Characteristic Functional Groups Research Articles

Changes in Soil Aggregate Carbon Components and Responses to Plant Input during Vegetation Restoration in the Loess Plateau, China

Vegetation restoration is an effective measure to cope with global climate change and promote soil carbon sequestration. However, during vegetation restoration, the turnover and properties of carbon within various aggregates change. The effects of plant source carbon input on surface soil and subsurface soil may be different. Thus, the characteristics of carbon components in aggregates are affected. Therefore, the research object of this study is the Robinia pseudoacacia forest located in 16–47a of the Loess Plateau, and compared with farmland. The change characteristics of organic carbon functional groups in 0–20 cm, 20–40 cm, and 40–60 cm soil layers were analyzed by Fourier near infrared spectroscopy, and the relationship between the chemical structure of organic carbon and the content of organic carbon components in soil aggregates was clarified, and the mechanism affecting the distribution of organic carbon components in soil aggregates was revealed in the process of vegetation restoration. The results show the following: (1) The stability of surface aggregates is sensitive, while that of deep aggregates is weak. Vegetation restoration increased the surface soil organic carbon content by 1.97~3.78 g·kg−1. (2) After vegetation restoration, the relative contents of polysaccharide functional groups in >0.25 mm aggregates were significantly reduced, while the relative contents of aromatic and aliphatic functional groups of organic carbon were significantly increased. The opposite is true for aggregates smaller than 0.25 mm. (3) With the increase in soil depth, the effect of litter on organic carbon gradually decreased, while the effect of root input on the accumulation of inert carbon in deep soil was more lasting.

Preparation of fully physically crosslinked double-network gel and its fire prevention mechanism

It is important to gain an in-depth understanding of the structure of fire prevention and extinguishing materials during self-heating of coal. In this paper, an Al3+-CMC/PAM-MMT fire prevention and extinguishing gel with double-network was prepared using sodium carboxymethyl cellulose (CMC) and polyacrylamide (PAM) as raw materials, and aluminum citrate (AlCit) and sodium montmorillonite (Na-MMT) as auxiliary materials, by introducing the fully physically crosslinking effect. The optimal amounts of CMC, PAM, AlCit and MMT were determined to be 2 %, 3 %, 8 %, and 3 %, respectively, based on gelation time, stability, and resistance of the gel. The micromorphological image of the double-network gel exhibited a laminar structure of parallel-aligned fibrous networks, where the pores and channels exhibited more complex shapes and became smaller in size, highlighting the superiority of the double-network architecture. The rheological tests showed that the double-network gel had superior structural stability and viscosity under varying shear rates, making it more effective in covering the fire source, enhancing extinguishing efficiency. Additionally, its higher storage and loss moduli indicated stronger elasticity and mechanical properties compared to the single-network gel, emphasizing its advantages in energy storage and recovery. The characterization of active functional groups showed that there was an effective suppression of reactions involving hydroxyl, hydrocarbon, and carbonyl functional groups, during the spontaneous combustion process of coal, following treatment with the gel. Additionally, a proposed mechanism for the gel formation was presented. In the sealing performance test, the pressure-bearing capacity of the double-network gel was approximately twice that of the single-network gel. It indicated that the multi-level structure formed by the gel led to higher density of physical cross-linking points, which provided better sealing performance. Thermogravimetric analysis showed significant decrease in total calorific value and increase in activation energy of coal, after treatment with the gel, rendering it more difficult for spontaneous coal combustion. In the small-scale fire extinguishing performance test, the double network of Al3+-CMC/PAM-MMT gel demonstrated effective suppression of spontaneous combustion of coal and reduced the susceptibility to re-ignition. The fire prevention mechanism of the gel was further explored experimentally.

