Chemical Aspects Research Articles

Analysis of Scientific Knowledge on The Process of Making Tempeh Gembus as Local Wisdom and Its Potential for Empowering Students' Analytical Thinking Skills

The lack of teacher information regarding the scientific knowledge contained in the process of making tempeh gembus has an impact on students' low analytical thinking skills. This study aims to: (1) analyze the scientific knowledge in the process of making tempeh gembus; (2) analyze the potential of scientific knowledge in the process of making tempeh gembus towards empowering students' analytical thinking skills; and (3) analyze the correlation of scientific knowledge in the process of making tempeh gembuswith the basic competencies in science learning materials. This research is a qualitative descriptive study with an ethnographic approach. The primary data sources for this research are from observations and interviews with tempeh gembus producers and junior high school science teachers in the Karangpandan District. The sampling technique used is snowball sampling. Data collection is carried out through observation, interviews, and documentation. The instrument validity test technique uses expert validation (two experts). Data validity test technique uses triangulation of data collection techniques. Data analysis is conducted using Miles and Huberman's interactive model analysis. The results show that the process of making tempeh gembus contains scientific knowledge (aspects of physics, chemistry, and biology). The scientific knowledge in the process of making tempeh gembus has the potential to empower students' analytical thinking skills. The scientific knowledge in the process of making tempeh gembus presented in booklet form is related to the basic competencies in junior high school science learning materials

Photocatalytic Tandem Protocol for the Synthesis of Bis(indolyl)methanes using Cu-g-C3N4-Imine Decorated on TiO2 Nanoparticles under Visible Light Irradiation.

In this article, the visible-light-assisted photocatalytic activity of TiO2 nanoparticles functionalized with Cu(II) g-C3N4-imine was exploited for aerobic oxidation of alcohols to aldehydes followed by condensation with indoles in the presence of 2,2,6,6-tetramethylpiperidinyloxy to present a one-pot tandem strategy for the synthesis of bis(indolyl)methanes (BIMs) under solvent-free conditions. The synergistic effect between the components to improve the photocatalytic activity of the as-prepared Cu-g-C3N4-imine/TiO2 nanoparticles resulting from electron-hole separation was approved by PL spectroscopy. Moreover, action spectra showed a light-dependent photocatalysis with effective visible-light responsivity of the photocatalyst. The present method includes different aspects of green chemistry: one-pot tandem synthesis of a variety of BIMs using alcohols that are less toxic, more available, more economical, and more stable than aldehydes; removing the byproducts resulting from overoxidation of alcohols and polymerization of aldehydes and indoles; the use of air as a safe oxidant; visible light as a safe energy source; and solvent-free conditions. A reusability test demonstrated that the catalyst retained its efficiency even after five runs.

Advances in mass spectrometry imaging for plant metabolomics-Expanding the analytical toolbox.

Mass spectrometry imaging (MSI) has become increasingly popular in plant science due to its ability to characterize complex chemical, spatial, and temporal aspects of plant metabolism. Over the past decade, as the emerging and unique features of various MSI techniques have continued to support new discoveries in studies of plant metabolism closely associated with various aspects of plant function and physiology, spatial metabolomics based on MSI techniques has positioned it at the forefront of plant metabolic studies, providing the opportunity for far higher resolution than was previously available. Despite these efforts, profound challenges at the levels of spatial resolution, sensitivity, quantitative ability, chemical confidence, isomer discrimination, and spatial multi-omics integration, undoubtedly remain. In this Perspective, we provide a contemporary overview of the emergent MSI techniques widely used in the plant sciences, with particular emphasis on recent advances in methodological breakthroughs. Having established the detailed context of MSI, we outline both the golden opportunities and key challenges currently facing plant metabolomics, presenting our vision as to how the enormous potential of MSI technologies will contribute to progress in plant science in the coming years.

