Сп. „Химия“, книжка 5/2016

Letters to the Editor

Obtaining Educational Minimum and New Curriculum in Geography in Lower Secondary Bulgarian School [In Bulgarian]

I. Drenovski

Education: Theory & Practice

Trends in Science Education Research: A Content Analysis of Bulgarian Educational Journals from 2001 to 2015 [In Bulgarian]

Резюме. The primary objective of this study is to outline the trends in science education research based on content analyses of publications from 2011 to 2015 in four Bulgarian educational journals: “Chemistry: Bulgarian Journal of Science Education”, “Strategies for Policy in Science and Education”, “Bulgarian Physics Education” and “i– Continuing Education”. A methodology for content analysis of the selected journals is described using quantitative and qualitative parameters. A total of 290 research papers were analyzed in terms of the following criteria: 1. Degree of education; 2. Research topics and 3.Components of the process of science instruction, on which educators focused their research in trying to find decisions of specific issues. The criterion “Research topics” was decomposed to ten main research fields: 2.1. Training for science teachers; 2. 2. Teaching of science; 2. 3. Cognitive aspects of science learning; 2. 4. Learning context and learner personality characteristics; 2. 5. Educational objectives, curriculum, content knowledge, and assessment; 2. 6. Reflective practice; 2. 7. History, philosophy, epistemology and nature of science; 2. 8. Educational technology; 2. 9. Cultural, social and gender differences between students; 2. 10. Informal learning. The results of this study found that most of the published articles were related to the secondary degree of science education. The research topic referred to the educational objectives, curriculum, content knowledge, and assessment was the most frequently investigated one in 2011-2015.
Keywords: journal content analysis, science education, trends in educational research

I. Hadjiali, T. Kolarova

New Approaches

Use of Vectors and Functionals for p2, d2, f2 Configurations and Description of the p2 Electron Configuration

Резюме. The aim of this research was to compute the number of microstates
for p2 configuration n = 6 and x = 2, for d2 configuration n =10 and x = 2
and f 2 configuration n =14 and x = 2 using vectors and the math function
factorial as well as to describe in detail the microstates for p2 configuration n = 6 and x = 2 . The following results were obtained: for p2 configuration n = 6 and x = 2 , N =15 microstates; for d2 configuration n =10 and x = 2,microstates; for f 2 configuration n =14 and x = 2 , N = 91 microstates. It was established that the 15 microstates of the p2 configuration. It was found that the 15 microstates of the p2 electron configuration belonged to three terms as followed:5 microstates corresponding to the 1D term; 9 microstates to the 3Р term and 1
microstate to the 1S term.
Keywords: vector, factorial, microstate
Keywords: vector, factorial, microstate

M. Ivanova, L. Dospatliev

New Approaches

Determination of the Rate and the Equilibrium Constant with Kinetic Approach

Резюме. So far, the kinetic approach for determination of the rate constants of reversible reaction is still using the equilibrium concentration. Basically, this is thermodynamic concept. This technique is not only needs a long time for the experiments but also gives only the exact value of the forward rate constant. The exact value of backward rate constant must be determined based on the postulated reaction mechanism. This study presents a simple technique on the determination of the exact value of both forward and backward rate constants using irreversible approach on three data at the early stages of a reaction and then used for the determination of equilibrium constant. This theoretical study is supported with statistical analysis on the experimental data adapted from the literatures. The results showed that the technique is valid and reliable.
Keywords: forward rate constant, backward rate constant, equilibrium constant, irreversible approach, chemical kinetics

Patiha, Maulidan Firdaus

Curriculum Matters

Study of the Appreciation by the Pupils of Second Baccalaureate Year of Knowledge Objects Relating to Acid-Bases Titrations

Резюме. This article aims to study the difficulties of the Moroccan high school pupils in teaching of the acid-base topic. Based on others similar context, particularly the Tunisian one, we have firstly carried out a classification of the knowledge objects relating to acid-base titrations in the empirical register and in the register of models. The analysis of the written productions of the pupils in situation of solving problem showed that the Moroccan pupils in classes of second Baccalaureate encountered difficulties to appropriate the knowledge objects relating to weak acide-strong base titrations and to adapt these knowledge as well as with the empirical register and with the register of models.

Keywords: acid-base titration, design, empirical register, knowledge object, register of models

Ali Ouasri

Curriculum Matters

College Students’Conceptions of Newtonian Mechanics: A Case of Surabaya State University Indonesia

Резюме. Students’ understanding of scientific phenomena have been of considerable interest to science education researchers. However, students’ conceptions might differ from those generally accepted by researchers as scientific concepts. This study was possessed the conception profile of college students in mechanics by using: Force Concept Inventory (FCI) and Mechanics Baseline test (MBT). The study identified the concept of supporting the cause of misconceptions. A descriptive quantitative approach was used, which included 90 college physics students at Surabaya State University as the participants. The results indicated that, first, students’ conceptions on Newtonian mechanics based on FCI performed that students at Junior level better than Sophomore and Freshman. Second, the overall level of misconception among college students was moderate (68.86%). The two highest levels of misconception were kinds of force with fluid contact (81.67%) and Newton’s second law (78.33%). Third, according to MBT, college students have a very low understanding regarding the kinds of acceleration, kinematics, energy conservation, superposition force, action-reaction, and free fall. Last, the overall level of misconception among college students was high (75.91%). The highest levels of misconception were the topics of kinematics; both centripetal and average acceleration (86.67% and 85.56%, respectively). The students also performed high level in misconception in general principles (such as, energy conservation, superposition of force, free fall, and action-reaction).
Keywords: Newtonian mechanics, conception, FCI, MBT

