Ferric Oxide Research Articles

Light Absorbing Particles Deposited to Snow Cover Across the Upper Colorado River Basin, Colorado, 2013–2016: Interannual Variations From Multiple Natural and Anthropogenic Sources

AbstractAtmospheric particulate matter (PM) as light‐absorbing particles (LAPs) deposited to snow cover can result in early onset and rapid snow melting, challenging management of downstream water resources. We identified LAPs in 38 snow samples (water years 2013–2016) from the mountainous Upper Colorado River basin by comparing among laboratory‐measured spectral reflectance, chemical, physical, and magnetic properties. Dust sample reflectance, averaged over the wavelength range of 0.35–2.50 μm, varied by a factor of 1.9 (range, 0.2300–0.4444) and was suppressed mainly by three components: (a) carbonaceous matter measured as total organic carbon (1.6–22.5 wt. %) including inferred black carbon, natural organic matter, and carbon‐based synthetic, black road‐tire‐wear particles, (b) dark rock and mineral particles, indicated by amounts of magnetite (0.11–0.37 wt. %) as their proxy, and (c) ferric oxide minerals identified by reflectance spectroscopy and magnetic properties. Fundamental compositional differences were associated with different iron oxide groups defined by dominant hematite, goethite, or magnetite. These differences in iron oxide mineralogy are attributed to temporally varying source‐area contributions implying strong interannual changes in regional source behavior, dust‐storm frequency, and (or) transport tracks. Observations of dust‐storm activity in the western U.S. and particle‐size averages for all samples (median, 25 μm) indicated that regional dust from deserts dominated mineral‐dust masses. Fugitive contaminants, nevertheless, contributed important amounts of LAPs from many types of anthropogenic sources.

Impact of Nanoparticles on Oxidative Stress and Inflammatory Pathways in Human Prostate Cancer

Prostate cancer is one of the most prevalent cancers among men and is fueled by oxidative stress and inflammation that drive tumor progression and resistance to therapy. Production of reactive oxygen species (ROS) and pro-inflammatory cytokine such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) establish a pro-tumor microenvironment. Iron oxide nanoparticles are believed to be promising micro/nano therapy agents because NPs such as ferric oxide (Fe2O3) play a critical role in antioxidant and anti-inflammatory events. Herein, we examine influences of NPs on oxidative stress and inflammatory pathways in prostate cancer models. NP treatment was used for cells exposed to oxidative and inflammatory stressors. We measured a variety of key markers including ROS, MDA, GSH, and activities of antioxidant enzymes (catalase [CAT] and superoxide dismutase [SOD]). The levels of inflammatory cytokines were determined by widely used biochemical methods and spectrophotomedically. This resulted in significant reduction in ROS and MDA (oxidative damage markers) and significant elevation in the reduced GSH levels and these results were supported by the increased levels of antioxidant enzymes namely catalase (CAT) and superoxide dismutase (SOD) activity in NP-treated. Moreover, NPs also inhibited inflammation by downregulating the release of cytokines, such as TNF-α and IL-6. These effects suggest that NPs are capable of restoring oxidative homeostasis and suppressing inflammation, ultimately leading to a more tumor-hostile microenvironment. Abstract Nanoparticles that alleviate oxidative stress and overwrite inflammation pathways synergistically offer two critical blockade points in prostate cancer therapy to counter plasma phase-induced cellular malfunctions required for tumor progression. These results reinforce the prospect of NP as complements to cancer therapy. Optimizing NP formulations could improve their efficacy and safety for potential clinical applications in the future and provide new approaches for improving prostate cancer treatment. CuO NPs with Anti-cancer Effect on Prostate Cancer: In Vivo Study Oxidative Stress along with Inflammation as Potential Pathogenesis Prostate Cancer Responsive Ferric Oxide Nanoparticles Release ROS Assist in Treating Prostate Cancer.

