rss_2.0Chemistry-Didactics-Ecology-Metrology FeedSciendo RSS Feed for Chemistry-Didactics-Ecology-Metrologyhttps://sciendo.com/journal/CDEMhttps://www.sciendo.comChemistry-Didactics-Ecology-Metrology 's Coverhttps://sciendo-parsed-data-feed.s3.eu-central-1.amazonaws.com/60060797e797941b18f2d887/cover-image.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20220811T020752Z&X-Amz-SignedHeaders=host&X-Amz-Expires=604800&X-Amz-Credential=AKIA6AP2G7AKP25APDM2%2F20220811%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Signature=e5e58baced2628844554c86739859f5d2faae1933d76a4cf48820e8eb43e2a69200300Congruence and Discrepancy Between Observation and Teachers’ Self-Report of Inquiry-Based Instructionhttps://sciendo.com/article/10.2478/cdem-2022-0002<abstract> <title style='display:none'>Abstract</title> <p>Opportunities for self-reflection and collaborative reflection support inquiry-based teaching. The presented study focuses on retrospective self-reports of 14 science teachers about teaching inquiry lessons in their regular science classes. Their self-reports were compared with observation reports of researchers. Data from semi-structured interviews were added. The results indicate that teachers overestimated their performance in the class in all observed areas of inquiry instruction. The most misinterpreted and overestimated area by teachers seems to be formulating research questions, analysing data and drawing conclusions, which are the most effective processes in student learning. Based on the results of the study, several implications are suggested in order to focus on the self-reflective skills of teachers.</p> </abstract>ARTICLE2022-05-27T00:00:00.000+00:00Study of Conceptual Knowledge and Mode of Reasoning Relating to the Characteristics of Covalent Bonds in Future Algerian Physics Teachershttps://sciendo.com/article/10.2478/cdem-2022-0001<abstract> <title style='display:none'>Abstract</title> <p>In this study we tried to analyse how future teachers of Ecole Normale Supérieure (ENS) school who are at the end of education have integrated the specifications of covalent bonds in the different bond orders in terms of symmetry, stability, length, localisation (in the case of structures of ethane, ethylene and acetylene) or delocalisation of electrons (case of benzene). The analysis of responses to a written questionnaire shows that the majority of students have only integrated some knowledge, which may be termed as procedural, on the structural elements of molecules such as stability and the length of bonds. Although possessing some conceptual knowledge, students tend to use an alternative way of reasoning arising from the mental representation that single and multiple bonds are independent entities: the single bond is a “σ bond” while the double bond is considered only as a “π bond”.</p> </abstract>ARTICLE2022-05-27T00:00:00.000+00:00Epigenetics is Promising Direction in Modern Sciencehttps://sciendo.com/article/10.2478/cdem-2021-0010<abstract> <title style='display:none'>Abstract</title> <p>Epigenetics studies the inherited changes in a phenotype or in expression of genes caused by other mechanisms, without changing the nucleotide sequence of DNA. The most distinguished epigenetic tools are: modifications of histones, enzymatic DNA methylation, and gene silencing mediated by small RNAs (miRNA, siRNA). The resulting m5C residues in DNA substantially affect the cooperation of proteins with DNA. It is organized by hormones and aging-related alterations, one of the mechanisms controlling sex and cellular differentiation. DNA methylation regulates all genetic functions: repair, recombination, DNA replication, as well as transcription. Distortions in DNA methylation and other epigenetic signals lead to diabetes, premature aging, mental dysfunctions, and cancer.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Low-Cost Sensors for Air Quality Monitoring - the Current State of the Technology and a Use Overviewhttps://sciendo.com/article/10.2478/cdem-2021-0003<abstract> <title style='display:none'>Abstract</title> <p>In recent years the monitoring of air quality using cheap sensors has become an interesting alternative to conventional analytical techniques. Apart from vast price differences conventional techniques need to be performed by the trained personnel of commercial or research laboratories. Sensors capable of measuring dust, ozone, nitrogen and sulphur oxides, or other air pollutants are relatively simple electronic devices, which are comparable in size to a mobile phone. They provide the general public with the possibility to monitor air quality which can contribute to various projects that differ in regional scale, commercial funding or community-base. In connection with the low price of sensors arises the question of the quality of measured data. This issue is addressed by a number of studies focused on comparing the sensor data with the data of reference measurements. Sensory measurement is influenced by the monitored analyte, type and design of the particular sensor, as well as by the measurement conditions. Currently sensor networks serve as an additional source of information to the network of air quality monitoring stations, where the density of the network provides concentration trends in the area that may exceed specific measured values of pollutant concentrations and low uncertainty of reference measurements. The constant development of all types of sensors is leading to improvements and the difference in data quality between sensors and conventional monitoring techniques may be reduced.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Chemical Electricityhttps://sciendo.com/article/10.2478/cdem-2021-0001<abstract> <title style='display:none'>Abstract</title> <p>In 1800 Alessandro Volta published the results of several years’ work on the phenomenon of electric shocks which he experienced from physical contact with the terminals of his newly developed battery. His work was prompted by Luigi Galvani's explanation of involuntary muscle spasms in frog's legs, which he induced and attributed to animal electricity. Volta's paper opened the floodgates for research in the new field of electrochemistry which has resulted in today's worldwide electric battery industry. This essay explains the sequence of natural events and their explanations which led to the publication of Volta's paper, and gives an overview of the scientific research resulting from Volta's work. This research includes attempts to improve batteries, and the development of ideas which led to a better understanding of matter and the way it interacts with energy. Practical details for the teaching of several important chemical concepts are listed in the appendix. The experiments are related to a reaction which has been known for many centuries - that between iron and copper sulphate solution.