Self-template synthesis of pitch-based hierarchical porous carbon for high performance supercapacitor in aqueous and ionic liquid electrolytes

Pitch-based hierarchical porous carbons (PHPCs) have been fabricated by means of self-templated method that is adopting metal oxides and metallic salts impurities originate from coal tar pitch (CTP) precursor serve as in-situ hard template along with KOH activation. The porosity properties of PHPCs are significantly influenced by the mass ratio of KOH to pitch. The micro-morphology, hierarchical porosity constituted of co-existing micro-/meso-/macropores, specific surface area, surface elementary composition and electrochemical properties have been comprehensively investigated. It is shown that the high specific surface area (2479 m2 g-1), lay-stacked microstructure, hierarchical porosity characteristic and considerable oxygen-containing functional groups (4.51 a.t %) that synergistically facilitate the electrochemical performance of PHPCs. The electrochemical measurements results exhibit that the gravimetric capacitance for the optimal sample PHPCs-4 is as high as 317 F g-1 at a current density of 0.2 A g-1, with retention of 213 F g-1 even at 10 A g-1 in a three-electrode configuration. In a two-electrode device, the PHPCs-4 based symmetric supercapacitor cell exhibits a specific capacitance of 245 F g-1 at 0.1 A g-1, along with a good rate capability of 75.5% (185 F g-1 at 10 A g-1) and a considerable energy density of 8.51Wh kg-1 at a power density of 50 W kg-1. When tested in EMIMBF4 ionic liquid electrolyte at a cell voltage of 3.5 V, the assembled symmetric supercapacitor cell demonstrates a high energy density of 77 Wh kg-1 at a power density of 175 W kg-1, maintaining 65.3 Wh kg-1 at a current density of 1 A g-1, and 32.1 Wh kg-1 at a high power density of 17500 W kg-1. Furthermore, the specific capacitance of the PHPCs-4 based symmetric supercapacitor retains nearly 100% of its initial value over 5000 cycles in 6M KOH aqueous electrolyte and 91.4 % after 2500 cycles in EMIMBF4 ionic liquid electrolyte. This strategy exploits a novel approach to synthesizing hierarchical porous carbons from coal tar pitch using a self-templating method, offering potential benefits for various applications.

Structural characterization, physicochemical properties and hypoglycemic activity of soluble dietary fibers from salt stressed mung bean sprouts

Low-salt stress germination is an effective way to improve the nutritional composition of food crops. A novel soluble dietary fiber (MS-SDF) was isolated from low-salt stress mung bean sprouts that were exposed to low-salt stress using anion exchange and gel permeation techniques. Structural analysis revealed that MS-SDF was a homogeneous heteropolysaccharide with an average molecular weight of 164.997 KDa. It featured a loose structure and contained the characteristic functional groups typical of polysaccharides. MS-SDF was composed of arabinose, galactose, glucose, and mannose with a molar ratio of 3.95:3.86:82.69:9.02. The structure was mainly composed of →6)-α-D-Glcp-(1→, →5)-α-L-Araf-(1→, and →3,6)-α-D-Glcp-(1→ as the main chain. Branched at O-3 position with single β-D-Manp-(1→ as major the side chain. Furthermore, in vitro hypoglycemic assays indicate that MS-SDF exhibits α-glucosidase inhibitory activity, significantly enhancing glucose uptake, glycogen synthesis, and pyruvate kinase activity in insulin-resistant HepG2 cells. Overall, MS-SDF could be used as a promising source of functional hypoglycemic foods.

Ligand-Engineered Structural and Physiochemical Properties of 1D Molybdenum-MOFs: A Seldom Explored System for Photocatalytic Applications.

As one of the seldom explored systems, molybdenum-based metal-organic frameworks (Mo-MOFs) with different ligands such as terephthalic acid (Mo-TA), 2-aminoterephthalic acid (Mo-ATA), benzenetricarboxylic acid (Mo-BTC), 2-methylimidazole (Mo-2MI), 2-bipyridine (Mo-2bpy), and 4-bipyridine (Mo-4bpy) were developed in this study. X-ray diffraction (XRD), Raman, and attenuated total reflectance-infrared (ATR-IR) analyses confirmed the ligand-dependent crystal structure of the Mo-MOFs along with the characteristic functional groups present in the respective systems. Interestingly, the morphology of all of these the developed Mo-MOFs was found to be a one-dimensional rod-like structure, which was attributed to the binding nature of the ligands onto the growing Mo-frameworks. Optical analysis indicated that all these Mo-MOFs exhibit ultraviolet (UV) light absorption properties with band gap energy in the range of 3.47-3.03 eV. Among the various Mo-MOFs developed, Mo-4bpy MOF degraded a maximum of ∼76 and 62% of malachite green and Congo red dyes, respectively, under sunlight irradiation. The observed improved photocatalytic efficiency of Mo-4bpy MOF was attributed to its appropriate band edge potential, confirmed by Mott-Schottky analysis, improved carrier lifetime (∼34.6 ns) estimated using the time-resolved photoluminescence (TRPL) spectrum, presence of elements with stable oxidation states in the system confirmed by X-ray photoelectron spectroscopy (XPS), improved charge transfer characteristics, and decreased recombination resistance, as confirmed by impedance and PL analyses, respectively. The degradation of Mo-4bpy MOFs mediated by superoxide (•O2-) and hydroxyl radicals (OH•) was further confirmed by scavenger studies. Cyclic studies performed for up to 5 cycles suggested that the degradation efficiency of the Mo-4bpy MOF was stable, attributed to its excellent structural, optical, and morphological features confirmed via postcharacterization of the recycled photocatalyst.