Methyl chavicol: Chemical aspects and therapeutic potential

Methyl chavicol: Chemical aspects and therapeutic potential

The effect of low salinity water on wettability alteration of oil-wet calcite surfaces

To shed light on the chemical and physical aspects of low-salinity (LS) water flooding to enhance oil recovery, we explored the impact of the brine salinity on the modifications of the oil-calcite interface using a multi-technique surface science approach based on FTIR, AFM, XPS, and Contact angle measurements. Our findings reveal that Nujol-model oil adsorbs on fresh-cleaved CaCO3 (104) surface and initially forms a continuous film. Chemical and morphological surface characterizations were performed on oil-wet calcite, followed by their conditioning with formation (FW), demineralized (DW), and low salinity water (LS25, LS50, LS75, and LS100). The oil removal was quantified by semi-quantitative FTIR analysis and was found to vary from ∼20 % for FW up to ∼81 % for LS75 conditioning. In the investigated experimental conditions the fresh-cleaved calcite surface is most efficiently converted from oil-wet to water-wet when conditioned with LS75 brines. Significant surface wettability alterations were observed for LS 75 brines as contact angle measurements were found to reach a minimum contact angle of ∼18°. The changes in calcite wettability correspond to the formation of fragmented oil islands and calcite step bunches, the signature of surface dissolution, and changes in the oil-calcite chemical interactions. A model for Nujol adsorption and its detachment from the calcite surface was proposed for oil removal, competitive mechanisms related to the brine chemical composition are discussed.

Nanostructural characterization of surfaces and interfaces of Portland cement mortars using atomic force microscopy

The characterization of Portland cement mortars is very important in the study of the interfaces and surfaces that make up the system mortar/ceramic block. In this sense, scanning electron microscopy and energy-dispersive (X-ray) spectrometer are important tools in investigating the morphology and chemical aspects. However, more detailed topographic information can be necessary in the characterization process. In this work, the aim was to characterize topographically surfaces and interfaces of mortars applied onto ceramic blocks. This has been accomplished by using the atomic force microscope (AFM) – MFP-3D-SA Asylum Research. To date, the results obtained from this research show that the characterization of cementitious materials with the help of AFM has an important contribution in the investigation and differentiation of hydrated calcium silicates (CSH), calcium hydroxide (Ca(OH)2, ettringite and calcium carbonate by providing morphological and microtopographical data, which are extremely important and reliable for the understanding of cementitious materials.

Coordination structures and stabilities of Am(III) adsorption complexes at kaolinite(0 0 1)-water interface

Understanding the structures and stabilities of actinide species is crucial for comprehending the sorption mechanisms at mineral–water interfaces. However, the relevant molecular-level fundamental aspects of actinide coordination chemistry at the mineral–water interface remain unclear. We herein conduct a systematic theoretical study of coordination structures and adsorption energies of Am3+ and Am(OH)2+ sorption complexes at the kaolinite(001)-water interface by integrating static density functional theory (DFT) calculations and ab initio molecular dynamics (AIMD) simulations. Computational results show that stable outer- and inner-sphere adsorption complexes are respectively formed through hydrogen bonding and coordinate bonding with surface aluminol groups. The most stable inner-sphere species are predicted to be tridentate surface complexes with an eight-folded coordination structure in the first coordination sphere of Am(III). This work deepens the understanding of Am(III) adsorption and complexation behaviors at the mineral–water interface, providing essential insights for actinide migration in natural environments and nuclear waste disposal. The synergy between static DFT calculations for initial screening and AIMD simulations for comprehensive dynamic analysis in this work enhances the efficiency and accuracy of theoretical predictions for actinide environmental chemistry and can be helpful for the broader research fields of geochemistry and environmental science.

Soft modeling strategies at work to follow and rationalize dopamine oxidative polymerization

The role of dopamine (DA) oxidation in Parkinson’s disease makes to investigate the chemical aspects behind this process: in this paper, we applied Design of Experiments and Principal Component Analysis, to model the DA oxidative polymerization, unveiling the effect exerted by pH, ionic strength (I), temperature, and metal ions. Higher pH and T, lower I and Cu over Fe were found to result in faster DA consumption and smaller oligomers formation. We demonstrated that soft modelling strategies provide a valuable approach to deal with complex biochemical phenomena, regardless system complexity.