Heat of Combustion and Thermal Decomposition of Ammonium Perchlorate/Sorbitol Solid Propellant with Metal Additives

Ammonium perchlorate (AP) stands out as the predominant oxidizer in solid rocket propulsion systems, while sorbitol, frequently employed as a fuel in sounding rockets, is expected to generate non-hazardous gases during combustion. This study reports on the effect of sorbitol as potential organic green fuel in addition to additive metals on heat of combustion, thermal properties and specific impulse for ammonium perchlorate based solid propellant. The specific impulse was measured using PROPEP 3.0 (Propellant evaluation program). Solid propellant characterization included measuring energy using a bomb calorimeter and conducting thermal analysis using DSC and TGA. Various compositions were prepared by varying the AP and sorbitol content in the propellant, and additive metals like magnesium and ferrite were introduced. The findings reveal that the formulation of 77% ammonium perchlorate into the 23 % sorbitol releases the optimum combustion energy at 2144.47 KJ/mol and lowers the thermal decomposition temperature of AP to 210.38 °C compared to common AP solid propellant formulation. Meanwhile, the addition of 1 % magnesium metal to the mixture significantly improves the combustion energy, propellant performance, and decreases thermal decomposition temperature of the AP/sorbitol. The addition of 0.05% ferrous oxide shows a catalytic capability to decrease the ignition temperature of the sample to 199.15 °C and merge two exothermic peaks into single peak. The main outcome of this work is, AP can interact synergistically with sorbitol mixed with both additive metals by increase the heat combustion, specific impulse, improve AP sensitivity toward heat and lower the thermal decomposition temperature.

Heat of Combustion and Thermal Decomposition of Ammonium Perchlorate/Sorbitol Solid Propellant with Metal Additives

Ammonium perchlorate (AP) stands out as the predominant oxidizer in solid rocket propulsion systems, while sorbitol, frequently employed as a fuel in sounding rockets, is expected to generate non-hazardous gases during combustion. This study reports on the effect of sorbitol as potential organic green fuel in addition to additive metals on heat of combustion, thermal properties and specific impulse for ammonium perchlorate based solid propellant. The specific impulse was measured using PROPEP 3.0 (Propellant evaluation program). Solid propellant characterization included measuring energy using a bomb calorimeter and conducting thermal analysis using DSC and TGA. Various compositions were prepared by varying the AP and sorbitol content in the propellant, and additive metals like magnesium and ferrite were introduced. The findings reveal that the formulation of 77% ammonium perchlorate into the 23 % sorbitol releases the optimum combustion energy at 2144.47 KJ/mol and lowers the thermal decomposition temperature of AP to 210.38 °C compared to common AP solid propellant formulation. Meanwhile, the addition of 1 % magnesium metal to the mixture significantly improves the combustion energy, propellant performance, and decreases thermal decomposition temperature of the AP/sorbitol. The addition of 0.05% ferrous oxide shows a catalytic capability to decrease the ignition temperature of the sample to 199.15 °C and merge two exothermic peaks into single peak. The main outcome of this work is, AP can interact synergistically with sorbitol mixed with both additive metals by increase the heat combustion, specific impulse, improve AP sensitivity toward heat and lower the thermal decomposition temperature.

Genetically Controlled Iron Oxide Biomineralization in Encapsulin Nanocompartments for Magnetic Manipulation of a Mammalian Cell Line

AbstractMagnetic nanoparticles have proven invaluable for biomechanical investigations due to their ability to exert localized forces. However, cellular delivery of exogenous magnetic agents often results in endosomal entrapment, thereby limiting their utility for manipulating subcellular structures. This study characterizes and exploits fully genetically controlled biomineralization of iron‐oxide cores inside encapsulin nanocompartments to enable magnetic‐activated cell sorting (MACS) and magnetic cell manipulation. The fraction of MACS‐retained cells showed substantial overexpression of encapsulins and exhibited both para‐ and ferrimagnetic responses with magnetic moments of 10−15 A m2 per cell, comparable to standard exogenous labels for MACS. Electron microscopy revealed that MACS‐retained cells contained densely packed agglomerates of ≈30 nm iron oxide cores consisting of ultrafine quasicrystalline ordered nuclei within an amorphous matrix of iron, oxygen, and phosphorus. Scanning transmission X‐ray microscopy, X‐ray absorption spectroscopy, and Raman microspectroscopy confirmed that the iron‐oxide species are consistent with ferric oxide (Fe2O3). In addition, the encapsulin‐overexpressing MACS‐retained cells can be manipulated by a magnetic needle and regrown in patterns determined by magnetic gradients. This study demonstrates that the formation of quasicrystalline iron oxide with mixed para/ferrimagnetic behavior in the cytosol of mammalian cells enables magnetic manipulation without the delivery of exogenous agents.

