rss_2.0Chemistry-Didactics-Ecology-Metrology FeedSciendo RSS Feed for Chemistry-Didactics-Ecology-Metrologyhttps://sciendo.com/journal/CDEMhttps://www.sciendo.comChemistry-Didactics-Ecology-Metrology Feedhttps://sciendo-parsed.s3.eu-central-1.amazonaws.com/647122aa2b88470fbea1588d/cover-image.jpghttps://sciendo.com/journal/CDEM140216Does Sendivogius’ Alchemy Cancel the Celebration of the 250th Anniversary of the Discovery of Oxygen?https://sciendo.com/article/10.2478/cdem-2023-0003<abstract> <title style='display:none'>Abstract</title> <p>Most chemistry textbooks claim that oxygen was discovered almost simultaneously by Carl Scheele and Joseph Priestley about 250 years ago. Priestley obtained oxygen by heating mercuric oxide (1774), and Scheele -by heating NaNO<sub>3</sub>, as well as by dissolving pyrolusite in sulfuric acid (1772). The name “oxygen” was given a few years later (1779) by Antoine Lavoisier. This great scientist, often accused of taking advantage of the discoveries of others, conducted experiments related to the decomposition of water vapour over heated iron, as well as the synthesis of water from hydrogen and oxygen. His work was of great importance because it revealed the elemental nature of oxygen and its role in the processes of combustion and respiration. The present article draws attention to the prehistory of the “oxygen theory”. It emphasises the natural philosophy of a forgotten alchemist, healer, and diplomat - Michael Sendivogius (1566-1636) - who popularised his belief that the substance (“Water of life that does not wet the hands”) obtained by heating the “Central Salt” (nitre, KNO<sub>3</sub>) is part of the air. It is the “secret food of life” used invisibly by every living thing.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00032024-01-25T00:00:00.000+00:00Environmental Contaminants of Emerging Concern: Occurrence and Remediationhttps://sciendo.com/article/10.2478/cdem-2023-0004<abstract> <title style='display:none'>Abstract</title> <p>Certain contaminants are termed as emerging (Contaminants of Emerging Concern, CEC) since all aspects of these pollutants are not known and their regulation is not ununiform across the nations. The CECs include many classes of compounds that are used in various industries, plant protection chemicals, personal care products and medicines. They accumulate in waterbodies, soils, organisms including humans. They cause deleterious effects on plant animal and human health. Therefore, alternative greener synthesis of these chemicals, sustainable economic methods of waste disposal, scaling up and circular methods using sludge for removing the contaminants are innovative methods that are pursued. There are several improvements in chemical waste treatments using electro-oxidation coupled with solar energy, high performing recycled granular activated charcoal derived from biomass are few advances in the field. Similarly, use of enzymes from microbes for waste removals is a widely used technique for bioremediation. The organisms are genetically engineered to remove hazardous chemicals, dyes, and metals. Novel technologies for mining economically the precious and rare earth elements from e-waste can improve circular economy. However, there is additional need for participation of various nations in working towards greener Earth. There should be pollution awareness in local communities that can work along with Government legislations.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00042024-01-25T00:00:00.000+00:00Virtual Laboratories in the Teaching of Mechanical Technologyhttps://sciendo.com/article/10.2478/cdem-2023-0008<abstract> <title style='display:none'>Abstract</title> <p>The aim of this article is to familiarise the reader with the issue of virtual laboratories and to demonstrate their possible use on a concrete example. This example deals with the use of virtual laboratories in the teaching of mechanical engineering in high schools and universities. The Covid-19 pandemic has led to significant changes in the teaching process and its organisation. In this period, teaching usually took place online, which was implemented using resources such as Google Classroom or MS Teams. This article presents a sample task -a project on which students of the second and third year of study at a secondary technical school are working. The project has an interdisciplinary character, because during its implementation students apply and further develop skills and knowledge from several subjects, namely physics, mechanics, chemistry and CAD design. The project is dedicated to the design of a pulley casting for a steel rope.