Degradation Reaction Research Articles

Assembly of artificial photo-enzyme coupling nanoreactor for boosting photodegradation of trace bisphenol A pollutant in water

It is a difficult issue to remove the trace persistent organic phenolic pollutants in water. Herein, a new artificial horseradish peroxidase (HRP)/hierarchical carbon nitride (HCN) photo-enzyme coupling nanoreactor is assembled by immobilizing HRP on HCN, which achieves the high-efficiency degradation performance for trace bisphenol A (BPA) in water. Besides the promoted charge separation efficiency as well as visible light harvest capacity, the hollow and abundant pores structure of HCN/HRP can provide a confinement effect and molecular diffusion channels to promote photo-enzyme synergic catalytic effect, thus boosting degradation reaction of BPA. Compared with original HCN, the optimal HCN/HRP-3 sample obtain a higher degradation rate of 0.0575 min−1, which is 3.60 and 125 times as large as that over original HCN (0.016 min−1) and HRP (0.00046 min−1), respectively. Meanwhile, the mineralization ability of the HCN/HRP photo-enzyme coupling nanoreactor is enhanced dramatically owing to the far higher TOC removal efficiency of BPA with 81.05 % within 60 min than original HCN (37.63 %). The photocatalytic reaction mechanism investigations demonstrate that h+, •O2− and •OH all take part in the degradation process of BPA and the importance order of h+ > •O2− > •OH. This work provides an innovative design philosophy for the assembly of photo-enzyme synergic catalytic system to effectively remove the organic pollutants in water.

Atmospheric Degradation Mechanism of Isoamyl Acetate Initiated by OH Radicals and Cl Atoms Revealed by Quantum Chemical Calculations and Kinetic Modeling.

Isoamyl acetate is one of the volatile organic compound class molecules relevant to agricultural and industrial applications. With the growing interest in isoamyl acetate applications in industry, the atmospheric fate of isoamyl acetate must be considered. Reaction mechanisms, potential energy profiles, and rate constants of isoamyl acetate reaction with atmospheric relevant oxidant OH radicals and Cl atoms have been obtained from the quantum chemical calculations and kinetic modeling. The geometry optimizations were conducted using M06-2X/6-311++G(3df,3pd) followed by single point-energy calculations at the DLPNO-CCSD(T) method with an extrapolated complete basis set. The rate constants were calculated by solving the master equation. A hydrogen-abstraction reaction dominates the first step of isoamyl acetate degradation, while the addition-substitution reaction plays a small role in the degradation products. The kinetic study was conducted to evaluate the rate constants within a temperature range of 200-400 K. The total rate constants for the isoamyl acetate degradation reactions initiated by the OH radical and Cl atom were determined to be 6.96 × 10-12 and 1.27 × 10-10 cm3 molecule-1 s-1, respectively, under standard temperature and pressure conditions. The product degradation mechanism, ozone formation potential, and atmospheric impacts were discussed.

Dual motion principal Au-Ni-PDA-CuS micromotors with NIR light and magnetic effect for detection of organic dye

Copper sulfide (CuS), despite some disadvantages such as rapid recombination, easy aggregation, photodegradation of oxidized CuS, and a limited ability to absorb light energy, is still a good photocatalyst. This semiconductor material with a narrow bandgap plays a significant role in the degradation of organic dyes. However, due to these mentioned drawbacks, it requires a linker. The polymer used as this intermediate binder is polydopamine (PDA). PDA not only eliminates the disadvantages of CuS but also facilitates its attachment to the carrier system, which is a micromotor. However, the purpose of using PDA here is not only to eliminate the disadvantages of CuS but also to enable light-triggered motion due to its sensitivity to near-infrared (NIR) radiation. Similarly, CuS, which is a good catalyst, has been used in the polymerization reaction to catalyze dopamine’s conversion to PDA. The micromotor used in the study, based on the dual-motion principle, exhibits high stability and good reusability. The synthesized Au-Ni-PDA-CuS composite micromotor demonstrates a good photocatalytic degradation performance under NIR irradiation. The degradation efficiency is 54.48% at the lowest concentration, while it is 17.72% at the highest concentration, indicating the effectiveness of the synthesized micromotors in achieving good photocatalytic degradation at low concentrations. As a result of the photocatalytic degradation reaction, cyclic voltammetry was performed for 100 cycles to demonstrate the stability of the micromotors.This study is based on the electrochemical method for the photocatalytic degradation of methyl red (MR), an azo dye, using micromotors with a dual-motion principle. Following the development on an azo dye, this study applied the same procedure on real samples, and through in vitro investigation, the photocatalytic degradation of the composite motor on real samples was observed electrochemically.

