EXAMINING THE ATTITUDE CHANGE OF PRE-SERVICE ELEMENTARY SCHOOL TEACHERS TOWARDS A COURSE OF MATHEMATICS EDUCATION WITHIN THE FRAMEWORK OF THEORY OF DIDACTICAL SITUATIONS

This study investigated whether the training program given within the framework of the Theory of Didactical Situations (TDS) within a mathematics education course could change the pre-service elementary teachers’ attitudes towards a mathematics education course in an 11-week teaching process. In the study, the mixed method was used. The participants were 86 pre-service elementary teachers (52 female and 34 male). In the study, the quantitative research data were collected using the Attitude Scale for Mathematics Education Courses (ASMEC), and the qualitative data were collected using semi-structured interviews. For the analysis of the quantitative data, paired samples t-test was applied, and for the analysis of the qualitative data, content analysis was conducted. The results revealed that the training program given in line with TDS created a statistically significant difference between the pre-test and post-test scores of the pre-service elementary school teachers with respect to their attitudes towards courses of mathematics education (t(85)=-2.22, p=.029) and that there was no statistically significant difference in terms of gender, though (t(84)=.987, p=.327 and t(84)=1.108, p=.258). It was found that the training program given in accordance with TDS had a positive influence on changing and developing the attitudes of the pre-service elementary teachers towards mathematics education courses

Examining mobile game experiences of prospective primary school teachers and their game designs about teaching math

In this study, we aimed at introducing to prospective primary school teachers how to present a pattern of numbers through designing a mobile game according to the Theory of Didactical Situations (TDS). Additionally, the games developed by teacher candidates were examined. In our study, the case study method was used, which is one of the qualitative research methods. The participants were 17 prospective primary school teachers (9-females, 8-males). The data were collected through video cameras, audio recorders, and files that include game designs of prospective teachers. In data analysis, the actions concerning mobile gaming experiences of prospective teachers were conducted according to the TDS stages.  The games designed by prospective teachers were examined in terms of basic gamification criteria. Findings of the study; it was demonstrated that mobile games designed according to TDS support the prospective teachers in many aspects, such as developing a milieu for using gamification in teaching math, internalizing processes of reflecting gamification criteria to the game, and positively influencing the affective characteristics. Moreover, concerning gamification criteria, it was determined that some prospective teachers are successful at gamification of mathematical knowledge; however, most of them have difficulties in game designing, particularly in giving feedbacks about games. In this study, we aimed at introducing to prospective primary school teachers how to present a pattern of numbers through designing a mobile game according to the Theory of Didactical Situations (TDS). Additionally, the games developed by teacher candidates were examined. In our study, the case study method was used, which is one of the qualitative research methods. The participants were 17 prospective primary school teachers (9-females, 8-males). The data were collected through video cameras, audio recorders, and files that include game designs of prospective teachers. In data analysis, the actions concerning mobile gaming experiences of prospective teachers were conducted according to the TDS stages.  The games designed by prospective teachers were examined in terms of basic gamification criteria. Findings of the study; it was demonstrated that mobile games designed according to TDS support the prospective teachers in many aspects, such as developing a milieu for using gamification in teaching math, internalizing processes of reflecting gamification criteria to the game, and positively influencing the affective characteristics. Moreover, concerning gamification criteria, it was determined that some prospective teachers are successful at gamification of mathematical knowledge; however, most of them have difficulties in game designing, particularly in giving feedbacks about games. 

Biodegradation of 2,4,6-Trinitrotoluene (TNT) with Bacteria Isolated from TNT-polluted Waste Pink Water

In this study, bacterial strains that can use TNT as a nitrogen source isolated from TNT contaminated pink water. We isolated 5 bacterial strains and the isolated bacteria were cultured in medium containing TNT and TNT degradation capacities of isolates were determined by spectrophotometric analysis. According to the results of the analysis that have done, 3 bacterial isolates that have high TNT degradation capacity were selected and the isolates were identified with firstly Gram-staining then with 16S rRNA sequence analysis method. According to the sequence of 16S rRNA, water isolates were identified as Stenotrophomonas maltophilia (SU K2), Klebsiella pneumoniae (SU K3), Raoultella planticola (SU K4). During the TNT degradation studies, at the end of 24 h incubation time, in the medium containing 100 mg/L TNT, TNT degradation rate for SU K2, SU K3 and SU K4 were determined 70 %, 96 % and 93 % respectively. 4-aminodinitrotoluene and 2-aminodinitrotoluene accumulations were detected in the culture medium of all isolates as intermediate products formed during the degradation of TNT by HPLC analysis. Additionally, nitrite accumulation was detected in the culture medium of all isolates and the influence of temperature and pH on the degradation of TNT was also investigated. It was determined that SU K2 isolates have the highest TNT degradation capacity at 35 °C, the others have at 30 °C and all isolates degraded TNT fastest at pH 7. The results of the study show that the new isolates can be useful for the removal of TNT in a wastewater treatment system

A Novel Design and Structural Analysis of Spring Landing Gear for Unmanned Air Vehicles

