The effects of post-deposition annealing conditions on structure and created defects in Zn0.90Co0.10O thin films deposited on Si(100) substrate

We analyze the effect of post-deposition annealing conditions on both the structure and the created defects in Zn0.90Co0.10O thin films deposited on the Si (100) substrates by RF magnetron sputtering technique using home-made targets. We concentrated on understanding the homogeneity of substituted Co+2 ions and the annealing effects on the amount of defects in the ZnO lattice. Orientations of thin films are found to be in the [0002] direction with a surface roughness changing from 67±2 nm to 25.8±0.6 nm by annealing. The Co+2 ion substitutions, changing from 7.5±0.3 % to 8.8±0.3 %, cause to form Zn–O–Co bonds instead of Zn–O–Zn and split the Co2p energy level to Co2p1/2 and Co2p3/2 with 15.67±0.06 eV energy difference. In addition, the defects in the lattice were revealed from the correlations between Zn–O–Co bonds and intensity of Raman peak at around 691 cm-1. Furthermore, the asymmetry changes of O1s peak positions in X-ray Photoelectron Spectra (XPS) were also found to be in accordance with the Raman results

A rare case of clostridium difficile infection-associated reactive arthritis

Clostridium difficile is an uncommon cause of reactive arthritis in children. We herein present a rare case of C. difficile infection-associated reactive arthritis (CDIAReA) in a child, who developed severe diarrhea and a knee effusion following a course of oral antibiotic treatment. Our report emphasizes that CDIAReA should be considered in the differential diagnosis of children presenting with acute and painful arthritis that develops in the setting of antibiotic associated diarrhea. © 2018 by Pediatric

The Role of Mathematical Modeling in STEM Integration and Education

With the rapidly developing technology, the labor force of the society has changed direction, and in the age of informatics, creative engineering applications have come to the forefront. Accordingly, the education levels of the labor force were also changed. The science, technology, engineering, and mathematics (STEM) education model in most countries aims to teach science, mathematics, technology, and engineering in relation to primary, secondary, high school, and higher education. STEM education, which has an impact in our country in recent years, has an important role in acquiring new skills, supporting creativity, innovation, and entrepreneurship, gaining the ability to transition between professions and adapting to new occupations. Nowadays, technology is expected to have different skills from individuals who will work in different fields with rapid development. Also, different teaching strategies play a major role in STEM integration and training. One of them, mathematical modeling, is the process of analyzing real-life or realistic situation using mathematical methods in the most general sense. The idea that mathematical modeling cycles should be used in STEM education at all levels from primary to tertiary education has gained importance in recent years, since it increases the students’ motivation towards the lesson and they learn better by concentrating their attention

An in vitro evaluation of the efficacy of a novel iontophoresis fluoride tray on remineralization

Objectives: The aim of this study is to determine the effects on remineralization of a novel iontophoresis device called "Fluorinex", conventional (acidulated phosphat fluoride) APF gel treatment, and conventional ionthophoresis device comparatively by laser fluorescence measurements. Study Design: Artificial incipient carious lesions were created on immature, 60 intact premolar and molar teeth with no defects. The specimens were randomly allocated to four groups. In the first group 1.23% APF gel was applied to specimens by conventional method for 4 minutes and in the second group 2% (sodium fluoride) NaF solution applied by conventional iontophoresis device for 4 minutes. In Fluorinex group specimens were pretreated with (copper chloride) CuCl 2 for 1 minute and then treated for 4 minutes with 1.23% APF gel in a Fluoritray. Control group was placed in distilled water for 4 minutes. After these applications all specimens were included to a pH cycling. DIAGNOdent pen measurement were obtained in three different time intervals; after incipient carious lesions, after fluoride treatments and after pH cycling. Specimens were studied by SEM(scanning electron micros - copy) after artificial caries lesions and fluoride treatments. Results: Alterations on DIAGNOdent pen measurements before and after treatment, the Fluorinex group was sta - tistically different from conventional APF gel ( p =0.011), conventional NaF iontophoresis ( p <0.001) and control group ( p <0.001). As the DIAGNOdent pen measurements before treatment and after pH cycling were compared, differences were statistically significant in Fluorinex and conventional APF gel groups ( p <0.001). Conclusions: The results of this in vitro study has shown that fluoride application by Fluorinex was superior to the conventional APF gel application and NaF iontophoresis on incipient carious lesions

Students’ View of the Problems Faced with the Measurement and Evaluation System in the Primary School Mathematics Education System

