Ion doping in transition metal oxides is always considered to be one of the most effective methods to obtain high-performance electrochemical supercapacitors because of the introduction of defective surfaces as well as the enhancement of electrical conductivity. Inspired by the smelting process, an ancient method, quenching is introduced for doping metal ions into transition metal oxides with intriguing physicochemical properties. Herein, as a proof of concept, α-Fe2O3 nanorods grown on carbon cloths (α-Fe2O3@CC) heated at 400 °C are rapidly put into different aqueous solutions of alkaline earth metal salts at 4 °C to obtain electrodes doped with different alkaline earth metal ions (M-Fe2O3@CC). Among them, Sr-Fe2O3@CC shows the best electrochemical capacitance, reaching 77.81 mF cm−2 at the current of 0.5 mA cm−2, which is 2.5 times that of α-Fe2O3@CC. The results demonstrate that quenching is a feasible new idea for improving the electrochemical performances of nanostructured materia... [more]

The law of gas initial desorption from coals is greatly important for understanding the occurrence mechanism and predicting coal and gas outburst (hereinafter referred to as ‘outburst’). However, dynamic characterization of gas initial desorption remains to be investigated. In this study, by monitoring the gas pressure and temperature of tectonically deformed (TD) coal and primary-undeformed (PU) coal, we established the evolution laws of gas key parameters during the initial desorption. The results indicate that the gas pressure drop rate, mass flow rate, initial desorption rate, and gas velocity increase with increasing gas pressure, with stronger gas dynamic effect, generating a high pressure gradient on the coal surface. Under the same gas pressure, the pressure gradient formed on the TD coal surface is greater than that formed on the surface of the PU coal, resulting in easily initiating an outburst in the TD coal. Moreover, the increased gas pressure increases temperature change... [more]

The present study summarizes the new strategies including advanced equipment and validation parameters of liquid and gas chromatography methods i.e., thin-layer chromatography (TLC), column liquid chromatography (CLC), and gas chromatography (GC) suitable for the identification and quantitative determination of different natural and synthetic bioactive compounds present in food and food products, which play an important role in human health, within the period of 2019−2021 (January). Full characteristic of some of these procedures with their validation parameters is discussed in this work. The present review confirms the vital role of HPLC methodology in combination with different detection modes i.e., HPLC-UV, HPLC-DAD, HPLC-MS, and HPLC-MS/MS for the determination of natural and synthetic bioactive molecules for different purposes i.e., to characterize the chemical composition of food as well as in the multi-residue analysis of pesticides, NSAIDs, antibiotics, steroids, and others in... [more]

Biochar-derived C-Dots from Picea, Molinia caerulea and Elaeis guineensis were synthesized through a hydrothermal process, and their physicochemical and optical characteristics and environmental effects were compared. These C-Dots were characterized by techniques such as Attenuated Total Reflection−Fourier Transform Infrared (ATR-FTIR), UV-Vis spectrophotometry, fluorescence spectroscopy, dynamic light scattering (DLS), Z potential, and High-Resolution Transmission Electronical Microscopy (HR-TEM). The ecotoxicity tests were performed using the Microtox™ test, making this study one of the few that use this method. The C-Dots from Molinia caerulea showed the best quantum yield (QY) of 8.39% and moderate ecotoxicity, while Elaeis guineensis has the lowest QY (2.31%) but with zero toxicity. Furthermore, the C-Dots from Picea presents good optical properties but showed high toxicity and limits its use. Finally, all C-Dots showed functional groups that could be biofunctionalized with biomol... [more]

Pharmaceuticals are an increasing problem in waterways due to improper disposal and lack of removal at wastewater treatment plants. Long-term exposure impacts to humans are unknown but have been observed in model organisms (i.e., fish), impacting reproduction, changing temperament, and causing organ damage. The application of activated carbon (AC) for organic contaminant removal is widespread and applied successfully for water treatment. The objective of this study is to rapidly adsorb ibuprofen using AC to determine the feasibility as a point-of-entry treatment option for removal of pharmaceuticals in the toilet. AC factors analyzed include type of AC raw material, adsorbent particle size, contact time, and competitive adsorption of ibuprofen and common toilet bowl cleaner components such as chlorine and methylene blue dye. A coconut-based AC with a high surface area adsorbed the highest quantity of ibuprofen. There was no significant impact to ibuprofen adsorption upon the introducti... [more]

