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Volume 18, Issue 6  (2009)

B.V. Toshev
43rd National Conference of the Chemistry Teachers

Full text: PDF (88 K)

Letters to the Editor:
M. Tsavkova
How to Survive in the New School Environment and Keep Up with Change? (Five Opportunities of the Five Educational Dimensions)

Full text: PDF (133 K)

D. Gadjanova
The Constructivist Classroom: First Steps

Full text: PDF (61 K)

New Approaches:
J. Elias, M. Lobato, A. Figueiredo, M. Santos, M. Farias, W. Macedo, J. Barbosa, J. Pinheiro
Teaching Computational Chemistry By Studyng Malaria

Full text: PDF (340 K)

Teaching Efficiency:
N. Tzanova, A. Asenova, K. Yotovska
Teachers' Training through the Prism of Quality

Full text: PDF (186 K)

D. Tasheva, P. Tsanova
41st International Chemistry Olympiad: Problems with Solutions

Full text: PDF (446 K)

Chemistry & History of Chemistry: An Online Supplement:
M. Singh, R.K. Kale
Study of Magnetic Effects on Interactions of Globular Proteins: Bovine Serum Albumin and Egg Albumin with Water

Full text: PDF (59 K)

M.-H. Sorouraddin, M. Saadati
Simple, Cheap, and Portable Colorimeter for Introductory Analytical Chemistry Laboratories

Full text: PDF (62 K)


Khimiya, Volume 18, Issue 6(2009)

Khimiya. 18, 414- (2009) Author(s): J. Elias, M. Lobato, A. Figueiredo, M. Santos, M. Farias, W. Macedo, J. Barbosa, J. Pinheiro:

Abstract.This paper describes our strategy to introduce Computational Chemistry in the undergraduate courses by studying malaria. Artemisinin and its 8-deoxyartemisinin derivative with significant differences in biological activities against this disease are studied. Complete geometry optimization is done with the Hartree-Fock-Roothaan (HFR) theory with several basis sets and with semiempirical methods. The Principal Component Analysis (PCA) and Hierarquical Cluster Analysis (HCA) methods are used to select the most appropriate method and basis set to model molecules. Maps of molecular electrostatic potential (MEP) and the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) are used to correlate structure-activity. Also the docking is employed to investigate the interaction between artemisinin and heme. By this strategy students can study Computational Chemistry, Theoretical Chemistry, Chemometrics and Medicinal Chemistry.

Keywords: in the classroom, computers in chemistry, theoretical chemistry, chemometrics, interdisciplinary


Khimiya. 18, 423- (2009) Author(s): N. Tzanova, A. Asenova, K. Yotovska:

Abstract.Among the priorities of Bologna process is the quality assurance of education by means of standards for qualifications. Basic criteria regulator is European Qualifications Framework where the systems of knowledge, skills and competences are defined as final results of education in educational cycles. It requires revaluation of the model of prospective teachers training including curriculum, structure and technology in different teaching disciplines and system for quality assessment. The paper gives an analysis on the subject and presents a technological model in the context of referent European Framework for insuring quality of students training in the case of Biology education.

Keywords: management, model of training, quality


Khimiya. 18, 443- (2009) Author(s): D. Tasheva, P. Tsanova:

Abstract.The paper describes both the experimental and theoretical problems of the 41st International Chemistry Olympiad. The solutions of theoretical problems are given. The difficulties with the Bulgarian team training are commented.

Keywords: International Chemistry Olimpiad (IChO), practical exams, theoretical problems and solutions


Khimiya. 18, E172- (2009) Author(s): M. Singh, R.K. Kale:

Abstract.Viscosities for 0.2, 0.4, 0.6, 0.8 and 1.0 milligram per 100 mL aqueous solutions of Bovine Serum Albumin (BSA) and Egg Albumin (EA) with 0.0, 1 and 2 magnetic fluxes at 298.15 K and one atmosphere were measured with Survismeter. An increase in viscosities inferred effect of magnetic flux on structural interaction on globular proteins. As compared to blank sample, the BSA and Egg Albumin showed 5 and 2.5 times increments in viscosities with the magnetic fluxes.

Keywords: viscosity, survismeter, magnetic flux, bovine serum albumin, egg albumin


Khimiya. 18, E176- (2009) Author(s): M.-H. Sorouraddin, M. Saadati:

Abstract.The construction and application of a cheap, simple and portable colorimeter is presented. The system employs an LED as a light source and a common photocell (photoresistor) as a detector. The device functions based on the level of light received by photocell, which is connected to a digit multimeter yielding resistance readings. Resistance increases with increasing the sample absorption. Due to the simplicity of the instrument it can be constructed in a laboratory or a classroom. The fabricated device is applicable to calculate the molar absorption of colored species and demonstrates the basics of the instrumentation of spectrophotometers.

Keywords: colorimeter, light emitting diode (LED), photoresistor, spectrophotometry, laboratory demonstration


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