Influence of ultrasound frequency, processing time, and cold temperature on quality characteristics of mutton subjected to ultrasonic nano-cooling with a preservative film

Refrigeration slows down microbial growth and oxidation in mutton, but it is not enough on its own to fully prevent spoilage. To promote preservation, this research evaluated the effectiveness of combining ultrasound treatment, nanocomposite packaging, and cold storage ― a method known as ultrasonic nano-cooling (UNC) on quality of mutton. Various ultrasound frequencies (40 and 80 kHz) and processing times (2–4 minutes) were applied to process the mutton. Thereafter, the products were packaged in nanocomposite film, made from sorghum starch and Azadirachta indica gum nanoparticles, and then stored under cold temperature condition: 2°C, 4°C, and 6°C. Analysis of the physical and biochemical properties revealed significant improvements in quality due to UNC preservation compared to the control (p < 0.05). Notably, the total bacterial load dropped from 5.4 × 10⁶ CFU/g in the control to 1.9 × 10⁶ CFU/g at 2°C with 80 kHz ultrasound after 4 minutes. This effect may be due to enhanced cavitation effects at higher frequencies, which, according to previous studies, can disrupt microbial cell walls. Lipid oxidation reduced from 0.45 mg MDA/kg to 0.20 mg MDA/kg, likely due to minimized thermal degradation and oxidative reactions, facilitated by lower temperatures and effective packaging. Water holding capacity increased from 70 % to 85 %, due to improved muscle fiber structure from ultrasound treatment, which aids moisture retention. The pH remained steady between 5.8 and 6.0, reflecting minimal spoilage and effective microbial control. This study demonstrates that UNC preservation is an effective method for extending mutton shelf life, aligning with the demand for high-quality, long-lasting mutton products.

High metal-loaded sub-nanocluster catalyst enhanced Fenton-like reaction activity for emerging contaminants degradation by generating high-valent copper

High-valent copper (Cu(III)) species are crucial intermediates in CH bond functionalization within both the biological and biomimetic processes, facilitated by copper enzymes and stabilized by multicopper oxidases. Herein, a nitrogen-doped copper sub-nanocluster catalyst (SNC) featured a high metal content (29.1 wt%) and uniform Cu distribution was synthesized by carbonizing the nanosheet-like metal–organic framework (MOF), enhancing bisphenol A degradation by activating peroxymonosulfate (PMS) to generate Cu(III). The degradation performance of the SNC outperformed the catalyst carbonized with the bulk-like MOF and matched the reported single-atom catalysts counterparts. Nitrogen doping decreased the electrons of Cu3d orbital, enhancing its bonding with the oxygen atom within the PMS molecule, thus promoting Cu(III) generation. The Cu-SNC/PMS system also showed robust resistance against anions, pH changes, and diverse water matrices. Importantly, it can selectively degrade electron-rich pollutants through oxygen atom transfer by Cu(III). This study provided new perspectives into SNC preparation, the controlled formation of high-valent metal species, and their role in Fenton-like reactions for pollutants degradation.

