Eğitim Kurumu Kaynakları, Aile Özellikleri ve Öğrenci Başarısı: Türkiye’den Ortaöğretim Kurumları Öğrenci Seçme Sınavı Örneği

The paper examines the determinants of student achievement on the secondary school entrance exam (SSEE). The data for this project were collected through a survey of 810 primaryschool graduates. The empirical work is carried out by forming a model on student achievement and three categories of school, student, and family characteristics from primary-school graduates who were successful in SSEE.Bu çalışmanın amacı, Ortaöğretim Kurumları Öğrenci Seçme Sınavı’na (OKS) katılan öğrencilerin başarısının hangi faktörlerden kaynaklandığını araştırmaktır. Veriler 810 ilkeğitim mezunuyla yapılan anket çalışması sonucu elde edilmiştir. Bu bilgilerden yararlanarak OKS’de yüksek puan alan ilkeğitim kurumu mezunlarının başarısı ile eğitim kurumu, öğrencinin ve ailenin nitelikleri arasındaki ilişki ortaya konulmaya çalışılmıştır

Some Dilemmas Regarding Teacher Training: On the Teacher’s (Not) Being a Role Model

In the research, the primary and secondary school teachers’ styles of teaching, beliefs and applications related to the teaching approach have been analyzed in terms of teaching applications. In the research, in which descriptive and qualitative analyses have been carried out, mixed method has been used. The research has been performed with totally 200 teachers consisting of 106 women, 94 men who are in charge in primary and secondary schools. In the research Anthony F. Grasha - Sherly Wetter Reichmann Learning Style scale and the constructivist learning environment scale developed by Tenenbaum, Naidu, Jegede and Austin have been used. Besides the diaries (80 diaries) written within the context of teaching applications by the 24 senior students in Faculty of Education have been analysed. Along with that the teachers have high levels of modelling, encouraging individualism, personal, advisor and counsellor teaching styles, it is seen that they have the teaching styles of information conveyor on a level higher than intermediate, and authoritative teaching style to a great extent. In the teacher candidates’ pre-service education, the differences between the existence of the role models “inappropriate” for the system or the approach and the beliefs and applications may cause the teacher candidates to suffer from some errors with regard to the role models in the education process

Fault detection based on coherence analysis for stator insulation in induction motors

