Iron Particles Research Articles

STUDY OF THE EFFECT OF ULTRAFINE PARTICLES ON MICROBIOCENOSIS OF THE BLIND INTESTINE OF BROILER CHICKENS

Introduction. Poultry farming, as the most knowledge-intensive and sustainably functioning branch of animal husbandry, makes a significant contribution to ensuring the country's food security. Considering the importance of the use of promising trace element preparations for modern poultry farming, studies have been undertaken to assess the effects of ultrafine particles of trace element metals on the poultry body. Trace elements are usually used in very small amounts in animal nutrition, but problems such as lower bioavailability, antagonism and a higher rate of excretion from the body limit their effectiveness. Recent studies have also demonstrated the modulation of intestinal health by nanoparticles by increasing the number of beneficial microbes (Lactobacillus and Faecalibacterium) and the production of short-chain fatty acids. The aim of the study was to evaluate the effect of ultrafine particles of copper and iron on microbiocenosis of the blind intestine of broiler chickens. Material and methods. During the experiment to assess the effect of ultrafine particles of copper and iron on growth and development, blood parameters, mineral metabolism and microbiocenosis of the blind intestine in the body of broiler chickens on a balanced diet, 105 week-old broiler chickens were selected, which were divided into 3 groups by the method of pairs of analogues (n=35). During the experiment, all the birds were in the same feeding and maintenance conditions. The duration of the main accounting period was 28 days. The poultry of the control group received an experienced diet (ED), I experimental – ED together with UP of iron at a dosage of 17 mg / kg, II experimental – ED together with UP of copper at a dosage of 1.7 mg / kg of feed. Results. The dosage of iron and copper were chosen taking into account the previously established positive effect. The additional introduction of UP copper into the diet had a growth-stimulating effect throughout the experimental study. At the end of the studies, the maximum increase in live weight was noted in the II experimental group – by 5.12%, in the I group – by 2.64%. Hematological blood parameters of broiler chickens demonstrated a change in the hemostasis system after administration of UP iron and copper. The evaluation of the data obtained indicates the variability of morphological and biochemical parameters within the physiological norm, with a tendency to decrease against the background of the introduction of ultrafine Fe and Cu particles. In the experimental group that received the UP iron preparation with food, Firmicutes (63.42%) dominated among the representatives of phylum, Bacteroidetes (17.34%) and Proteobacteria (7.43%) were also present. Ruminococcaceae (23.03%) and Lachnospiraceae (13.05%) prevailed among the families. Representatives of phylum Firmicutes (67.36%), Bacteroidetes (19.48%) and Proteobacteria (5.23%) were present in the cecum of broiler chickens treated with UP copper at a dosage of 1.7 mg/kg of feed. Among the families, the most numerous were such taxa as Ruminococcaceae (21.58%), Lachnospiraceae (18.67%) and Sphingobacteriaceae (13.10%). Conclusion. The results of our study demonstrate the need to study the bacterial diversity in the intestines of broiler chickens in order to study the effect of various feed additives on the metabolism and condition of the gastrointestinal tract of poultry.

The Influence of Iron Particle Contamination on the Breakdown Characteristics of Circulating Mineral Oil under DC Voltage

The presence of metallic particles can lead to the degradation of transformer oil due to the intensification of the electric fields near the conductive components. The primary objective of this research was to investigate the impact of iron impurities on the electrical properties of Mineral Oil (MO), particularly under conditions of continuous flow. Five distinct samples with varying levels of contaminants were carefully prepared for analysis. A specialized chamber was designed to replicate the circulation conditions of oil within an operating transformer. The focus of the investigation was on the breakdown characteristics under DC voltages. The results indicated that higher concentrations of iron impurities were associated with a reduction in breakdown voltage although the circulation of oil exhibited a beneficial effect. To validate these findings, Finite Element Method (FEM)-based simulations were conducted. The analysis of the electric field distribution revealed that iron impurities amplified the electric field intensity, while circulation served to mitigate this effect. Furthermore, the simulations tracking the trajectory of iron particles demonstrated that circulation hindered the particles from reaching the electrodes, thereby diminishing discharge events and lowering the risk of dielectric failure. In conclusion, the circulation of MO enhanced its breakdown voltage, although the presence of iron contamination could still pose a risk under DC voltage conditions.