Aircraft are subjected to an impact load during landing. This situation becomes more important for unmanned aerial vehicles that are remotely controlled and must serve in extreme conditions. Because the landing gear should absorb this impact load as much as possible and prevent damage to the unmanned aerial vehicle body and its components. In this study, a landing gear design was developed for unmanned aerial vehicles that can absorb more impact load during landing. Numerical analyzes were performed to determine the fa-tigue life and the maximum impact load that the developed design could withstand. In addi-tion, a conventional landing gear was modeled and the results were compared. The properties of 7075-T6 Aluminum alloy were used as the landing gear material. As a result of the finite element analyzes made with Ansys software, it had been understood that the newly designed landing gear could absorb more energy than the conventional landing gear. It had also been determined that it could be used at values up to 3700N impact loa

The modeling of the vertical interference test and parameter estimation

Bu çalışmada, düşey yöndeki geçirgenlik değerlerinin belirlenmesine de olanak tanıdığı için endüstride yaygın kullanım alanı bulan bir kuyunun farklı noktalarında yerel olarak yapılabilen düşey girişimli basınç-zaman seti verilerinden (örneğin çoklu-prob ve paker-prob testleri) kayaç özelliklerinin belirlenmesi problemi üzerinde durulmuştur. Yatay ve düşey yöndeki heterojenlikten etkilendiği bilinen düşey girişim testi basınç verilerinin yatay ve düşey yöndeki heterojenliğin çözümlenmesinde ne derece etkili olduğu bu çalışmada araştırılmıştır. Bunun için, düşey girişim testleri bu çalışmada geliştirilen üç boyutlu (3-B) r-q-z tek-fazlı sayısal akış simülatörü ile modellenmiştir. Bu sayısal simülatöre ters problem metodolojisi üzerine kurulu doğrusal olmayan parametre tahmin yöntemi entegre edilmiştir. Doğrusal olmayan parametre tahmini, gradyent temelli Levenberg-Marquardt algoritması kullanılarak gerçekleştirilmiştir. Bu çalışmada geliştirilen model kullanılarak, sentetik olarak tasarlanmış bir paker problu ve bir çoklu problu düşey girişim testinin analizi sunulmuştur.  Anahtar Kelimeler: Düşey girişimli basınç testi, heterojen kayaç özellikleri, rezervuar simülasyonu, doğrusal olmayan parametre tahmini.  In this study, determining heterogeneity in rock properties from vertical (multi- probe and packer-probe formation test) interference pressure data sets, which has a widespread usage in the industry for allowing particularly the determination of vertical permeabilities along the wellbore, was investigated. It is known that spatial pressure data sets of the vertical interference test contain information about heterogeneity in rock properties in both lateral and vertical directions. Thus, it was examined to what degree the heterogeneity in lateral and vertical directions can be resolved from vertical interference tests. Therefore, vertical interference tests were modeled with a three dimensional (r-q-z) single-phase flow simulator developed in this study. The simulator was extensively verified by comparing its results with analytical solutions given in the literature and with the results of commercial simulator ECLIPSE 100, for a variety of cases. Non-linear parameter estimation capability based on this inverse problem theory has been integrated into this 3-D simulator to solve non-linear parameter estimation problem. Non-linear parameter estimation is achieved by using the well-known gradient-based Levenberg-Marquardt algorithm. The use of three different methods (finite difference, gradient simulator, and adjoint) for efficiently computing sensitivities coefficients required in the Levenberg-Marquardt algorithm has been investigated. Synthetic examples of multi-probe and packer-probe vertical interference test were shown by using model developed in this study.Keywords: Vertical interference pressure test, heterogeneous rock properties, reservoir simulation, non-linear parameter estimation

Demir yükü artmış karaciğerde i̇nce i̇ğne aspirasyon sitolojisi (IIAS) ve tru-cut biyopsisi: deneysel bir çalışma

Objective: Fine needle aspiration cytology (FNAC) is safer, simpler, faster and cost effective, compared to tru-cut biopsy, and patient compliance is generally better. There is not much data on the use of FNAC, which is used in many organs and lesions, in parenchymal diseases in the liver. Therefore, in this study, the benefit of FNAC in showing iron deposition and injury of liver is evaluated. Methods: There were 2 control groups in the study. At the end of the study, FNAC and tru-cut biopsy samples were taken from these groups, where no administration was performed. FNAC and tru-cut biopsy procedures were also performed to the study groups after the iron overload was created by intraperitoneal iron dextran (88 mg/kg) administration for 28 days. Hepatocyte injury, inflammation and iron deposition were evaluated histopathologically in the preparations. The sensitivity, specificity, positive and negative predictivity and diagnostic accuracy of both methods were calculated based on the hepatectomy material. Results: In hepatocyte injury; sensitivity (60%), diagnostic accuracy (66.7%) and negative predictivity (50%) were found to be significantly higher in tru-cut group. It was observed that the methods were not superior to each other in the evaluation of inflammation, and FNAC almost approached tru-cut biopsy rates (100%) with a sensitivity of 83.3% and diagnostic accuracy in iron deposition. Conclusion: In iron-induced liver damage, the gold standard should be tissue examination, so tru-cut biopsy must be the first choice. However, based on the present study results, it is suggested that FNAC may be preferred over more invasive options in cases where tru-cut biopsy can not be used in terms of susceptibility to bleeding, situations where surgical accessibility is not available, patient orientation and cooperation is poor, or in presence of different accompanying diseases