The purpose of the study is to investigate the possibility of using wine industry wastes, such as red and white grape bagasse, to produce bacterial cellulose (BC) instead of using a costly commercial medium. BC was produced using grape bagasse as a carbon source replacement and the sole nutrient in the medium. The BC films were evaluated for their productivity and water-holding capacity. The BC films were also investigated for their morphology using scanning electron microscopy (SEM), their viscoelastic properties using dynamic mechanical analysis (DMA), and their chemical composition using Fourier-transform infrared spectroscopy (FTIR). Although the use of grape bagasse as the sole nutrient was successful in the preparation of BC, the BC films had inferior viscoelastic properties to other produced BC films. White grape bagasse proved to be an excellent carbon substitute as the production of BC and its water-holding capacity were five times higher and the produced BC films were up to 7... [more]

Statins are important drugs in the regulation of cholesterol levels in the human body that have as a primary target the enzyme β-hydroxy-β-methylglutaryl-CoA reductase (HMGR). This enzyme plays a crucial role in the mevalonate pathway, catalyzing the four-electron reduction of HMG-CoA to mevalonate. A second reduction step of this reaction mechanism has been the subject of much speculation in the literature, with different conflicting theories persisting to the present day. In this study, the different mechanistic hypotheses were evaluated with atomic-level detail through a combination of molecular dynamics simulations (MD) and quantum mechanics/molecular mechanics (QM/MM) calculations. The obtained Gibbs free activation and Gibbs free reaction energy (15 kcal mol−1 and −40 kcal mol−1) show that this hydride step takes place with the involvement of a cationic His405 and Lys639, and a neutral Glu98, while Asp715 remains in an anionic state. The results provide an atomic-level portrait o... [more]

The BbRib gene participates in the infection process of Beauveria bassiana (B. bassiana). It also helps pathogenic fungi to escape and defeat the insect host immune defense system by regulating the innate immune response. However, model insects are rarely used to study the mechanism of fungal ribosomal toxin protein. In this study, BbRib protein was produced by prokaryotic expression and injected into silkworm (Bombyx mori) larvae. The physiological and biochemical indexes of silkworm were monitored, and the pathological effects of BbRib protein on immune tissues of silkworm were examined by Hematoxylin and Eosin (HE) staining. BbRib protein can significantly affect the growth and development of the silkworm, causing poisoning, destroying the midgut and fat body and producing physiological changes. The ROS stress response in the adipose tissue and cells of the silkworm was activated to induce apoptosis. These results indicated that the BbRib gene not only participates in the infection... [more]

The paper is an extensive monographic review of the literature, and also uses the results of the authors’ own experimental research illustrating the noticed developmental tendencies of the filling material based on gutta-percha. The whole body of literature proves the correctness of the research thesis that this material is the best currently that can be used in endodontics. Caries is one of the most common global infectious diseases. Since the dawn of humankind, the consequence of the disease has been the loss of dentition over time through dental extractions. Both tooth caries and tooth loss cause numerous complications and systemic diseases, which have a serious impact on insurance systems and on the well-being, quality, and length of human life. Endodontic treatment, which has been developing since 1836, is an alternative to tooth extraction. Based on an extensive literature review, the methodology of qualifying patients for endodontic treatment was analyzed. The importance of sele... [more]

In 2005, a 60 kt/a alkylation (ALK) unit began to resume production in the Second Oil Refinery Plant of Beijing Yanshan Petrochemical Company. There have been many leak cases from pipeline welds, valve body, flange, etc. After a half-year period of operation, production process is stable. However, the operation of the hydrofluoric (HF) acid ALK unit has been suffered from corrosion problems. There are no clear answers and references to the following problems. What types of corrosion are currently in the main equipment for HF acid ALK unit? What does cause equipment corrosion? What are the main influencing factors for corrosion? What measures can be taken to reduce the corrosion of HF acid? In this paper, considering the acid-related conditions of the ALK unit, the damage mechanism and damage rate analysis were carried out to calculate the safety risk of the static equipment of the ALK unit. Based on the damage mechanism and failure history, the material suitability of the ALK unit was... [more]