Efficacy of mesoporous TiO2–ZrO2@g-C3N4 produced using a simple ultrasonic approach for copper ion removal from wastewater

The present study describes ultrasonically produced ternary composite material composed of carbon nitride nanosheets, zirconium, and titanium oxides for elimination of copper ions. The formation of monoclinic ZrO2, anatase TiO2, and g-C3N4 phases with respective crystallite sizes 6, 11, 13 nm were verified by the X-ray diffraction technique. The dispersion of the metal oxides nanoparticles with the graphitic nanosheets, the elemental composition of Zr, Ti, O, C and N, and the characteristic functional groups were verified respectively by TEM, EDX, and FTIR analysis that confirmed the successful formation and composition of the nanocomposite TiO2–ZrO2@g-C3N4 (TZCN). The good porosity of the composite that show a surface area, pore volume, and pore diameter values of 47.42 m2/g, 0.056 cm3 g−1, and 20.3 Å that nominate it for adsorption application. The adsorption capabilities of the nanocomposite were studied for copper ion removal from an aqueous solution, as well as the impacts of pH and starting Cu2+ concentration. The results show that the adsorption process is pH and starting concentration-dependent, with a maximum adsorption capacity of 447.8 mg/g. The Cu2+ adsorption is a monolayer chemisorption process that is well described by the Langmuir adsorption model and follows pseudo-second-order kinetics. Moreover, a plausible mechanism for Cu2+ ion adsorption on the surface of TZCN nanocomposite particles is proposed.

Influence of calcination temperature on the 3D nanoscale topography of LaMnO3 thin films: A comprehensive surface analysis

In this paper, we present a comprehensive study on the 3D nanoscale topography of LaMnO3 thin films, focusing on the influence of calcination temperature on surface morphology. The study reveals significant structural, chemical, and morphological changes as a function of the calcination temperature. XRD analysis confirmed the formation of the orthorhombic LaMnO3 structure at 700 °C, 750 °C, and 800 °C, with increasing unit cell volume and crystallite size observed at higher temperatures. FTIR spectra identified characteristic functional groups associated with molecular vibrations, indicating the perovskite structure. SEM imaging showed grain growth with temperature, while EDS analysis confirmed compound formation and substrate interactions. AFM analysis revealed increased surface roughness with temperature, attributed to nucleation and crystal growth. Morphological and microtextural analyses further detailed changes in surface features, peaks, valleys, and voids. Fractal characterization highlighted variations in surface texture with temperature, with a decrease in dominant wavelength indicating changes in microtexture complexity. Overall, the findings provide insights into the temperature-dependent properties of LaMnO3 thin films, essential for optimizing growth conditions and understanding their potential applications in various fields.

Study on the structural, magnetic, and magnetodielectric properties of M-type BaFe12O19 and SrFe12O19 hexaferrite nanoparticles

