Сп. „Химия“, книжка 4/2014

Letters to the Editor

E-Manual for the Students of 10th Grade: „From the Atom to the Space“ [In Bulgarian]

S. Boyanova

Letters to the Editor

Conventional Teaching versus Power Point Presentation: A Comparative Study for Undergraduate Organic Chemistry Students

S. Chandra, R.N. Yadav, B.K. Banik

Education: Theory & Practice

The Essay as an Integrative Construct: Normative, Procedure and Assess-Resultative Aspect [In Bulgarian]

Резюме. Essay is one of the forms of materialization of concept on integration of education’s content. Simultaneously, it represents unified integration of skills and content. By essay competence of the person for communication in different contexts is realized and ‘visualized’. Therefore, it reflects key competencies of different groups and takes essential part of the curriculum in many subjects. An analysis of essay is done in three interconnected sections: normative – essay in the context of key competencies of European framework for life-long learning and in curriculum; procedure – stages of essay composing and groups of skills by stages; assess-resultative – specificity of assessment of essay as integrative construct.
Keywords: essay, integration, key competencies, assessment

N. Raycheva, I. Kapurdov, N. Tzanova, I. Hadjiali, S. Tomova

Experiments

Isolation and Characterization of Collagen from the Skin of Syrian Sheep

Резюме. Acid soluble collagen (ASC) and Pepsin soluble collagen (PSC) from the skin of Syrian sheep were isolated and characterized. The yields of ASC and PSC were 6% and 14.4%, based on the weight of skin. ASC and PSC were exhibited a maximum absorbance at 230 and 240nm, respectively. Fourier transform infrared spectroscopy (FT-IR) showed regions of amides A,B, I, II and III for ASC and PSC. From Zeta potential analysis, isoelectric points (pI) of collagen from the skin of sheep were 5.2 and 5.6 for ASC and PSC respectively. The concentration of protein in extracted collagen ASC and PSC was 875, 930mg/g, respectively. Qualitative analysis of amino acids shows absence the cysteine and histidine from ASC and PSC and existence the amino acids distinguishing of collagen.
Keywords: acid soluble collagen (ASC), pepsin soluble collagen (PSC), zeta potential, FTIR, sheep skin.

M. Abu-Hassan, A. Malo

Problems

Developing Students Graphical Knowledge and Skills Through Solving Physical Problems with Graphical Method [In Bulgarian]

Резюме. Classification of graphical problems in physics education and algorithms for their solution are both presented. The application of graphs in teaching and learning Physics helps students to understand easier the meaning of natural laws.
Keywords: graphical method, graphical skills, graphical problems, algorithms, physics education

H. Petrova

Problems

The Problem in the Context of Reflective Technology for Teaching Biology [In Bulgarian]

Резюме. This paper presents an idea about for various types of teaching and learning problems used as tools for developing students’ reflective skills in Biology education. The structure of these types of problems is explained in the context of cognitive-performers, cognitive-constructive and cognitive-analytic source of the task.
Keywords: problem, reflection, technology

I. Hadjiali, N. Raycheva, N. Tzanova

Problems

44th International Chemistry Olympiad [In Bulgarian]

Резюме. The paper represents problems (theoretical and practical) of the 44th International Chemistry Olympiad and the solutions of theoretical problems. Comments of Bulgarian team presentation are given.
Keywords: International Chemistry Olympiad (IChO), practical exam, theoretical problems and solutions

D. Tasheva, P. Vasileva

From the Research Laboratories

Ab Initio Study on Structural Properties and Vibrational Analysis of Z-(1-Pyridine-2-yl-Methylene)-Thiosemicarbazone Compound

Резюме. In this work, we will report a combined experimental and theoretical study on molecular structure, vibrational spectra and energies of Z-(1-pyridin-2-yl-methylene)- thiosemicarbazone. The FTIR spectra of Z-(1-pyridin-2-yl-methylene)-thiosemicarbazone (1) molecule have been recorded using Bruker Tensor 27 spectrometer in the range of 400–4000 cm−1. The molecular geometry and vibrational frequencies and energies in the ground state are calculated by using the HF methods with 6-31G(d,p) basis sets. The calculated HOMO and LUMO energies also confirm that charge transfer occurs within the molecule. The geometries and normal modes of vibrations obtained from HF/6-31G(d,p) calculations are in good agreement with the experimentally observed data.
Keywords: thiosemicarbazone, HF, IR, HOMO, LUMO

M.M. Akbarzadeh, H. Sahebalzamani

Personalities in Science

Alexander Atanassov Panajotov [In Bulgarian]

Резюме. This material traces the life and creative path of Dr. Alexandar Atanasov Panaiotov, DSc, an Associate Professor at the Department of Biology Education, University of Sofia. His name stands out as a founder in the development of contemporary methodology of Bology education in Bulgaria, the region and internationally.
Keywords: Panaiotov, biological education, Methodology of biology education

N. Tzanova, I. Hadjiali, N. Raycheva

New Information Media

Compurer Assisted Learning System for Studying Analytical Chemistry

Резюме. The article describes the system of computer assisted learning (CAL) designed for classes in analytical chemistry. The system is developed in the Ural State University of Economics (USUE, Yekaterinburg, Russia). The CAL system consists of two subsystems for organizing students’ laboratory (in class) work and independent study (outside of class) and includes over a dozen computer programmes (from 1 to 10 MB) written in Delfi, HTML, CSS, and JavaScript. The CAL system has been implemented in USUE for teaching and learning analytical chemistry with students majoring in Commodities Management and Expertise; and Food Processing Technologies and Public Catering. The use of the CAL system ensures clarity in presenting complex subject matter, better understanding of the subject; develops students’ information processing skills, and stimulates their creativity; and, thus, enhances efficiency of the learning process.
Keywords: information technology, higher education, laboratory work, student self-study

N.Y. Stozhko, A.V. Tchernysheva, L.I. Mironova

Science Fiction

With Rocket Grenade to the Moon in the Year 3000 AC. 3 (1929) [In Bulgarian]

B. Burgel

Свързани статии:

Сп. „Химия“, книжка 1/2014 Сп. „Химия“, книжка 2/2014 Сп. „Химия“, книжка 3/2014 Сп. „Химия“, книжка 5/2014