Nanoemulgel: A Comprehensive Review of Formulation Strategies, Characterization, Patents and Applications

&lt;p&gt;Background: Delivering hydrophobic or poorly soluble drugs has become increasingly challenging, with issues like stability and bioavailability complicating the process. Among various strategies devised to address these problems, nanoemulgels have proven effective. Nanoemulgels combine a gel base and an emulsion at the nanoscale, making them excellent for drug delivery. The nanoemulsion component protects the active ingredient from degradative reactions like hydrolysis and enzymatic degradation. Meanwhile, the gel base enhances the emulsion's thermodynamic stability by increasing the viscosity of the aqueous phase and reducing surface and interfacial tension. &lt;/p&gt;&lt;p&gt; Objective: The primary objective of this review was to explore nanoemulgels as a drug delivery system in the pharmaceutical industry. It delves into the advantages and applications of nanoemulgels in various medical fields, compares them with conventional emulgel, and examines formulation strategies, preparation methods, patent trends, future prospects, and evaluation methods in detail. &lt;/p&gt;&lt;p&gt; Method: An exhaustive literature survey was conducted keeping in view the various aspects of nanoemulgel. Information from various resources, such as books, review articles, scientific reports, research articles, and patents, were searched, read, analyzed, and summarized. &lt;/p&gt;&lt;p&gt; Conclusion: This review article thoroughly examines nanoemulgels, discussing their formulation strategies, characterization techniques, and applications in various fields. It highlights their benefits, such as enhanced drug solubility, controlled release, improved stability, and targeted delivery. The article also covers patents related to nanoemulgel technology and explores its future prospects, emphasizing potential applications in pharmaceuticals, cosmetics, dermatology, and other industries.&lt;/p&gt;

Electrochemical aspects of Li[Ni0.6Co0.2Mn0.2]O2 cathode materials doped by various ionic radius cations

The capacity of Li[Ni0.6Co0.2Mn0.2]O2 cathode materials decreases rapidly due to layer structure degradation, grain cracking, and electrolyte side reaction during cycling. In this paper, metal ions with different ionic radius (W6+= 0.62 Å, Mg2+= 0.72 Å, Y3+= 0.90 Å) were doped into single crystal Li[Ni0.6Co0.2Mn0.2]O2, which were synthesized by high-temperature solid-phase technology. X-ray diffraction (XRD), energy dispersive spectrometry (EDS) and scanning electron microscopy (SEM) were employed to characterize various samples doped with different ionic radius. The results reveal that the radius of the doped ions plays a crucial role in improving the stability of material structure. It is attributed to the incorporation of metal ions into the Li+ or Ni2+ site, thus maintaining the integrity of the layer and reducing cation mixing. However, it is also detrimental to the performance of single crystal Li[Ni0.6Co0.2Mn0.2]O2 because of lattice distortion caused by the ionic radius of the doped metal being much greater than that of the doped site. These results show superior capability and reveal the performance trend of Li[Ni0.6Co0.2Mn0.2]O2 with metal ions of different radius. The initial discharge capacity at 0.1 C for the undoped sample was 183.8 mAh/g, compared with 189.9, 192.3 and 199.8 mAh/g for NCM622-W, NCM622-Mg, and NCM622-Y, respectively. After 100 cycles, NCM, NCM-W, NCM-Mg, and NCM-Y delivered retentions of 90.88 %, 98.16 %, 97.13 %, 94.37 %, respectively. The defect model is mainly responsible for the improvement in electrochemical performance.

On the Selection of the Current Collector for Water Processed Activated Carbon Electrodes for Their Application in Electrochemical Capacitors

AbstractElectrode manufacturing for electrochemical energy storage technologies often relies on hazardous fluorine‐containing compounds and toxic organic solvents. To align with sustainability goals and reduce costs, there is a pressing need for water‐processable alternatives. These alternatives can halve electrode processing costs and ease regulatory burdens. While progress has been made with water‐processed graphite electrodes using eco‐friendly binders, challenges persist for high‐mass loading activated carbon (AC) electrodes. This study investigates the impact of modified aluminium current collectors on water‐processed AC electrodes, focusing on compatibility, processability, and electrochemical performance. Various aluminium foils, including etched and carbon‐coated types, were evaluated. The results show that modifications at the interface significantly improve the wetting properties and mechanical stability. Electrochemical tests revealed that carbon‐coated aluminium provided the lowest internal resistance and highest rate capability due to intimate contact between the electrode components. In contrast, etched aluminium foil exhibited higher contact resistance and poorer performance. Ageing studies demonstrated that carbon‐coated foils maintained better electrochemical performance over time, as the carbon layer reduced degradation reactions and contact resistance. These findings suggest that uniformly carbon‐coated aluminium current collectors are the optimal choice for high‐power electrochemical capacitors, balancing performance, sustainability, and cost‐efficiency.