This study addresses the synthesis and characterization of hexagonal barium hexaferrite (BaFe12O19) and strontium hexaferrite (SrFe12O19) nanoparticles, aiming to enhance their structural and magnetic properties for potential applications. Using the sol–gel method, nanoparticles were synthesized and calcinated at 1000 °C, 1100 °C, and 1200 °C for 5 h. A comprehensive analysis was conducted on the prepared nanoparticles' structural, functional, morphological, and magnetic properties. X-ray diffraction confirmed the hexagonal structure and single-crystal phase for BaFe12O19 and SrFe12O19 across all calcination temperatures. The Rietveld analysis of XRD patterns of all the samples have been carried. Fourier transform infrared spectroscopy identified fundamental vibrations at octahedral and tetrahedral sites, verifying the presence of characteristic functional groups. Morphological studies revealed that at an annealing temperature of 1100 °C, the average nanoparticle diameters were 335 nm for BaFe12O19 and 302 nm for SrFe12O19. The elemental analysis and distribution of elements of hexaferrites were studies using Energy Dispersive X-ray Analysis with color mapping method. Magnetic properties were extensively analyzed, including saturation magnetization (Ms), coercivity (Hc), retentivity (Mr), anisotropy field (Ha), squareness ratio (Mr/Ms), and magnetocrystalline anisotropy (K1). At 1100 °C, the magnetic properties of BaFe12O19 are Ms = 55.96 emu/g, Hc = 4308 G, Mr/Ms = 0.51, Ha = 31.30 kG, and K1 = 5.65 × 105 erg/cm3. For SrFe12O19, these values are Ms = 50.80 emu/g, Hc = 3507 G, Mr/Ms = 0.52, Ha = 21.20 kG, and K1 = 5.65 × 105 erg/cm3. Additionally, the study explored the magnetodielectric properties of BaFe12O19 and SrFe12O19 nanoparticles. At a magnetic field of 6000 G, the magnetocapacitance percentage (MC%) and magnetotangent loss percentage (ML%) for BaFe12O19 are −6.23 % and −8.85 %, respectively, while for SrFe12O19, these values are −4.38 % and −1.0 %. The findings indicate that the synthesized hexaferrite BaFe12O19 and SrFe12O19 nanoparticles exhibit significant potential for applications in sensors, permanent magnets, and data recording, with optimized structural and magnetic properties achieved at specific calcination temperatures.

Study of 14-Substituted-14H-Dibenzo[a,j] Xanthene Derivatives

Xanthene derivatives of the 14-aryl-14H dibenzo[a.j] xanthene type were exploited in our study because of their interesting biological profile as well as their innumerable applications described in previous studies. They were synthesized by one-pot condensation of [Formula: see text]-naphthol with arylaldehydes and catalyzed by zinc trifluoromethanesulfate Zn(OTf)2 under conventional heating without solvent. Their characterization was carried out by Ultraviolet–Visible spectrophotometry (UV–Vis), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). First, spectral analysis in the UV–Vis range showed that all xanthene derivatives had similar absorption spectra at an absorption maximum [Formula: see text] in the region of 310–340[Formula: see text]nm. Similarly, the infrared spectra suggested the presence of characteristic bands for each product in the range of 500–3500[Formula: see text]cm[Formula: see text]. In addition, the analysis of their crystalline structures was carried out by the XRD technique and reported in our study. Finally, their sizes and morphologies were highlighted by SEM. The obtained results revealed the presence of microcrystals in the form of micro-cubes having an average length of 10[Formula: see text][Formula: see text]m for the compound C[Formula: see text]H[Formula: see text]O and micro-shuttles of average size of 20[Formula: see text][Formula: see text]m for the compound C[Formula: see text]H[Formula: see text]BrO. It was therefore concluded that the xanthene derivatives synthesized have characteristic functional groups and structures which will provide them with various therapeutic properties and can therefore be exploited as bioactive molecules in several fields.

Investigating the properties and agronomic benefits of onion peel and chicken feather-derived biochars

Biochar production from unconventional biomass, specifically onion peel (OP) and chicken feathers (CF), was investigated in this study. Two distinct biochars were produced by doping each biomass with the other, with the aim of exploring the synergistic effects of different feedstock combinations on biochar properties. The biochar production process was conducted using a retort heating method and characterized using several techniques. A yield of 36 % was obtained for OP-doped biochar (OP92CF8-BC) and 23 % for CF-doped biochar (F92OP8-BC). Fourier Transform Infrared Spectroscopy analysis revealed characteristic functional groups from cellulose, hemicellulose, and lignin in OP92CF8-BC, while CF92OP8-BC displayed keratin-related peaks. Scanning Electron Microscopy imaging showed surface morphology differences, with OP92CF8-BC exhibiting a rougher and more porous structure compared to CF92OP8-BC. Energy-Dispersive X-ray Spectroscopy analysis confirmed the elemental composition, with OP92CF8-BC having higher carbon, calcium, and sulfur contents and CF92OP8-BC having higher nitrogen and oxygen contents. The biochar had specific surface areas of 342.4 and 200.80 m2/g for OP92CF8-BC and CF92OP8-BC, respectively. According to the results, using biochar treatments-more especially, CF92OP8-BC-can significantly enhance cob weight. This could be good for agricultural productivity. These findings highlight the influence of feedstock composition on the properties of biochar and provide insights for its potential applications in soil amendment and pollutant removal.