Asenkron motorlar bütün endüstriyel süreçler içinde en sık kullanılan elemanlardır. Endüstriyel sistemlerin ekonomik ve daha güvenli çalışabilmeleri için arızaların erken tespit edilmesi ve izole edilmesi çok önemlidir. Bu nedenle, endüstrinin birçok alanında kritik sistemlerde öngörülü bakım amaçlı olarak durum izleme çalışmaları yapılmaktadır. Durum izleme sayesinde elde edilen verilerin kullanılması ile aniden ve plansız olarak meydana gelen kesintiler önlenebilmektedir. Bu çalışmada, asenkron motorlarda stator sargısı yalıtım arızası göz önünde tutulmuş, stator yalıtımında arıza özellikleri suni olarak yaşlandırma işlemi uygulanarak oluşturulmuş ve veriler spektral analiz yöntemi ile analiz edilmiştir. Stator yalıtım arızasının temel spektral özellikleri 5 BG gücünde bir  asenkron  motora hızlandırılmış yaşlandırma uygulanması ile elde edilmiştir. Hedefe ulaşmak üzere, tek başına akım ve titreşim işaretlerine ait verilerle yapılan spektral analizlerle sargı yalıtım arıza tanısına ait belirgin sonuçlar elde edilememiştir. Stator akımı ve titreşim işaretlerinin arasındaki koherens yaklaşımı ile ise çift harmonik değerlerinde kuvvetlenmeler olduğu belirlenmiş ve bunların stator yalıtımı arızasının göstergesi olarak kullanılabileceği belirlenmiştir. Bir motora ait akım ve titreşim verileri ile elde edilen çıkarımlar, aynı deneye tabi tutulan iki eşdeğer motora ait verilerle yapılan analizlerle de doğrulanmıştır. Moment bilgisinin stator akımı ve dolayısıyla magneto-motor kuvvet (mmk)  ile olan ilişkisine dayalı olarak titreşim işaretlerine yansıması dolayısıyla, akım-titreşim ilişkisinin daha belirleyici olacağı kararına varılmıştır. Bu çalışma, bu uygulamada 4. ve 16. harmonikler arasındaki çift harmoniklerin yalıtım arızasının en önemli imzası olduğunu göstermiştir. Anahtar Kelimeler: Asenkron motorlar, yaşlandırma işlemi, koherens, çift harmonikler, stator yalıtım arızası.Induction motors are the most frequently used components in almost every type of industrial processes. Early detection and isolation of faults that cause catastrophic system failure are crucial for more reliable and economic operation of industrial processes. For this reason, condition monitoring studies are performed for predictive maintenance purposes of the critical systems in most areas of the industry. Hence, sudden and unscheduled downtimes can be prevented by performing correct and timely maintenance activities using the information provided by condition monitoring studies. Through the statistical studies on induction motor failure distribution, it is reported that 40 % of all induction motor failures are caused by stator related faults such as insulation faults (Bonnett and Soukup, 1992). In the last two decades, the wide use of the motor drives based on the power electronics devices, caused current harmonics to occur and resulted in stator and bearing related problems. Hence, the use of motor drives creates some undesirable effects with the eventual failure of motors. In the related literature, there are several studies based on the stator degradation using the signal analysis methods for rotating machineries in recent years. Some of these investigators have reported the role of pulse-width modulated (PWM) devices on the stator winding insulation. They also indicate the effect of the even harmonics in the stator current of induction machines by using the spectral analysis approaches (Kueck, 2002; Filippetti, 2000). In this research, stator-winding insulation damage in induction motors is considered and fault features developed during the artificial aging process of the stator insulation are extracted from the collected data by the spectral analysis methods. Even harmonic effects are determined as a common feature between the phase currents and vibration signals using the coherence analysis and this feature indicates the stator insulation fault. This research is aimed to extract certain spectral features of the stator insulation damage based on an experimental study in the laboratory environment. This was determined by a signal processing application using the collected data. In order to get a database for induction motor failures from the experimental study, 5-HP, three phases, four poles induction motors are artificially aged by electrical methods. Several aging processes are performed. After each cycle of accelerated aging, the test motor was put on a motor performance test platform. From the experimental setup, high frequency data with a sampling frequency of 12 kHz were acquired and include 3-phase motor currents and voltages, rotor speed, torque, and six vibration measurements. The spectral analysis on the current signals is not so much informative. As an alternative approach, to determine the insulation failure, the cross approach which is defined between the current and vibration signals, is used. This new approach is the calculation of coherence function between the motor current and vibration signals regarding to the initial and aged cases. Hence the following functional relationship is calculated and it shows the effective harmonics with the huge amplitudes to extract the failure information related to motor insulation. Through the coherence analysis between the current signal and torque measurements for the initial and aged cases, the existence of all the harmonic components like the even and odd harmonics of the fundamental frequency at 60 Hz was clearly observed. Thereupon, the coherence application was used to reveal the relationship between motor current and vibration and then, as a result of this application, some special frequency values represented by the even harmonics of the line frequency at 60 Hz are determined at 240, 360, 480, 600, 720, 840 and 960 Hz. These even harmonics can be interpreted as the characteristic property of the insulation aging. These harmonics are present as a result of the stator current imbalances based upon the stator insulation damage occurring after the aging processes. These current imbalances act on the stator magneto motor force (mmf) and cause motor vibrations. Hence high correlated amplitudes in coherence variations as appeared in the figure 7(a) can be interpreted as indicators of the stator insulation damage. Results obtained by using time information of one of three motors have been analysed for remaining motors and similar results have also obtained for them. At the final part of the study, extracted failure features have been monitored by Artificial Neural Networks (ANN) method. Keywords: Induction motors, aging process, coherence, even harmonics, stator insulation faults

The efficacy of albendazole treatment in a patient with hydatid cyst disease of multiorgan involvement