Effect of ultradispersed iron particles on carbon matrix on carp growth and development

Effect of ultradispersed iron particles on carbon matrix on carp growth and development

Sustainable straightforward synthesis of hierarchically porous graphitised carbon foams with nanodispersed magnetite and elemental iron particles

Sustainable straightforward synthesis of hierarchically porous graphitised carbon foams with nanodispersed magnetite and elemental iron particles

The influence of radiative heat transfer on flame propagation in dense iron-air aerosols

It is demonstrated that in the (near) zero-gravity experiments conducted by Tang et al. (Combust. Flame; 2009, 2011) iron powder aerosols created using the finest powders are optically thick, implying that radiative heat transfer between particles should not be neglected. To test this concept, an iron particle oxidation model has been implemented in OpenFOAM, including a coupling with the P1-model for radiative heat transfer.For flame simulations in which radiation is not included, obtained flame propagation velocities deviate less than 8% with results obtained using Chem1D-Fe and also show a good correspondance with algebraic models for optically thin aerosols. No significant difference in predicted flame propagation velocity is observed between 1D and 3D simulations: contrary to what is seen in gaseous flames, including the curvature of the flame does not increase predicted flame speeds substantially. However, measured flame propagation velocity values exceed numerically obtained predictions excluding thermal radiation by a factor of three to four. To the authors’ knowledge, this discrepancy is exemplary for the difference between experimentally obtained values for flame propagation velocities, and predictions made using numerical simulation tools neglecting radiative heat transfer.Accounting for radiation increases predicted flame propagation velocities, in the absence of confining boundaries, by approximately a factor of 10 which is in line with algebraic models for optically thick aerosols. In 3D simulations for the two finest iron powders in the experiments, including radiation and accounting for the presence of the confining tube wall results in an error of 11% and 35% with respect to measured flame propagation velocities, significantly smaller than predictions obtained excluding thermal radiation. Although these flames are not purely radiation-driven, inclusion of particle-to-particle radiative heat transfer enhances flame propagation velocities in simulations to values that correspond much better with experimental values than if radiation would not be taken into account.

Ultra-high molecular weight polyethylene filled with iron by mechanical alloying

The ultra high molecular weight polyethylene (UHMWPE) shows properties that provide wide industrial and technological interest. To study the influence of iron particles on UHMWPE, the polymer was filled with Fe-powder in different stoichiometries through mechanical alloying (MA). The MA resultant samples were subjected to various analyses aiming at the characterization of mechanical, structural, and hyperfine properties. The tensile test indicated a small change in the stress-strain curves, this change was related to the yield stress. The X-ray diffraction showed the presence of a monoclinic phase, a metastable phase induced by deformation. Mössbauer spectroscopy pointed at the presence of three iron sites: metallic iron, Fe2+ e Fe3+. Considering these results, it is possible to ascertain that the iron weakly changes some properties of the polymer without degradation. There is a clear indication that iron atoms interact with carbon atoms, between the polymer chains, creating cross-links.

Synthesis of bagasse-derived magnetic biochar for the removal of fluoride from water solution

ABSTRACT Fluoride levels in drinking water pose a significant environmental threat, and adsorption is a common technique. However, many adsorbent materials have drawbacks such as poor adsorption capabilities, extended contact times, high pH levels, and large dosages. A biochar-based magnetic composite adsorbent has been developed for water defluoridation using a chemical co-precipitation process to immobilize iron particles on the biochar surface. X-ray diffraction analysis, Fourier transformed infrared spectroscopy, Brunauer–Emmett–Teller, and scanning electron microscopy were used to analyse the composite. The central composite design was used to design laboratory tests, which included four input variables: solution pH, dosage, contact time, and initial concentration. The adsorbent dosage was 5.92 g/L, the aqueous pH was 5.79, the contact time was 66.48 min, and the initial fluoride concentration was 12.38 mg/L. The removal efficiency was predicted to be 98.61%, with a 98.55% removal efficiency at optimum conditions. The study concluded that the composite adsorbent can be a reliable and sustainable solution for fluoride removal from water.

