Сп. „Химия“, книжка 5/2017

News

47th National Conference of Bulgarian Teachers in Chemistry

Online

News

Journal of Interest: A Review (2016) – Bulgarian Journal of Science and Education Policy (BJSEP)

B. V. Toshev

Letters to the Editor

Teaching of Geography in 7th Grade: Difficulties When Applying the New Education Law

I. Drenovski, I. Russeva

Letters to the Editor

How Should the New Curriculum on Geography and Economy for the 8th Grade Look Like?

I. Drenovski, I. Russeva

Letters to the Editor

On the Placement of Hydrogen and Helium in the Periodic System: A Response of Cvetkovic and Petrusevski

M. Labarca, A. Srivaths

Letters to the Editor

A Comment on the Srivaths – Labarca Periodic Table

E. Scerri

Education: Theory & Practice

The Enjoyment – A Factor of Wellbeeng in Biology Education [In Bulgarian]

Резюме. The communication in the classroom could be analyzed from different points of view – effectiveness of learning and instruction, emotional and social development of pupils, social inequality and so on. The present research was designed to investigate the relationships of the mother’s education to the general patterns of pupil enjoyment regarding their classroom experience. It was concluded that there aren’t significant differences between pupils based on the social marker mother’s education. Understanding the family background and its influence upon the education is the very consequential task for the policy makers. Along with this, the experience of pleasure from pupils can be defined as an influential dimension of the effectiveness of learning and instruction in the school.Although there are not found consistently significant differences between the assessments of the statements on the scale “enjoyment“, developed by the group of German researchers, it is obvious that the organizing strategies of teaching determine pupil’s feelings during the classroom interaction.
Keywords: communication, social, interaction, teacher, enjoyment, wellbeing

N. Gerdzhikova

Education: Theory & Practice

Higher Education in Engineering and Technology – The Present Scenarion

Резюме. The Higher Education system all over the world in general has over the years been evolving and changing to meet the essentialities of its citizens. In order to improve and sustain, standard efforts are put in to create better atmosphere for reaching higher echelons. Education systems that are introduced enhances the social, environmental and quality of the country in general. The type of education and access to education has a direct relationship to the economical development and the country’s progress. Though we could see progress happening but we have to ensure that quality education is provided. With specific reference to India, we have at present 6,415 engineering/technology institutions with an intake capacity of 1,844,642 students at the under-graduate level. At times it seems that due to mushrooming of technical institutions in India, the challenge in maintenance of quality in technical education takes a very serious dent. In fact this issue remains upper most in the minds of the students, the parents, the faculty and the industry alike. There is a strong correlation between a country’s competitiveness and the quality of education, more so of higher education. Developing nations like India should start to explore and exploit its excellent potential and move forward, to attain a higher level of quality in engineering education, by strengthening its talent. The various quality assurance approaches and models that are in place elsewhere in the world could be studied, compared and applied in shaping the national vision.
Keywords: higher education, Indian scenario, regulating bodies

T.G. Balachandran, S. Sendilvelan

Curriculum Matters

Design of an Educational Technology in Engineering Ecology [In Bulgarian]

Резюме. The effectively formed professional competence is a guarantee, that the graduating students are prepared for the future professional challenges. A technological model of teaching and learning in a compulsory course in engineering ecology from the Bachelor program „Heat Engineering“ of TU-Sofia is presented in the article. The technology has been developed on a broad, integrative theoretical basis and on the basis of an international and national studies which are related to the preparation of future engineers. The outlined components of the model – goal setting, learning content, teaching and learning activities, resources and diagnostics are based on a survey of teachers, employers and students on the ability to create the necessary professional competencies. The obtained results prove that the applied model corresponds to the set training objectives, the strategy and the vision for development of TU-Sofia and the requirements of the business. The introduction of modules related to risk assessment, uncertainty, sustainability and environmental impact assessment significantly broadens the prospects of future engineers at the beginning of their careers. The developed technology provides opportunities for creating and validating the appropriate tools for studying students’ achievements and the degree of formation of their professional competencies.
Keywords: engineering education, engineering ecology, professional competence, educational technology

N. Ilieva, E. Boiadjieva

Curriculum Matters

Dissipation of Heat: Essential Feature of Cyclic Irreversible Processes

Резюме. The article discusses one key characteristic of irreversible processes: in order to bring the system back to its original state following such a process, some energy is inevitably dissipated as heat into the surroundings. Greater dissipation indicates greater irreversibility. In the limit that the amount of energy dissipated approaches zero, the process is said to be reversible. This concept is illustrated by considering isothermal expansion of an ideal gas, free expansion of an ideal gas into vacuum, heat transfer from a hotter object to a colder one, phase change, and chemical reactions.
Keywords: reversible process, irreversibility, cyclic process, isothermal expansion, phase change, heat transfer