Prenatal radiation exposure

Pregnant women may be exposed to nonionizing, ionizing radiation and contrast media via diagnostic or therapeutic procedures and workplace exposure. When computed tomography or magnetic resonance imaging is performed on a pregnant woman, the effects of exposure to radiation, high magnetic fields and contrast media, which can be risky for a fetus, should be considered. Nonionizing radiation that is not significantly risky for a fetus includes microwave, ultrasound, radio frequency and electromagnetic waves, while ionizing radiation that can be teratogenic, carcinogenic or mutagenic includes particles and electromagnetic radiation. The effects of radiation are associated with the level of exposure and stage of fetal development. Organogenesis (two to seven weeks after conception) and the early fetal period (eight to fifteen weeks after conception) are the most sensitive stages for a fetus. Noncancerous health effects have not been determined at any stage of gestation with less than 50 mGy (5 rad) exposure dose of ionizing radiation. Higher exposure levels may lead to spontaneous abortion, growth restriction, and mental retardation. The risk of cancer is increased regardless of the dose. Although the use of iodinated contrast media is generally thought to be safe during pregnancy, the risk of fetal hypothyroidism should be considered and it should be used only when necessary. The use of gadolinium-based contrast media during pregnancy is controversial because of the lack of clinical data. The purpose of this article is to review the existing literature regarding the prenatal radiation exposure and to discuss fetal risk of radiation

QT and JT dispersion in children with familial mediterranean fever

Objectives: This study aims to determine QT dispersion and JT dispersion, and their relationship with conventional echocardiography values in a group of children with familial Mediterranean fever (FMF). Patients and methods: The study included 48 FMF patients (26 males, 22 females, mean age 11.10±3.42 years; range 5 to 18 years) as the FMF patients and 31 healthy children (17 males, 14 females, mean age 9.61±2.83 years; range 5 to 17 years) as the healthy controls. Electrocardiography and conventional echocardiography were performed on the FMF patients and healthy controls. Both groups were evaluated with a standard 12-lead electrocardiography. QT, JT and RR distances were measured in both groups. The corrected QT (QTc) and corrected JT (JTc) were calculated. QTcd and corrected JT dispersion (JTcd) were detected. Results: There was no statistically significant difference between the FMF patients and healthy controls in terms of RR, QT, QTd, QTcd, JT, JTc, JTd, and JTcd measurements and echocardiography parameters. QTc value was higher in the FMF patients than the healthy controls. Conclusion: QTc value indicates increased ventricular sensitivity and is an important marker of cardiovascular mortality. It has an important effect on sudden cardiac death and arrhythmia. Our study results suggest that electrocardiographic monitoring may be useful in patients with FMF

Microstructure and physical properties of clayey-ceramic materials with lightweight mineral additives

Low density ceramic structures have an important place in application areas such as heat, noise and noise insulation. Besides, being durable and inexpensive is also a demand for producers and consumers. In this study, it is aimed to produce lightweight insulation ceramic materials from a binder clay containing diatomite and vermiculite raw materials in different proportions which is a local and natural mineral raw material source for low temperature applications. For this purpose, firstly, powdered raw materials is characterized for particle size distribution, chemical composition (x-ray fluorescence, XRF), thermal behavior (thermal gravimetric analysis, TGA), morphological structure (scanning electron microscope, SEM) and crystal phase structure (x-ray diffraction, XRD). Specific prescriptions were then prepared and pellet samples were obtained using the pressing method. The bulk density and porosity, dimensional changes, thermal conductivity coefficients and microstructural properties of the samples fired at temperatures between 900, 1000 and 1100 °C were compared. As a result of the study, the porosity of the ceramic samples containing 60% diatomite, 10% vermiculite and 30% binder clay increased up to 47%, while the bulk density values were obtained at 1.3 g/cm3 and the thermal conductivity coefficient was at 0.439 W / mK

Split-bolus MR urography: synchronous visualization of obstructing vessels and collecting system in children

Several vascular abnormalities related with urinary system such as crossing accessory renal vessels, retroiliac ureters, retrocaval ureters, posterior nutcracker syndrome, and ovarian vein syndrome may be responsible for urinary collecting system obstruction. Split-bolus magnetic resonance urography (MRU) using contrast material as two separate bolus injections provides superior demonstration of the collecting system and obstructing vascular anomalies simultaneously and enables accurate preoperative radiologic diagnosis. In this pictorial review we aimed to outline the split-bolus MRU technique in children, list the coexisting congenital collecting system and vascular abnormalities, and exhibit the split-bolus MRU appearances of concurrent urinary collecting system and vascular abnormalities