Fe3O4-viral-like Mesoporous Silica Nanoparticle(Fe3O4-vMSN)-Sustained Release of Lenvatinib for Targeted Treatment of Hepatocellular Carcinoma

Background: Lenvatinib is an oral tyrosine kinase inhibitor that selectively inhib-its receptors involved in tumor angiogenesis and tumor growth. It is an emerging first-line treatment agent for hepatocellular carcinoma (HCC). However, there is no intravenous ad-ministration of Lenvatinib. Aims: This study aimed to construct nanocomposites that can efficiently support Lenvatinib and target liver cancer tissues and cells. Objective: In this study, ferric oxide-viral-like mesoporous silica nanoparticles-folic acid (Fe3O4-vMSN-FA) nanocomposites loaded with Lenvatinib were constructed, and their anti-hepatocellular carcinoma effects were evaluated. Methods: The hydrothermal method was used to synthesize ferric oxide (Fe3O4). Ferric ox-ide-viral-like mesoporous silica nanoparticles (Fe3O4-vMSN) were synthesized using a two-phase method. Then, Fe3O4-vMSN was modified with folic acid (Fe3O4-vMSN-FA) to better target tumor cells. Results: The experimental data showed that Fe3O4-vMSN-FA nanocomposites were suc-cessfully synthesized and could be loaded with Lenvatinib (Len@ Fe3O4-vMSN-FA). Fe3O4-vMSN-FA had good stability and biocompatibility, and it can release the loaded Len-vatinib faster in an acidic environment (pH 5.5). CCK8 assay and flow cytometry showed that HepG2 cells in the Len@ Fe3O4-vMSN group had the lowest cell viability and the high-est apoptosis rate, confirming the anticancer properties of Len@ Fe3O4-vMSN-FA in vitro. In addition, transwell experiments showed that the migration and invasion ability of HepG2 cells in the Len@ Fe3O4-vMSN-FA group were significantly inhibited. In vivo fluorescence imaging in mice confirmed the enhanced tumor-targeting ability of Fe3O4-vMSN-FA. The tumor volume of the Len@ Fe3O4-vMSN-FA group was significantly reduced, and there was no significant effect on body weight. Moreover, serum liver function index (ALT and AST) and HE staining showed that Len@ Fe3O4-vMSN-FA did not cause obvious damage to organ tissue. Conclusion: Len@ Fe3O4-vMSN-FA has a good anti-liver cancer effect. Fe3O4-vMSN-FA can be used as an alternative platform for MSCs for drug delivery, providing more options for cancer therapy.

A DNA origami-based enzymatic cascade nanoreactor for chemodynamic cancer therapy and activation of antitumor immunity.

Chemodynamic therapy (CDT) is a promising and potent therapeutic strategy for the treatment of cancer. We developed a DNA origami-based enzymatic cascade nanoreactor (DOECN) containing spatially well-organized Au nanoparticles and ferric oxide (Fe2O3) nanoclusters for targeted delivery and inhibition of tumor cell growth. The DOECN can synergistically promote the generation of hydrogen peroxide (H2O2), consumption of glutathione, and creation of an acidic environment, thereby amplifying the Fenton-type reaction and producing abundant reactive oxygen species, such as hydroxyl radicals (•OH), for augmenting the CDT outcome. The DOECN is decorated with targeting groups to achieve efficient cellular uptake and efficiently induce tumor cell apoptosis, ferroptosis, and immunogenetic cell death, thus realizing potent anticancer therapeutic effects. Intravenous injection of the DOECN effectively promoted the maturation of dendritic cells, triggered adaptive T cell responses, and suppressed tumor growth in a murine cancer model. The DOECN provides a programmable platform for the integration of multiple therapeutic components, showing great potential for combined cancer therapy.

Fungal communities in boreal soils are influenced by land use, agricultural soil management, and depth.