A numerical study of internal transport in oxidizing liquid core–shell iron particles

In an effort to improve the understanding of the rate-limiting mechanisms in liquid iron particle combustion, this study investigates the impact of internal transport within a core–shell structure. The two-dimensional axisymmetric transient continuum model as presented in previous publication (Thijs et al., 2023) is extended, such that the boundary layer between the particle and the gas, surface processes at the particle–gas interface, as well as the internal oxide layer within the particle, considering the transport of reactive O and Fe ions, are resolved. Information from the equilibrium phase diagram, which is included as supplementary data, is used to determine oxidation rate of the particle. The study reveals that finite-rate internal transport significantly alters the temperature evolution compared to models assuming infinitely fast transport. At elevated oxygen concentrations, internal transport becomes rate-limiting, restricting the maximum particle temperature. The core–shell assumption leads to a higher local oxidation degree at the particle–gas interface than the average in the particle, reducing the overall oxygen consumption rate. The maximum particle temperature is reached when heat loss exceeds heat release. Although internal transport limits the maximum temperature, the initial heating rate remains overestimated, suggesting that the initial phase is not solely limited by external oxygen diffusion, and the L2-gas surface is not at thermodynamic equilibrium. The model does not account for the particle size effect on maximum temperature as observed in some experiments. A hypothetical explanation is that internal convection, more pronounced in larger particles, may reduce the internal transport limitation, leading to higher maximum temperatures in larger particles.Novelty and significanceThis study advances the understanding of oxidation rate-limiting mechanisms in liquid iron particle combustion by numerically investigating the impact of internal transport within a core–shell structure. By using a two-dimensional axisymmetric transient continuum model, the research reveals that finite-rate internal transport significantly affects temperature evolution of an oxidizing micron-sized iron particle, particularly at elevated oxygen concentrations where it becomes rate-limiting. The findings demonstrate that a finite-rate internal transport leads to a higher local oxidation degree at the particle–gas interface, reducing the oxygen consumption rates. The study highlights that finite-rate internal transport limits the maximum particle temperature at elevated oxygen concentrations, a trend observed in isolated iron particle combustion experiments. Furthermore, this study provides a hypothetical explanation for the experimentally observed particle size effects on the maximum particle temperature, emphasizing the role of internal convection in larger particles

Ultrasonic-assisted pre-concentration of iron values in bauxite residue suitable for reduction-roasting purpose

The study aims to explore the feasibility of using low-frequency ultrasonic washing to pre-concentrate iron values in waste bauxite residue (BR) containing 32.60 wt. % iron. This novel approach involves ultrasonication followed by water-washing to pre-concentrate iron before reduction-roasting of BR. Conventional reduction-roasting of BR is more expensive compared to pre-concentrated BR, making this method potentially cost-effective. The process consists of a two-stage ultrasonic treatment procedure. In the first stage, ultrasonication at 30 °C, with 40% solid content (w/v) for 30 min, improves the iron grade to 41.2 wt. % with 82% recovery. However, a second stage of ultrasonication is necessary to further upgrade the iron. The study optimized the ultrasonication time, temperature, solid content (%, w/v), and water washing parameters. Under optimal conditions (ambient temperature, 30% solid content (w/v), 45 min of ultrasonication), the iron grade reached 49.1 wt. % (Fe2O3 70.2) with 66% recovery. Water-washing parameters were found to be less effective compared to ultrasonication parameters. The settling time after water washing significantly affects the grade and recovery of the product. The ultrasonic effect on the BR particle surface leads to the breakage of surface-alkali coating and the disintegration of locked particles to generate free iron and other particles. Particle size analysis supports the disintegration of BR particles into smaller pieces. The physicochemical characterizations of different products were carried out using ICP-OES, XRD, FTIR, and FESEM studies to support the experimental findings. The possible iron separation mechanism is discussed utilizing available literature, as well as experimental and characterization evidence.