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00082024-01-25T00:00:00.000+00:00Evaluating Experimental Activities in Czech Chemistry Textbooks: A Critical Analysishttps://sciendo.com/article/10.2478/cdem-2023-0006<abstract> <title style='display:none'>Abstract</title> <p>This study analysed the nature and integration of experimental activities in Czech lower-secondary chemistry textbooks which are currently in use. Focusing on four dominant textbook series (published since 1990’s), and one recently (2019) published and certified, it investigated the offered types of student activities, their cognitive demands, placement in the educational process, and inquiry levels. The findings reveal two distinct groups of textbooks based on the quantity of experimental activities. Some textbooks align with traditional teaching methods, emphasising teacher-led demonstrations, while others attempt a balance between safety concerns and student engagement. However, a general lack of focus on higher-order cognitive skills and inadequate scaffolding for scientific process skills development was found. The results showed future research should investigate the impact of experimental activities on student outcomes, highlighting the need for more modern approaches in chemistry education.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00062024-01-25T00:00:00.000+00:00Substrates with Different Magnetic Properties Versus Iron-Nickel Film Electrodepositionhttps://sciendo.com/article/10.2478/cdem-2023-0009<abstract> <title style='display:none'>Abstract</title> <p>The hereby work presents the iron-nickel alloys electroplated on the different metallic substrates (aluminium, silver, brass) using galvanostatic deposition, with and without presence of the external magnetic field (EMF). The films were obtained in the same electrochemical bath composition - mixture of iron and nickel sulphates (without presence of additives) in the molar ratio of 2 : 1 (Ni : Fe), the electric current density (50.0 mA/cm<sup>2</sup>), and the time (3600 s). The mutual alignment of the electric (E) and magnetic field (B) was changeable - parallel and perpendicular. The source of EMF was a set of two permanent magnets (magnetic field strength ranged from 80 mT to 400 mT). It was analysed the surface microstructure, composition, morphology, thickness and the mechanical properties (roughness, work of adhesion). The surface morphology and the thickness of films were observed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). The elemental composition of all FeNi films was measured using Wavelength Dispersive X-Ray Fluorescence (WDXRF). The crystalographic analysis of the deposits was carried out by X-Ray Diffraction. Depending on the used substrate, modified external magnetic field orientation influenced the tribological and physio-chemical properties of the deposited layers. The diamagnetic substrates and EMF application reduced the FeNi thickness and the average crystallites size, in contrast to the paramagnetic substrate. Parallel EMF increased the value of the tribological parameters for CuZn and Ag but decreased for Al. The content of FeNi structure was rising in the case of diamagnetic substrate and the dependence was opposite on the paramagnetic substrate.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00092024-01-25T00:00:00.000+00:00The Effect of Co and Cu Co-Doping Zno Thin Films on Structural and Optical Propertieshttps://sciendo.com/article/10.2478/cdem-2023-0010<abstract> <title style='display:none'>Abstract</title> <p>Using a spray pneumatic technique, cobalt (Co) and copper (Cu) co-doped zinc oxide thin films were effectively deposited on a glass substrate. The goal of this work was to create a semiconductor with good optical and electrical properties by co-doping ZnO thin films with Cu and Co. The ZnO thin films obtained from the Co and Cu co-doping exhibit patterns of x-ray diffraction spectra that suggest they are hexagonal ZnO (wurtzite, JCPDS 36-1451). The thin film elaborated with 2 % Co and 7 % Cu has the lowest value of crystallite size (<italic>D</italic> = 14.67 nm). The transmission spectra demonstrate that all films have good optical transparency in the visible spectrum, with 7 % Cu achieving the highest transmission. Increasing Cu contents raised the band gap energy. The value at the minimum was 3.31 eV. The optical band gap’s broadening is a significant characteristic of advanced materials and may be useful in applications involving metal oxide nanostructures for visible light gas sensing.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00102024-01-25T00:00:00.000+00:00The Extraordinary World of Sulphur Part 1https://sciendo.com/article/10.2478/cdem-2023-0002<abstract> <title style='display:none'>Abstract</title> <p>Sulphur is a highly reactive element, and is therefore able to enter into a great variety of chemical combinations, resulting in the formation of compounds of widely differing properties. Reactions involving sulphur, and the compounds which they produce, have stimulated and inspired people throughout the ages. Sulphur has always been associated with volcanoes, fires and smells. However, its story goes much further. Sulphur is present in thousands of products of the chemical industry, which are in everyday use. These include car batteries, car tyres, matches, paints, paper, textiles, food, detergents and pharmaceuticals. In part 1 of this essay, the evolution of the role of sulphur in the history of mankind is explained, through the eyes of etymology, geology, literature, art, and chemistry. In part 2 the role of sulphur in biochemistry and chemical technology is reviewed. In so doing, a case is established, to show that sulphur is the most extraordinary substance known to Man.