Land use and agricultural soil management affect soil fungal communities that ultimately influence soil health. Subsoils harbor nutrient reservoir for plants and can play a significant role in plant growth and soil carbon sequestration. Typically, microbial analyses are restricted to topsoil (0-30cm) leaving subsoil fungal communities underexplored. To address this knowledge gap, we analyzed fungal communities in the vertical profile of four boreal soil treatments: long-term (24 years) organic and conventional crop rotation, meadow, and forest. Internal transcribed spacer (ITS2) amplicon sequencing revealed soil-layer-specific land use or agricultural soil management effects on fungal communities down to the deepest measured soil layer (40-80cm). Compared to other treatments, higher proportion of symbiotrophs, saprotrophs, and pathotrophs + plant pathogens were found in forest, meadow and crop rotations, respectively. The proportion of arbuscular mycorrhizal fungi was higher in deeper (>20cm) soil than in topsoil. Forest soil below 20cm was dominated by fungal functional groups with proposed interactions with plants or other soil biota, whether symbiotrophic or pathotrophic. Ferrous oxide was an important factor shaping fungal communities throughout the vertical profile of meadow and cropping systems. Our results emphasize the importance of including subsoil in microbial community analyses in differently managed soils.

Preparation of Fe3O4/C Composite Material from Red Mud for the Degradation of Acid Orange 7.

This study presents a novel Fe3O4/C composite material synthesized from red mud through a process of magnetic roasting and separation. The research explores the impact of Fe3O4/C dosages, sodium persulfate (PS) concentrations, and initial solution pH on the chemical oxygen demand (COD) removal efficiency using Acid Orange 7 as a model pollutant. Optimal conditions were identified as 3 g/L Fe3O4/C, 20 mM PS, and an initial pH of 2, achieving a 94.11% COD removal efficiency within 30 min. X-ray diffraction and photoelectron spectroscopy analyses confirmed that the magnetization roasting process effectively transformed red mud's ferric oxide (Fe2O3) into magnetite (Fe3O4). Concurrently, Fe3O4 interacted with residual carbon to form the Fe3O4/C composite. This composite demonstrated superior catalytic performance, along with excellent recyclability and reusability.

Mathematical solutions for coupled nonlinear equations based on bioconvection in MHD Casson nanofluid flow

<p>The mathematical formulation of fluid flow problems often results in coupled nonlinear partial differential equations (PDEs); hence, their solutions remain a challenging task for researchers. The present study offers a solution for the flow differential equations describing a bio-inspired flow field of non-Newtonian fluid with gyrotactic microorganisms. A methanol-based nanofluid with ferrous ferric oxide, copper, and silver nanoparticles was considered in a stretching permeable cylinder. The chemical reaction, activation energy, viscous dissipation, and convective boundary conditions were considered. The Casson fluid, a non-Newtonian fluid model, was used as flowing over a cylinder. The fundamental PDEs were established using boundary layer theory in a cylindrical coordinate system for concentration, mass, momentum, and microorganisms' field. These PDEs were then transformed into nonlinear ODEs by applying transforming variables. ODEs were then numerically solved in MATLAB software using the built-in solver bvp4c algorithm. We established an artificial neural network (ANN) model, incorporating Tan-Sig and Purelin transfer functions, to enhance the accuracy of predicting skin friction coefficient (SFC) values along the surface. The networks were trained using the Levenberg–Marquardt method. Quantitative results show that the ferrous ferric oxide nanofluid is superior in increasing Nusselt number, Sherwood number, velocity, and microorganism density number; silver nanofluid is superior in increasing skin friction coefficient, temperature, and concentration. Interestingly, heat transfer rate decreases with the magnetic and curvature parameters and Eckert number, whereas the skin friction coefficient increases with the magnetic parameter and Darcy–Forchheimer number. The present results are validated with the previous existing studies.</p>

Detecting ferric oxide adulteration in chilli Powder: A Multimodal analytical approach for enhanced food safety

