Investigation the effectiveness of laboratory works related to “acids and bases” on learning achievements and attitudes toward laboratory

AbstractThis study aims to investigate the effectiveness of laboratory works related to ‘Acids and Bases’ over teacher centred traditional approach on high school students’ learning achievements and attitudes toward chemistry laboratory. The effects of laboratory works were assessed by the participations of 108 10th grade students from four classes in two high schools, which were were randomly assigned to experimental (NE-1=21, NE-2=32) and control (NC-1=24, NC-2=31) groups. Before the instruction, the pre-test (KR-20=0.81), applied on all the students to identify their prior knowledge about the basic subjects to learn ‘Acids and Bases’, and no significantly differences were found between experimental and control groups in each school (p>0.05). While the subject of “Acids and Bases” was taught supported with laboratory experiments in the experimental groups, traditional approach was used in the control groups. The results of the post-test (KR-20=0.77), applied after the instruction, indicated that students, who performed experiments was significantly higher mean scores than those of control groups (p<0.05). Students’ pre and post-attitudes towards chemistry laboratory were assessed by using Attitude toward Chemistry Laboratory Scale (α=0.87), and found that mean scores of the experimental groups significantly increased from 77.29 to 96.00 and from 80.03 to 97.66 (p<0.05). Students’ answers to the scale were analysed in four dimensions as (i) Laboratory environment and using equipments; (ii) Experimental process in the laboratory; (iii) Assessment in the laboratory and (iv) Cooperative learning in the laboratory, and significantly increases in the mean scores of experimental group were determined for all the dimensions in comparison with control groups students (p<0.05)

Promoting active learning in high school chemistry: learning achievement and attitude

AbstractThis study was conducted to investigate the effects of active learning applications, based on constructivism, related to the subject of “Acids and Bases”, on high school students’ learning achievements and attitudes toward chemistry lesson. For this purpose, a new active learning material was developed by considering students’ misconceptions and learning difficulties, and its effects were determined by participation of forty-five students from two different classes which were randomly assigned to experimental (N=21) and control (N=24) groups. The results of the pre-test (KR-20=0.81) showed no significantly differences between groups (F(1-43)=2.66, p>0.05). The instructions of “Acids and Bases” were accomplished with active learning material in the experimental group and with teacher-centred approach in the control group. After the instruction, the ‘Acids and Bases Achievement Test’ (KR-20=0.79) was administered to determine students’ learning achievements, and significantly differences were found between experimental (M=80.76) and control (M=47.83) groups (F(1-43)=102.529, p<0.05). Students’ answers to the test and also individual interviews indicated that in contrast to control group, experimental group students had significantly lower proportion of misconceptions about Acids and Bases. Students’ answers to the ‘Attitude toward Chemistry Lesson Scale’ (α=0.81) also reflected positive increases in four dimensions as (i) Interest in chemistry lesson; (ii) Understanding and learning chemistry; (iii) The importance of chemistry in the life, and (iv) Chemistry and occupational choice (F(1-43)=89.40, p<0.05)

Amycolatopsis Orientalis Besi Ortaminda Karbon Kaynaği Olan Glikoz Ve Gliserolün Konsantrasyonuna Bağimli Vankomisin Üretiminin Değişimi

DergiPark: 245897trakyafbdDeğişen glikoz (5-20 g/L) ve gliserol (2.5-20 g/L) derişimlerde büyütülen A.orientalis in vankomisin üretim düzeyinin yanısıra ekstrasellüler glukoz, gliserol ve pH düzeyleri inkübasyon periyodu süresince incelenmiştir. A. orientalis büyüme hızı artan glikoz ve gliserol derişimleriyle artış gösterirken besi ortamının pH düzeylerinde anlamlı düzeyde azalışlar belirlenmiştir. Bununla birlikte, besi ortamındaki glikoz seviyeleri ile glikozun tüketim zamanı arasında pozitif korelasyon saptanmıştır. Benzer sonuç gliserol içeren ortamda da gözlenmiştir. Glikopeptid antibiyotiklerden biri olan vancomisinin A. orientalis de üretimi, besi ortamındaki glikozun 15 g/L ve gliserolün 10 g/L ye kadar artmasıyla anlamlı düzeyde artış göstermiştir. Karbon kaynağı olarak gliserolün yerine glikozun kullanılması, A. orientalis in vancomisin üretim düzeyinde anlamlı düzeyde artışa neden olmasına rağmen büyüme hızında etkili olmamıştırVancomycin production as well as extracellular glucose and glycerol level and pH level of A.orientalis growth in different glucose (5-20 g/L) and glycerol (2.5-20 g/L) concentrations of the medium was investigated during the incubation period. A. orientalis growth rate increased with the increases in glucose and glycerol concentration while pH levels of the growth medium decreased significantly. In addition, a positive correlation was determined between consumption time of extracellular glucose levels and glucose concentration in the culture medium. Similar results were also determined in glycerol supplemented medium. As a glycopeptid antibiotic, vancomycin production of A. orientalis increased with the increases in glucose and glycerol concentrations up to 15 and 10 g/L, respectively. In addition, substitution of glycerol with glucose significantly affected vancomycin antibiotic productions whereas the growth rate was close to that of the each othe