Development of Audiovisual-Based PowToon Animation Video on Chemical Bonds for Tenth Grade

This research aimed to develop an audiovisual-based PowToon animation video on the subject matter of chemical bonds and analyze the quality of the audiovisual-based animated video as learning media to study chemical bonds based on the assessment of material experts, media experts, chemistry teachers, and students’ responses. This research used development research methods (R&D) with a 4D development model (Define, Design, Development, and Dissemination). However, the 4D development model was limited to the dissemination stage in this research. The product is an animated video, which is in the form of mp4, containing chemical bond materials. Based on product quality assessment by a material expert, it gained a percentage of 84.375% with very good (VG) category; from the media expert’s assessment, it obtained a percentage of 96.428% with very good (VG) category; and according to assessment by chemistry teachers of high school, it got a percentage of 98.48% in the very good (VG) category. The product was responded to positively by students with a percentage of 95%. Based on the results of assessments, the animated video can be used as an alternative media for the chemistry learning process in the classroom

Towards a Density-Based Description of Chemical Bonds and Noncovalent Interactions with Pauli Energy

Chemical bonds and noncovalent interactions are extraordinarily important concepts in chemistry and beyond. Using density-based quantities to describe them has a long history in the literature, yet none can satisfactorily describe the entire spectrum of interactions from strong chemical bonds to weak van der Waals forces. In this work, employing Pauli energy as the theoretical foundation, we fill in that knowledge gap. Our results show that the newly established density-based index can describe single and multiple covalent bonds, ionic bonds, metallic bonds, and different kinds of noncovalent interactions, all with unique and readily identifiable signature shapes. Two new descriptors, NBI (nonbonding and bonding identification) index and USI (ultra-strong interaction) index, have been introduced in this work. Together with NCI (noncovalent interaction) and SCI (strong covalent interaction) indexes already available in the literature, a density-based description of both chemical bonds and noncovalent interactions is accomplished.

Understanding the Nascent Plasmons and Metallic Bonding in Atomically Precise Gold Nanoclusters

The metallic bond is arguably the most intriguing one among the three types of chemical bonds, and the resultant plasmon excitation (e.g. in gold nanoparticles) has garnered wide interest. Recent...

Влияние обработки в He:O плазме на структуру многостенных углеродных нанотрубок

The functionalization of multi-walled carbon nanotubes in He:O plasma is investigated. It's shown that plasma treatment leads to the removal of defective outer graphene layers and their fragments due to oxidation. It is established that the surface of functionalized multi-walled carbon nanotubes contains numerous uncoordinated carbon atoms and oxygen-containing functional groups. The preservation of the structure of the internal graphene layers of nanotubes and the formation of broken chemical bonds ensures a decrease in electrical resistance. At the same time, there is a narrowing of the distribution of electrical resistance values of nanotube ensembles.

Metal-Free Allylic C-H Nitrogenation, Oxygenation, and Carbonation of Alkenes by Thianthrenation

Selective functionalization of allylic C-H bonds into other chemical bonds are among the most straightforward and attractive, yet challenging transformations. Herein, a transition-metal-free protocol for direct allylic C-H nitrogenation, oxygenation,...

Potential therapy of Sambiloto plant (Andrographis paniculata) using multi-compounds analysis

Introduction: Sambiloto plant (Andrographis paniculata) is often used as herbal medicine plant in Indonesia. Previous evidence indicates the use of a whole plant or single-compound approach. Analysis of multi-compounds is needed to determine the therapeutic potential for standardizing herbal medicine to provide a reliable effect. Methods: An exploratory study searching for the active content of A. paniculata was carried out in the Knapsack program. The chemical structure is analyzed computationally using Prediction of Activity Spectra for Substances (PASS) software. The analysis of the mechanism of action of drug molecules was analyzed using the Search Tool for Interacting Chemicals (STITCH) software. Results: The active content of A. paniculata is 46 types, with 5 of them having 6 effects based on chemical bonds and targeting 12 receptor proteins. Five active contents of A. paniculata include andrographidin A, caffeic acid, chlorogenic acid, wogonin 5-glucoside, and cinnamic acid. Analysis of the mechanism of action of A. paniculata based on 12 target proteins from active ingredients using a multi-compound approach shows 6 unique biological processes. Based on the chemical bonds, 5 active contents of A. paniculata have six effects, including anaphylatoxin receptor antagonist, a beta-adrenergic receptor kinase inhibitor, GABA C receptor agonist, G-protein-coupled receptor kinase inhibitor, Aryl hydrocarbon receptor agonist, and Nicotinic alpha6beta3beta4alpha5 receptor antagonist. Conclusion: There is a therapeutic potential of A. paniculata with multi-compounds analysis. A molecular docking analysis is needed to predict the affinity between the ligand (active ingredient) and the target protein.

Comparison of the usage of fines and PCC pigment in handsheets

Purpose This paper aims to investigate the influences of fines and precipitated calcium carbonate (PCC) pigment and their contents on the fundamental properties of handsheets and also evaluate these results in terms of mechanical and chemical data. Design/methodology/approach A design research approach has been based on the production of various laboratory handmade papers. Any of the paper additives were not added to the paper web to compare the results of the effects of fines and PCC pigment in a literal way. For this purpose, the target grammages of handsheets and the production variables such as pulp consistency, temperature and other variables of formation, pressing and drying processes were kept constant and studied meticulously. Findings This study is confirmed that with the addition of fines to the pulp of the control handsheets, an increase of up to 125% has been observed in the tensile index values, while a decrease of up to 30% has been observed with the addition of PCC pigment as filler. The tensile results have been changed depending on the pulp content and hence chemical bonds formed in the paper web. These mechanical changes have been explained by correlating with the data of FT-IR spectrums. Especially, the variations have been seen at 950–1150 cm−1, which referring to C-OH and C-O-C stretching vibrations. Originality/value The originality of this work is based on understanding and comparing the effects of fines and the effect of PCC pigment as a paper filler on the structural and chemical characteristics of laboratory-made handsheets.