Chilli powder, a widely used spice in global cuisine, faces rampant adulteration, posing significant health risks to consumers. One common adulterant is ferric oxide red, challenging to identify through visual inspection alone. To address this, a study was conducted to detect ferric oxide red in chili powder using various analytical techniques. Samples of chili powder, sourced from diverse locations, were adulterated with varying amounts of ferric oxide red. Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, and ultraviolet–visible spectroscopy (UV–Vis) were employed for analysis. FTIR spectra revealed characteristic peaks of chili powder at 1385 cm−1, 1600 cm−1, and 2935 cm−1, alongside peaks indicative of ferric oxide red at 460 cm−1 and 540 cm−1. Raman spectra displayed peaks at 260 cm−1, 615 cm−1, and 1315 cm−1 for chili powder and at 225 cm−1, 306 cm−1, and 670 cm−1 for ferric oxide red. UV–Vis spectra exhibited an absorption band at 478 nm for ferric oxide red. Elemental mapping analysis further differentiated adulterated and unadulterated samples. Principal component analysis (PCA) and soft independent modelling of class analogy (SIMCA) effectively distinguished between them based on spectral data. These findings underscore the efficacy of the proposed analytical methods in detecting ferric oxide red adulteration in chilli powder, ensuring its safety and quality.

Co-electrolysis carbon dioxide and ferrous oxide in Ca-based molten salt to iron-encapsulated carbon nanotubes with enhanced microwave absorption

Co-electrolysis carbon dioxide and ferrous oxide in Ca-based molten salt to iron-encapsulated carbon nanotubes with enhanced microwave absorption

Molecular-level insights into the degradation of dissolved organic matter from cyanobacteria-impacted water by electro-oxidation and electro-Fenton with carbon-based electrodes

Algal organic matter (AOM) originating from cyanobacteria-impacted reservoirs presents a significant risk to drinking water. Electrochemical oxidation is an emerging technology effective in AOM degradation. This study focuses on the elimination of AOM, including extracellular organic matter (EOM) and intracellular organic matter (IOM), extracted from Microcystis aeruginosa (MA). Electro-Fenton (EF) and electro-oxidation (EO) techniques were used, with a boron-doped diamond (BDD), a modified graphene-Fe2O3 (GFe) anode, and a graphite felt (GF) cathode. The results showed that BDD and GFe electrodes can effectively degrade AOM, particularly IOM, via EO and EF. BDD with high overpotential exhibited significant IOM degradation via EF, where dissolved organic carbon reduction reached up to 85%. In EO reactions, H2O2 generation by GFe-30 (obtained at the optimal ferric oxide to graphene ratio) is slightly higher than that in BDD, but it cannot fully transform into •OH in the EF process, which inhibits its AOM degradation capability. Furthermore, soluble microbial product-like substances and humics are more effectively degraded by EF and EO using either BDD or GFe. High-molecular weight (>103 Da) fractions, such as biopolymers and humic substances, are principally degraded by both EF and EO regardless of the BDD and GFe anode. This process leads to significant reductions in the haloacetic acids (HAAs) formation potential. EO and EF with GFe-30 are more effective in reducing specific disinfection by-product formation potential during IOM suspension degradation compared to BDD. In conclusion, GFe serves as a novel electrode material to replace BDD as a potent carbon-based anode when utilizing EO or EF treatments for effective AOM removal from cyanobacteria-infested water for drinking water treatment.

Geochemical speciation and activation risks of Cd, Ni, and Zn in soils with naturally high background in karst regions of southwestern China.

Agricultural soils in karst regions present a remarkable paradox where high geochemical background levels of heavy metals correspond with unexpectedly low crop uptake, challenging traditional risk assessment frameworks and limiting agricultural development. To decode this paradox, we investigated the geochemical speciation of cadmium (Cd), nickel (Ni), and zinc (Zn) in soil-rice systems in southwestern China, which collectively constitute the world's largest continuous karst region and represent diverse soil weathering stages. We employed three chemical extraction methods that revealed reactive pools ranking as Cd (58.74 %) > Zn (7.31 %) > Ni (4.65 %) and risk patterns varying with soil type (Andosols > Cambisols/Gleysols > Lithosols), while multi-surface speciation model (MSM) elucidated the underlying mechanisms. We identified a stage activation-contamination model (SACM) that demonstrates how pH-dependent weathering controlled heavy metal distribution among dissolved, surface-active, semi-stable carbonate, and nonactive species, thereby explaining the observed risk patterns. Specifically, in alkaline soils (pH > 7.50), Cd and Zn were primarily humic acid (HA)- and carbonate-bound, while Ni was goethite-bound. As weathering intensified, the reactive pool shifted to more active HA- and hydrous ferric oxide (HFO)-bound species. In acidic soils (pH < 6.50), dissolved and HA-bound species dominated. Both random forest, offering robust predictions using readily available data, and MSM stepwise regression models, providing high accuracy with mechanistic insights, effectively predicted rice risks. This study from speciation and activation model to prediction model clarifies why standardized risk assessments fail in karst regions and offers practical tools for accurate risk evaluation and management in these agricultural environments.