Unveiling the synergism and reaction pathway of ethyl acetate removal in DBD/absorption integrated reactor

The experiment employs dielectric barrier discharge (DBD) combined with absorption integrated reactor (DCAIR) for higher concentration ethyl acetate removal and studies the synergism of DCAIR technology and the reaction pathway of ethyl acetate. Among three technologies of DCAIR, DBD and DBD combined with absorption series reactor (DCASR), DCAIR achieved the highest removal efficiency (RE) of ethyl acetate at similar input power. Fixed gas flow rate of 1000 ml/min and cC4H8O2in of 5000 mg/m3, the average REs of DCASR and DCAIR are higher than that of DBD by 31.2 % and 34.2 %, respectively. For the efficiency compensation mechanism, one of synergies in DCAIR, RE of ethyl acetate could exceed 80 % at the input power of 15 W. Energy consumption evaluation shows when RE > 80 %, the max energy efficiency of three technologies is in the order 70.0 g/kWh (DCAIR) > 5.1 g/kWh (DCASR) > 3.0 g/kWh (DBD). Tail gas and absorbent analysis reveals DCAIR can enhance mineralizing ethyl acetate and eliminating the secondary pollutants (e.g., O3, gaseous organic intermediates, and COD, etc.) effectively, due to its special structure of reactor. According to FT-IR spectra, the degradation mechanism and reaction pathway of ethyl acetate in DCAIR has been unveiled.

MoS2 sponge co-catalytic Fenton reaction for efficient degradation of antibiotics: Performance, mechanism and reactor operation

Levofloxacin (LEV) residue is one of the key issues with livestock wastewater, posing a threat to aquatic ecosystems and human health. Herein, MoS2 sponge (MS) co-catalyst was synthesized using a simple impregnation method to construct a MS/Fenton system. Under suitable conditions, MS/Fenton could achieve 95.8 % LEV degradation in 30 min, with a reaction rate constant 9.75 times higher than that of Fenton. The results of the reactive oxygen species identification and material characterization indicated that the massive decomposition of H2O2 generated ROS (•OH and 1O2) and accelerated Fe2+ regeneration were the main factors for pollutant removal. MS/Fenton performed well in various aqueous matrices, reflecting excellent adaptability and anti-interference performance. MS was structurally stable with minimal Mo leaching after the reaction. Furthermore, an external circulation packed-bed reactor was designed for application feasibility verification of the system. The system demonstrated excellent removal efficiency during 20 days of continued operation (without MS regeneration). In addition, MS/Fenton demonstrated a remarkable purification effect on real livestock wastewater. This study offered new insights for the large-scale preparation of recyclable co-catalysts, and the constructed long-acting and stable MS/Fenton system and reactor provide a reference for the green and efficient treatment of practical wastewater.

Mechanical-vibration-driven piezocatalytic degradation of organic pollutants over microcrystalline SnSe with selenium vacancies

Two-dimensional piezoelectric materials are attractive candidates to trigger piezoelectric catalytic reactions for organics degradation. Microcrystalline structures can endow them with enhanced piezocatalytic activity due totheir large surface area and abundant defect structures. In this work, microcrystalline SnSe with selenium vacancies (mc-SeVs SnSe) was synthesized and employed for piezocatalytic degradation of aqueous organics for the first time. Various instrumental testing results demonstrated that this unique microcrystalline SnSe has strong piezoelectric responses, abundant selenium vacancy defects and large active edges. Compared with crystalline SnSe, mc-SeVs SnSe showed superior piezocatalytic activity for the degradation of various organics in water. More importantly, mc-SeVs SnSe could induce the piezoelectric effect through mild mechanical energy to facilitate the efficient degradation of organic pollutants. The degradation efficiency of Crystal violet, p-nitrophenol, Malachite green, Congo red and Rhodamine B approached 100 % within 60 min reaction time. Superoxide and hydroxyl radicals were detected as the main reactive oxygen species generated in the piezocatalytic process. The degradation pathways of Rhodamine B were proposed based on high performance liquid chromatography-quadrupole-time of flight mass spectrum. The impact of strain on the alterations of dipole moment and electronic structure was investigated using density functional theory. The change in electron band structure induced by the polarized electric field was the underlying reason for the generation of hydroxyl radicals. This work will enrich the piezoelectric materials for organics degradation and provide fresh light on the mechanism of mechanically driven piezoelectric catalytic reactions.