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00022024-01-25T00:00:00.000+00:00Science and Society - A New Era for Science Communication in the Context of Sustainable Developmenthttps://sciendo.com/article/10.2478/cdem-2023-0007<abstract> <title style='display:none'>Abstract</title> <p>The high degree of interest in scientific topics (science and research) has been observed especially since the pandemic. This includes the ongoing transition of the chemical industry toward sustainability because the accompanied changes have to be coordinated in dialogue with society. Parallelly, there is increasing interest in science communication in general, as well as the increasing need for its proper understanding. How we communicate is probably today as important as what we communicate. The purpose of this study is to explore how society perceives science, research, scientific results, and their role in the modern world. The method used in the study was a diagnostic survey, and the data was collected using an online questionnaire. This study used a quantitative method. The results showed that science communication needs to be developed much more with special attention paid to the economic, social, and political context. The results analysed and integrated in this article could provide substantive suggestions and help develop science communication.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00072024-01-25T00:00:00.000+00:00Health Hazard Related to Fine Road Dust in Polandhttps://sciendo.com/article/10.2478/cdem-2023-0005<abstract> <title style='display:none'>Abstract</title> <p>Air pollution emissions from road vehicles majorly contribute to particulate pollution. This poses significant threats to the environment and human health. Road dust contains various potentially toxic elements, which, when exposed to humans, can lead to severe illnesses such as asthma, cardiovascular diseases, and cancer. This study assessed adult health risks through accidental ingestion, inhalation, and dermal contact associated with heavy metals (Cr, Cu, Ni, Pb, and Zn) in road dust (with a fraction size &lt; 0.1 mm). The analysis covers areas between sound-absorbing screens (S), in open spaces without screens (F), and at highway/express exits (E) with different surfaces: asphalt (A) and concrete (C). Results indicate the highest health risk levels are associated with Zn in road dust in S and E areas, indicating its potential negative impact on human health. When comparing results for all metals, road dust collected from A surfaces might pose a greater health risk than C surfaces. The carcinogenic risk for Cr and Ni found in road dust collected from A and C surfaces at points S, F, and E is medium. The most significant carcinogenic risk (medium-high) is associated with Cr in road dust from A surfaces in the F area, whereas the lowest risk (low-medium) for both A and C surfaces is linked to Ni exposure in the S point. The contributions of Cr and Ni highlight the need to reduce emissions of these elements in areas surrounding heavily trafficked roads.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00052024-01-25T00:00:00.000+00:00“Covid-19 Shock” and Identified Benefits for Improved Pre-Service Chemistry Teacher Educationhttps://sciendo.com/article/10.2478/cdem-2023-0001<abstract> <title style='display:none'>Abstract</title> <p>The global pandemic has forced many people to make significant changes in their work, personal lives, and everyday duties and activities. This metamorphosis has also significantly affected education systems. Implemented research activity in the learning process and emphasised the development of children’s cooperation have recently been limited and often unattainable because of learner isolation, prevailing home education, and different countries’ COVID-19 quarantine measures. Herein, we investigated and tested the 2020 European spring preparedness, commitment, and erudition of in-service and pre-service teachers and parents in remote education. We profiled the following three paradigm models of successful remote education; specific experience of in-service and pre-service chemistry teachers and the parents of school-age children. Here, we concentrated on sensitive identification of the most common problems, disadvantages, and risks. Prospective teacher training should concentrate more on remote education. It should help develop teachers’ didactic competencies and increase their motivation and willingness to participate in this mode of education.