Ferric oxide nanofluid on functional properties of parabolic trough solar collector under different flow rate

Ferric oxide nanofluid on functional properties of parabolic trough solar collector under different flow rate

Analysis of the Shear Strength of Iron Oxide-Kaolinite Cementing Materials in Granite Red Soil

Shear strength is the key index to determine the stability of a soil slope, and cementation between iron oxide and clay minerals is one of the internal factors affecting soil shear strength; however, the effects of the form of iron oxide on the shear strength of granite-weathered red soil are still unclear. Kaolinite, which is the main clay mineral of granite red soil, was selected as the research object, and the effects of three different forms of iron oxide (hematite: HT, goethite: GT, and amorphous iron oxide: AIO) on the soil microstructure, microscopic quantitative parameters, cohesion, internal friction angle, and shear strength were analyzed by scanning electron microscopy, X-ray diffraction, and the shear strength test. The results revealed that the iron oxide promoted the cementation of soil particles, and the cementation characteristics differed with the different forms of iron oxide. Hematite mainly showed flocculent cementation, poor cementation, and simple soil microstructures. Goethite mainly exhibited acicular cementation and the best cementation effect. The degree of aggregation of the soil particles was increased by the coatings, thus forming larger aggregate particles. The cementation effect of amorphous iron oxide was between those of hematite and goethite but included both the flocculation cementation of hematite and acicular cementation of goethite. Amorphous iron oxide and goethite effectively increased the contact area and friction degree between soil particles, while hematite had the opposite effect. The addition of three kinds of ferric oxide reduced the fractal dimension of soil, increased the apparent porosity, and promoted the irregularity of particles to a certain extent, among which hematite had the most significant growth on the long and short axes of the particles. At a content of 10 g kg−1, the addition of AIO and GT increased the soil cohesion and internal friction angle, and therefore increased the soil shear strength, and it was mainly determined by the soil microstructure: the contact area, apparent porosity, and particle short axis. These results indicated that GT and AIO are the main cementing materials affecting soil mechanical properties, and the transformation of iron oxide should be paid attention to when predicting soil slope stability.

Chemical thermodynamics of fluoride-ammonium processing of ash and slag technogenic waste

Relevance. The need to replace the import of alumina in the aluminum industry with its production from domestic raw materials for solving the problem of raw material safety, and accumulation of a large amount of ash and slag technogenic waste of thermal power plants. On the one hand, they violate the environmental situation, and, on the other hand, are a kind of minerals located on the surface of the Earth and, therefore, are not required the cost of their extraction from the bowels of the earth. Aim. To study chemical thermodynamics of reactions of ammonium fluoride processing of technogenic ash and slag raw materials in order to optimize the technological process using a program for preliminary calculations of thermodynamics of chemical reactions. Methods. Theoretical analysis, computer calculation, experimental research using chemical, X-ray phase, emission and absorption spectral and of other types of analysis. Results and conclusions. The authors have studied chemical thermodynamics of ammonium fluoride technology for processing ash and slag man-made waste from thermal power plants of the Amur region. They obtained various useful products: nanoscale amorphous silica, alumina grades G0 and G1, red iron oxide pigment Fe2O3, concentrate (Ca, Y)F2 enriched with rare earth and refractory elements, noble metals and other useful components. For preliminary calculations of thermodynamics of chemical reactions, the authors applied a vb program with thermodynamic potentials and their derivatives of more than 300 chemicals database, which they created on the basis of a text file. The program allowed calculating the changes of enthalpy, Gibbs potential, equilibrium constants, as well as errors of calculations of Gibbs potential and enthalpy changes.

