Letters to the Editor
145th Anniversary of the Bulgarian Academy of Sciences [In Bulgarian]
D. KlissurskiВлезте в системата, за да прочетете пълната статия
Education: Theory & Practice
Service Learning in Science Teacher Preparation Program: Concepts and Practices
Резюме. Service learning is now challenging higher education in the 21st century. The concepts of service learning influenced to science teachers preparation program in terms of outcome-based education. The purpose of this paper aims to represent concepts relevant to service learning in science teacher preparation program and also practices of how service learning meet the 21st century skills. Documentary analysis and empirical study are employed for qualitative explanation. Finding revealed that service learning is an important instructional strategy in science teacher preparation program and it needs to be incorporated into curriculum for developing 21st century science teachers.
Keywords: service learning, preservice teacher, science teacher, teacher preparation
P. NuangchalermВлезте в системата, за да прочетете пълната статия
Vapor Pressure of Solutions [In Bulgarian]
Резюме. At a given temperature the vapor pressure of dilute solutions is lower the vapor pressure of a pure solvent. This conclusion follows from the analysis of the so called solution perpetuum mobile.
Keywords: vapor pressure,solutions
B.V. ToshevВлезте в системата, за да прочетете пълната статия
Improvement of STEM Education with the Integration of Data-Loggers in the Shining Star Project, 2007-2011 in Southern Indiana
Резюме. This paper describes a regional program that involved directly four middle schools and indirectly a large number of secondary schools in southern Indiana in a partnership with Indiana University Southeast working with middle school science educators to improve STEM education in their classroom. The program predated the Next Generation Science Standards (NGSS); we used the Indiana Academic standards and the National Science Teachers Association Science Standards. This program (2007-2011) raised student standardized exam scores in mathematics, improved participation in the classrooms and encouraged student participation and interest in STEM education. This program was success because the university asked the teachers â€œwhat-do-you-wantâ€ and â€œhow-can-we-help-youâ€. The Shining Star program spent time researching teacher in-service to maximize our time with the teachers and to promote best practices. We chose to do professional development with educators so they would share what they learned with colleagues and students.
Keywords: technology, data-loggers, middle school science-mathematics teaching
J. E. HollenbeckВлезте в системата, за да прочетете пълната статия
Astronomical Educational Project „My Kepler“: A Link between Science and Education [In Bulgarian]
Резюме. The article presents highly effective constructivist methods in the extracurricular form of education in astronomy and the results from the participation of students in an international astronomical educational project. Justified is the conduct of teaching using the methods and achievements in the science of astronomy and using the method of discovery of new knowledge for new astronomical objects. The main goal of the authors, reflected in this article, is the transformation of the educational process into a stimulating challenge for the acquisition of new knowledge and for the accurate processing of the astronomical data. The inclusion in the learning process of working with data from the mission of the Space Telescope Kepler, and the opportunity to make a real astronomical discovery, motivates students to deeply and lastingly utilize the astronomical knowledge.
Keywords: learning through discovery, extra-solar-planets, variable stars
V. Radeva, D. Kyurkchieva, D. DimitrovВлезте в системата, за да прочетете пълната статия
Effect of Students’ Background Knowledge of Mathematics on Senior Secondary School Students’ Achievement in Physics
Резюме. The study investigated the effect of studentsâ€™ background knowledge of mathematics on academic achievement in physics. The moderating effect of gender was also examined. The sample consisted of 300 senior secondary school year one science/mathematics students in Lagos State. The study adopted pre-test and post-test control group non-equivalent quasi-experimental design using a 2Ã—2 factorial matrix with one experimental group and one control group. Five research questions and three null hypotheses were raised, answered, and tested in the study. Two research instruments, Mathematics Achievement Test (MAT) (r = 0.82) and Physics Achievement Test (PAT) (r = 0.78) were administered on the sample and data gathered were analysed, using Mean, Standard deviation, Independent Samples t-test statistic and analysis of covariance. Results showed that there were no statistically significant differences in the mean pre-test achievement scores in mathematics (t=1.426, p=0.155) and physics (t=0.416, p=0.667) between the treatment groups prior to the intervention. Results also revealed that there was no statistically significant difference in the mean pre-test achievement scores in mathematics (t=-1.63, p=0.103) and physics (t=0.356, p=0.722) based on gender. However, there was a statistically significantly positive relationship between achievement score in physics and mathematics prior to the intervention (r=0.602, p=0.002). Treatment and gender had statistically significant main effects on studentsâ€™ posttest achievement score in physics (F(1, 299)=440.413, p=0.000, Î·2p=0.599; F(1, 299)=9.611, p=0.002, Î·2p=0.032) respectively. There was no statistically significant interaction effect of treatment and gender on studentsâ€™ post-test achievement score in physics (F(1, 299)=0.52, p=0.820, Î·2p=0.000). Based on the results, the study recommended that the teaching of prerequisite mathematics concepts in physics before physics teaching should be adopted as instructional technique for enhancing meaningful learning in physics.
Keywords: studentsâ€™ background knowledge of mathematics, physics achievement
A. Ogunleye, A.O.A. Awofala, E.A. AdekoyaВлезте в системата, за да прочетете пълната статия
Synthesis and Characterization of Mixed Ligand Co(II) and Ni(II) Complexes with L-Phenylalamine and Hippuric Acid
Резюме. The mixed ligand complexes, [M(HA)(Phe).2H2O].2H2O, where HA and Phe are the anions of hippuric acid and phenylalnine respectively and M=Co(II) and Ni(II) ions, were synthesized and characterized by FTIR, UV-vis, elemental analysis, TGA and magnetic measurements. Both the ligands act as bidentate, coordinating through carboxylate oxygen and nitrogen atoms. The two coordination positions are occupied by water molecules, hence six fold octahedral geometry has been suggested to both the complexes.
