Volume 26, Issue 6  (2017)
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Volume 26, Issue 6  (2017)

Letters to the Editor:
N. Syla, G. Hodolli
The Teaching Method Named "Starter-Experiment-Approach"

Full text: PDF (485 K)

807
Education: Theory & Practice:
Y. Rahmawati, A. Ridwan
Empowering Students' Chemistry Learning: The Integration of Ethnochemistry in Culturally Responsive Teaching

Full text: PDF (505 K)

813
New Approaches:
V. Radeva, D. Kjurkchieva
"The Bulgarian Names in the Solar System" - Astronomy Education with the Application of Innovative Methods, Emotional Impact and Commitment [In Bulgarian]

Full text: PDF (1077 K)

831
Teaching Efficiency:
M. Bozova
Development of Science Literacy by a Model of Active Education and Study by Cooperation [In Bulgarian]

Full text: PDF (579 K)

845
Problems:
G. Kalpachka
Computer Educational Technologies in the Lessons to Solving Physics Problems [In Bulgarian]

Full text: PDF (1251 K)

856
I. Dukov
Balancing of Oxidation-Reduction (Redox) Reactions with Higher Boranes Participation: Oxidation Number Method or Material Balance Method?

Full text: PDF (667 K)

874
Personalities in Science:
D. Platikanov
Professor Alexey Scheludko (1920-1995) [In Bulgarian]

Full text: PDF (1513 K)

881
Science and Society:
Z. Berdenov, E. Mendibaev, T. Salihov, K. Akhmedenov, G. Ataeva
Geoecological Analysis of Industrial Cities: On the Example of Aktobe Agglomeration

Full text: PDF (1154 K)

890
K. Dzhanaleyeva, G. Mazhitova, A. Zhanguzhina, Z. Berdenov, T. Bazarbayeva, E. Atasoy
Technogenesis of Ecoecological Systems of Northern Kazakhsstan: Progress, Development and Evolution

Full text: PDF (2379 K)

903
F. Faiku, A. Haziri, B. Faiku
Antioxidant Activity, Phenols, Flavonoids, Flavonols and Anthocyanins Content of Tussilago farfara (L.) Growing Wild in Kosovo

Full text: PDF (958 K)

922
News:
B. V. Toshev
Prof. Dimo Platikanov (1936-2017) [In Bulgarian]

Full text: PDF (662 K)

934
Past Times:
B. V. Toshev
Enlightenment: A Magazine (1938) [In Bulgarian]

Full text: PDF (2634 K)

938
 

Khimiya, Volume 26, Issue 6(2017)

Khimiya. 26, 813-830 (2017) Author(s): Y. Rahmawati, A. Ridwan:

Abstract.The overall aim of this two-year longitudinal study is to empower chemistry students in secondary schools through the integration of ethnochemistry as a Culturally Responsive Teaching (CRT) approach. The CRT approach in this study refers to the position promoted by Gay (2000) and the following five basic principles of CRT by Hernandez, Morales, and Shroyer (2013): content integration, facilitating knowledge construction, prejudice reduction, social justice, and academic development. The integration of ethnochemistry is applied to the basic principle of content integration to engage students with their Indonesia indigenous knowledge. Indonesia has around 300 ethnic groups with differences in values, beliefs, and practices which are explored in a limited way in the context of chemistry education. This research was conducted in four secondary schools using qualitative methodology with multiple methods of observation, interviews, and reflective journals. The results showed that the model of ethnochemistry integration in CRT approach was developed in this study and involved five main steps of self-identification, cultural understanding, collaboration, critical reflective thinking, and transformative construction can be implemented in Indonesia chemistry classrooms. The students were empowered to explore their cultural identity and develop their cultural awareness of appreciating differences. The learning model provides opportunities for students to develop their abilities in collaboration skills, empathy communication, and higher order thinking skills alongside their engagement in chemistry learning. Students found that the learning experiences have empowered them to engage in critical self-awareness of their cultural identity, and character development within meaningful learning experiences which are relevant to current Indonesia curriculum reform.

Keywords: culturally responsive teaching, ethnochemistry, chemistry learning, character development, culture identity

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Khimiya. 26, 831-844 (2017) Author(s): V. Radeva, D. Kjurkchieva:

Abstract.The article presents an innovative extracurricular education in astronomy. The topic of the training "The Bulgarian names in the Solar system" is being studied for the first time in the Bulgarian astronomy education. The combination of research methods for learning and the strong emotional impact on students resulting from the choice of topic results in high motivation in students and high effectiveness in the learning process. The students' personal attitude and commitment towards the investigated topic contributes to a high extend to the acquisition of lasting and profound astronomical knowledge. The result of the education is the creation of a richly illustrated informative database of regions with Bulgarian names on objects from the Solar system.