Correction to: Roles of Solvent in the Catalytic Hydrogen Release from Liquid Organic Hydrogen Carriers: Chemical, Thermodynamical and Technological Aspects

Correction to: Roles of Solvent in the Catalytic Hydrogen Release from Liquid Organic Hydrogen Carriers: Chemical, Thermodynamical and Technological Aspects

Overview of the Impact of Compost on Bulk Density, Aggregate Consistency and Cation Exchange Capacity of Soils and its Consequential Effect on Crop Productivity

Organic fertilizers offer several advantages over chemical fertilizers and are an environmentally friendly alternative that could help sustainably farmed land. Reviewing indigenous knowledge of the agronomic applications of organic manure and its possible contribution to agricultural growth was the goal of this article. It is evident that organic manures from various plant and animal sources can be used to satisfy certain field needs. However, the use of organic manures is still primarily conventional since they have not been well received by agricultural strategies. When bulky organic manures are directly applied to soil, they accelerate mineralization and reduce the rate at which nutrients, especially nitrogen, are released. Compared to raw resources, which have limited value and certain disadvantages, composting these wastes appears to offer significant potential. The majority of researchers verified that adding compost might enhance the soil's organic matter content, nutrient status, and physical, chemical, and biological properties. Soil organic matter concentrations rise in every long-term compost treatment study. But since they contain more stable carbon than fresh or immature composts, mature composts raise Soil organic matter considerably more effectively. Furthermore, because compost has so many beneficial effects on the physical, chemical, and biological aspects of soil, it helps to stabilize and improve crop quality and yield. As a result, the majority of studies have demonstrated that compost has an equalizing influence on seasonal and annual variations in soil temperature, air, water, and plant nutrient availability, as well as crop yields. mostly due to the nutrients' gradual release and availability in compost-combined fertilization techniques, which frequently yield positive outcomes. Therefore, composting can be a useful choice for building effective plant-nutrient management methods in many settings for sustainable agricultural systems within small-scale farming in impoverished nations.

Chemical upcycling of polyolefins into liquid refinery feedstock from the circularity and chemical engineering aspects

Three quarters of all plastics produced each year are discarded to landfill after a single use without proper waste management practices, causing a global environmental crisis: waste plastics suffocating our world at enormously large volumes. Discarding plastics into landfill, inefficiently processing them to lower value materials, or incinerating them cause an irreversible loss of the stored energy in plastics. These plastics, however, represent a tremendous resource for the production of chemicals and can be upcycled into high-quality value-added refinery feedstock that could be used to produce virgin polyolefins. In this article, we review pyrolysis and hydrogenolysis based chemical transformations to convert waste polyolefins into liquid hydrocarbons with a special emphasis on life cycle assessment (LCA), reactor technologies, and integration to existing refineries. Several patented technologies are described in detail to shed a light on engineering aspects of the chemical recycling. Liquid products obtained from chemical recycling are examined from the circularity point of view. Feedstock and stream locations in existing refineries and around steam crackers are recommended to feed and/or blend the products obtained from chemical recycling of polyolefins. Challenges, perspectives, and emerging areas of research and engineering are mentioned.