Keywords: hippuric acid, phenylalanine, Co(II), Ni(II) complexes, synthesis, characterization
G. Kumar, A. Munyaneza, G. DitsieВлезте в системата, за да прочетете пълната статия
Lubrication Properties of Different Pentaerythritol-Oleic Acid Reaction Products
Резюме. The esterification reactions between pentaerythritol and oleic acid have been followed in the presence of para toluene sulfonic acid catalyst at 4:1, 2:1, 1.5:1, and 1:1 acid â€“alcohol mole ratios. Considering the lubrication properties of the resulting products in each reaction indicates systematic increase of vis@40 Â°C, vis@100 Â°C, pour point, and flash point upon decreasing of the moles of oleic acid. In the case of viscosity index the reverse trend is observed. The lubrication properties were also compared with the corresponding data regarding some of mineral and synthetic base oils. The advantages and disadvantages of esteric products relative to recent oils were discussed. Finally, several industrial oils were equalized successfully by using the esteric base oils.
Keywords: pentaerythritol, oleic acid, esteric base oils, mineral oils, synthetic oils
A. Semnani, H.S. Langeroodi, M. ShiraniВлезте в системата, за да прочетете пълната статия
Foreign Educational Tradition
The Origins of Secondary and Tertiary General Education in Russia: Historical Views from the 21st Century
Резюме. The first steps of education in gymnasiums and universities in the main East Slavonic states are described. The first town with teaching in Slavic languages was Lithuanian Vilnius. Slavic education spread step by step from Lithuania via Polotsk and Kyiv to Moscow. The first institution of higher education in Moscow was established in 1687. It was Ellino-Greek Academia. First Russian Academic Gymnasium and University with the traditional curriculum were founded in 1725 in Saint-Petersburg. Yet, many years after that, the students in the first Russian university were absent. The university educational process in Russia started in 1755 at Moscow. So it took about 200 years to bring University education from Lithuania via Belarus and Ukraine to Russia.
Keywords: Slavic language, Western oriented curriculum, theological schools, Moscow University
V. Romanenko, G. NikitinaВлезте в системата, за да прочетете пълната статия
From the Research Laboratories
Allelopathic and Cytotoxic Activity of Origanum Vulgare ssp. Vulgare Growing Wild in Bulgaria
Резюме. Origanum L. (Lamiaceae) is a valuable aromatic plant. Recently aromatic plants have gained interest as potent allelopathic plants. Secondary metabolites in allelopathic plants may lead to discovery of new classes of herbicides. On the other hand, these toxic secondary metabolites could affect adversely the consumers. Influence on mitotic cells has shown to be of importance for humans. The present study aimed to evaluate allelopathic and cytotoxic effects of water infusions made from the aerial parts of Origanum vulgare ssp. vulgare growing wild in Bulgaria in laboratory conditions. For monitoring the allelopathic effect germination and root elongation test were used. The effect on mitotic cells was determined using Allium cepa L. test. Infusions had minor effect on germination, but significantly decreased root length of Cucumis sativus L. and Triticum aestivum L. Oregano exerted mitodepressive and genotoxic effect in Allium cepa. These results demonstrated the potential of infusions as a source of bioactive substances that could be use in agriculture. The observed effects provide also information on safety evaluation of plant tested.
Keywords: Origanum vulgare ssp. vulgare, root growth inhibition, mitodepressive and genotoxic effect
A.P. Dragoeva, V.P. Koleva, Z.D. Nanova, M.Z. Kaschieva, I.R. YotovaВлезте в системата, за да прочетете пълната статия
Personalities in Science
Chemometry and Professor Vassil Simeonov: Interview [In Bulgarian]
B.V. ToshevВлезте в системата, за да прочетете пълната статия
New Information Media
E-Learning Project at Faculty of Chemistry and Pharmacy, University of Sofia [In Bulgarian]
Резюме. The topics of E- learning is extremely popular in the last decade since the application of this didactic approach makes it possible to realize a set of advantages most important of them being distant education and life-long education. Very often the practical introduction of the method is a result of the enthusiasm and personal attitude of given teacher or the ambitious intentions of a certain educational institution. Different programs have been created and funded within the frames of the European Union encouraging creation and dissemination of lecture courses and seminars based on the principles of E â€“ learning. A team of over 60 university teachers from Faculty of Chemistry and Pharmacy, University of Sofia â€œSt. Kliment Okhridskiâ€ created modules of materials for E â€“ learning of students from bachelor and master programs from the three faculties from the University of Sofia â€œSt. Kliment Okhridskiâ€ within the frames of a big project funded by Operational Program for human resources development and the European social fund (ECF). The project was called â€œCreation and application of electronic forms of distant education in Faculty of Chemistry and Pharmacy at University of Sofia (Project â„– BG051PO001-43.04-0033, â„– Ð”Ðž1 â€“ 3792/12.03.2013 Ð³.), led by Prof. Dr. Stefan Tsakovski. The present communication reflects the efforts of the team for correct and professional attitude to the project goals.
Keywords: E â€“ learning, distant education, electronic courses, European project, human resources development program
S. Tsakovski, V. SimeonovВлезте в системата, за да прочетете пълната статия
With Rocket Grenade to the Moon in the Year 3000 AC. 5 (1929) [In Bulgarian]
B. BurgelВлезте в системата, за да прочетете пълната статия