Keywords: planetary nomenclature, inquiry-based learning, astronomical observations, planets, аsteroids

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Khimiya. 26, 845-855 (2017) Author(s): M. Bozova:

Abstract.The article presents an innovative school model for introducing active learning where students develop competences and scientific literacy, rationalize ideas and processes through interdisciplinary projects and research work. Teachers, united in professional communities, are adapting learning content, planning interdisciplinary lessons, discussing situations. Parents and external experts are involved as partners in planning and organizing activities and managing processes in the school organization.

Keywords: active learning, scientific literacy, teachers’ professional communities, interdisciplinary lessons

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Khimiya. 26, 856-873 (2017) Author(s): G. Kalpachka:

Abstract.Мethodical possibilities for using computer education technologies in the lessons to solving physics problems are described and discussed. The topic e “Harmonic oscilations”, 9th grade. Quantitative, qualitative and experimental problems are presented.

Keywords: computer educational technologies, secondary education, physics teaching, multimedia programs, computer programs to solving physics problems

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Khimiya. 26, 874-880 (2017) Author(s): I. Dukov:

Abstract.As a result of the complex structure of the higher boranes, the balancing of redox reactions with their participation by the oxidation number method is connected with the acceptance of non-integer values of the oxidation numbers of the boron atoms which is in contradiction with some IUPAC recommendations. An alternative method is the material balance method (algebraic method) based on the natural law of mass conservation in chemical reactions. Its modified form permits easy and fast balancing of redox reactions without any restrictions.

Keywords: higher boranes, redox reactions, oxidation number method, material balance method

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Khimiya. 26, 881-889 (2017) Author(s): D. Platikanov:

Abstract.Professor Alexey Scheludko, Fellow of the Bulgarian Academy of Sciences, is a founder of the Bulgarian Colloid Chemistry School. His course of life, scientific activities and scientific achievements are described in the present paper.

Keywords: A. Scheludko, colloid chemistry, Sofia University

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Khimiya. 26, 890-902 (2017) Author(s): Z. Berdenov, E. Mendibaev, T. Salihov, K. Akhmedenov, G. Ataeva:

Abstract.Landscape-geochemical assessment of the industrial areas is of particular interest to many researchers. This study describes the micro element composition of soils and hydrochemical composition of surface waters of the Aktobe region in Kazakhstan. A landscape-geochemical analysis was conducted in Aktobe agglomeration. Biogeochemical data is used to indicate the state of the degree of pollution. According to a study compiled agglomeration modern landscape map and identified anthropogenic impact on the total pollution index.

Keywords: geosystem, landscape, industry, technogenic anomalies

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Khimiya. 26, 903-921 (2017) Author(s): K. Dzhanaleyeva, G. Mazhitova, A. Zhanguzhina, Z. Berdenov, T. Bazarbayeva, E. Atasoy:

Abstract.The article is about landscape-geochemical research on techno-agricultural systems of Northern Kazakhstan. The following four techno-agricultural geoecosystems of Northern Kazakhstan are displayed hereunder: Tobyl-Kostanay, Yesil, Yertis-Pavlodar and Central Yesil. Travel and spread of pollution and heavy metals in soil layers play critical part during such researches. The result of this work is a map model of techno-agricultural geoecosystems of Northern Kazakhstan.

Keywords: techno-agricultural geoecosystems, geosystems, pollution, technogenic factors

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Khimiya. 26, 922-933 (2017) Author(s): F. Faiku, A. Haziri, B. Faiku:

Abstract.Total phenols, flavonoids, flavonols and anthocyanis content and antioxidant activity were quantitatively determined to the Tussilago fatfara (L.) growing wild in Sharr (South part of Kosova). In the tested extracts of plant species Tussilago fatfara (L.) quantitative composition of total phenols, flavonoids, flavonols and anthocyanins were determined by spectrophotometric method. Total phenols determined by Folin-Ciocalteu reagent and their amounts in the range of 56.50 mg/g to 84.70 mg/g (expressed as gallic acid equivalent, mg GAE/g).The amounts of flavonoids in plant extracts are in the range of 2.75 mg/g to 8.76 mg/g (expressed as rutin equivalent, mg RE/g).The amount of total flavonols in Tussilago farfara (L.) extracts ranged from 0.21 mg RE/g to 0.51 mg RE/g. The contents of total anthocyanosides in the Tussilago farfara (L) ranged from 1.44 (ethanol extract) to 1.86 (acetone extract) anthocyanins determined as mg yanidin 3-glucoside/g dry weight. Antioxidative activity was determined in vitro, using the DPPH reagent by spectrophotometric method.The results demonstrated that extract RSC was dependent on the solvent polarity, and the type of free radical used in the reaction. The IC50 values extracts in DPPH• assay was from 0.10 mg/ml (ethanol extract) to 0.20 mg/ml (acetone extract).

Keywords:Tussilago farfara (L), phenols, flavonoids, flavonols, anthocyanins, antioxidant activity

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