Chemical Product Engineering (CPE) is marked by numerous challenges, such as the complexity of the properties−structure−ingredients−process relationship of the different products and the necessity to discover and develop constantly and quickly new molecules and materials with tailor-made properties. In recent years, artificial intelligence (AI) and machine learning (ML) methods have gained increasing attention due to their performance in tackling particularly complex problems in various areas, such as computer vision and natural language processing. As such, they present a specific interest in addressing the complex challenges of CPE. This article provides an updated review of the state of the art regarding the implementation of ML techniques in different types of CPE problems with a particular focus on four specific domains, namely the design and discovery of new molecules and materials, the modeling of processes, the prediction of chemical reactions/retrosynthesis and the support for... [more]

This comparative study inspects the MHD three-dimensional revolving flow and temperature transmission of a radiative stretching surface. The flow of nanofluid is modeled using the Tiwari and Das model. Water is the base fluid, and the nanoparticles are composed of two different types of nanoparticle, i.e., gold and silver (Au and Ag). The non-radiative heat flow notion is examined in a temperature field that results in a nonlinear energy equation. Conformist transformations are used to generate a self-similar arrangement of the leading differential system. The resulting system has an intriguing temperature ratio constraint, which shows whether the flow has a little or significant temperature differential. By using a powerful mathematical technique, numerical results are obtained. The solutions are influenced by both stretching and rotation. The difference in velocity constituents with the elements’ volume fraction is non-monotonic. Results for the rotating nanofluid flow and heat trans... [more]

Hybrids and composite materials offer a synergic combination of polymer and inorganic features [...]

The production of blue hydrogen through sorption-enhanced processes has emerged as a suitable option to reduce greenhouse gas emissions. Sorption-enhanced steam−methane reforming (SESMR) is a process intensification of highly endothermic steam−methane reforming (SMR), ensured by in situ carbon capture through a solid sorbent, making hydrogen production efficient and more environmentally sustainable. In this study, a comprehensive energy model of SESMR was developed to carry out a detailed energy characterization of the process, with the aim of filling a current knowledge gap in the literature. The model was applied to a bench-scale multicycle SESMR/sorbent regeneration test to provide an energy insight into the process. Besides the experimental advantages of higher hydrogen concentration (90 mol% dry basis, 70 mol% wet basis) and performance of CO2 capture, the developed energy model demonstrated that SESMR allows for substantially complete energy self-sufficiency through the process.... [more]

The process of removing indium ions from aqueous solutions by applying capacitive deionization (CDI) is reported in this manuscript. First, a modified carbon material was prepared by incorporating titanium dioxide (TiO2) into activated carbon (AC). A microwave-assisted ionothermal synthesis (MAIS) method was used to produce evenly distributed nanostructured anatase TiO2 on the surface of AC. A polyurethane (PU) elastomer was then synthesized as the binder material instead of using conventional polyvinylidene fluoride (PVDF). By combining the aforementioned materials, a MAIS TiO2/AC-PU electrode was synthesized and applied to CDI tests. Scanning electron microscopy (SEM) was used to characterize the size and dispersion of the composites. For electrochemical properties, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to analyze the synthesized electrode. The performance of the prepared electrode during the CDI process was tested in different concentrati... [more]

The paper presents a study on the performance of a conventional plant-producing ethyl acetate from ethanol and acetic acid. Process models were compiled in the simulator Chemcad 7. The impact of key parameters on the performance of individual installation nodes was examined by sensitivity analysis. Three installation approaches are presented and compared: two classic with different heat duties and an improved one. An improved technological solution, with a closed circulation of the extractant as well as the azeotrope subcooling for better extraction is demonstrated. The energy and mass balance of the installation were developed. The proposed enhancement of a technology with significantly reduced consumption of the fresh extractant also offers a deep recovery of the raw materials, i.e., ethyl acetate and ethanol from wastewater. We assumed that the same energy consumption relative to the classic strategy consumption of ethanol was reduced from 0.531 to 0.524 t/tproduct (−1.2%), fresh pr... [more]