Magnetic Hercules Swarm for Precise and Effective Deep Biofilm Eradication

AbstractOver the past decade, significant advancements in micro‐nano robots have enabled non‐invasive operations in hazardous, confined environments, particularly targeting persistent bacterial biofilms in hard‐to‐reach areas. However, many of these robots are limited by poor magnetic properties, hindering their effectiveness against biofilms. This study proposes a novel strategy using a swarm with strong magnetic effects (Hercules swarm) combined with near‐infrared (NIR) light for effective biofilm eradication. Carbonyl iron particles coated with polydopamine (CI@PDA), averaging ≈3 µm in diameter, demonstrate clustering and significant magneto‐force under a rotating magnetic field due to their large magnetic saturation. This enables the Hercules swarm to achieve rapid delivery (100 mm s−1), efficient cargo transport (carrying twice its own weight), and effective catheter clearance (1 mm min−1). The controllable motion and high photothermal activity enable precise biofilm eradication without toxic agents. The aggregation of magnetic particles into chains and their rotation are explored by improved particle dynamic model. Simulations also reveal enhanced fluid convection and mechanical pressure around the particle chain. Due to its easy operation, straightforward controllability, and environmental compatibility, the magnetic Hercules swarm emerges as a promising treatment modality for eliminating biofilms entrenched within intricate, narrow, and convoluted medical implants or industrial conduits.

Unveiling trends in migration of iron-based nanoparticles in saturated porous media

Nanoscale zero-valent iron (nZVI) particles are routinely used for environmental remediation, but their transport dynamics in different settings remain unclear, hindering optimization. This study introduces a novel approach to predicting nZVI transport in saturated porous model environment. The method employs advanced long column devices for real-time monitoring via controlled magnetic susceptibility measurements. Numerical modeling with a modified version of the MNMs 2023 software was then used to predict nZVI and its derivatives mobility in field-like conditions, offering insights into the radius of influence (ROI) and shape factor (SF) of their distribution. A standard nZVI precursor was compared with its four major commercial derivatives: nitrided, polyacrylic acid-coated, oxide-passivated, and sulfidated nZVI. All these iron-based nanoparticles exhibited identical particle sizes, morphologies, surface areas, and phase compositions, isolating surface properties, dominated by charge, as the sole variable affecting their mobility. The study revealed optimal transport when the surface charge of nZVI and its derivatives was strongly negative, while rapid aggregation of nZVI derivatives due magnetic attraction reduced their mobility. Modeling predictions based on column scale-up, indicated that detectable concentrations of 20 g L⁻1 were found at distances ranging from 0.4 to 1.1 m from the injection well. Slightly sulfidated nZVI traveled farther than the nZVI precursor and ensured more homogenous particle distribution around the well. Organically modified nZVI migrated the longest distances but showed particle accumulation close to the injection point. The findings suggest that minimal sulfidation combined with organic modification of nZVI surfaces may effectively enhance radial and vertical nZVI distribution in aquifers. Such improvements increase the commercial viability of modified nZVI, reduce their adverse impacts, and boosts their practical applications in real-world scenarios.

Endogenous formation of Fe-bearing particles and their differentiation from exogenous exposure

Accurately distinguishing between the endogenous formation and exogenous exposure of Fe-bearing particles (e.g., magnetic Fe particles) within biological organisms is the prerequisite for scientifically evaluating their health risks. However, this remains a challenging task due to lacking the comprehensive understanding of the endogenous formation process of Fe-bearing particles. Here, we report the formation dynamics of Fe-bearing particles under conditions closely resembling actual physiological conditions, and compare the morphological and structural differences between endogenous and exogenous Fe-bearing particles. We find that Fe-bearing particles can indeed form under physiological conditions at 37°C. In this process, phosphate plays a crucial role in the oxidation and mineralization of iron ions. Moreover, endogenously formed Fe-bearing particles typically have a diameter of less than 8 nm, and iron is the only metal element present. Therefore, we propose that Fe-bearing particles found in the body with a diameter larger than 8 nm are mainly derived from exogenous exposure. For Fe-bearing particles smaller than 8 nm, it is necessary to combine associated elements and crystal structure characteristics to distinguish between endogenous and exogenous sources. This study provides direct evidence from endogenous metabolism for tracing Fe-bearing particles, especially magnetic iron particles, within the human body.

