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Öğe Effect of Thermal, Acid and Alkaline Pretreatments on Biogas Production from Cattle Manure(Springer, 2024) Yilmaz, Ayhan; Baskan, Gulsah; Acikel, UnsalThis study examined biogas production from cattle manure obtained from Sivas (T & uuml;rkiye) province under anaerobic conditions. Thermal, acid, base and thermochemical pretreatment methods were applied to cattle manure to increase the biogas production rate. The biogas production rate of cattle manure was found as 150.3 mL/gsolid waste without any pretreatment in the fermentation media. Thermal pretreatments were applied at 25-180 degrees C for 60 min. The highest biogas production rate was found to be 282.6 mL/gsolid waste at 150 degrees C. By increasing the temperature to 150 degrees C, the biogas production rate increased by 88.02% compared to the normal condition. In the next stage of the experimental studies, acidic (15% H2SO4 and 15% HNO3 by mass) and basic (8N KOH and 8N NaOH) pretreatments were applied to the cattle manure. Pretreatments were carried out by adding acid and base at the rates of 5, 10, 20 and 30% of the mass of the solid material in the reactor. The highest biogas production rate was found as 235.7 mL/gsolid waste in the media containing 20% KOH. This value showed a 56.82% increase in biogas production rate compared to the normal condition media. The combined effects of temperature, acid and base on the rate of biogas production were investigated in the last section of the study. The highest biogas production rate was as 320.2 mL/gsolid waste in media containing 20% KOH at 150 degrees C. This value showed a 113.04% increase in biogas production rate compared to the normal condition media.Öğe Ethyl 2-(9-methylsulfonyl-1-oxo-2,3,4,9-tetrahydro-1H-carbazol-2-yl)acetate(BLACKWELL PUBLISHING, 2007) Ozbey, Suheyla; Karayel, Arzu; Yilmaz, Ayhan; Uludag, NesimiThe title compound, C17H19NO5S, crystallizes with two molecules per asymmetric unit; these do not exhibit the same pattern of hydrogen bonds. The indole part of the carbazole skeleton is almost planar, while the cyclohexenone ring is twisted.Öğe The evaluation of the attitudes of science teacher candidates towards chemistry lesson(HACETTEPE UNIV, 2007) Hancer, Ahmet Hakan; Uludag, Nesimi; Yilmaz, AyhanThe aim of this study is to determine the science teacher candidates' attitude towards chemistry, which is among the field lessons, and to search whether there is a relation between the attitude and the academic success. In addition, the aim is to examine the relations with gender and school status of these factors. The research has the comparison features and was realized on 147 teacher candidates studying in the Faculty of Education, Department of Science-teaching of Cumhuriyet University; in 2005-2006 school year, spring season (Semester II). "Attitude Scale towards Chemistry Lesson for the Teacher Candidates" (OAKTO) has been applied as the tool of supplying data. The analysis of Pearson's correlation coefficient has been used to determine the part of the relation between attitude points and academic success points. As a result of the study, it's observed that there are differences in respect of gender and high schools from which they graduated but in general there is an average relation between their attitude towards chemistry and their academic success level. (r=0,623 p<0,01).Öğe The Effect of the Project "Reflections from Daily Life to the Chemistry Classroom" on Pre-service Teachers' Teaching Image and Teaching Styles(Turkish Chemical Society, 2022) Bilir, Volkan; Tufan, Yüksel; Yilmaz, Ayhan; Yavuz, Soner; Sarıtaş, Davut; Şenler, Burcu; Türk, Gülseda EyceyurtThis research aims to examine the effects of online activities, which include reflections from daily life in different teaching methods and techniques, on the teaching images and teaching styles of pre-service chemistry teachers. The activities include methods such as context-based learning, argumentation, project-based learning, problem-based learning, guess-eye-explain, STEM, out-of-school learning, inquiry-based learning, mobile learning and nature of science teaching methods and techniques, which include reflections from daily life. In the 2021-2022 academic year, 34 pre-service chemistry teachers studying in the third and fourth years of chemistry teaching from seven different state university education faculties participated in the research. In this study, a pretest-posttest experimental research design without a control group, one of the quantitative research methods, was used to examine the changes in the teaching images and teaching styles of pre-service chemistry teachers towards themselves. The data were collected with the checklist created for analysis of the drawings, and the pre-service chemistry teachers participating in the research were asked to think of themselves as a teacher in the future and to draw these thoughts. For the analysis of the data obtained, the related samples t-Test from parametric tests was used. As a result of the research, it was determined that online activities, which include reflections from daily life, among the teaching methods and techniques that pre-service chemistry teachers will apply in the education-teaching process, have a statistically significant effect on their teaching images and teaching styles. While pre-service chemistry teachers had both student and teacher-centered teaching images at the beginning of the research, it was concluded that they had student-centered images at the end of the research. In addition, at the beginning of the research, pre-service chemistry teachers generally had a conceptual teaching style, but at the end of the research, it was concluded that they had exploratory teaching styles.