Liquefaction of waste lignocellulosic biomass is a viable technology for replacing fossil fuels and meeting sustainable development goals. In this study, bio-based epoxy resins were prepared from polyhydric-alcohol-liquefied cotton stalk by glycidyl etherification. The cotton stalk was liquefied in a polyethylene glycol/glycerol cosolvent under H2SO4 catalysis. Epon 828 and cotton-stalk-based epoxy resins could be cured using methylhexahydrophthalic anhydride as the curing agent, and the curing process was exothermic. The thermal properties and tensile strength of cured resins were investigated to examine the effect of adding cotton-stalk-based resin on the performance of the copolymerized epoxy resin. Further, the liquefied-cotton-stalk-based epoxy resin was blended with Epon 828 at different ratios (10, 20, and 30 mass%) and cured with a curing agent in the presence of 2-methylimidazole catalyst. An increase in the peak temperature and a reduction in the heat of curing and activation... [more]

nucleopolyhedrovirus (BmNPV) is a kind of pathogen that causes huge economic losses to silkworm production. Although Autographa californica nucleopolyhedrovirus (AcMNPV) and BmNPV are both baculoviruses, the host domains of these two viruses have almost no intersection in nature. Recently, it has been found that some silkworms could be infected by recombinant AcMNPV through a puncture, which provided valuable material for studying the infection mechanism of baculovirus to silkworm. In this study, comparative transcriptomics was used to analyse the hemolymph of two differentially resistant strains following AcMNPV inoculation. There were 678 DEGs in p50 and 515 DEGs in C108 following viral infection. Among them, the upregulation and downregulation of DEGs were similar in p50; however, the upregulated DEGs were nearly twice as numerous as the downregulated DEGs in C108. The DEGs in different resistant strains differed by GO enrichment. Based on KEGG enrichment, DEGs were mainly enriched... [more]

Melt processing is considered one of the favored techniques to produce polymer nanocomposites with various inorganic fillers such as graphene and carbon nanotubes (CNTs). Due to their superior conductivity and tensile properties, among others, CNTs have been applied in broad applications. When a low filler fraction is desired, a high degree of dispersion is required in order to benefit from the intrinsic properties of CNTs. However, due to their high cohesive energy, dispersing CNTs in polymer melts is a difficult task. This study employed the melt mixing technique with a controlled residence time of 20 min to disperse single-walled carbon nanotubes (SWNTs) into a polypropylene matrix. The composites were prepared by using a corotating twin-screw extruder equipped with a back-conveying element with varying amounts of SWNTs from 0.29 to 6.56 wt.%. Mechanical, electrical, morphological, and rheological properties were evaluated. Due to the filler effect, storage, loss modulus, and comple... [more]

Glycerol is a major byproduct obtained in the production of biodiesel, an important renewable fuel. The presence of free glycerol in fuel can have structural and performance consequences with respect to the engine, making fuel quality control important. The standard method to analyze glycerol in biodiesel is gas chromatography, a time-consuming and expensive technique. In this context, an electrode based on glassy carbon electrodes (GCEs) modified with reduced graphene oxide and core-shell gold@palladium nanoparticles was developed for the determination of glycerol in biodiesel. The free glycerol analysis was performed in the aqueous phase obtained by liquid−liquid extraction from a biodiesel sample. Cyclic voltammetry was chosen as the method for glycerol electrochemical analysis to regenerate active sites and promote greater sensor stability. The modified Au@Pd/rGO/GCE electrode showed an excellent performance, obtaining a linear range of 18.2 to 109 µmol L−1 with a correlation coeff... [more]