Roles of fuel composition on the ignition process of endothermic hydrocarbons

Due to the characteristics of heat absorption and decomposition, endothermic hydrocarbon fuels (EHFs) have been widely used in scramjets for thermal protection and heat recirculation. The understanding of ignition characteristics of EHFs is of great importance for their safe and efficient utilization. In this paper, the ignition processes of EHFs were numerically simulated at atmospheric pressure and with an initial temperature of 500 K. Three different ignition stages were identified based on the chemical heat release and flame kernel propagation. A 3-component kerosene surrogate model composed of n-dodecane, methyl cyclohexane and m-xylene was adopted, as well as the corresponding chemical kinetic model with 369 species and 2691 reactions. Results showed that the discrepant decomposition characteristics of n-alkanes and cycloalkanes affected the chemical heat release and propagation during the ignition process. Two-stage exothermic characteristic was observed in the time evolutions of chemical heat release rate and fuel decomposition. The mass production of molecules and accumulation of radicals dominated the first and second exothermic peaks, respectively. Furthermore, the minimum ignition energies (MIEs) of EHFs with various methyl cyclohexane were determined to quantify the effect of fuel composition on ignition performance. Characteristically, the MIE dramatically decreased from 10.2 to 2.15 mJ when 20% n-dodecane was replaced by methyl cyclohexane. However, it was slightly increased as methyl cyclohexane continued to increase. Analyses from both physical and chemical aspects were conducted to elaborate the dependence of MIE on fuel composition. The dominant effects of flame-dynamic and chemical effects on different ignition stages were analysed. The faster propagation speed and stronger endothermic ability of methyl cyclohexane led to the nonlinear variation of MIEs. The results in this study provide useful guidance for composition optimization and safety evaluation of EHFs.

Quantitative Structure–Property Relationship Analysis in Molecular Graphs of Some Anticancer Drugs with Temperature Indices Approach

The most important application of anticancer drugs in various forms (alkylating agents, hormones agents, and antimetabolites) is the treatment of malignant diseases. Topological indices are widely used in the field of chemical and medical sciences, especially in studying the chemical, biological, clinical, and therapeutic aspects of drugs. In this article, the temperature indices in anticancer drugs molecular graphs such as Carmustine, Convolutamine F, Raloxifene, Tambjamine K, and Pterocellin B were calculated and then analyzed based on physical and chemical properties. The analysis was performed by identifying the best regression models based on temperature indices for six physical and chemical features of anticancer drugs. The results indicated that temperature indices were essential topological indices that predict the properties of anticancer drugs, such as boiling point, flash point, enthalpy, molar refractivity, molar volume, and polarizability. It was also observed that the r value of the regression model was more than 0.6, and the p value was less than 0.05.

Biomedical applications of graphene-based nanomaterials: recent progress, challenges, and prospects in highly sensitive biosensors.

Graphene-based nanomaterials (graphene, graphene oxide, reduced graphene oxide, graphene quantum dots, graphene-based nanocomposites, etc.) are emerging as an extremely important class of nanomaterials primarily because of their unique and advantageous physical, chemical, biological, and optoelectronic aspects. These features have resulted in uses across diverse areas of scientific research. Among all other applications, they are found to be particularly useful in designing highly sensitive biosensors. Numerous studies have established their efficacy in sensing pathogens and other biomolecules allowing for the rapid diagnosis of various diseases. Considering the growing importance and popularity of graphene-based materials for biosensing applications, this review aims to provide the readers with a summary of the recent progress in the concerned domain and highlights the challenges associated with the synthesis and application of these multifunctional materials.

Role of Gold Nanoparticles for Diagnosis and Therapy of Malignancy

Abstract: Cancer is the second leading cause of global mortality. Modern medical technologies, including chemotherapy, radiation treatment, and surgery, are extending the lifespan of cancer patients. The potential of nano medicine opens up a new way to get over the restrictions of traditional cancer treatments. Due to their unique basic features, gold nanoparticles (AuNPs) have been extensively explored and used in the field of tumor diagnostics and therapy. Two perspectives are presented on the physical and chemical aspects of AuNPs' characteristics. Localized surface plasmon resonance (LSPR), radioactivity, and a high X-ray absorption coefficient are among the physical characteristics of AuNPs that are commonly employed in tumor diagnostics and therapy. AuNPs also have some advantages like customizable size and shape, as well as various physiochemical properties. Additionally, they can effectively encapsulate drugs to enable simultaneous therapy and incorporate supplementary imaging labels. Recent research has emphasized the use of multifunctional AuNPs in techniques that involve simultaneous diagnosis and therapy. This article explores the use of AuNPs in cancer diagnosis and treatment, detailing clinical trials and providing insights for researchers on their physiochemical properties.

