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Volume 29, Issue 1  (2020)

Editorial:
B. V. Toshev
The Scientific Recognition [In Bulgarian]

Full text: PDF (349 K)

7
Letters to the Editor:
P. Vasileva
Physics Around Us: The Honey [In Bulgarian]

Full text: PDF (355 K)

11
B. Yankova, S. Demirova, T. Miteva, Y. Knyazov, H.Zhelev, D. Georgiev, G. Stoyanova
The Pleasure Molecules [In Bulgarian]

Full text: PDF (303 K)

19
P. Nikolaeva
Out-of-Class Activities in the School: Letter of a Teacher

Full text: PDF (284 K)

27
Education: Theory & Practice:
L. Lazov, H. Deneva, G. Gencheva
Water Purification with Laser Radiation

Full text: PDF (482 K)

32
S. Petrova
Observation of Meteor Showers [In Bulgarian]

Full text: PDF (975 K)

41
I. Pancheva, M. Nedyalkova, P. Petkov, H. Alexandrov, V. Simeonow
General Assessment of the Efficiency of Actions for Achieving Optimal Training Environment, Research, Innovation and Sustaible Development of Human Capital in the Chemical Sciences Sphere [In Bulgaria

Full text: PDF (422 K)

51
New Approaches:
D. Marvakov, M. Avramov
One Lesson on the de Broglie Waves [In Bulgariam]

Full text: PDF (374 K)

62
Foreign Educational Tradition:
I. Emilov
Robert College - The First American College Around the World

Full text: PDF (1554 K)

69
Advanced Science:
M. Avramov, D. Marvakov
First Steps in Quantum Physics: Basics - 1. Method [In Bulgarian]

Full text: PDF (728 K)

85
History and Philosophy of Science:
B. Mutafschiev
Physicochemical School of Rostislav Kaischew in the Period 1950 - 1957: Reminiscences of a Witness [In Bulgarian]

Full text: PDF (421 K)

97
New Information Media:
M. Kirova, N. Kirkova - Kostova
Study of the Attitudes of Bulgarian Teachers in Science for the Application of Computer Technologies in Class [In Bulgarian]

Full text: PDF (581 K)

113
 

Khimiya, Volume 29, Issue 1(2020)

Khimiya. 29, 32-40 (2020) Author(s): L. Lazov, H. Deneva, G. Gencheva:

Abstract.In the report an assessment has been made of the possibilities for disinfection of drinking water from bacteria and viruses causing diseases, and in some cases death. The effect of ultraviolet radiation on microorganisms is examined. Also the report analyzes disinfecting of water with the help of UV lamps, LEDs and laser sources from the UV-range. Some advantages and disadvantages of water purification technology have been identified using the mentioned UV sources.

Keywords: disinfection, drinking water, UV sources, laser

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Khimiya. 29, 41-50 (2020) Author(s): S. Petrova:

Abstract.In this paper are presented observations of meteor showers from 2015, 2016, and 2017, made during the National astronomy and astrophysics camp, Beli brezi, Ardino, Bulgaria. Concepts of meteor, meteor shower, and radiant are defined and the basic features of the meteor showers: Perseids and Alpha-Capricornids are explained. Additionally a description of the way observations are made according to the International Meteor Organization - IMO in Germany for the exchange of data is discussed and a comparison between the gathered data and the summary data from other observers is made.

Keywords: meteor, meteor showers, comet, Perseids, Alpha-Capricornids

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Khimiya. 29, 51-61 (2020) Author(s): I. Pancheva, M. Nedyalkova, P. Petkov, H. Alexandrov, V. Simeonow:

Abstract.The present study aims to present as an inquiry the results of the general assessment of the organization, financing and the results obtained by the realization of the work program activities within the project frames. The participants (totally 102) gave response to totally 14 questions from an inquiry resuming basic activities of the work program for the duration o the project. The responses were presented in an evaluation scale with marks from 1 to 5 covering the whole aspect of assessment starting with “completely approve” till “not approve”. The digital assessment of each participant to each of the questions were treated, classified, and interpreted by the use of two traditional methods of the multivariate statistics, namely cluster analysis and principal components analysis. Specific relationships between the objects of the study (inquiry participants) as well as between the type of inquiry questions (variables for each participant) are found and discussed in the manuscript such as age and qualification characteristics. On a whole the basic activity within the frames of the project is assessed very positive as critical remarks are also involved as useful element for performing other European projects targeting young scientists and PhD students.