XCT images-based modeling for elucidating electrochemical inert phase-dependent multiscale electrode kinetic behaviors

The electrochemically inert phase (EIP) within the electrode is formed by the combination of carbon black and binder, characterized by a highly heterogeneous spatial distribution and structural morphology. This heterogeneity impairs electrode performance under varying discharge rates and temperatures. In this study, X-ray computed tomography is employed to image the original electrode. The resulting grayscale images are digitally processed to reveal the two-dimensional (2D) and three-dimensional (3D) features of the EIP morphology, thereby providing a design window to understand the influence of EIP morphology. The physical structure characterization indicates that, compared to bulk-like EIP (B-EIP), film-like EIP (F-EIP) tends to cover the active surface of the active material (AM), exacerbating the heterogeneity of the lithiation reactions within the electrode. The reduction in the AM active surface area correlates the state of lithiation (SOL) of particles with their active specific surface area (αa). At low temperatures, the temperature sensitivity of electrodes intensifies the risk of αa loss, promoting heterogeneous reaction transfer between particles. The Biot number (Bi) is used to evaluate the competing mechanisms between interfacial reactions and bulk diffusion within particles. In electrodes with a high EIP content, the reaction rate at the particle/electrolyte interface is accelerated, causing particle performance to be dominated by interfacial reactions. Finally, the electrochemistry and heat generation from the particle-level to the electrode-level in thicker electrodes are examined. It demonstrates that ion diffusion in the pore controls interfacial reactions and heat transport behavior. Aggregated high-flux reactions and localized hot spots exacerbate the heterogeneous degradation and side reactions within the electrode.

Influence of hot-pressing temperature and density on the physical and mechanical properties of bamboo scrimber

Bamboo scrimber (BS) has been widely used as a high-performance engineering composite in construction and outdoor applications, typically employing a thermosetting adhesive that requires hot-pressing. Previous studies have focused on the effects of resin content and BS curing temperature, often overlooking the self-bonding of bamboo during the hot-pressing process. This study investigated the impact of hot-pressing temperature and density on the physical and mechanical properties of BS containing phenol–formaldehyde resin, with a particular focus on regulating BS self-bonding by adjusting these parameters. The study also examined the effects on the chemical composition and pore structure of BS. The results showed that increasing the hot-pressing temperature from 140 to 180 °C broke unstable bonds in the hemicellulose, cellulose, and lignin components of the BS, leading to new crosslinks through dehydration and thermal degradation reactions. This process enhanced self-bonding, improved water resistance, and resulted in different surface colors. Raising the density from 0.9 to 1.3 g/cm3 made the density distribution of BS more uniform and reduced the size and number of internal pores. These characteristics promoted interfacial bonding and impeded water flow through the material, thereby enhancing its water resistance and mechanical properties. This study elucidates the mechanism behind the performance enhancement of BS and offers insights for its low-cost and environmentally friendly production.

Combined kinetic analysis of thermal degradation characteristics and reaction mechanism of thin intumescent fire-retardant coating of steel structure

To determine the thermal kinetic triplets and elucidate the reaction mechanism of thin intumescent fire-retardant coatings (IFR) of steel structures, one efficient combined kinetic approach was implemented in this study. Thermogravimetric experiments were conducted in air atmosphere at four heating rates, and the whole IFR thermal degradation process was divided into two stages. The average activation energy values derived by model-free methods were 78.9 kJ/mol and 175.16 kJ/mol for Stage I (0<α < 0.2) and Stage II (0.2<α < 0.9), respectively. Furthermore, the linear Coats-Redfern (CR) and non-linear Masterplots models were applied to identify the possible reaction mechanism. It was found that the F3/2 mechanistic model was better suited to the main thermal degradation process. Then model reconstruction based on the F3/2 mechanism model was performed. The results showed that the reconstructed model had a strict linear relationship in the independence analysis and KCE analysis, along with a good agreement between the theoretical and experimental results. The current study provided new insights into the systematic thermal degradation mechanism of IFR, and the proposed kinetic model would be helpful for the thermal protection prediction for steel structure during fire.