AbstractThe main purpose of this study is to determine the problems that have been encountered in assessment and evaluation system of mathematics examinations in primary school learners’ 6th, 7th and 8th grade students in the North Cyprus. Unstructured interviews were collected from 14 students who were studying in the 6th, 7th and 8th year of primary school. A qualitative research design was used to examine the student beliefs about evaluation and testing mathematics examinations. According to the findings, it showed that the lack of time devoted to mathematics examinations that teachers prepared for their students were insufficient. Students indicated that the scoring system and exam questions were inadequate. Exam questions were highly difficult with respect to the lecture given in the class and education program. Also, bonus points were not given in the examinations and exam papers not fairly scored by mathematics teacher, that because of the assessment and evaluation system

Effect of antibacterial agents on the surface hardness of a conventional glass-ionomer cement

In atraumatic restorative treatment (ART), caries removal with hand excavation instruments is not as efficient as that with rotary burs in eliminating bacteria under the glass ionomer cements (GICs). Thus, different antibacterial agents have been used in recent studies to enhance the antibacterial properties of the GICs, without jeopardizing their basic physical properties. OBJECTIVE: The objective of this study was to evaluate the effect of antibacterial agents on the surface hardness of a conventional GIC (Fuji IX) using Vickers microhardness [Vickers hardness number (VHN)] test. MATERIAL AND METHODS: Cetrimide (CT), cetylpyridinium chloride (CPC) and chlorhexidine (CHX) were added to the powder and benzalkonium chloride (BC) was added to the liquid of Fuji IX in concentrations of 1% and 2%, and served as the experimental groups. A control group containing no additive was also prepared. After the completion of setting reaction, VHN measurements were recorded at 1, 7, 15, 30, 60, and 90 days after storage in 37°C distilled water. A one-way ANOVA was performed followed by a Dunnett t test and Tamhane T2 tests and also repeated measurements ANOVA was used for multiple comparisons in 95% confidence interval. RESULTS: VHN results showed significant differences between the control and the experimental groups at all time periods (

Ecoles préparatoires attitudes envers les médias sociaux pour apprendre l'anglais

The aim of this study is to analyse the attitude of preparatory school students towards social media in learning English in terms of different variables. In this study, the survey method, which is one of the types of qualitative research, was used. The study group comprised 220 beginner and intermediate-level students studying at the Preparatory School of Near East University. An attitude scale for the attitudes towards social media in learning English, which was devised by the researchers used to collect data for the research. Consequent to the study, it was observed that the students who took part in the study used social media sites frequently in order to improve their foreign language by watching TV programmes, series and videos in English language as well as to find about English words which they are not familiar with. It was also stated that the social media application used most frequently by the students was “Facebook”. It was finally found out that the attitude of the students towards social media in learning English was positive and it is independent of gender, having a social media account and web page, the frequency of using social media environments and the time spent online.Le but de cette étude est d'analyser l'attitude des élèves des classes préparatoires envers les médias sociaux pour apprendre l'anglais en fonction de différentes variables. Dans cette étude, la méthode d’enquête, qui est l’un des types de recherche qualitative, a été utilisée. Le groupe d’étude comprenait 220 étudiants débutants et intermédiaires de l’école préparatoire de l’Université du Proche-Orient. Une échelle d'attitude pour les attitudes vis-à-vis des médias sociaux dans l'apprentissage de l'anglais, qui a été conçue par les chercheurs et utilisée pour collecter des données pour la recherche. Suite à l’étude, il a été observé que les étudiants qui participaient à l’étude utilisaient fréquemment des sites de médias sociaux afin d’améliorer leur langue étrangère en regardant des programmes télévisés, des séries et des vidéos en langue anglaise, ainsi que de rechercher des mots anglais ils ne sont pas familiers avec. Il a également été déclaré que l’application de média social utilisée le plus souvent par les étudiants était «Facebook». Il a finalement été découvert que l’attitude des étudiants à l’égard des médias sociaux dans l’apprentissage de l’anglais était indépendante du sexe, qu’elle disposait d’un compte et d’une page Web sur les médias sociaux, de la fréquence d’utilisation des environnements de médias sociaux et du temps passé en ligne

RBF solution of MHD stokes flow and MHD flow in a constricted enclosure

This paper presents the radial basis function (RBF) approximation for the numerical solution of Stokes and Navier-Stokes equations in a constricted enclosure under the effect of magnetic field with different orientations. RBFs are used for the approximation of the particular solution which becomes also the approximate solution of the problem satisfying the boundary conditions. Numerical results are obtained for several values of Hartmann number and constriction ratio. As the strength of the horizontally applied magnetic field increases, Stokes flow extends covering the whole pipe. Applied magnetic field in the pipe-axis direction generates the electric potential exhibiting behavior similar to streamlines. When the constriction ratio increases, flow squeezes through the left wall regardless of the direction of the magnetic field.Publisher's Versio