2019: TWO IMPORTANT EVENTS

A CONTENT ANALYSIS OF THE RESULTS FROM THE STATE MATRICULATION EXAMINATION IN MATHEMATICS

Abstact. This paper presents an analysis of the results from the State Matriculation Examination in Mathematics achieved by the students from the Science and Mathematics High School “Acad. S. Korolyov” within the period of 2012 – 2014.

VARIANTS OF LEARNING BASED ON CONSTRUCTIVISM

Constructivism is the methodological basis of active learning and its variants: learning by experience, learning by doing, autonomous learning, contextual learning, problem solving and problem-based learning, project-oriented learning, collaborative learni...

SOME CONCEPTS FROM PROBABILITY AND STATISTICS AND OPPORTUNITIES TO INTEGRATE THEM IN TEACHING NATURAL SCIENCES

The aim of the suggested approach is to focus on acquisition of elements of Probability and Statistics that are included in the curricula of Mathematics, Informatics and Information Technologies in Bulgaria. The educational tools offered show the opportunitie...

REVIEW AND IMPROVED TECHNIQUE OF THE INITIAL RATE METHOD

It is claimed that, in certain circumstances, initial-rate method (IRM) has advantages over the integral method (IM). But, the IRM will only be effective if the concentration change is less than \(5 \%\) and the rate constant \((k)\) obtained should be ch...

\(45^{\text {th}}\) INTERNATIONAL CHEMISTRY OLYMPIAD

The paper represents problems (theoretical and practical) of the \(45{ }^{\text {th }}\) International Chemistry Olympiad and the solutions of theoretical problems. Comments of Bulgarian team presentation are given.

SEMI-EMPIRICAL COMPUTATIONAL STUDY OF THE LIGAND AND ITS METAL COMPLEXES DERIVED FROM 4- AMINOANTIPYRINE AND 2, 4-DIHYDROXY BENZOIC ACID

Theoretical molecular structures of the ligand and its Co(II), Ni(II), Cu(II) and Zn(II) complexes have been studied using the semi-empirical quantum chemical methods. The experimental IR, electronic and NMR data of the investigated compounds are compared w...

ADVANCES OF PHOTOTHERMAL MICROSCOPY OF COMPOSITE MAGNETOELECTRIC NANOLAYERS USING LASER HETERODYNE PROBE

A theoretical solution advances the potential for photothermal microscopy of nanostructured composite magnetoelectrics and high-temperature superconductors. Photothermal displacement (PTD) is a sensitive effect employed as a fingerprint of the physical and s...

CONSIDERATIONS ON DADNE ISOMERS – A DFT TREATMENT

Isomers of diaminodinitroethylene (DADNE) are subjected to quantum chemical treatment within the realm of density functional theory at the level of B3LYP/6-311++G(d,p). Mono anions and cations of them are also considered (UB3LYP/6-311++G(d,p)). The possibil...

6,6’,8,8’-TETRAMETYL-4,4’,7.7’-TETRAHYDROS-7,7’BI-1,2,4,5-TETRAZOCINE-3,3’(2H,2’H)-DITHIONE, A NOVEL HYDRAZONE SCHIFF BASE WITH PROMISING PHARMACOLOGICAL EFFECTS

Novel hydrazone Schiff base viz. 6,6’,8,8’-tetramethyl-4,4’,7,7’tetrahydro-7,7’-bi-1,2,4,5-tetrazocine-3,3’(2H,2’H)-dithionehas been synthesized from3,4-diacetylhexane-2,5-dione and thiocarbohydrazideandcharacterized. The bicyclichydrazone Schiff basehas bee...