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2023-00012024-01-25T00:00:00.000+00:00The Biological Monitoring as a Source of Information on Environmental Pollution with Heavy Metalshttps://sciendo.com/article/10.2478/cdem-2022-0006<abstract> <title style='display:none'>Abstract</title> <p>The influence of environmental pollution on living organisms has been known for a long time, but it was not until the second half of the twentieth century that methodical studies on the influence of anthropopressure on changes in ecosystems began. Living organisms began to be used as biological indicators of environmental pollution. Cyclical and quantitative studies of pollutant concentrations in bioaccumulators have become the basis of modern biological monitoring (biomonitoring) of environmental pollution. Biomonitoring studies are carried out with the passive method (passive biomonitoring), in which living organisms occurring in their natural environment are analysed, and with active methods (active biomonitoring), in which, for example, plants living in the environment with low pollution are transferred and displayed in more polluted ecosystems e.g. heavy metals. The analysis of trace elements, including heavy metals accumulated in algae, mosses and lichens used in biological monitoring provides a lot of information on, among others concentration and origin of pollutants and the directions of their spread. Biomonitoring is used to assess the level of contamination of selected ecosystems, as well as the impact of individual emitters on the environment. An important element in determining the concentrations of trace elements in biological material used in biomonitoring is the proper planning of the experiment, taking into account, among others: methods of collecting or exposing samples, selection of analytical methods and methods of evaluation and interpretation of results. The aim of the presented long-term research, conducted by the Research Team of the Institute of Biology of the University of Opole, was to show that analytical techniques using biota samples can provide reliable data on the past, present and future state of the environment. However, it should be remembered that in order for the results of biomonitoring studies to be reliable and comparable, the applied research methodologies should be consistent and repeatable. In the presented research, <italic>Palmaria palmata</italic> and <italic>Spirogyra</italic> sp. algae, <italic>Pleurozium schreberi</italic> mosses, <italic>Hypogymnia physodes</italic> and bark of deciduous trees were used. In samples of biological material by the method of atomic absorption spectrometry, the concentrations of heavy metals, including Ni, Cu, Zn, Cd and Pb, were determined. On the basis of the conducted research, it was unequivocally stated that the biomonitoring methods are a good complement to the classic methods of environmental quality assessment. The analysis of the elements accumulated in the biological material provides us with information about the quality of the examined ecosystems, the introduced pollutants and their potential sources. This information allows for the introduction of effective measures to improve the quality of the environment.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00062023-02-01T00:00:00.000+00:00Microwave-Aided Reactions of Aniline Derivatives with Formic Acid: Inquiry-Based Learning Experimentshttps://sciendo.com/article/10.2478/cdem-2022-0008<abstract> <title style='display:none'>Abstract</title> <p>The synthesis of amides belongs to traditional experimental tasks not only in organic chemistry exercises at universities but also at chemically focused secondary schools or in special practices at general high schools. An example of such a synthesis may be the preparation of acetanilide <italic>via</italic> reaction of aniline with acetic acid or acetic anhydride. However, both of these reactions are associated with a rather long reaction time and certain hazards that limit their straightforward use in pedagogical practice. Conveniently, the reaction of aniline with acetic acid may be significantly optimised if it is performed under solvent-free conditions in the presence of microwaves, which reduces considerably the reaction time and provides very good yield, compared to traditional heating by a heating nest. In this study, the main pedagogical aim of the experimental design is elucidation of the influence of the structure of the amines on the course of the reaction with formic acid through inquiry-based learning. Specifically, the proposed experiments consist in investigation of the chemical yield achieved in microwave assisted reactions of aniline and its derivatives with formic acid in such a way that is adequate for constructive learning of undergraduate chemistry students. The selected series of amines involves aniline, 4-methoxyaniline, 4-chloroaniline, and 4-nitroaniline. In accordance with the chemical reactivity principles, students gradually realise that the influence of the substituent is reflected in the reaction yield, which grows in the following order: N-(4-nitrophenyl)formamide ˂ N-(4-chlorophenyl)formamide ˂ N-phenylformamide ˂ N-(4-methoxyphenyl)formamide. Therefore, the results of the experiments enable students to discover that stronger basicity of the amine increases the yield of the amide. In order to deepen the students’ chemical knowledge and skills, the concept of the experiments was transformed to support inquiry-based student learning. The proposed experiments are intended for experimental learning in universities educating future chemistry teachers, but they may be also utilised in the form of workshops for students at secondary schools of a general educational nature.