Bio-artificial dura mater in head trauma patients based on a kombucha-chitosan-collagen combination

Introduction: Kombucha scoby shows potential as a biomaterial applicable to patients with head trauma that results in tearing of the dura mater layer. This research aims to characterize kombucha scoby with chitosan and collagen as in vitro modification materials. The artificial dura mater is derived from kombucha scoby synthesized in green tea media and added with glycerol as a plasticizer. Objective: This study used four composition variations: Scoby-Kombucha (Control), Kombucha-Glycerol, Kombucha-Chitosan-Glycerol, and Kombucha-Chitosan-Collagen-Glycerol. Characterization was performed based on functional group analysis through Fourier Transform Infrared (FTIR) testing, tensile strength, swelling, degradation, Scanning Electron Microscope (SEM), and (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) (MTT Assay). The characterization of functional groups confirmed the presence of functional groups from kombucha Scoby, chitosan, collagen, and glycerol. The data were analyzed using descriptive analysis. Results: The results of tensile strength characterization showed that the three sample composition variations have UTS values (4-20 MPa) and Elongation (7-20%) in accordance with artificial dura mater standards. The swelling characterization of the four samples showed a liquid absorption value that does not exceed the swelling ratio limit (<70%). The highest degradation was obtained in the Kombucha-Chitosan-Collagen-Glycerol sample composition with a degradation rate of 20%. The SEM test found a pore diameter that meets the standards for artificial dura mater in the sample compositions of Kombucha-Chitosan-Glycerol and Kombucha-Chitosan-Collagen-Glycerol. Cytotoxicity characterization through the MTT Assay showed that the material does not contain substances toxic to the body. Conclusion: The Kombucha-Chitosan-Collagen-Glycerol membrane was an optimal composition as a candidate for artificial dura mater.

Recent advances in liquid-phase NMR of the coal-derived products.

Present review focuses on the most recent advances in a liquid-phase nuclear magnetic resonance (NMR) of the coal-derived products-coal tar pitches, asphaltenes, and humic and fulvic acids, covering exclusively the results in the liquid-phase NMR studies leaving apart an overwhelming amount of publications dealing with the solid-state NMR investigations in this field (which are comprehensively reviewed elsewhere). Owing to the complexity of the coal-derived products, their 1H and 13C NMR spectra consist of a number of overlapping signals belonging to different hydrocarbon types. Comprehensive studies of coal tar pitches, asphaltenes, and humic and fulvic acids by means of NMR over the past several decades revealed characteristic functional groups of those fractions together with spectral regions in which they resonate. Quantitative 1H and 13C NMR spectra characterize aromatic and saturated carbons spread over many structural moieties, which provides a solid guideline into molecular structure of the coal-derived products. Nowadays, quantitative 13C NMR measurements yield information about a variety of structural parameters such as functional group distribution, aromaticity, degree of condensation of aromatic rings, and medium chain lengths together with many other more specific parameters. The structural NMR studies of coal and coal-derived products are developing on a backdrop of a marked progress in computational NMR. At present, we are witnessing an unprecedentedly fast development of theoretical and computational methods in the field of NMR spectroscopy. Discussed in the present review are the most recent advances in the NMR studies of the processing products of peat, lignite or brown coal, anthracite or hard coal, and graphite in solution, like coal tar pitches, asphaltenes, and humic and fulvic acids.

Phytochemical Profiling, Antioxidant and Antimicrobial Potentials of Ethanol and Ethyl Acetate Extracts of Chamaenerion latifolium L.

