FROM THE RESEARCH LABORATORIES
Investigation of 238U, 234U And 210Po Content in Selected Bulgarian Drinking Water
Abstract. The radioactivity of selected sources of drinking water in Southern Bulgaria was investigated using 238U, 234U and 210Po activity measurements and dose calculation, respectively. The activities of 238U, 234U and 210Po varied from 226 to 826 mBq/L, 274 to 1623 mBq/L and < 0.6 to 25.5 mBq/L, respectively, being lower then derived concentrations for radioactivity in water intended for human consumption of the considered radionuclides, given in EC Directive 2013/51/EURATOM. In some drinking waters the mass concentration of natural uranium exceeded the set maximum chemical concentration level of 0.030 mg/L.
A radioactive disequilibrium between 234U and 238U in water was detected.
Based on the radionuclide activity concentrations total annual effective ingestion doses for adults, as well as contribution of each particular radionuclide to the total doses, were assessed and discussed. Тhe lowest contribution to the annual effective doses was found for 210Po and the highest for 234U. The results show that the annual effective doses of residents are below the reference level of 100 µSv/y according to the recommendations of the World Health Organization. The obtained new results are used to assess the radiation status of the investigated water.
Keywords: drinking water; natural radioactivity; 238U; 234U; 210Po; annual effective dose
1)Bozhidar Slavchev, 1)Elena Geleva, 2)Blagorodka Veleva,
1)Hristo Protohristov, 1)Lyuben Dobrev,
1)Desislava Dimitrova, 1)Vladimir Bashev, 1)Dimitar Tonev
1)Institute for Nuclear Research and Nuclear Energy – BAS (Bulgaria)
2)National Institute of Meteorology and Hydrology (Bulgaria)
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TEACHING EFFICIENCY
The Reflective Skill – Constructive-Prognostic Analysis In Methodological Context
Abstract. In historical aspect, the skill is among the key categories in the realm of human practice, which are often an object of different researches – psychological, pedagogical, and last but not least methodological. This is a fact, because the skill is a vital term for the description of productivity of learning experience at least in two dimensions – personally fundamental, guaranteeing its effective functioning in different situations and personally pragmatic, as a multi-level transformation of the cognitive experience, for the completion of certain social roles and the necessary qualities of the subject for this. The skill is a blend between those two dimensions of productivity both in higher education and in secondary school. The reflective skills are a structural and functional part of the transformation of the cognitive, affective, and psycho-motor experience and as such are included in the individual educational reality of the subject, and to a higher degree it defines it. This is the reason why the constructive-prognostic analysis of the reflective skill in the area of Methodology is pointing at the answer of the questions: What is this, what is its structure, how does it get integrated in the system of skills, how does it form and develop. The answers of those questions are basis of its methodological decoding in the process of training teachers and students in Biology. All of this describes the territory of the methodological context of analysing the reflective skill.
Keywords: reflective skill; relationships in the cognitive experience; technology quality
Наталия Цанова, Надежда Райчева, Иса Хаджиали
Sofia University „St. Kliment Ohridski“
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Methodological Framework To Develop Meaning Formation Categories In Methodology Of Biology Education
Abstract. Science could be thought as mature in cases it obtains clear terminology and methodology i.e. recognizable scientific language and object to be researched. The integrative sciences, such as the methodology of biology education, face the challenge to look for themselves “overshadow” of other sciences related to object or methodology. In search for defined territory among sciences, critically important is elucidating the categories and deducing fundamental concepts of a given science. Transfer of experience takes place in four-dimensional system – on first place, are ideas, on the second, are symbols, signs, and terms related with ideas; the third dimension is objective meaning, other words representation in reality (in culture as values – technological, ethical, aesthetical and so on) and the last dimension is methodological that marks interaction subject-object in research field. These four dimensions encompass the territory of scientific and educational sense and can be used as a methodological framework in developing fundamental categories of a specific science.
Keywords: categories; methodology of biology education; scientific methodological framework
Dr. Nadezhda Raycheva, Assoc. Prof.
Sofia University „St. Kliment Ohridski“
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EDUCATION: THEORY AND PRACTICE
First Steps In Quantum Physics: Basics – 2. Model Examples (Square Wells)
Abstract. Cases of a particle in a one-dimensional square well – infinitely deep and with finite depth – are also analyzed in detail. As an example, the adsorption of a hydrogen atom on a metal surface by a qualitative and accurate solution of the problem is considered.
Keywords: quantum physics; square well; metal surface; adsorption
Dr. Mihail Avramov, Dr. Dimitar Marvakov
Sofia University „St. Kliment Ohridski“
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CURRICULUM MATTERS
Functional Analisis Of Desing Of Pedagogical Decision As Profesional Skill
Abstract.A part of a professional teacher’s competency is making the pedagogical design in the territory of the defined situation and includes numerous skills that function as a whole and are visible in final result related to evaluation and choice of educational resources or develop ideas for parts or for the whole process of education in a defined pedagogical context. Some of these skills that regulate professional decisions are related to retrospection of experience (learning, teaching, cognitive and affective), with an evaluation of elements of experience and after that with a choice what and how to take a part in the final professional decision. Adequacy with professional purpose and internal consistency and coherency in the decision are criteria for analysis of pedagogical construct. In the present report are discussed relations between fundamental pedagogical and methodological professional skills and their evaluating-reflective shell in context of design of professional pedagogical decision from perspective of ideal pre-defined situation.
Keywords: professional skills; biology teacher; pedagogical solution
Dr. Nadezhda Raycheva, Assoc. Prof.
Sofia University „St. Kliment Ohridski“
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NEW APPROACHES
A Study On Reflection With 15 – 17 Year Olds In School Biology Education In An Intellectual And Personality Aspect
Abstract. The report highlights into an empirical study of the intellectual and personality reflection correlations with 15 to 17- year old students in school biology education. The experiment draws upon two research groups, control group consisting of 80 students and an experimental one made up of 90 students instructed in various secondary schools around Bulgaria. All analyses have been performed using SPSS 13 software (statistics) and the correlation coefficients of Spearman – Brown (rsb) and Pearson (r). They provide ample evidence that the designed model of technology, based on reflection, helps students develop and enhance their reflective, cognitive and self-awareness skills in genetics and biotechnology classes.
Keywords: correlation; intellectual reflection; personal reflection; reflective approach; reflective technology.
Dr. Isa Hadjiali, Assoc. Prof.
Sofia University „St. Kliment Ohridski“
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