A RESEARCH ON FACTORS AFFECTING DISTANCE EDUCATION SATISFACTION OF UNIVERSITY STUDENTS IN THE COVID-19 PROCESS

The aim of this study is to determine the factors affecting students' satisfaction and the problems they experience regarding distance education, which is mandatory in higher education due to the coronavirus. The research was designed as an explanatory and cross-sectional quantitative research. The population of the study consists of 3334 students studying at a vocational school affiliated to a public university and an independent vocational school. In the study, convenience sampling method was used and 1234 students voluntarily participated in the study. SPSS program was used in the analysis of the research data, and frequency analysis, exploratory factor analysis, reliability analysis, correlation and regression analysis were performed, respectively. The open-ended question was analyzed with the descriptive analysis technique, one of the qualitative analysis methods. As a result of the research, it was revealed that the technical dimension, advantages, and independent learning style of distance education positively affected the satisfaction of distance education, while the disadvantages of distance education affected the satisfaction of distance education negatively. In addition, it was unearthed that students experienced difficulties in three dimensions as technical, educational, and social in the distance education process

FINITE-ELEMENT MODEL OF THE INDENTATION FOR YBCO-BASED SUPERCONDUCTOR THIN FILMS

Superconducting films with poor mechanical properties are useless even if they possess good transport and flux-pinning properties. Since additive particles as pinning centers are important changes in a microstructure, their effect on the micromechanical properties such as Young's modulus and hardness have to be investigated with respect to the additional-particle type and quantity, using experimental and numerical methods. In this study, films were dip-coated onto (001) SrTiO3 (STO) single-crystal substrates with metalorganic deposition using the trifluoroacetate (TFA-MOD) technique. The phase analysis and the microstructure of the superconducting thin films were determined with an X-ray diffractometer (XRD) and a scanning electron microscope (SEM). The mechanical-property variations of the pure YBCO and the YBCO thin films with Mn (reacting as BaMnO3) were experimentally obtained with nanoindentation techniques. Thus, the BaMnO3 nanoparticle effects on the structural and mechanical properties of the films were observed. According to the nanoindentation results, the Young's modulus and indentation hardness of the films decreased from 88.54 GPa to 76.47 GPa and from 12.51 GPa to 3.88 GPa, respectively, depending on the additive particles. In addition, the finite-element modeling (FEM) of the indentation was applied to estimate the failure stress/stress distribution relation at the contact region between the indenter and the surface of a YBCO-based thin film, obtaining the same force/penetration depth curve as with the indentation experiment. According to these main aims of FEM, the mesh-design effect, material properties and the boundary condition of the axisymmetric model were chosen and optimized to obtain the mechanical results of the instrumented indentation