Investigation of kinetics, reaction mechanisms, thermodynamics, and synergetic effects in co-pyrolysis of wood sawdust and linear low-density polyethylene using the thermogravimetric approach.

This study focused on investigating thermal degradation behaviors, kinetics, reaction mechanisms, synergistic effects, and thermodynamic parameters of wood sawdust (WSD), linear low-density polyethylene (LLDPE), and their blends (LW1:3, LW1:1, and LW3:1) during co-pyrolysis in a thermogravimetric analyzer (TGA). Thermal behavior exhibited a LW1:3 blend (25 wt.% LLDPE) showing significant mass loss at lower temperatures (150 to 300°C) compared to the individual feedstocks, such as 150 to 400°C and 300 to 520°C for WSD and LLDPE, respectively. The iso-conversional methods (KAS, FWO, and FM) were used to determine the kinetic parameters (Ea and A), and the activation energy drop was highest for the LW1:3 blend. According to the master plots, the third-order reaction (O3), nucleation (P2/3), and diffusional model (D4) were the predominant reaction mechanisms for the co-pyrolysis of the LW1:3, LW1:1, and LW3:1 blend, respectively. The thermodynamic parameters demonstrate that a small amount of plastic addition into WSD can improve the reactivity of the blend, shorten the reaction time, and cause less energy-intensive reactions. The values of ΔH, ΔG, and ΔS also confirmed the co-pyrolysis process's spontaneity and endothermic nature. The Fourier transforms infrared spectrometer (FTIR) spectra of raw feedstock, blends, and their biochar revealed some of the peaks were shifted, the intensity was reduced, and disappearance can happen when the temperature was increased. Using the experimental and theoretical/predicted activation energies, the parity chart illustrates the synergistic effects of co-pyrolysis of different blends, and the LW1:3 blend has a favorable synergistic impact. These results could be helpful in process optimization and designing an effective reactor system for co-pyrolysis.

Regulating reaction kinetics used for the preparation of ethylene-vinyl acetate copolymer with high grafting ratio

A feasible and innovative reaction kinetics control method was proposed to reduce the degradation, cross-linking and other side reactions during the melt grafting process. The components in the melt grafting system were firstly blended at a temperature lower than the half-life (170 °C) of the radical initiator. After the system was homogeneous, the temperature was raised to the half-life temperature for high-temperature melting reaction. By regulating the reaction kinetics of silane grafted EVA system, the collision probability between macromolecular free radicals and grafted monomers was effectively increased. The efficiency and grafting rate of EVA grafted by silane were significantly improved, which reached a maximum of 74.45 % and 4.81 wt%, respectively. The thermal behavior, crystallographic, mechanical and electrical properties of the grafts were further characterized, which made the structure-activity relationship of polymers construct and investigate.

Boosting Photogenerated Electrons Transfer from FeVO4 to Peroxymonosulfate via Cu Doping for Stable Degradation of Organic Contaminants

