In a recent works Liu and Wang (2008; 2007) study the Mannheim partner curves in the three dimensional space. In this paper, we extend the theory of the Mannheim curves to ruled surfaces and define two ruled surfaces which are offset in the sense of Mannheim. It is shown that, every developable ruled surface have a Mannheim offset if and only if an equation should be satisfied between the geodesic curvature and the arc-length of spherical indicatrix of it. Moreover, we obtain that the Mannheim offset of developable ruled surface is constant distance from it. Finally, examples are also given.

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This study aims to provide information about the Q Concept defined as the division of journal impact factors into quartiles based on given field categories so that the disadvantages resulting from the direct use of journal impact factors can be eliminated. While the number of "Original articles published in the Web of Science (WoS) database-indexed journals like SCI, SSCI and A&HCI" is an important indicator for research assessment in Turkey, neither the journal impact factors nor the Q Concept of these papers have been taken into account. Present study analyzes the scientific production of the Amasya University researchers in journals indexed in WoS database in the period 2014-2018 using the Q concept. The share of publications by Q category journals as well as the average citations received by the works from Amasya University were compared to the average situation in Turkey and other different countries in the world. Results indicate that the articles published by Amasya University researchers were mostly published in low impact factor journals (Q4 journals) (36.49%), in fact, only a small share of papers were published in high impact journals (14.32% in Q1 journals). The share of papers published in low impact journals by researchers from Amasya University is higher than the Turkish average and much higher than the scientific leading countries. The average citations received by papers published in Q1 journals was around six times higher than papers published in Q4 journals (8.92 vs. 1.56), thus papers published in Q1 journals received 30.02% citations despite only 14.32% of the papers was published in these journals. The share of papers published which were never cited in WoS was 27.48%, increasing from 9.68% in Q1 to almost half (48.10%) in Q4. The study concludes with some suggestions on how and where the Q Concept can be used.

This study aims to reveal the bibliometric characteristics of publications on educational research from diverse perspectives, including the level of national-international collaborations, the percentage change in open-access papers, and interactions with other disciplines. Through bibliometric analysis, the data were collected from Web of Science (WoS), “Education and Educational Research (E&ER),”“Psychology, Educational (PE),”“Education, Special (ES)” and “Education Scientific Disciplines (ESD)” categories, during 2011 to 2020. The findings suggest that the number of publications in each category and the percentage of open-access publications have increased regularly. However, it was observed that categories, especially the ES category, were partially falling behind, as compared to the growth in WoS; while the ES and the PE categories were the highest regarding national-international collaborations over time. Both collaboration levels were the highest in the E&ER category. It was concluded that the multi-authorship trend has rapidly increased, the number of references has regularly increased, and specifically, the PE category has been distinguished from others in terms of the references used. Meanwhile, the change over time in the aggregate impact factor, calculated for each category as a measure of the widespread impact of the studies, pointed to inflation. The results show that educational research is becoming more organized and international, while less fragmented. Moreover, the findings support that educational research is interdisciplinary in essence and diverse in content.

In order for a community to continue one's existence, it is necessary to instill the basic values to its children. This instillation can be accompanied by a teacher in a school environment, or in a child's out-of-school working environment, even unconsciously while working with a book. Therefore, the values in the textbooks gain importance. In this research, it is aimed to examine the 5th grade mathematics textbook in terms of values in mathematics teaching program. These values are justice, friendship, honesty, self-control, patience, respect, love, responsibility, patriotism and helpfulness. Qualitative research method was adopted in the study and data were collected by document analysis. Descriptive analysis technique was used to analyze the data. According to the results, the most frequently mentioned values are self-control, fairness, helpfulness and responsibility, and the least mentioned are values of friendship, honesty, patriotism, respect and love. The distribution of values according to the units was found to be irregular and descriptive analyzes were given in detail with examples.