J. Ahmad

Teaching Efficiency

Investigating the Ability of 8th Grade Students to Design an Experiment Through Guidelines as a Part of the National Chemistry Competition Test

Резюме. A study was conducted to test the ability of 8th grade students to design an experiment using previously provided guidelines. The sample comprised 64 students chosen to participate at the National chemistry competition in 2016/17 school year. The students were tested on the following topics: state of matter; metals and non-metals; elementary substances, compounds and mixtures; chemical reactions and introduction to organic chemistry. An analysis of students’ scores was performed, but the qualitative analysis of their answers and drawings was of great importance in such way that it helped the authors to get deeper insight into students’ thinking processes and to further understand the origin of their misunderstandings. The findings showed quite high achievements. Still, many misunderstandings, erroneous notions and lack of conceptual and procedural knowledge were detected among students. Most problems were observed in answering the item III-3, while the greatest success was noticed in the item II. Many students did not have firm knowledge and clear awareness about the process of boiling – they did not appreciate the presence of both liquid and gaseous form of the substance at the boiling point, could not determine the boiling point of a liquid using the heating curve and were not able to locate the point on the curve where boiling occurs.
Keywords: conceptual understanding, heating curve, lower-secondary education, designing an experiment, National chemistry competition

M. Stojanovska, V.M. Petrusevski

Teaching Efficiency

Contest-Based Student Research Project Work Within the Framework of the Analytical Chemistry Course

Резюме. The paper discusses student research project work as an essential component of the context-based approach to teaching analytical chemistry. The key principles of student research project work were formulated. Step-by-step planning and organization of this work was proposed considering different functions of the teacher and the student in the research project activity. The context-based approach was illustrated by an interdisciplinary project on designing software for measuring nitrates in vegetables. The effectiveness of the research project work was evaluated by a students’ survey. Attitudes toward research projects were very positive and students developed a better understanding of practical importance of analytical chemistry.
Keywords: student research project, interdisciplinary project learning, context-based learning, software resource for analytical chemistry

N. Stozhko, B. Bortnik, A. Tchernysheva, E. Podshivalova

Experiments

Synthesis of ToO2-M (Cd, Co, Mn) as a Photocatalyst Degradation of Methylene Blue Dyw

Резюме. TiO2-M (M = Cd, Co, Mn) were synthesized by sol-gel method using titanium(IV) isopropoxide (TTIP) and cadmium sulfate octahydrate (CdSO4.8H2O), manganese(II) sulfate monohydrate (MnSO4.H2O), cobalt(II) sulfate heptahydrate (CoSO4.7H2O) as precursors. M-doped TiO2 was performed with molar ratio 1:3; 1:2; 1:1; 2:1; 3:1 (mol Ti / mol M) and photocatalytic processes using visible light with irradiation time for 5, 10, 15, 20, 25 and 30 minutes. This study was carried out to determine the effect of different metal ions, the composition of Ti:M and the exposure time on the photocatalytic degradation of methylene blue dye. The results showed that different metal ions influenced crystal size and affected electronic properties (band gap). Crystal size of TiO2 > TiO2-Mn > TiO2-Co > TiO2-Cd and band gap of TiO2 > TiO2-Cd > TiO2-Co > TiO2-Mn. In addition, differences of Ti:M composition also influenced the photocatalytic activity. The longer of applied time exposure, the higher photocatalytic degradation of methylene blue was achieved. The optimum composition of Ti:M was obtained at Ti:M ratio by 3:1 with degradation values by 92.56% (TiO2-Cd), 90.44% (TiO2-Co), and 89.42% (TiO2-Mn).
Keywords: methylene blue, metal doping, photocatalytic degradation, TiO2-M, visible light