Comprehensive SummaryElectron transfer is an important way to activate persulfate. Currently, the electrons for persulfate activation mainly originate from organic contaminants or the catalyst itself, which can lead to selective activation of persulfate or oxidation of the catalyst, respectively, and thus become a bottleneck restricting its application. In this work, Cu−doped FeVO4 (Cu−FVO) was prepared, and the results showed that Cu doping can significantly improve the photocatalytic activity and stability of FVO for peroxymonosulfate (PMS) activation. The optimized Cu−FVO/PMS/light system exhibited a high BPA degradation rate that is 4.3 times higher than that of the FVO/PMS/light. This system manifested a broad applicability to various organic contaminants even with complex matrix. Photoelectrochemical analysis and DFT theoretical calculations revealed that Cu doping boosted the photogenerated charge separation and the adsorption of PMS on FVO. Furthermore, Cu doping led to the establishment of an electron transfer channel from Cu−FVO to PMS, through which photogenerated electrons achieved an efficient PMS activation. Meanwhile, holes were consumed by organic contaminants to avoid the oxidation of catalyst. These collectively enhanced the photocatalytic activity and stability of Cu−FVO, which also maintained high catalytic activity even after 20 cycling degradation reactions.

Impact of cyclophosphamide on the morphological and histological changes in polyglycolic acid spacers.

In radiotherapy for pediatric abdominal tumors, determining the effect of concurrent chemotherapy on polyglycolic acid (PGA) spacers is crucial; yet this effect has not been validated. Therefore, we aimed to evaluate the impact of cyclophosphamide (CPA) chemotherapy on the PGA spacer using a rat model. Twenty-four rats were implanted with the spacer, and morphological changes in the spacer were assessed on CT for both the CPA-dosed group (40mg/kg) and the control group. The size and volume of the spacer were quantified using CT, while the degree of adhesion and microscopic examination of the tissue were determined using pathology specimens. Morphologically, the size of the spacer decreased over time in both the CPA-dosed and control groups, with no significant differences observed between groups. No significant differences in adhesion were observed between the two groups. Macrophages were observed around the PGA fibers, suggesting their involvement in the degradation of the PGA spacer. These results suggest that CPA does not cause significant clinically problematic degradation or adverse tissue reactions to the PGA spacer. This study reinforced the benefits of PGA spacers; however, future research focusing on in vivo longitudinal monitoring of individual rats, as well as on humans, is required.

Characterization of wind effect on environmental dispersion for a shallow wetland flow

The present work focuses on the dispersion of pollutants under the influence of wind and ecological degradation in a fully developed steady flow for a shallow wetland. The dispersion coefficient is determined by Aris’ method of moments and Meis’ multi-scale analysis. Based on the comparison study, the concentration profiles obtained using multi-scale analysis converge with Aris’ method of moments, indicating that both analytical approaches provide reliable and consistent descriptions of pollutant dispersion in the system. In first-order degradation reaction rates, high degradation rates lead to lower mean concentrations and potentially more pronounced concentration gradients, while low degradation rates result in higher mean concentrations. The critical length of the region influenced by the contaminated cloud is computed analytically. It shows that for the common contaminant constituent lead (Pb), initially, it increases gradually to reach the maximum; after that as time increases, it decreases to zero under wind conditions.

MnO2 decorated silicon nanowires: A novel photocatalyst for improved Rhodamine B removal under visible light exposure

Pollution triggered by organic dyes is a prominent global concern. Thus, it is imperative to devise an effective preventative strategy to tackle this matter. Herein, using the chemical electroless deposition process, a novel SiNWs/MnO2 photocatalyst was successfully manufactured for efficacious photocatalytic purification under visible lighting. Through a series of characterization techniques, the structural, morphological, compositional, and optical features of MnO2-deposited silicon nanowires were thoroughly investigated. The photocatalytic ability of the resultant sample was reckoned by degrading Rhodamine B upon visible exposure. Following 180 min of brightness, the findings found that SiNWs/MnO2 displayed remarkable effectiveness, with a lessening of 93.4 %. The findings demonstrated a significant enhancement in degradation performance linked to the rising surface area and enhanced electron-hole segregation efficiency provided by silicon nanowires. Also, the sample's recyclability was assessed, exhibiting an encouraging sustainability with a slight fall in effectiveness (∼10%) after 6 straight utilizes. Furthermore, scavenging tests have shown that •OH and •O2− were prevalent species accountable for the RhB degradation reaction. Eventually, founded on the results, a plausible mechanism for RhB decomposition was suggested. Altogether, given the straightforward manufacturing method and impressive performance, the study argues that the novel SiNWs/MnO2 might be an intriguing photocatalyst for water contaminant remediation.