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Volume 27, Issue 3  (2018)

Education: Theory & Practice:
T. Yovcheva
Physics Is an Ever Young Science

Full text: PDF (270 K)

J. Gariopova, P. Georgieva, A. Georgiev
Empirical Bayesian Estimates of Operational Reliability Related to Electronic Items for Medical Purpose

Full text: PDF (717 K)

V. Radeva
International Astronomical Program for the Search of Asteroids - Collaboration between Scientists, University Students and High School Students [In Bulgarian]

Full text: PDF (457 K)

G. Karafezieva
Three Ideas for Effective Teaching [In Bulgarian]

Full text: PDF (772 K)

T. Gancheva
Optical Phenomena in Nature [In Bulgarian]

Full text: PDF (338 K)

G. Dobreva, J. Jekova, M. Chonos
The Magic of Creativity as a Path of Successful Learning [In Bulgarian]

Full text: PDF (806 K)

R. Kostadinova
Extracullicular Activities in Astronomy [In Bulgarian]

Full text: PDF (411 K)

V. Stoyanova, P. Georgieva
Early Science Education Through Thinking Cards [In Bulgarian]

Full text: PDF (822 K)

N. Dimitrova, D. Dimova
Interactive Methods and Environmental Education in Teaching "Man and Nature" in Grades 5th -6th [In Bulgarian]

Full text: PDF (596 K)

R. Kichukova, T. Marinova
The Dominoes Games During Physics [In Bulgarian]

Full text: PDF (521 K)

V. Radeva
Student Space Agency: An Educational Program in Astronomy and Cosmonautics [In Bulgarian]

Full text: PDF (515 K)

S. Stoyanova, A. Marinova
Dark Matter in the Classroom [In Bulgarian]

Full text: PDF (1512 K)

A. Dimitrova
Visualizations in Teaching Physics and Astronomy [In Bulgarian]

Full text: PDF (378 K)

A. Hristova, G. Vangelov, I. Tashev, M. Dividov
Problems in Teaching Physics at Nikola Vaptsarov Naval Academy [In Bulgarian]

Full text: PDF (993 K)

Z. Raykova, G. Vuldzhev, N. Moneva, N. Komsalova, A. Nabi
Constructing a System of Internet-Based Learning Resources in Physics: Evaluation of the Didactic Value [In Bulgarian]

Full text: PDF (494 K)

N.T. Dolchinkov
Competition in Applied Electronics for Military Students [In Bulgarian]

Full text: PDF (923 K)

N.T. Dolchinkov
Photo and Poster Competition in Vasil Levski National Military University - Veliko Tarnovo [In Bulgarian]

Full text: PDF (927 K)

G. Varbanov, R. Michaylov, D. Simeonova, Y. Eneva
Innovations in the Treatment of Malignet Neoplasms: Treatment with Brochytherapy

Full text: PDF (1004 K)

D. Kosturkov, T. Uzunov, P. Uzunova
Influence of the Gingival Tissues on the Measured Saturation Level of the Dental Pulp Blood Flow

Full text: PDF (553 K)

N. Ivanova, B. Manusheva
Natural Radionuclides in Drinking Water

Full text: PDF (556 K)


Khimiya, Volume 27, Issue 3(2018)

Khimiya. 27, 319-320 (2018) Author(s): T. Yovcheva:

Abstract.A Conference - Varna, October, 27-29, 2017


Khimiya. 27, 321-333 (2018) Author(s): J. Gariopova, P. Georgieva, A. Georgiev:

Abstract.This paper is focused on a reliability analysis of the exponential model parameters by a reliability parametric Bayesian estimation in regard to one type of medical items. The analysis is based on using a priori data for analyzing current incoming information. The t case study aims at formalizing prior and accumulated sampling data obtained from operational events occurring during the operation in the form of reliability empirical data with respect to a type of semi-automatic blood pressure monitors. As a result of the case study and the analysis, the point estimates of the operational reliability indices valid for the medical items under study are experimentally obtained.

Keywords: E-Bayesian point estimates, parametric Bayesian approach, reliability data analysis, type I censored data


Khimiya. 27, 334-339 (2018) Author(s): V. Radeva:

Abstract.An International Astronomical Program for the discovery and tracking of asteroids has been developed. The results from the work of students in observational campaigns are discussed. The collaboration between scientists, university students and high school students is outlined.

Keywords: astronomy education, international astronomical collaboration, asteroids


Khimiya. 27, 340-343 (2018) Author(s): G. Karafezieva:

Abstract.Three ideas for facilitating the process of teaching high school physics are proposed and discussed in brief: using the program “hot potations”, using the so called “cloud computing”, and using the Power Point in VBA programing language.