Keywords: training school; European operational program; final report

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Khimiya. 29, 62-68 (2020) Author(s): D. Marvakov, M. Avramov:

Abstract.The proposed lesson was developed in the program for the 10th grade of the secondary school, which comes into force from the 2019-2020 school year. It presents de Broglie's hypothesis about the particle wave properties, numerical estimates of the de Broglie wavelength of micro- and macro-objects in order to clarify the conditions under which their wave properties may manifest, the experimental proof of de Broglie waves is analyzed. Particular attention is paid to the physical nature of the de Broglie waves. Several questions and problems have been suggested on the material presented to assist in understanding and mastering the material.

Keywords: lessons, de Broglie waves, teaching, physics, astronomy

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Khimiya. 29, 69-84 (2020) Author(s): I. Emilov:

Abstract.Robert College (RC), the first American college around the world, was founded by Mr. Christopher Rheinlander Robert in Istanbul (Constantinople) in 1863. The college started education with 20 students with the leadership of Dr. Cyrus Hamlin. Initially two departments of instruction were planned: preparatory and collegiate.

Keywords: Robert College, Bogazici (Bosphorous) university, chemistry education, Bulgarian graduates of RC

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Khimiya. 29, 85-96 (2020) Author(s): M. Avramov, D. Marvakov:

Abstract.The work uses a method that takes into account the wave properties of particles and shows how de Broglie's wave can be used to construct a wave function in the case of one-dimensional motion, with the potential energy being constant in a given region, but changing abruptly when passing from one area to another.

Keywords: quantum physics; simple introduction

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Khimiya. 29, 97-112 (2020) Author(s): B. Mutafschiev:

Abstract.This text is written by Professor Boian Mutaftschiev (1930-2020). The years of the Depertment of Physical Chemistry of the University of Sofia after the WWII, when the intensive research studies were renewed, are described.

Keywords: Physical Chemistry in Sofia, Department of Physical Chemistry, University of Sofia, R. Kaischew

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Khimiya. 29, 113-132 (2020) Author(s): M. Kirova, N. Kirkova - Kostova:

Abstract.Information and communication technologies participate in all aspects of personal and social life nowadays. Thus, they become part of the learning environment. Тhe teachers with their knowledge, skills, attitudes, values and competencies are the main factors for effective application of technologies. The article presents the results of a survey on the attitudes of chemistry and science teachers to use computer technology in the classroom. The conceptual model of the study was developed on the basis of theories linking attitudes with behaviour and technology acceptance. Each element of this conceptual model is studied by a different part of the questionnaire, which contains a total of 35 items. The study was conducted online in 2019, with a link to the Bulgarian language questionnaire provided to 150 teachers and responses from 48 received. Based on the data, a Cronbach's alpha coefficient of 0.92 was calculated. Descriptive statistics and analysis of the frequencies of respondents' opinions were made based on the data. The results obtained show that the teachers involved in the survey: (a) perceive the conditions for the application of computer technology in their schools as encouraging and forming positive attitudes; (b) they are convinced of the usefulness of the application of technology in their own business and firmly believe that they improve it, especially with regard to the presentation of information and teaching aids; (c) they are not fully convinced about the benefits of technology in student learning, especially in class, which reduces the positive impact of perceived usefulness of ICT on teachers' attitudes.

Keywords: teacher attitudes toward ICT; science teachers; chemistry teachers; online survey

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