The study investigates the phytochemical profile, antioxidant capacity, and antimicrobial activities of ethanol (ChL-EtOH) and ethyl acetate (ChL-EtOAc) extracts from Chamaenerion latifolium L. (ChL) harvested in Kazakhstan. The ChL-EtOH extract exhibited higher total phenolic (267.48 ± 3.44 mg GAE/g DE) and flavonoid content (24.18 ± 1.06 mg QE/g DE) compared to ChL-EtOAc. HPLC-UV-ESI/MS identified key phenolic acids and flavonoids, including gallic acid, chlorogenic acid, and quercetin 3-glucoside. FT-IR analysis confirmed the presence of characteristic functional groups. Antioxidant assays revealed strong DPPH scavenging and FRAP activities, with ChL-EtOH showing superior results (IC50 = 21.31 ± 0.65 μg/mL and 18.13 ± 0.15 μg/mL, respectively). Additionally, ChL-EtOH displayed notable antimicrobial efficacy against Gram-positive and Gram-negative bacteria, as well as the fungal strain Candida albicans. These findings suggest that ethanol extraction is more efficient for isolating bioactive compounds from ChL, underscoring its potential for pharmaceutical and nutraceutical applications.

Interactions of graphene oxide with the microbial community of biologically active filters from a water treatment plant

With widespread occurrence and increasing concern of emerging contaminants (CECs) in source water, biologically active filters (BAF) have been gaining acceptance in water treatment. Both BAFs and graphene oxide (GO) have been shown to be effective in treating CECs. However, studies to date have not addressed interactions between GO and microbial communities in water treatment processes such as BAFs. Therefore, in the present study, we investigated the effect of GO on the properties and microbial growth rate in a BAF system. Synthesized GO was characterized with a number of tools, including scanning electron microscopy (SEM), energy dispersive x-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Raman spectrometry. GO exhibited the characteristic surface functional groups (i.e., C-OH, C=O, C-O-C, and COOH), crystalline structure, and sheet-like morphology. To address the potential toxicity of GO on the microbial community, reactive oxygen species (ROS) generation was measured using nitro blue tetrazolium (NBT) assay. Results revealed that during the exponential growth phase, ROS generation was not observed in the presence of GO compared to the control batch. In fact, the adenosine triphosphate (ATP) concentrations increased in the presence of GO (25 μg/L - 1000 μg/L) compared to the control without GO. The growth rate in systems with GO exceeded the control by 20 % to 46 %. SEM images showed that GO sheets can form an effective scaffold to promote bacterial adhesion, proliferation, and biofilm formation, demonstrating its biocompatibility. Next-generation sequencing (Illumina MiSeq) was used to characterize the BAF microbial community, and high-throughput sequencing analysis confirmed the greater richness and more diverse microbial communities compared to systems without GO. This study is the first to report the effect of GO on the microbial community of BAF from a water treatment plant, which provides new insights into the potential of utilizing a bio-optimized BAF for advanced and sustainable water treatment or reuse strategies.

Synthesis of Zn0.87(Fe, Al)0.065O – MO (MO = NiO, Fe2O3, CuO, and CoO) nanocomposites: Structural, vibrational, optical and antibacterial studies

One of the most effective strategies for achieving high-performance antibacterial activity is the synthesis of nanocomposites by combining different nanoparticles. Hence, Zn0.87(Fe, Al)0.065O – MO (NiO, Fe2O3, CuO and CoO) nanocomposites (NCs) with a 7:3 molar ratio were synthesized via the solution combustion method. The produced NCs structural, vibrational, and optical characteristics were investigated using XRD, FTIR, UV–Vis, and PL spectroscopies. The standard disc diffusion method was used to evaluate the antibacterial efficacy of the NCs. The lattice constant, crystallite size, bond length, dislocation density, and other relevant parameters of the NCs were also evaluated. XRD analysis revealed a well-defined mixed-phase structure for all 0.7Zn0.87(Fe, Al)0.065O – 0.3NiO (ZFA-Ni), 0.7Zn0.87(Fe, Al)0.065O – 0.3Fe2O3 (ZFA-Fe), 0.7Zn0.87(Fe, Al)0.065O – 0.3CuO (ZFA-Cu) and 0.7Zn0.87(Fe, Al)0.065O – 0.3CoO (ZFA-Co) NCs, indicating successful mixing of each metal oxide with the ZnO matrix. The average crystallite size within the NCs ranged from 14.21 to 18.10 nm, suggesting a degree of nanocrystallinity nature of all NCs. FTIR confirmed the presence of characteristic functional groups within the NCs. Moreover, all the synthesized NCs exhibited significant optical activation in the ultraviolet radiation range but visible light absorption was also observed when the composite formed with CuO and Fe2O3 nanoparticles. The band gap energy values exhibited variation between 2.72 eV for ZFA-Co NC and 2.90 eV for ZFA-Ni NC. Photoluminescence (PL) emission in the composite formation of ZnO NPs with other metal oxide were significantly influenced by the absorption range of the composite with pn-junction formation in a notable enhancement of antibacterial efficacy against bacterial strains of Escherichia coli and Staphylococcus aureus. Particularly, ZFA-Co NC exhibited an excellent antibacterial performance against both bacterial strains.