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00A Comparative Analysis of Text Difficulty in Slovak and Canadian Science Textbookshttps://sciendo.com/article/10.2478/cdem-2021-0007<abstract> <title style='display:none'>Abstract</title> <p>One of the main purposes of textbooks is the mediation of educational content to students. The factual accuracy of information, as well as the clarity of the text for students plays a crucial role in this aspect. The inadequate text difficulty can complicate students' learning. Comparing different approaches to the text in textbooks, considering the objectives of education, represents key knowledge for teaching materials innovation. This research was therefore focused on the comparison of the Slovak and Canadian science textbooks for lower secondary education. The methodology for assessing text difficulty according to Nestler, Prucha and Pluskal was used for this purpose. The samples of text from the textbooks for 6th and 8th grade of lower-secondary school were assessed. It was found that the text in Slovak textbooks is significantly more difficult. While from the syntactic difficulty point of view differences were rather partial, the significant differences were found in the semantic difficulty of the text. The Slovak textbooks are burdened with an excessive number of professional terms. Considering the results in measuring scientific literacy, this approach to the text in the Slovak textbooks is not effective. The results obtained are therefore an incentive to revise used educational materials.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00The Assessment of Heavy Metal Contamination of the Cultivated Soils in the Odra River Floodplainhttps://sciendo.com/article/10.2478/cdem-2021-0004<abstract> <title style='display:none'>Abstract</title> <p>The aim of the study was to assess the contamination of selected heavy metals in cultivated soils of the Odra river floodplain. The heavy metals Mn, Fe, Cu, Zn, Ni, Cd and Pb were determined in soil samples collected in the autumn of 2020 - after the vegetation period of plants from designated measurement points. Concentrations of the analytes were measured using an atomic absorption spectrometer (F-ASA). A comparison was made between concentrations of heavy metals in soil samples collected from areas flooded in 1997 and from areas flooded as a result of rainfall, snowmelt and winter floods. The results of the studies were compared with the data for soils taken from non-flooded areas. The studies confirmed enrichment of soils subjected to precipitation, snowmelt and winter floods in heavy metals. Also samples taken from two measurement points located on floodplains of the Odra river were characterised by high concentrations of Zn, Cd and Pb.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Heavy Metals Accumulation in Silver Fir Needles in Swietokrzyski National Parkhttps://sciendo.com/article/10.2478/cdem-2021-0005<abstract> <title style='display:none'>Abstract</title> <p>The article demonstrates the results of the research studies related to the air polluted with heavy metals in the area of Swietokrzyski National Park. The two-year-old needles of <italic>Abies alba</italic> (<italic>Mill</italic>) were used as the bioindicator with the intention of carrying out the research. The studies were conducted in the autumn of 2012. The results showed the spatial variability of concentrations in the range of the analysed metal deposition patterns in the needles of <italic>Abies alba</italic> (<italic>Mill</italic>). The average content of the analysed elements seemed to be the highest in the case of zinc (26.6 mg·kg<sup>−1</sup> d.m.), strontium (6.5 mg·kg<sup>−1</sup> d.m.) and nickel (1.6 mg·kg<sup>−1</sup> d.m.). The research studies revealed that the significant role in determining the content of heavy metals in the two-year-old needles was played by the communication. The highest values were recorded at the research sites situated in the immediate neighbourhood of the voivodeship roads. It was also confirmed that the content of metals was influenced by the so-called low emission from the household and welfare sector together with the remote imission.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Using the Raspberry Pi Microcomputers in STEM Education in Technically Oriented High Schoolshttps://sciendo.com/article/10.2478/cdem-2021-0006<abstract> <title style='display:none'>Abstract</title> <p>The article deals with learning using the project-based method in STEM education. The article describes the use of ICT technologies, specifically Raspberry Pi microcomputers in bending experiment. The bending experiment was designed for students of technically oriented high schools. Pedagogical research was conducted to determine whether the knowledge and skills of students who have been educated by the project-based method in STEM education are more complex, more systematic and more permanent than the knowledge and skills of students taught by standard forms of teaching. The article presents the results of pedagogical research, which lasted for three years. The results confirm that project-based learning and using ICT in STEM education developed complex knowledge and skills in STEM education. Comprehensive knowledge and problem-solving skills are important for the sustainable development of technological education.