N. Suprapto, D.A. Syahrul, S. Agustihana, C.A. Pertiwi, C.-H. Ku

Experiments

Estimation of Ignition Temperature for Two Kinds of Energetic Materials by Thermal Analysis and Kinetic Evaluations

Резюме. Some kind of energetic materials are substantially unstable and decompose slowly during their storage at room temperatures. Decomposition releases heat and gases which cause decomposition processes was accelerated. This process reduces performance and storage lifetime. Also because of released heat, this process could results to an unsafe situation like unexpected thermal explosion. Thermal analysis is an important tool for evaluation thermal hazard of energetic materials. Kinetic calculations are done by thermal analysis and kinetic parameters are obtained by thermal analysis. Determination of thermal explosion temperature is very important. Our study is based on two kinds of methods, first Invariant Kinetic Parameters (IKP) method such as Iso-kinetic Point and second method is based on Kissinger method. In this article for two kinds of propellants ignition temperatures (Tign) were calculated from TGA experiments in some various heating rates. At final part, this temperature was validated by Differential Scanning Calorimetry (DSC) experiments at isothermal mode. Experimental results are shown that IKP method predicted more accurate results than Kissinger method.
Keywords: ignition, thermal analysis, energetic materials, isokinetic, invariant kinetic parameters

M.R. Nayeb-Hosseini, M. Ferdowsi

From the Research Laboratories

Spectroscopic Studies and Potential Complex between TNT and Folic Acid: A DFT Study

Резюме. The interaction between TNT and an indispensably substantial biological molecule, folic acid (FA), has been investigated at the level of density functional theory. Two models are assembled: (i) an intimate pair of TNT and FA and (ii) Ï€-complex of them. The calculations (in vacuum conditions) have showed that these molecules in the intimate pair model orient themselves in an angular geometry. A Ï€-complex formation between these molecules is quite likely in the case of parallel arrangement of aromatic rings. The calculated UV and NMR spectra support the idea of a strong interaction between TNT and FA.
Keywords: folic acid, TNT, NMR, UV-VIS, complex, DFT

L. Turker, S. Varis

Science and Society

Quality Assessment and Correlation Coefficients Study of Chemical Parameters of the Well Water of Pleshina (Kosova)

Резюме. A water quality is one of the most important standards of supply service for the fact that it has a direct impact on the health of the population. In this study the assessment of water quality and correlation coefficients between different pairs of variables of 36 well water samples of Pleshina were investigated Also the quality of well water after chemical treatment was assessed. Statistical studies have been carried out by calculating of basic statistical parameters, anomalies (extremes and outliers) and correlation coefficients between different pairs of variables.. From the results of field work and laboratory analyses it was found out that well water not fulfill the criteria set by the World Health Organization and the distribution of low pollutants indicated lithological pollutants. The statistical regression analysis has been found a moderately high positive correlation relationship between EC with pH, Cl- and NO2-. Turbidity showed a moderately high positive correlation relationship with NH3. Consumption of KMnO4 showed a moderately high positive correlation relationship with Mn2+ and NO3-. After chemical treatment, the study found that the Pleshina’s well water was generally fulfill the criteria set by the World Health Organization.
Keywords: quality assessment, correlation coefficients, drink water, Pleshina, statistical analysis

F. Gashi, F. Faiku, N. Troni, A. Gashi

Science and Society

Quality Assessment of River Water of Gracanica (Kosovo) and Correlation Study of Chemical Data

Резюме. In this study the assessment of river water quality and correlation coefficients between different pairs of variables of water samples, were investigated. The main objective of this study was to perform assessment of water quality of Graqanica River. Statistical studies have been carried out by calculating of basic statistical parameters, anomalies (extremes and outliers) and correlation coefficients between different pairs of variables. The statistical regression analysis has been found a high positive correlation relationship between turbidity and EC, hardness, Ca2+ and SO42-. EC showed high significant positive relationship with turbidity, hardness, COD, Ca2+, Mg2+, and SO42-. Consumption of KMnO4 showed high significant positive relationship with COD, TOC, NO2- and PO43- (possible sign of waste waters from settlements influence). From the results of field work and laboratory analyses it was found out that river water quality not fulfill the criteria set by the World Health Organization and the distribution of pollutants indicated anthropogenic sources of pollutants mainly from Kishnica and Badovci flotation tailing dams and waste waters.
Keywords: water, quality assessment, correlation coefficients, Graqanica river, statistical analysis

F. Gashi, N. Troni, R. Hoti, L. Latifi, V. Kolshi, A. Goshi

New Information Media

New Functions of Teachers When Training with Information-Communication Technologies

Резюме. The application of information and communication technologies (ICT) in education changes educational role of the teacher. The special features of the activities of teachers during application of ICT in class are presented. The emphasis is on the skills that must be developed by teachers in order to achieve success in their lessons in class.
Keywords: activity, information-communication technologies, teacher, students

H. Petrova

Archives

Assessment of Student Personality (1941)

B.V. Toshev

Свързани статии:

Сп. „Химия“, книжка 1/2016 Сп. „Химия“, книжка 2/2016 Сп. „Химия“, книжка 3/2016 Сп. „Химия“, книжка 4/2016