Keywords: ICT, physics education


Khimiya. 27, 344-348 (2018) Author(s): T. Gancheva:

Abstract.The article presents the experience in the extra-curricular activity of using information technologies and interdisciplinary links between the subjects of physics and astronomy, geography and economics and biology and health education in the lower secondary level as means of interactivity.

Keywords: nature, optical phenomena


Khimiya. 27, 349-356 (2018) Author(s): G. Dobreva, J. Jekova, M. Chonos:

Abstract.The report examines the extra-curricular activities of the Club "Multi-Visually" - creating projects, exhibitions, brochures, etc. Work on them is an appropriate means of forming new knowledge, skills and competencies to provoke creative thinking and natural learning through the use of interactive methods and tools.

Keywords: creativity, motivation, interactive learning, club activity, group work


Khimiya. 27, 357-364 (2018) Author(s): R. Kostadinova:

Abstract.The aim of this paper is to present opportunities for extracurricular work in astronomy. The participants in the extracurricular activities are students from the 6th to the 12th grade of Ivan Vazov Secondary School in Varshets, as well as from Montana and the country. Tasks for implementing extracurricular forms are: planning and preparation; construction; realization; analysis of results. Extracurricular activities on astronomy develop capabilities for monitoring and analysis of astronomical phenomena, creating skills for making conclusions, broaden the minds of students about natural phenomena and laws that explain them.

Keywords: extracurricular work, astronomy


Khimiya. 27, 365-375 (2018) Author(s): V. Stoyanova, P. Georgieva:

Abstract.The educational capabilities of mind maps are presented. Topics on physics and astronomy are discussed with thought cards being included in the process of teaching. The results of this innovative method of education and pedagogical ideas for the development of their creation and implementation are presented.

Keywords: creative thinking, educational cards, natural science, thinking cards


Khimiya. 27, 376-385 (2018) Author(s): N. Dimitrova, D. Dimova:

Abstract.The report explores the learning content of the 5th and 6th Grades Man and Nature curricula in order to highlight key environmental issues. The aspect of the psychological and cognitive characteristics of 11- and 12-year-old students is considered. On the basis of the analysis of these two key aspects of the effectiveness of science education, opportunities are offered to use interactive learning methods and to to help teachers in early science education to form of environmental awareness in the pupils.

Keywords: environmental education, school science education, interactive learning methods


Khimiya. 27, 386-392 (2018) Author(s): R. Kichukova, T. Marinova:

Abstract.This article describes a physics and astronomy revision lesson for pupils in grade 9. The aim of the lesson is students to exercise and reiterate everything learned during that year while still having fun. The non-traditional way of revision touches on physics terms, their meaning and usage in the field of electrostatic interaction. Apart from the scientific side of the lesson, this article touches on the ways the teams for the group work are formed as well as the ways their answers are being checked. The feedback on the teams' answers is also acquired by other interactive means such as intellectual card and dynamic poster. Finally, based on the results from the lesson as well as the attitude shown from a questionnaire filled in by the students, the pros and cons are discussed and how effective the lesson was.

Keywords: innovations in teaching, physics, electrostatic interaction


Khimiya. 27, 393-400 (2018) Author(s): V. Radeva:

Abstract.“Student Space Agency” was established and many students were educated in its different forms and programs. This initiative can be considered as successful for the students, as well for the teachers. The activity of this Agency during the years was listed and commented.

Keywords: astronomy & space education, inquiry-based learning, astronomical observations, planets, аsteroids, space settlements


Khimiya. 27, 401-410 (2018) Author(s): S. Stoyanova, A. Marinova:

Abstract.This report illustrates a possibility for using modern computer
technologies for the purpose of involving students in real research projects,
modernizing the educational content and increasing the number of astronomy
classes. Students acquire methodological skills, they profit from their knowledge in physics and computer sciences and see their application in real life.

Keywords: radio telescopes; dark matter; students


Khimiya. 27, 411-414 (2018) Author(s): A. Dimitrova:

Abstract.Visual aids are the basis of teaching. They have an active leadership in thinking and perception; they are included in the teacher's exposition and are often based on them; allow concordance of hearing and visual perception; allow the teacher to accomplish a variety of didactic goals and tasks; allows them to be applied in the process of self-employment. They can also be used in a complex way to place learning problems, to instruct the students before their practical work with naturally supervised means of activating the learning process. The various visual aids should be combined wisely to give pupils more specific and, in turn, versatile ideas about physics and physical phenomena studied.