C. Purnawan, S. Wahynningsihr, D.N. Aisyah

Experiments

A Novel Approach for Kinetic Study of Alkaline Hydrolysis of Ethyl Acetate

Резюме. We present an innovative electromotive force (EMF) measurement technique to study the kinetic behavior during alkaline hydrolysis of ethyl acetate. The explicit feature of this research is the application of green chemistry ideas that are inherent in the experiment. Using the new approach, we find that the kinetic behavior of the reaction under study follows second order with an estimated rate constant value at 25°C to be 2.45 × 10-3 cm–3 min–1. This value is in excellent agreement with the conventional end-point neutralization titration method discussed previously in the literature. The novel EMF measurement technique is simple, fast, accurate and eco-friendly. Keeping in view of long-term sustainability of the ecosystem, we feel that there is an urgent need to switch over from conventional laboratory practices to green chemistry approaches. Further, the method discussed here may prove to be extremely useful for teachers, researchers and students who wish to carry out kinetic study of other systems.
Keywords: kinetic study, emf measurement, eco-friendly

Mala Das Sharma, U.S.V.R. Hymavathi

From the Research Laboratories

Effect of Different Cadmium Concentration on Some Biochemical Parameters in ‘Isa Brown’ Hybrid Chicken

Резюме. The objective of this study was to verify an impact of different Cd ion concentrations on metabolic (biochemical) parameters in blood of egg chickens. Taking in to consideration that change of these values reflects the level of damage of the vital organs like liver, kidneys, hart etc. These vital organs determine the health status, growth and development of organisms. In the total of four groups of chickens have been included in the experiment. Three groups were treated with different concentrations of cadmium (2, 4 and 6 mg/kg) while one group was set as a control group without treatment. Eleven different biochemical parameters have been measured and analyzed such as: total proteins, albumins, globulins, aspartate transaminase, alanine transaminase, lactate dehydrogenase, gamma-glutamyl transferase, alkaline phosphatase, blood urea nitrogen, creatinine and glucose. The results indicate the significant changes on the level of biochemical parameters in blood, by increasing the cadmium concentration. The level of albumins, alanine transaminase, lactate dehydrogenase, gamma-glytamyl transferase, and creatinine has been decreased significantly compared to control group while other parameters were increased. The biochemical parameters between treatments were changed significantly. Total levels of proteins, globulins, aspartate transaminase, alanine transaminase, gamma-glutamyl transferase, creatinine and glucose has been increase by increased the cadmium concentration. While in another hand, biochemical parameters such as lactate dehydrogenase and alkaline phosphatase has been decreased significantly when the Cadmium was increased. Changes on biochemical parameters are an indication showing that, cadmium effects are negatively oriented on metabolic processes of feed on egg-layer chickens.
Keywords: cadmium, biochemical analyses, body weight, chickens

I. Haziri, A. Rami, F. Latifi, D. Beqiraj-Kalamishri, I. Mehmeti, A. Haziri

Science and Society

Phytochemical and In Vitro Antioxidant Studies of Primula Veris (L.) Growing Wild in Kosovo

Резюме. The antioxidant capacities, total phenolic and flavonoid content of five different extracts (Et2O, CHCl3, EtOAc, n-BuOH and H2O) of Primula veris (L.) growing wild in Kosovo were analyzed. Total phenolic and flavonoid content were quantitatively determined to the Primula veris (L.) growing wild in North-Western part of Kosovo in two different altitude levels (670 m and 1200 m). The amount of total phenolics in Primula veris (L.) extracts ranged from 5.10 mg GAE/g d.e. in altitude 1200 m to 17.30 mg GAE/g d.e. in altitude 670 m. The amount of total flavonoids in Primula veris (L.) extracts ranged from 12.15 mg RE/g d.e. in altitude 670 m to 31.43 mg GAE/g d.e. in altitude 1200 m. Free radical scavenging capacity (RSC) was evaluated by measuring the scavenging capacity of extracts on DPPH, NO as well as on hydrogen peroxide (H2O2). EtOAc, n-BuOH and H2O extracts of Primula veris (L.) expressed very strong scavenger activity. On the other hand, Et2O and CHCl3 extracts showed much weaker effect in the neutralization of DPPH, NO and H2O2. The observed differences in antioxidant activity could be partially explained by the levels of phenolics and flavonoids in extracts of Primula veris (L.). Hence, this plant can be used to discover bioactive natural products that may serve as leads in the development of new pharmaceuticals.
Keywords: Primula veris L., extracts, phytochemical, antioxidant

I. Rudhani, F. Raci, H. Ibrahimi, A. Mehmeti, A. Kameri, F. Faiku, M. Majlinda, S. Govori, A. Haziri

Past Times

Pedagogical Poem (Makarenko, 1949) [In Bulgarian]

B. V. Toshev

Свързани статии:

Сп. „Химия“, книжка 1/2017 Сп. „Химия“, книжка 2/2017 Сп. „Химия“, книжка 3/2017 Сп. „Химия“, книжка 4/2017