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00082023-02-01T00:00:00.000+00:00Renewable Energy and Sustainable Digitalisation: Challenges for Europehttps://sciendo.com/article/10.2478/cdem-2022-0003<abstract> <title style='display:none'>Abstract</title> <p>The key to a successful strategy for Europe is sustainable innovation. The current political, economic and military crisis should be used to accelerate the shift to sustainable innovations in order to exit the path dependency of fossil energies. Such as diversity of portfolios at stock markets, diversity of energy and digital technologies ensures resilient behaviour in an innovation portfolio to respond flexibly to the risks of the future and to recover overall in the event of selective setbacks. Sustainable technologies must not be based on a single solution, but rather the entire technological potential must be bundled in an innovation portfolio. A case study is presented in which energy-efficient digitalisation is linked to a sustainable circular economy. A democratic legal system is not only an expression of the human rights highlighted in the UN Charter, but also provides a certain and reliable legal framework for innovations and markets on which technological and economic competition takes place.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00032023-02-01T00:00:00.000+00:00Environmental Emissions Dispersion Modelling, Principles and Algorithms; Cross-Border CZ-PL Course for Master’s Studentshttps://sciendo.com/article/10.2478/cdem-2022-0010<abstract> <title style='display:none'>Abstract</title> <p>Regular mathematical modelling of the dispersion of emissions from large sources is required by law in all EU countries. It is also used in risk analysis to predict releases of toxic substances from various technologies, from volcanic activity and possibly also terrorist acts. However, there is a shortage of experts in this very specific and demanding profession in the labour market in most EU countries. In a collaboration between academicians from neighbouring University of Hradec Králové and University of Opole and experts from important ecological companies of both regions we designed and verified as a part of a four-year pedagogical project supported by the EU a comprehensive education system in mathematical modelling of emission dispersion with exchange field trips and internships of students during cross-border Polish-Czech university education. The paper consists of two separate parts. The first part is focused on implementation of innovative lesson “Principles, algorithms, and differences of environmental dispersion emissions models”, used on both sides of Polish-Czech border region. An example of the use of the educational package of the Gaussian plume model with PC Templates, who was modified in cooperation between teachers from both cross-border universities and experts from professional companies is presented here too. Our four-year experience with student motivational field trips to professional companies in both border regions and exchange one-month professional internships for interested students to two Czech professional companies, where students learn to work with to the Gaussian plume model and one Polish professional company, where students are introduced to the Gaussian puff model is also discussed. The following separate second part will be focused on the innovative lesson of multivariate statistical methods of environmental data analysis, which are required for processing materials for modern mathematical modelling of the dispersion of emissions in practice. The target users of this two-part innovative courses are students of the MSc degree in Physical Measurement and Modelling at the University of Hradec Králové and students of the MSc degree in environmental studies at the University of Opole. However, it is also open to other Czech and foreign students and professionals.