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Civilisation and Its Environmental Consequenceshttps://sciendo.com/article/10.2478/cdem-2021-0002<abstract> <title style='display:none'>Abstract</title> <p>This work is devoted to examining civilisation's environmental consequences and the military confrontation between civilised and barbaric societies. The authors examine antique and ancient Chinese ideas about the phenomenon of barbarism, and also highlight common cultural features inherent in the Germans and Celts and opposed to Rome, and the Far Eastern nomads who were adjacent to imperial China. Moreover, the authors seek to analyse the substantial effects of civilisation on the environment and ecosystem. Having analysed the military potential of civilised societies, the authors come to the conclusion that the victory of barbarism is possible only in the case of civilisation internal collapse. The article outlines other important aspects, including the relationships between civilisation and war and between civilisation and the environment. It concludes with a discussion about rethinking and restructuring some of our perspectives on civilisation.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Environmental Benefits of Catch Crops Cultivationhttps://sciendo.com/article/10.2478/cdem-2021-0009<abstract> <title style='display:none'>Abstract</title> <p>The role of catch crops in modern agriculture has increased in recent years. In addition to a production of animal feed, they have a positive impact on quality of soil. This study determined the suitability of selected stubble catch crops (white mustard, lacy phacelia, and a mixture of faba bean + spring vetch) to improve production, economic and energy effects of spring wheat grown in 3-year monoculture relative to the control treatment (without catch crops). Two tillage systems were used: conventional tillage and no-tillage (conservation tillage). A field study was conducted over the period 2014-2016 at the Czeslawice Experimental Farm, Lubelskie Voivodeship, Poland. The study proved the high suitability of catch crops to increase the spring wheat yields (under both tillage systems). Regardless of the catch crops, the productivity of wheat was higher under conventional tillage. The catch crops (in particular white mustard) and the conservation tillage system contributed to an improved energy efficiency index of production. The white mustard catch crop also had the most beneficial effect on the economic profitability of spring wheat production. This was due to the low cost of cultivation of this catch crop and its beneficial impact on obtaining high yields of spring wheat.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Evaluation of Czech Non-Chemical Vocational School Chemistry Textbooks’ Text Difficultyhttps://sciendo.com/article/10.2478/cdem-2021-0008<abstract> <title style='display:none'>Abstract</title> <p>The paper follows the first author's continuous work on chemistry textbook analysis. In the previous paper published in CERP, attention was given to the procedure and results for analysing text-difficulty in lower-secondary chemistry textbooks in Czechia. In this paper, attention was given to non-chemical vocational school chemistry textbooks. They are intended for the most numerous group of upper-secondary students. The goal of the study was to assess the to what extent could students read the textbook texts on their own with appropriate understanding. Therefore, only the textual component was evaluated. The same method (Nestler-Prucha-Pluskal) as in the previous paper was used to analyse the textbooks’ text-difficulty (readability). The results show there are two books which are suitable for students’ own learning. However, there are four textbooks which contain text of high difficulty, including too many scientific terms that they are suitable as teacher's guide through terms rather than student's textbooks. The analysis may serve teachers with their textbook choice as well as researchers who operate in the same field who can easily adopt the methodology and compare results.</p> </abstract>ARTICLE2022-01-21T00:00:00.000+00:00Conditions for Experimental Activities at Elementary and High Schools from Chemistry Teachers’ Point of Viewhttps://sciendo.com/article/10.2478/cdem-2020-0006<abstract><title style='display:none'>Abstract</title><p>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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Pupils’ Preconceptions About Heat, Temperature and Energyhttps://sciendo.com/article/10.2478/cdem-2020-0005<abstract><title style='display:none'>Abstract</title><p>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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Determining Cellulolytic Activity of Microorganismshttps://sciendo.com/article/10.2478/cdem-2020-0010<abstract><title style='display:none'>Abstract</title><p>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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Water Quality and Ichthyofauna Habitat Conditions in Lake Czolnowskie (N-W Poland)https://sciendo.com/article/10.2478/cdem-2020-0008<abstract><title style='display:none'>Abstract</title><p>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/dm<sup>3</sup>) and permanently elevated level of general phosphorus (0.15-0.27 mg/dm<sup>3</sup>) and ammonium acid (0.16-0.27 mg/dm<sup>3</sup>), which degraded the quality of life for ichthyofauna inhabiting the lake.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Remediation of CO in Boudouard’s Reaction as an Example of Reversible Chemical Reactionhttps://sciendo.com/article/10.2478/cdem-2020-0007<abstract><title style='display:none'>Abstract</title><p>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 CO<sub>2</sub> 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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Lower-Secondary School Chemistry Textbooks’ Didactic Equipmenthttps://sciendo.com/article/10.2478/cdem-2020-0004<abstract><title style='display:none'>Abstract</title><p>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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Hydrogen - Some Historical Highlightshttps://sciendo.com/article/10.2478/cdem-2020-0001<abstract><title style='display:none'>Abstract</title><p>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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00Human Resources and R&D at the Institute for Nanomaterials, Advanced Technologies and Innovation (TUL)https://sciendo.com/article/10.2478/cdem-2020-0003<abstract><title style='display:none'>Abstract</title><p>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&amp;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&amp;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.</p></abstract>ARTICLE2021-01-29T00:00:00.000+00:00en-us-1