Succession characteristics of phytoplankton functional groups and ecological assessment in a cold spring-type urban lake, China.

Phytoplankton functional groups have been increasingly utilized in elucidating and predicting the response of phytoplankton species to environmental conditions and seasonal succession in various aquatic systems including lakes, rivers and reservoirs. However, it is still unclear whether the trait-based functional classification can be applied to spring-type lakes. To understand the temporal and spatial characteristics of phytoplankton functional groups and their responses to environmental factors in spring-type urban lake in northern China, an investigation was conducted in Daming Lake from May 2020 to September 2021. The findings revealed the identification of 98 phytoplankton taxa belonging to 6 phyla, predominantly being Chlorophyta (39.8%), Bacillariophyta (35.7%) and Cyanophyta (15.3%). The dominant species were Microcystis sp., Merismopedia minima, Synedra acus and Scenedesmus quadricauda. These phytoplankton taxa were categorized into 21 functional groups, with 6 dominant functional groups (abbreviated as D, MP, P, J, Lo, and W1). Among them, the functional group D, primarily constituted by S. acus, exhibited absolute predominance. The seasonal succession sequence of the dominant functional groups was as follows: D/P/J/MP/ Lo →→ D/P/W1/MP/Lo/J → D/P/J → D/MP → D/P/MP. Throughout the investigation period, the trophic level index (TLI) ranged from 39.10 to 71.13, and the Q index was from 1.91 to 2.91, both indicating a medium health state for Daming Lake, which was consistent with the evaluation results of the diversity index. The results of redundancy analysis revealed that the main driving factors of phytoplankton FG biomass and composition were water temperature (WT), total nitrogen (TN), transparency (SD), TN:TP (N:P), redox potential (ORP), chemical oxygen demand (CODMn) and pH. The dominance of the functional group D positively correlated with water temperature, TN, CODMn, pH and N:P but negatively correlated with SD. It was observed that functional groups and the Q index can objectively indicate the seasonal succession of phytoplankton and the water quality status of Daming Lake. Our discoveries have significant implications for the comprehension of the effects of urbanization on phytoplankton dynamics and for enhancing lake management practices to foster sustainable urban development.

Mechanism of action of plasma-activated water on biomacromolecules in Salmonella Enteritidis: Biological effect, computer simulation, and transcriptomics-based analysis

Salmonella enterica serovar Enteritidis (S. Enteritidis) is one of the most important causes of foodborne illness in the food industry. In this work, plasma-activated water (PAW) generated from the plasma jet was employed to reduce S. Enteritidis contamination. The antibacterial mechanism of PAW was revealed from biological changes, molecular docking, and transcriptomics. Results revealed that the addition of lactic acid could improve the antibacterial activity and efficiency of PAW, and confirmed the existence and antibacterial activity of free radicals (OH, 1O2, and NO) in PAW. Meanwhile, PAW treatment caused damage to characteristic functional groups of biomolecules, and led to the oxidation of lipids and degradation of DNA. Molecular docking results further suggested that the reactive species could interact with amino acid residues around key binding sites through hydrogen bonding, affecting the stability of structures. Furthermore, the transcriptomics results indicated that PAW is primarily active on bacterial proteins and to a lesser extent on membrane lipids and DNA. Overall, the action mechanism of PAW on biomacromolecules is comprehensively analyzed in this work, and it provides a theoretical basis for the broad application of plasma technology.