HPLC-DAD method for concurrent estimation of netarsudil, latanoprost and benzalkonium chloride: Stability indicating study, impurity separation, assay of ophthalmic preparations and greenness/whiteness valuation

A validated, stability indicating, multiuse and sustainable HPLC-DAD method was developed for simultaneous determination and separation of the ophthalmic ternary mixture of netarsudil (NTS), latanoprost (LTP) and benzalkonium chloride (BZC) in presence of four related compounds and suspected impurities. Effectual liquid chromatographic separation was accomplished by using a Zorbax-SB Phenyl column with gradient elution of a mobile phase consisting of buffer mixture solution of phosphate and sodium pentane sulfonate (pH 3.0) and acetonitrile at flow rate 1.5 mL/min. DAD was tuned at 254 nm for measuring peak area of NTS and 210 nm for LTP and BZC. The proposed procedure showed to be effective in the stability investigation of the cited drugs. The suggested HPLC procedure was validated based on the International Council for Harmonization (ICH) guiding principles. The three analytes were determined within linearity ranges of 1–100 µg/mL, 5–200 µg/mL and 10–200 µg/mL for NTS, LTP and BZC respectively with excellent analytical performance. Assay of several ophthalmic preparations was successfully carried out using the validated method, which was further appraised together with some relevant reported methods in regard to green and white analytical chemistry aspects using AGREE and RGB-12 tools. Very few published analytical records were found for NTS/LTP mixture. After surveying the scientific literature, no documentation was retrieved for a similar inclusive stability-indicating impurity-profiling separative method for the synchronized quantitation of NTS, LTP together with co-formulated preservative BZC.

Analisis Pengaruh Sisa Klor Terhadap Air Distribusi PDAM Surya Sembada IPAM Karang Pilang 3 Kota Surabaya

The provision of drinking water for the community must meet quality standards that include physical, chemical and bacteriological aspects. The use of chlorine gas as a disinfectant can affect the quality of drinking water in an installation. One method to reduce bacteria in the water treatment process is to use disinfectants, among which chlorine is often used. The use of chlorine as a disinfectant in water treatment plays an important role in eliminating bacteria in water. This research aims to evaluate the quality of water treated by PDAM Surya Sembada, with the hope of providing an understanding to the public about the impact of residual chlorine on distributed water

Buriti (Mauritia flexuosa) shell flour: Nutritional composition, chemical profile, and antioxidant potential as a strategy for valuing waste from native Brazilian fruits

The Cerrado is one of the most biodiverse biomes in the world, characterized by a wealth of native fruits with unique nutritional characteristics. In this sense, the social, economic, and environmental importance of fully utilizing food is widely recognized. Therefore, generally considered waste, fruit shells can be transformed into a coproduct with high added value. The objective of this work was to carry out a comprehensive assessment of the physicochemical properties, carbohydrate and fatty acid profile, phytochemical compounds, phenolic profile, and antioxidant potential of the recovered extracts of buriti (Mauritia flexuosa) shells in natura and dehydrated at 55 °C (flour). In addition, the functional properties were verified by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) from buriti shell flour. The results indicated high fiber content and energy value for the sample processed at 55 °C (58.95 g/100 g and 378.91 kcal/100 g, respectively) and low lipid and protein content (1.03 g/100 g and 1.39 g/100 g, respectively). Regardless of the sample analyzed, maltose was the majority sugar (37.33 – 281.01 g/100 g). The main fatty acids detected were oleic acid (61.33 – 62.08 %) followed by palmitic acid (33.91 – 34.40 %). The analysis of the mineral profile demonstrated that the samples did not differ significantly from each other, showing that the drying process did not interfere with the results obtained (p ≤ 0.05). The analysis of individual phenolics allowed the identification of six phenolic compounds in buriti shells. However, it is possible to observe that the drying method had a positive and significant influence on the phenolic profile (p ≤ 0.05), with chlorogenic acid (2.63 – 8.27 mg/100 g) and trigonelline (1.06 – 41.52 mg/100 g), the majority compounds. On the other hand, it is important to highlight that buriti shells have a high content of carotenoids, mainly β-carotene (27.18 – 62.94 µg/100 g) and α-carotene (18.23 – 60.28 µg/100 g), also being positively influenced by the drying process at 55 °C (p ≤ 0.05). The dried shells showed a high content of phytochemical compounds and high antioxidant activity based on the different methods tested. The results show that buriti shell flour can be fully utilized and has nutritional and chemical aspects that can be applied to develop new sustainable, nutritious, and functional food formulations.

