Lower-Secondary School Chemistry Textbooks’ Didactic Equipment

Textbooks’ fundamental influence on teaching is caused not only by their subject matter, but also by their didactic elaboration. Textbooks’ individual functions are fulfilled through incorporated structural elements. Their pool is referred to as the didactic equipment of the textbook and represents qualities of the textbook through the options it gives to its users. The presented overview of lower-secondary chemistry textbooks’ didactic equipment included 7 series of currently available textbooks. Results of the analysis serve not only as a possible guide for chemistry teachers’ textbook selection, but they also provide insight into the current state to authors of textbooks and other didactic materials. Chemistry textbooks for lower-secondary schools achieve relatively high didactic equipment (75-92 %). The best equipped are the series of textbooks published after the current state curriculum introduction (by publishing houses Fraus and Nova Skola). Surprisingly, however, the most recently published textbooks by the Taktik publishing house showed the lowest didactic equipment.

Determining Cellulolytic Activity of Microorganisms

Decomposition of cellulose to glucose requires complex cooperation of glycoside hydrolase enzymes. As a result of glycoside β-1,4 bonds hydrolysis, shorter chains of cellulose, oligodextrin, cellobiose and glucose are created. A number of bacteria and fungi demonstrate the capacity to degrade cellulose. Their activity can be assessed with the use of qualitative and quantitative methods. Qualitative methods with the use of e.g. Congo red, are used in screening studies, however, they do not provide information about the quantity of the produced enzyme. Spectrophotometric methods are more accurate and they measure the quantities of reducing sugars with the use of appropriate substrates, e.g. carboxymethylcellulose is used to determine endoglucanases, avicel cellulose to determine exoglucanases and Whatman filter paper to determine total cellulolytic activity. Activity of microorganisms depends not only on their species or type but also, among others, on substratum composition, cultivation conditions and the appropriate selection of parameters of the carried out enzymatic reactions.

Conditions for Experimental Activities at Elementary and High Schools from Chemistry Teachers’ Point of View

School experiments represent a necessary means of subject-matter presentation in chemistry education and are important for chemical (scientific) thinking. Despite being a focus of several texts, a complex view on the experimental activity in chemistry education in Czechia is missing. The results of a questionnaire survey among 466 lower-secondary, lyceum and grammar school teachers focused on types of conducted experiments, their frequency, the place they are conducted. The most frequently used chemicals and sources of inspiration are presented in the paper. The results show that despite experiments’ significant role in education, its occurrence is rather seldom and teacher’s demonstrations prevail over students’ experiments. The list of the most often used chemicals suggests the experiments are mostly focused on inorganic chemistry. These results open further questions regarding occupational safety at schools as an important factor which could also be the reason for such a low representation of experiments in Czech chemistry education.

Hydrogen - Some Historical Highlights

The early history of experiments in which an inflammable air was prepared is outlined. Once hydrogen had been discovered by Cavendish in 1766, the world of science and technology was given a colossal impetus. Its scientific and social consequences form the main focus of this essay. Special attention is given to explain why experiments were done, and their aims. The many difficulties which confronted scientists in the interpretation of their results are discussed. Timelines have been used in order to facilitate an understanding of the evolution of ideas. A particular emphasis is given to the story of how, through spectral analysis of the hydrogen atom, our understanding of atomic structure developed. Experiments involving hydrogen constitute important teaching material in schools. Detailed instructions are given for making hydrogen in the laboratory and for demonstrating its lightness and flammability. Suggestions are made of how to use these reactions to teach a wide variety of chemical concepts and facts.

Remediation of CO2 in Boudouard’s Reaction as an Example of Reversible Chemical Reaction

One of the fundamental elements of a scientist's work is the ability to lead observations of the phenomena that surround us and based on them making conclusions. These observations are conducted within the so-called scientific experiments. Lessons learned based on the results obtained in experiments allow researchers to better understand the essence of the phenomena occurring in the world around us. Drawing conclusions is not always easy. In order to achieve this skill, we must possess a well-established knowledge in the field of the phenomenon that interests us. The most striking example of how important skills are observation and drawing proper conclusions is the phenomenon of global climate warming. The main parameter influencing temperatures registered on Earth is the concentration of greenhouse gases in the atmosphere, and especially carbon dioxide created from combustion processes. A significant role in studies of the reduction of CO2 emissions plays chemists. To be sure that conducted by them experiments are optimally designed, it is necessary to ensure them with proper education already at the secondary school level. The main aim of this article was to conduct the study in order to explain chemical issues that create the greatest cognitive difficulties among students. The second aim of the article was to propose a chemical experiment to students that would allow them to find out more about the phenomena governing in the area of problematic issues. The proposed experiment is based on the concept of solubility equilibrium. Results of preliminary tests that have been carried out after applying this experiment on a small group of students, indicated their better understanding of the studied subject.