Keywords: visual resources, teaching, auditory and visual perception, sampling


Khimiya. 27, 415-423 (2018) Author(s): A. Hristova, G. Vangelov, I. Tashev, M. Dividov:

Abstract.In technical universities the discipline of Physics is studied by the majority of the students. Many of the first-year students at the Military Academy "N. J. Vaptsarov"do not have the necessary groundwork for this. The weaker results of the students in recent years show that they are not ready to acquire the necessary knowledge and practical skills for the short time of fundamental preparation. Even the most elementary university course teaches many new key concepts that remain undigested from the beginning. This leads to a misunderstanding or mechanical reproduction of their applications, which is the complete opposite of the ultimate goal of training future engineers. The presented project studies the dependency between the different levels of preparation of the students in mathematics and physics at the beginning of the semester and their results at the end of the training. For the purpose of the study, 215 first-year students were interviewed and a statistical analysis of the collected data was carried out. The obtained results will help to develop, discuss and propose initiatives to improve the training in the Department of Mathematics and Physics.

Keywords: physics teaching, diagnosis of the learning process, level of training, exam results


Khimiya. 27, 424-430 (2018) Author(s): Z. Raykova, G. Vuldzhev, N. Moneva, N. Komsalova, A. Nabi:

Abstract.A didactical model of training of students in physics and engineering was developed by using of different internet-based learning sources. An attempt of evaluation the didactic value has been made.

Keywords: ICT in physics education, modern teaching approaches, active learning


Khimiya. 27, 431-437 (2018) Author(s): N.T. Dolchinkov:

Abstract.During the last two years at the Vasil Levski National Military University there was a student competition, which is not directly related to the military training. In 2016 the "Best young physicist in electronics” competition was held. The competition was attended by 70 military students, mainly from the first term, and 12 students were finishing the final. A year later, the same competition was held in two rounds.

Keywords: competition, electronics, physics, military school


Khimiya. 27, 438-444 (2018) Author(s): N.T. Dolchinkov:

Abstract.These students’ competitions were realized in the Vasil Levski National Military University – Veliko Tarnovo, Bulgaria. They appear to be successful tools for enhancing the interest of students to physics in collaboration with people from other universities and secondary schools.

Keywords: photo contest, poster, exhibition, students, school, awards


Khimiya. 27, 445-453 (2018) Author(s): G. Varbanov, R. Michaylov, D. Simeonova, Y. Eneva:

Abstract.This report shows one of the contemporary methods of malignant neoplasms' treatment - brachytherapy. Solid or liquid radioactive sources are used. Brachytherapy is a type of intercellular radiotherapy in which the source of radioactive energy is placed near the organ or directly in it. The ionizing energy destroys the structure of DNA and thus hinders cell division. During the treatment, specially targeted radiation is delivered to the tumor without any damages to the surrounding tissues and organs. The advantage of brachytherapy, compared to EBRT is that the damaged cells are fewer. In brachytherapy, radioactive materials are implanted in the form of seeds or liquids via feeder. The radioactive seeds consist of a titanium capsule containing a redioactive element 125I or 192Ir and a metal radiographic marker for tracking the capsule. Brachytherapy is used for treatment of cancer of the prostate, vagina, cervix, breast, skin, esophagus, face and neck, gallbladder, etc. In Bulgaria, brachytherapy is practiced in Sofia, Stara Zagora, Shumen and Veliko Tarnovo. In the oncology center in Shumen between 150 and 170 patients are treated with brachytherapy every year which is 1/6 of all patients, being treated in the center.

Keywords: brachytherapy, malignant neoplasms, radiotherapy


Khimiya. 27, 454-459 (2018) Author(s): D. Kosturkov, T. Uzunov, P. Uzunova:

Abstract.Pulse oximetry is a method by which the oxygen saturation of the blood is measured. It is based on the specific absorption of red and infrared light from the hemoglobin. In dentistry, when teeth are tested by pulse oximeter, the oral mucosa could change the light signal entering the photodetector of the device. The aim of this study is to investigate the influence of the gingival tissues on the results when teeth are tested by pulse oximeter. To realise the goal, 44 teeth of 22 patients aged 23-29 years are examined. The teeth аre examined with pulse oximeter Contec CMS 60 D by positioning the diodes on the labial side of the teeth and on the photodetector from the oral. Two tests are conducted on each tooth. The first is by directly attaching the probe to the tooth. In the second test, the gingival tissues are isolated by condensation silicone.The following mean values of saturation of the pulp are determined - in the group of direct examination of the teeth: 83% ± 1%; when the gingiva is isolated with silicone: 83% ± 1%. Analysis by SPSS v.19 show that there is no statistically significant difference between the measured saturation of the teeth in the two groups. Gingival tissues does not affect the results obtained and does not change the measured saturation levels of the dental pulp. Pulse oximetry can be used for vitality test of the teeth without the need for gingival tissues to be isolated.

Keywords: pulse oximetry, dental pulp, gingiva, diagnostics, saturation


Khimiya. 27, 460-465 (2018) Author(s): N. Ivanova, B. Manusheva:

Abstract.This article summarizes data from an examination of drinking water performed in the Varna region concerning content of natural uranium.

Keywords: drinking water, control, natural radionuclides, Varna region, natural uranium


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