Adsorption removal of copper(II) from water by zero valent iron loaded dendritic mesoporous silica

The object of research is synthesized dendritic mesoporous nanoscale silica (DMSN) modified with zero-valent iron (Fe0@DMSN). This material exhibits a high adsorption capacity for heavy metal ions, in particular copper, whose increased content in the aquatic environment poses a threat to living organisms. In this regard, the main physicochemical features of the removal of copper cations from the aqueous medium using the obtained sample were investigated. The morphology of the obtained dendritic silicas was studied by electron microscopy and the presence of a layer of zero-valent iron was confirmed by X-ray diffraction analysis and infrared spectroscopy. The parameters of the porous structure of the synthesized materials were determined. It was found that after modification of mesoporous silica with particles of zero-valent iron, the value of its specific surface area decreased from 504 m2/g to 312 m2/g. This may be due to the formation of a Fe0 layer not only on their surface but also in the channels of the inorganic matrix, which has a unique dendritic structure characteristic of this type of particles. At the same time, the number of active centers increases due to the enrichment of the silica surface with functional modifier groups that show a high affinity for metal cations. The adsorption capacity of Fe0@DMSN towards Cu2+ ions has been studied and it has been shown that the maximum adsorption value is 39.8 mg/g, which is significantly higher than that of the initial synthesized DMSN sample (0.7 mg/g). The experimental data obtained indicate that the obtained sorption material based on dendritic mesoporous silica nanoparticles with a layer of reactive zero-valent iron can be used for the purification of water contaminated with metal ions. In addition, the magnetic properties of such materials, known and proven by various scientists, will make it easy to separate the solid phase in the processes of sorption water purification using magnetic separation.

Single-layer iron network microstructure magnetorheological elastomer for transparent soft actuator

The motion of a soft magnetic magnetorheological elastomer, a composite material consisting of soft magnetic fillers and an elastomeric matrix, is limited by the gradient of the applied magnetic field, making its application as an out-of-plane soft actuator difficult. In this study, an anisotropic soft magnetic magnetorheological elastomer-based transparent soft actuator with large out-of-plane deformation was fabricated using a very low concentration (1 vol%) of carbonyl iron particles as the soft magnetic fillers. An applied AC electric field treatment method was used to manipulate iron particles in silicone oil, assembling and depositing them onto a glass substrate to form a single-layer iron-network microstructure. A single-layer iron-network microstructure-based magnetorheological elastomer (SL-sMRE) film with initial self-buckling was fabricated by exploiting the swelling properties of the residual silicone oil and polydimethylsiloxane. The SL-sMRE film exhibited out-of-plane deformation with a very short reaction time (228 ms) under a uniform magnetic field. When stimulated by a non-uniform magnetic field, the SL-sMRE film deformed away from the permanent magnet, which was not possible with an isotropic film. An optically transparent SL-sMRE film was applied to a transparent flexible gripping device that could detect the surface of a gripped object in real time.

Effect of Na<sub>2</sub>CO<sub>3</sub> and CaCO<sub>3</sub> on deep dephosphorization by the direct reduction of high-phosphorus oolitic hematite

The direct reduction–magnetic separation process based on coal is considered to be one of the most important methods that can effectively utilize high-phosphorus oolitic hematite. In this study, the mechanism of the effects of CaCO<sub>3</sub> and Na<sub>2</sub>CO<sub>3</sub> on the dephosphorization of high-phosphorus oolitic hematite during the direct reduction process was investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The results showed that Na2CO3 and CaCO3 reacted with Al<sub>2</sub>O<sub>3</sub> and SiO<sub>2</sub> during the direct reduction process, inhibited the generation of hercunite (FeAl<sub>2</sub>O<sub>4</sub>) and fayalite (Fe<sub>2</sub>SiO<sub>4</sub>), and promoted the reduction of metallic iron (Fe). Furthermore, the reaction inhibited the reduction of apatite and prevented the generation of FeP<sub>2</sub>. Na<sub>2</sub>CO<sub>3</sub> could change the form of phosphorus in the gangue from Ca<sub>3</sub>(PO<sub>4</sub>)<sub>2</sub> to Na<sub>2</sub>Ca<sub>4</sub>(PO<sub>4</sub>)<sub>2</sub>SiO<sub>4</sub>. Increasing the dosages of Na2CO3 and CaCO3 in the dephosphorization agent and increasing the content of Na<sub>2</sub>CO<sub>3</sub> in the dephosphorization agent were beneficial to the growth of metallic iron particles, and increasing the dosage of Na<sub>2</sub>CO<sub>3</sub>, CaCO<sub>3</sub> in the dephosphorization agent had more significant effects on metallic iron particles than increasing the content of Na<sub>2</sub>CO<sub>3</sub> in the dephosphorization agent. The research conducted in this study is expected to provide a basis for the effective exploitation of complex and refractory iron ores.