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00102023-02-01T00:00:00.000+00:00Experiments Safety - The State of Art at Schools in Czechiahttps://sciendo.com/article/10.2478/cdem-2022-0009<abstract> <title style='display:none'>Abstract</title> <p>Chemistry experiments have been an issue of vivid discussion for more than fifty years now. Though there are many who hold a stand-offish position, there is a general notion chemistry experiments inherently belong to chemistry instruction. In this study, attention was given first to the frequency that Czech teachers at both lower and upper-secondary schools use experiments, demonstrations, laboratory work etc. A random, generalisable sample of 354 teachers filled in a questionnaire. The results showed experiments are used only seldom at lower-secondary schools and lyceums, more frequently at grammar schools, yet just “at least once a month”. Safety showed as one of the barriers. The teachers expressed general knowledge about a norm which covers the topic, however in their further responses they expressed a lack of awareness of the compounds their students are allowed to work with. These findings are a call for measures such as: developing a database of well-described procedures including safety regulation remarks or a simplified, easy to follow list of up-to-date regulations.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00092023-02-01T00:00:00.000+00:00Science Curiosities Cabinet And The Chemical Showcasehttps://sciendo.com/article/10.2478/cdem-2022-0007<abstract> <title style='display:none'>Abstract</title> <p>With the drastic reduction of the school chemistry teaching program in England in 1986, large quantities of apparatus and chemicals became redundant. The disused apparatus at Highgate School inspired the construction of a chemical showcase for pupils; this has encouraged pupils to develop a passion for chemistry. The idea of a “miniature museum” came from a visit to a local primary school in London, which had a beautiful science curiosities cabinet in one of its rooms. In both schools, sciences thrive, and are popular among pupils. Undoubtedly a display of assorted artefacts, which can be readily accessed by pupils, makes a significant impact on developing their interest in science. It is hoped that the story of these ventures will inspire teachers to make their own versions of these excellent and easily constructed educational facilities.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00072023-02-01T00:00:00.000+00:00Congruence 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>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00022023-02-01T00:00:00.000+00:00Pharmaceuticals and Personal Care Products in the Environment with Emphasis on Horizontal Transfer of Antibiotic Resistance Geneshttps://sciendo.com/article/10.2478/cdem-2022-0005<abstract> <title style='display:none'>Abstract</title> <p>Pharmaceuticals and personal care products (PPCPs) discharged into environment has several adverse impacts. PPCPs are widely utilised for veterinary as well as cosmetic and personal health reasons. These are members of the expanding class of substances known as Contaminants of Emerging Concern (CECs). Antibiotic resistance in the environment and garbage generated by PPCP endanger life. The World Health Organisation (WHO) now recognises antibiotic resistance as a significant global health problem due to the expected increase in mortality caused by it. In the past ten years, mounting data has led experts to believe that the environment has a significant impact on the development of resistance. For human diseases, the external environment serves as a source of resistance genes. It also serves as a major pathway for the spread of resistant bacteria among various habitats and human populations. Large-scale DNA sequencing methods are employed in this thesis to better comprehend the dangers posed by environmental antibiotic resistance. The quantification of the number is an important step in this process. Metagenomic measurement of the number of antibiotic resistance genes in various contexts is a crucial step in this process. However, it’s also crucial to put this data into a broader context by integrating things like taxonomic information, antibiotic concentrations, and the genomic locations of found resistance genes.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00052023-02-01T00:00:00.000+00:002,3-Dihydro-Quinazolin-4(1H)-One as a Fluorescent Sensor for Hg Ion and its Docking Studies in Cancer Treatmenthttps://sciendo.com/article/10.2478/cdem-2022-0004<abstract> <title style='display:none'>Abstract</title> <p>The 2,3-dihydro-quinazolin-4(1H)-one was synthesised via the deployment of SBA-Pr-SO<sub>3</sub>H and its application was explored as a highly selective fluorescent sensor for Hg<sup>2+</sup> ion; fluorescence intensity was decreased selectively by Hg<sup>2+</sup> ions. Furthermore, this compound also indicated for its superb anti-interference ability among other ions. It is important to mention that this compound could be employed to detect a very low amount of Hg<sup>2+</sup> ions, which are highly toxic and general contaminants. The docking study shows that the molecule, 2,3-dihydro-quinazolin-4(1H)-one, is a good inhibitor for the 5ACC enzyme.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00042023-02-01T00:00:00.000+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>ARTICLEtruehttps://sciendo.com/article/10.2478/cdem-2022-00012023-02-01T00:00:00.000+00:00en-us-1