Basic Multivariate Statistical Methods for Environmental Monitoring Data Mining: Introductory Course for Master Students

The present introductory course of lectures summarizes the principles and algorithms of several widely used multivariate statistical methods: cluster analysis, principal components analysis, principal components regression, N-way principal components analysis, partial least squares regression and self-organizing maps with respect to their possible application in intelligent analysis, classification, modelling and interpretation to environmental monitoring data. The target group of possible users is master program students (environmental chemistry, analytical chemistry, environmental modelling and risk assessment etc.).

Human Resources and R&D at the Institute for Nanomaterials, Advanced Technologies and Innovation (TUL)

Within the next few years, Europe’s economic paradigm will change fundamentally. Its manufacturing base will continue to shrink, and therefore future growth and social welfare will rely increasingly on knowledge-intensive industries and services, and ever more jobs will require a higher education qualification. Human resources are a core determinant of quality in higher education and research. Universities must therefore work to enhance their human potential, both qualitatively and quantitatively, by attracting, developing and keeping talent in teaching/research careers. Excellence may only emerge from a favourable professional environment based in particular on open, transparent and competitive procedures. Research and development (R&D) has proven to be a crucial factor in shifting the world’s technological frontiers, while at the same time facilitating new technological and scientific innovations. This paper will focus on R&D at the Institute for Nanomaterials, Advanced Technologies and Innovation at the Technical University of Liberec, Czech Republic. After a description of a literary search in the introduction, the specific real situation at this institute is mentioned, i.e. the number of submitted and solved national and international projects, statistics on research and development sources, and of course human resources at the institute. In the conclusion, the reader will be able to get a picture of how to increase the institute competitiveness in international collaboration.

Pupils’ Preconceptions About Heat, Temperature and Energy

This article is focused on finding out pupils’ preconceptions about heat, temperature and energy. As a research tool we used a didactic test with individual types of tasks about the concepts. A total of 122 respondents aged 12 to 14 participated in the research. The research sample consisted of two groups of pupils. One group consisted of pupils attending a school assigned for talented pupils, for simplicity they are referred as talented pupils. The second group consisted of pupils who do not attend this type of school, we marked them as “general population”. The number of respondents in the sample of talented pupils was 54. The number of respondents in the sample “general population” was 68 pupils. In the research we compared ideas about concepts heat, temperature and energy of talented pupils and pupils of the “general population”. We also compared talented pupils and pupils of the “general population” in solving of conceptual and algorithmic tasks in didactic test. We found out pupils of the age from 12 to 14 have misconceptions about the concepts. We also identified the misconceptions and the most common are also mentioned in this article.

Study on in vitro Toxicity of Biometal(II) Monensinates Against Rat Zajdela Liver Tumour

The ability of Monensic acid A (MonH∙H2O) and its neutral metal complexes [M(Mon)2(H2O)2]with ions of Mg2+, Ca2+, Mn2+, Co2+, Ni2+ and Zn2+ to decrease viability and proliferation of primary cell cultures, originating from a chemically induced transplantable liver tumour of Zajdela in rats, and bone marrow cells from the same tumour-bearers, was evaluated. Experimental data revealed that manganese(II) and nickel(II) complexes of Monensin A are relatively more selective against the tumour as compared to the healthy bone marrow cells.

Water Quality and Ichthyofauna Habitat Conditions in Lake Czolnowskie (N-W Poland)

Increasing anthropopressure affects natural ecosystems and may express itself in regional or spot contamination of water and soil environment. The quality of ground and surface waters depends to a large extent on drainage area management, where biogenic substances (i.e. nitrogen, phosphorus and potassium) are transported with surface run-offs to the environment. The article discusses results of studies on the drainage area of Lake Czolnowskie (Zachodniopomorskie Province). Studies covered physical and chemical assessment of soil conditions and water quality; additionally, fish was caught using two independent methods - gillnets and power generator (pursuant to CEN EN 14011 2003 and PN-EN 14011 2006). Results obtained confirm regular run-off of biogenic materials from the surface of farmed drainage area to Lake Czolnowskie. During the period of studies, the reservoir was exposed to i.e. reduction of water oxygen (3.56 mg/dm3) and permanently elevated level of general phosphorus (0.15-0.27 mg/dm3) and ammonium acid (0.16-0.27 mg/dm3), which degraded the quality of life for ichthyofauna inhabiting the lake.