Microwave-assisted acid extraction of high-methoxyl kinnow (Citrus reticulata) peels pectin: Process, techno-functionality, characterization and life cycle assessment

The present study assessed the efficacy of kinnow peel pectin-acetic acid extraction using microwave heating at 110 °C, pH 2.2 for 10 min with a 1:2 ratio supernatant to ethanol for higher yield. The kinnow peel was freeze dried and grinded to fine powder for pectin extraction. The microwave extracted (ME) kinnow pectin showed 833 mg equivalent weight, 7.44 % methoxyl content, 66.67 % degree of esterification, 63.15 % galacturonic acid content and evinced higher purity than commercial citrus pectin. ME kinnow pectin exhibited shear thinning behaviour while higher apparent viscosity (Pa. s) at 20 % concentration. The ME kinnow pectin showed characteristic functional groups and a less crystalline structure as deduced from FT-IR, SEM and XRD respectively, and a higher thermal decomposition analysed from TGA. Further, life cycle assessment (LCA) predicted that the ethanol and acetic acid were major contributors toward climate change in this study. ME kinnow pectin has the potential to be used as a commercial pectin in various food applications.

Analysis of the Impact of Waste Fly Ash on Changes in the Structure and Thermal Properties of the Produced Recycled Materials Based on Polyethylene.

This paper presents the results of the research on the structure and thermal properties of materials made from fly ash based on high-density polyethylene (HDPE). Composites based on a polyethylene matrix with 5, 10, and 15 wt% fly ash from hard coal combustion content were examined. Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) was used to identify characteristic functional groups present in the chemical structure of polyethylene and the composites based on its matrix. Structural analysis was performed using X-ray diffraction (XRD), a differential scanning calorimeter (DSC), and microscopic examinations. Mechanical properties were also examined. Analysis of the thermal effect values determined by the DSC technique, XRD, and FTIR-ATR allowed the evaluation of the crystallinity of the tested materials. Polyethylene is generally considered to be a two-phase system consisting of crystalline and amorphous regions and is a plastic characterized by a significant crystalline phase content. Based on the FTIR-ATR spectra, DSC curves, and XRD, the effect of the filler and the changes occurring in the materials studied resulted in a decrease in the degree of crystallinity and a change in the melting point and crystallization temperature of the polymer matrix were established. Microscopic examinations were carried out to analyze the microstructure of the composites to collect information on the distribution and shape of the filler particles, indicating their size and distribution in the polymer matrix. Furthermore, the use of scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDS) allowed for the microanalysis of the chemical composition of the filler particles.

Extraction and characterization of Bougainvillea glabra fibers: A study on chemical, physical, mechanical and morphological properties

Bougainvillea glabra fibers (BGFs) present a promising avenue for sustainable material development owing to their abundance and favorable properties. This study entails a thorough investigation into the composition, physical characteristics, mechanical behavior, structural properties, thermal stability, and hydrothermal absorption behavior of BGFs. Chemical analysis reveals the predominant presence of cellulose (68.92 %), accompanied by notable proportions of hemicellulose (12.64 %), lignin (9.56 %), wax (3.72 %), moisture (11.78 %), and ash (1.75 %). Physical measurements ascertain a mean fiber diameter of approximately 232.63 ± 8.59 μm, while tensile testing demonstrates exceptional strength, with stress values ranging from 120 ± 18.26 MPa to a maximum of 770 ± 23.19 MPa at varying strains. X-ray diffraction (XRD) elucidates a crystalline index (CI) of 68.17 % and a crystallite size (CS) of 9.42 nm, indicative of a well-defined crystalline structure within the fibers. Fourier-transform infrared spectroscopy (FTIR) confirms the presence of characteristic functional groups associated with cellulose, hemicellulose, wax, and water content. Thermogravimetric analysis (TGA) delineates distinct thermal degradation stages, with onset temperatures ranging from 102.76 °C for water loss to 567.55 °C for ash formation. Furthermore, hydrothermal absorption behavior exhibits temperature and time-dependent trends, with absorption percentages ranging from 15.26 % to 32.19 % at temperatures between 30 °C and 108 °C and varying exposure durations. These comprehensive findings provide essential insights into the properties and potential applications of BGFs in diverse fields such as bio-composites, textiles, and environmentally friendly packaging solutions.