This study aims to identify the potential of gold mining waste for CO2 sequestration and its utilization for carbon storage in cementitious material. Samples of mine waste were identified from a gold mine for mineralogical and chemical composition analysis using X-ray diffractogram and scanning electron microscopy with energy-dispersive X-ray. Mine waste was utilized in a brick-making process as supplementary cementitious material and as an agent for CO2 capture and storage in bricks. Carbonation curing was incorporated in brick fabrication to estimate CO2 uptake of the brick product. Results indicated that the mine wastes were composed of silicate minerals essential for mineral carbonation such as muscovite and illite (major) and chlorite-serpentine, aerinite, albite and stilpnomelane (moderate/minor phases). The mine wastes were identified as belonging to the highly pozzolanic category, which has a great role in improving the strength properties of brick products. Carbonated minerals... [more]

Isolation of anti-proliferative compounds from plants is always hindered by the complexities of the plant’s nature and tedious processes. Clinacanthus nutans (Burm. f.) Lindau is a medicinal plant with reported anti-proliferative activities. Our study aimed to isolate potential anti-proliferative compounds present in C. nutans plant. To start with, for our study, we came up with a strategy by first profiling the volatile compounds present in the leaf, stem and root of C. nutans using GC-MS. Comparing the plant’s volatile profiles greatly narrowed down our target of study. We decided to start with the isolation and characterization of a pentacyclic terpenoid, i.e., lupeol from the roots of C. nutans, as this compound was found to present abundantly in the roots compared to the leaf or stem. We developed a simple maceration and re-crystallization method, without the necessity to go through the fractionation or column chromatography for the isolation of lupeol. Characterizations of the is... [more]

Heavy metal pollution of aquatic media has grown significantly over the past few decades. Therefore, a number of physical, chemical, biological, and electrochemical technologies are being employed to tackle this problem. However, they possess various inescapable shortcomings curbing their utilization at a commercial scale. In this regard, nanotechnology has provided efficient and cost-effective solutions for the extraction of heavy metals from water. This review will provide a detailed overview on the efficiency and applicability of various adsorbents, i.e., carbon nanotubes, graphene, silica, zero-valent iron, and magnetic nanoparticles for scavenging metallic ions. These nanoparticles exhibit potential to be used in extracting a variety of toxic metals. Recently, nanomaterial-assisted bioelectrochemical removal of heavy metals has also emerged. To that end, various nanoparticle-based electrodes are being developed, offering more efficient, cost-effective, ecofriendly, and sustainable... [more]

The present work deals with the transferability of Friction Riveting joining technology from laboratory equipment to adapted in-house, low-cost machinery. A G13 drilling machine was modified for the requirements of the selected joining technique, and joints were performed using polyethermide plates and AA2024 aluminum alloy rivets of 6 mm diameter. This diameter was not previously reported for Friction Riveting. The produced joints were mechanically tested under tensile loading (pullout tests) with ultimate tensile forces of 9500 ± 900 N. All tested specimens failed through full-rivet pullout, which is the weakest reported joint in Friction Riveting. In order to understand this behavior, FE models were created and analyzed. The models produced were in agreement with the experimental results, with failure initiated within the polymer under stress concentrations in the polymeric material above the deformed metallic anchor at an ultimate value of the stress of 878 MPa at the surface of th... [more]

This work reports a detailed experimental study that is aimed at investigating the failure mechanisms of highly porous cementitious foams used as heat insulation under triaxial stress states. The designed target dry density of the considered foam mixture was 180 kg/m3 by setting the water-to-cement ratio of the considered cement paste to 0.4. The mechanical experiments were accompanied by thermal tests to observe the effect that specific air void structures have on the resulting insulation properties and by micro-to-meso geometric studies to identify and classify the inner structure of the considered mineralized foams. Unconfined compressive strengths were performed first, obtaining peak stresses of 0.252, 0.283, 0.223, and 0.251 (results in MPa), corresponding to peak strains of 39.0, 28.6, 45.3, and 20.6 (in ×10−3 mm/mm), respectively. Moreover, three triaxial confinement levels of 33%, 66%, and 90% of the mean uniaxial compressive strength (fc) were adopted. The results showed that... [more]