Hydatid cyst disease, which is caused by echinococcusgranulosus still poses a serious problem in endemic areas.The disease frequently involves liver and lung. Otherorgan involvements are rare. In a 18-year old patient, bilaterallung, right ventricle of heart, liver and spleen involvementwere detected. With albendazole treatmentcyst in heart was completely disappeared, and liver cystwas found to be decreased in size. However, no declinein the number and size of cysts in lung was observed.Therefore, it was concluded that albendazole may not beeffective in pulmonary hydatid disease compared to otherorgans.Key words: Albendazole, hydatid cyst, multiorgan involvemen

The impact of trade openness on global carbon dioxide emissions: Evidence from the top ten emitters among developing countries

This study aims to analyze the relationship between carbon dioxide (CO2) emissions, trade openness, real income and energy consumption in the top ten CO2 emitters among the developing countries; namely China, India, South Korea, Brazil, Mexico, Indonesia, South Africa, Turkey, Thailand and Malaysia over the period of 1971-2011. In addition, the possible presence of the EKC hypothesis is investigated for the analyzed countries. The Zivot-Andrews unit root test with structural break, the bounds testing for cointegration in the presence of structural break and the VECM Granger causality method are employed. The empirical results indicate that (i) the analyzed variables are co-integrated for Thailand, Turkey, India, Brazil, China, Indonesia and Korea, (ii) real income, energy consumption and trade openness are the main determinants of carbon emissions in the long run, (iii) there exists a number of causal relations between the analyzed variables, (iv) the EKC hypothesis is validated for Turkey, India, China and Korea. Robust policy implications can be derived from this study since the estimated models pass several diagnostic and stability tests

The impact of trade openness on global carbon dioxide emissions: Evidence from the top ten emitters among developing countries

This study aims to analyze the relationship between carbon dioxide (CO2) emissions, trade openness, real income and energy consumption in the top ten CO2 emitters among the developing countries; namely China, India, South Korea, Brazil, Mexico, Indonesia, South Africa, Turkey, Thailand and Malaysia over the period of 1971-2011. In addition, the possible presence of the EKC hypothesis is investigated for the analyzed countries. The Zivot-Andrews unit root test with structural break, the bounds testing for cointegration in the presence of structural break and the VECM Granger causality method are employed. The empirical results indicate that (i) the analyzed variables are co-integrated for Thailand, Turkey, India, Brazil, China, Indonesia and Korea, (ii) real income, energy consumption and trade openness are the main determinants of carbon emissions in the long run, (iii) there exists a number of causal relations between the analyzed variables, (iv) the EKC hypothesis is validated for Turkey, India, China and Korea. Robust policy implications can be derived from this study since the estimated models pass several diagnostic and stability tests

Determination of factors affecting the aggregate stability in wheat cultivated field