Assessment of indoor air quality of the furniture manufacturers in Binh Duong industrial parks, Vietnam

Abstract Wood furniture and related products are created from raw wood and or wood products that require cutting, sanding, and other handling activities that generate wood dust. Exposure to indoor factory air pollutants can have significant health consequences for workers and nearby communities. Therefore, it was necessary to implement the assessment of indoor air quality in furniture manufacturers. This study mainly aimed to assess the indoor air quality status of physical and chemical aspects at 3 different furniture factories. Each sample was analysed for eight parameters including TSP, PM10, PM2.5, noise, temperature, humidity, wind, and light. Sampling and sample handling techniques were performed based on the usage test methods of Vietnam standards. The concentrations of TSP (194 – 493 μg/m3), PM10 (106.7 – 153.8 μg/m3), PM2.5 (72.8 – 95.6 μg/m3); and, the variables of noise (70.4 – 80.3 dBA), temperature (29.4 – 32.4 °C), humidity (58.0 – 69.4 %), wind (0.29 – 0.49) and light (327 – 573) these considered at 3 furniture manufacturers were within the allowable thresholds of QCVN 02:2019/BYT (Permissible exposure limit value of dust at the workplace), QCVN24:2016/BYT (Permissible exposure levels of noise in the workplace), QCVN26:2016/BYT (Permissible value of microclimate in the workplace); and, QCVN22:2016/BYT (Permissible levels of lighting in the workplace). However, long-term direct exposure of workers to these pollutants would also result in potential health risks. This study also suggested the management and technical control solutions to contribute to improving air quality for furniture manufacturers.

Multidimensional water level and water quality response to severe drought in Xingyun Lake

Drought stress has a significant impact on the quality and quantity of lake water. Understanding this impact is crucial for preventing water security risks and pollution recovery. However, there is a lack of systemic understanding of how drought affects water quality and quantity, and how they change in multiple dimensions. This manuscript established a synthesized methodology with the principles to judge the applicability and three steps of application to detect the change in water quality and water level under severe drought in Xingyun Lake, China. Results show that (1) The water level and water quality of Xingyun Lake have a synchronous and evident response to drought during 2009–2014. The rainfall during 2008–2015 declined by 22.9 % to normal, and the inundated area and lake water depth in 2012 decreased by 10.50 % from 2002 to 1.38 m to the average depth, respectively. The pollution index climbed above 1.21 after 2008, fluctuating around 1.42. (2) Under drought, the water quality indicators significantly changed in the terms of the overall feature, trend, eigenvalue, and morphological characteristics. The water quality indicators of Set2008-2015 are significantly different from set2000-2007 and not in the groups of set1994-2000. The morphological characteristics of water quality indicators in set2008-2015 differs significantly from that in set2000-2007 shown by the minimum, maximum, median, quartiles, and extreme values. (3) Although NH3–N showed no significant change, the water quality deteriorated in the physical, chemical, and biological aspects. The TP, IMN, and BOD5 changed more evidently than DO and NH3–N. (4) Water quality grade and indicator concentration deteriorated significantly and sharply under severe drought and are threatened deeply by TP and TN. The synthesized methodology is scientifically constructed and canbe employed in the characteristics cognition of water quality and water level to severe drought in and out of this research. And the intervention time and various regulating measures for pollution degradation and water quality recovery canbe constructed based on the multi-dimensional analysis of water quality change under drought evolution.