pesquisa, a relação entre o comprometimento organizacional e a satisfação no trabalho foi examinada. Um método de pesquisa quantitativa foi aplicado para testar entre as variáveis. Foi utilizada a técnica do questionário. Os dados foram coletados junto a 218 funcionários que trabalham em hotéis cinco e quatro estrelas na cidade de Ancara, capital da Turquia. Primeiramente, foram calculados os coeficientes de correlação entre as variáveis. Em seguida, o teste T e a análise One Way Anova foram conduzidos para determinar se havia uma diferença entre as variáveis e características demográficas. Por fim, verificou-se que existe uma relação positiva e significativa entre o comprometimento emocional, uma subdimensão do comprometimento organizacional e a satisfação no trabalho. Outros resultados indicaram que há uma relação negativa e significativa entre a satisfação no trabalho e outras subdimensões do compromisso organizacional, compromisso normativo e compromisso de continuidade.  Palavras-chave: Compromisso Organizacional, Satisfação no Trabalho, Funcionários de Hotelaria, Estabelecimentos de Turismo, Recursos Humanos, Turismo

Correlation of diffusion weighted MR imaging and ADC values of hepatic metastasis of gastrointestinal stromal and gastroenteropancreatic neuroendocrine tumors

Background: DWI and ADC-mapping was performed to analyze hepatic metastasis of GIST, GEP-NET. Objective: The objective of this study is to present hepatic metastasis of GIST and GEP-NET with Diffusion weighted MR imaging(DWI) and the Apparent diffusion coefficients (ADC) values of masses. Methods: 18 GIST patients and 8 GEP-NET patients were examined retrospectively. 11 males and 6 females were present in GIST group, 7 males to 5 females were involved in GEP-NET group. 18 primary GIST and 10 hepatic metastasis of GIST, 8 original GEP-NET and 19 hepatic metastasis of GEP-NET; total 55 GIST and GEP-NET masses were analysed by ADC mapping. MR images were acquired by 1,5 T MR units (32 mT/min gradient strength-Achieva; Philips Healthcare, Best, Netherlands and 32 channel GE Signa GE-Wisconsin-USA); by using a 4-8 channel standard phased-array torso XL coil, all images were evaluated by an Abdominal MRI experienced radiologist. DWI was performed in the transverse plane by using spin-echo-planar imaging sequence. Results: No statistical differences were observed between GIST and GEP-NET patients according to age and gender variations. No significant statistical differences were observed according to the diameters and ADC values of GIST and GEP-NET patients. A significant statistical difference was observed between GIST and GEP-NET groups in terms of size of liver metastasis which was significantly higher in GIST patients. All three groups (GIST_Hep. MET, GEP-NET_Liver_Met and normal) were statistically differed according to ADC values. With the ROC curve analysis: Hepatic metastasis of GIST(n=10) and normal liver (n:47) had cut-off value for ADC: 0.925 under AUC: 0.939 with regard to ADC values and regarded 89.4% Sensitivity, 100% Specificity, 100% PPV and 66.7% PPV. ROC curve of GEP NET_ Hepatic metastasis (n=19) group and normal liver (n:47) group presented cut-off value for ADC: 0.860 under AUC: 0.967 correlated to ADC values with 93.6% sensitivity, 89.5% specificity, 95.7% PPV and 85% PPV. Conclusion: High cellular tumors resulted from liver metastasis of GIST and GEP-NET’s, and a positive correlation was observed between ADC values and cellularity/differentiation ratios of metastatic masses