Agregat stabilitesi değeri; toprakların yapısal gelişiminde etkili olan bir indikatördür. Topraklar yapısal olarak farklılıklar göstermektedir ve bu yapısal farklılıklar çeşitli faktörler ile uyarılmaktadır. Toprak kil çeşitliliği ve miktarları, CaCO3 içerikleri, katyon değişim kapasitesi, kolloidal demir ve alüminyum oksitler, mikroorganizmalar, ıslanma-kuruma, donma-çözülme ve toprak işleme, toprak yapısının oluşmasında başlıca faktörlerdir. Toprakların yapısal oluşumunda bu faktörlerin etkileri birbirinden oldukça farklıdır.Yapılan bu çalışmanın amacı; Konya ili Çumra ilçesinde Alibey serisi olarak tanımlanmış toprakların agregat stabiliteleri ile buna etki eden faktörler arasındaki ilişkiyi açıklamaktır. Bu amaçla 0-20 cm derinlikten alınan 27 adet toprak örneği çeşitli fiziksel ve kimyasal analizlere tabi tutulmuş ve bulunan sonuçlar istatistiki olarak değerlendirilmiştir. Toprakların tekstürü kil (C), killi tın (CL) ve kumlu killi tın (SCL) sınıfında yer almakta, agregat stabilitesi değerleri ise %5,91 ile %41,40 arasında değişmektedir. Çalışma alanı topraklarının agregat stabilitesi ile tekstür, organik madde, kireç, Ca, Mg, Na ve K değerleri arasında istatistiksel olarak önemli ilişkiler bulunmuştur. Söz konusu topraklarda agregasyonu artırmak için toprak üzerinde mekanizasyon faaliyetlerin minimum düzeyle sınırlandırılması, organik madde miktarının arttırılması ve toprak agregasyonuna olumsuz etkisi olabilecek her türlü faaliyetin azaltılması gerekmektedir.Aggregate stability is an index of the structural stability of the soil. Soil show differences in structural formation and these structural differences are induced by different factors. Soil clay variety and amounts, CaCO3 contents, cation exchange capacity, colloidal iron and aluminiumoxides, microorganims, wetting-drying, freezing-thawing and soil cultivation are the main factors in the formation of the soil structure. Furthermore effects of these factors on the structural formation of soils are quite different from each other.The aim of this study was to determine the effects of some soil properties on aggregate stability in Konya-Çumra plain (Alibey serie). For this purpose soil samples were collected from 27 points and 0-20 cm depth. The samples were analyzed for some soil parameters such as aggregate stability and particle size distribution, organic matter, CaCO3, Ca, Mg, Na, K contents using standard routine laboratory tests. The textures of the soil samples were found to be C, CL and SCL. The soil aggregate stability ranged from 5,91 to 41,40 %. The result indicated that particle size distribution, organic matter, CaCO3, Ca, Mg, Na, K contents significantly affected aggregate stability. As a result, it is required to increase the organic matter content and to reduce the agricultural practices to the minimum tillage in order to increase aggregate stability in the research soils

Investigation of the Distribution of Fetal Nasal Bone Percentile Values in First-Trimester Fetal Anomaly Screening

INTRODUCTION: We aim to determine the fetal nasal bone length (NBL) percentile values that can be used in the prediction of the fetal anomaly at 11-14 weeks of gestation in a low-risk population. METHODS: Our prospective and cross-sectional study included four hundred and eighty-six singleton pregnancies who applied for the first-trimester aneuploidy screening test at 11-14 weeks of gestation. We excluded pregnant women with fetal structural or chromosomal anomaly, nuchal translucency >3mm, an absent nasal bone, and in utero fetal death. Reference and percentile values of the NBL were calculated separately for 11,12,13,and 14. gestational weeks. RESULTS: Standard NBL measurements were performed in 486 pregnancies according to inclusion and exclusion criteria. Median NBL values were computed for each gestational age (GA), for 11,12,13 and 14. weeks of gestation was found 1.6mm (range=1.1-2.5), 1.8mm (range=1.1-3.0), 2.0mm (range=1.4-3.1), and 2.2mm (range=1.7-2.8), respectively. A positive significant correlation was found between NBL and the crown-rump length (CRL) (NBL (mm) = [0.02xCRL(mm)] + 0.73, r=.483; p<.001). The 5th percentile of NBL for GA was calculated, for 11,12, 13, and 14. weeks of gestation was found 1.2mm,1.4mm,1.5mm, and 1.7mm respectively. DISCUSSION AND CONCLUSION: We revealed the reference value of NBL for each gestational week in the first trimester of the low-risk population. The data obtained in our study can be used in the screening of genetic syndromes, especially Down syndrome, associated with nasal bone hypoplasia. Our reference value of NBL for the first trimester in singleton pregnancy varies from both previous racial and ethnic groups studies, and other Turkish studies

Elementary and middle school students’ school attitudes and extracurricular activities

The study aims to determine elementary and middle school students’ school attitudes. A school attitudes measurement tool was used in the study. The participants of the study comprised 410 students. The results of the current study show that willing participation in school activities affects school attitudes. The results also show that with increasing grade level, the rate of willing participation drops. It was also found that there is a significant correlation with participation in extracurricular activities. The school attitudes mean score of students willingly participating in extracurricular activities is significantly higher than that of students participating involuntarily