An Evaluation of the Damping Characteristics of Some Silicon Rubber/Ferric Oxide Composites

ABSTRACTGenerally, polymeric materials with superior damping characteristics are in great demand for many advanced functional applications, such as in building, aerospace, electronics, and transport sectors. However, it still remains a challenge to improve the damping characteristics of such materials owing to the lack of adequate practical knowledge in this area. Here, we report on the successful fabrication of silicon rubber (SR)/ferric oxide (Fe3O4) composites with excellent damping characteristics. The results obtained from the study showed that the damping characteristics of the specimens increased with the loading of Fe3O4 within a range of −105°C to 200°C. Specifically, the damping factor (tanδ) is 0.45 at room temperature, and the effective working temperature, the temperatures that correspond to the tanδ &gt; 0.3, ranged from −105°C to 165°C for the loading of Fe3O4 at 60 phr. The scanning electron microscopy results showed that the excellent damping characteristics of composites can be attributed to the good dispersion of Fe3O4 in the SR matrix. This work, therefore, opens up a pathway toward a relatively easy and up‐scalable means for fabricating polymer composites that have superior damping characteristics and ones with a wider applicability.

Crystallization behavior of smelting slag for recovery of platinum group metals from spent automotive catalysts and preparation of foamed glass-ceramics

Spent automotive catalysts (SAC), as a significant secondary resource for platinum group metals (PGMs), can be recovered on a large scale through high-temperature smelting. Besides, as a byproduct, the glass slag lacks high-value applications. This paper proposes a recyclable method to convert slag, graphite powder (GP), and ferric oxide (Fe2O3) into foamed glass-ceramics through low-temperature sintering, significantly reducing environmental impacts and production costs. Non-isothermal differential thermal analysis was used to explore the transition and crystallization temperature range, transition kinetic, crystallization kinetic, and crystallization behavior of the glass slag. Furthermore, the influence of the foaming agent composition and heat treatment temperature on the physical properties, chemical resistance, and mechanical properties of the foamed glass-ceramics was investigated. Foamed glass-ceramics composed of 60wt% slag-30wt% Fe2O3-10wt% GP exhibited the excellent properties of a geometric density of 1.43 g/cm3, a volumetric water absorption of 26.32%, a compressive strength of 8.08 MPa, and a mass loss of 3.56% in strong acid and 0.08% in strong alkali after low temperature heat treatment at 1160°C. This study provides an insight into transforming low-value waste into high-performance foamed glass-ceramics.

Assessment of multifunctional activity of graphene oxide and guar gum-based nanomaterials against Aedes aegypti

Nanomaterials have been receiving much research attention in controlling insect pests and vectors. Properties, such as small surface-to-volume ratio, low dosages, durability, solubility, enhanced target activity, pore size and surface characteristics have enabled the design of precise and targeted insecticides through adsorption, encapsulation, and conjugation. The reported study aims to evaluate the efficacy of graphene oxide (GO) and guar gum (GG)-based nanomaterials against early fourth instar of Aedes aegypti, a mosquito responsible for transmitting diseases like dengue fever, Zika virus, and chikungunya, among many others. GO and a total of eight nanomaterials (SA-1 to SA-8) were formulated using GO, GG and their combinations with ferrous oxide and copper oxide. Each material was characterized using various biophysical techniques. The materials were evaluated for larvicidal potential by assessing their efficacy on the survival and morphology of Ae. aegypti, while the contact irritancy activity focused on determining their irritant properties upon direct exposure to the female adults. The larvicidal and irritant bioassays, conducted with these nanomaterials at different concentrations, demonstrated concentration-dependent mortality and significant behavioral responses. The exposures with nanomaterials also resulted in a deposition of black soot on the larval cuticle. The most effective nanomaterial was found as ferrous oxide nanomaterial which induced 100% larval mortality as well as significant contact irritancy. The results indicate the potential use of GO and GG-based nanomaterials against Ae. aegypti after concentration optimization.