Iron chelation therapy failed to improve cardiac dysfunction caused by mitochondrial injury in rats with iron overload cardiomyopathy a 7T Cardiac MR research in vivo

Abstract Purpose To assess the efficacy of iron chelation therapy in improving cardiac function in iron overload cardiomyopathy (IOC) rats by using Cardiac magnetic resonance feature-tracking (CMR-FT). Methods The IOC rat model was induced by intraperitoneal injection of iron dextran over 2 months. Subsequently, 7 rats with IOC were assigned as IOC group to receive continued intraperitoneal injections of saline for an additional 2 months, while another group of 5 rats received intraperitoneal injections of deferoxamine (DFO) for the same duration, forming the IOC+DFO group. Meanwhile, a control group consisting of 7 healthy rats received intraperitoneal injections of saline for the entire duration of 4 months. All rats underwent a 7T CMR scan to assess cardiac function, myocardial iron overload, and myocardial fibrosis via cine, T2 mapping, and late gadolinium enhancement (LGE) scanning, respectively. The cardiac function analysis included left ventricular ejection fraction (LVEF) and left ventricular global longitudinal strain (GLS) using cine images. Following CMR scans, all rats underwent open-chest blood collection to detect serum iron levels, and cardiac gross specimens were then subjected to pathological staining, including hematoxylin and eosin (HE) for cardiomyocytes injury, Prussian blue for iron deposition , and Masson staining for myocardial fibrosis. Furthermore, the ultrastructure of cardiomyocyte was examined using transmission electron microscopy (TEM). Results The T2 value, measured in the septum wall at the mid-layer of the LV, and LVEF, and GLS exhibited a significant decrease in the IOC or IOC+DFO group, compared to the control group, while there were no significant difference observed between the IOC and IOC+DFO group (Fig. 1A, B, C). Myocardial fibrosis was not detected in the LGE images in both IOC and IOC+DFO group. Compared to the control group (37.5±12.5μmol/L) , serum iron levels were significantly elevated in the IOC group (368.6±181.0μmol/L) and in chelation treatment group (106.1±32.2μmol/L). Histological examination with HE staining revealed a normal arrangement of myocardial cells in all rats, without cellular degeneration or necrosis. Prussian blue staining highlighted the presence of iron particles within the myocardial interstitium in the IOC and IOC+DFO groups. Masson staining demonstrated intact myocardial muscle bundles without any evidence of myocardial fibrosis. Transmission electron microscopy (TEM) revealed myocardial mitochondria injury, characterized by ruptured outer membranes, reduced cristae, and vacuolization. Conclusions Following iron chelation therapy, the excessive iron burden in the bloodstream was alleviated. However, myocardial iron overload persisted in IOC rats, with no significant improvement in cardiac function observed. This persistence may be attributed to mitochondrial injury. The findings underscore the importance of monitoring cardiac dysfunction in patients with iron overload.CMR parameters analysis in IOC rats

Eco-friendly green synthesised nano iron particles from weed leaf extract: a potential nutritional source for enhancing the germination and yield of aerobic rice

Eco-friendly green synthesised nano iron particles from weed leaf extract: a potential nutritional source for enhancing the germination and yield of aerobic rice

Heteronuclear Fe-Mn Cyclopentadienyl Complexes Supported on Boehmite. Thermochemistry and Thermodynamics of their Decomposition

Boehmite samples with compounds of the composition (C5H5)2FeMnX2(μ-CO)n, where X=Cl, Br and n=1.2, precipitated at room temperature from tetrahydrofuran solutions and then heated in an air flow up to 873 K were obtained and characterized using X-ray diffractometry, infrared Fourier spectroscopy, electron magnetic resonance and temperature-programmed desorption methods. It was shown that the thermal decomposition of these compounds applied to the boehmite samples in the range from room temperature to 873 K occurs stepwise and consists of at least two stages. The first stage of thermal decomposition occurs in the range of 453–753 K, and the second – in the range of 813–843 K. The XRD data show that when calcining at 873 K the boehmite samples with the applied compounds of the above composition and containing these compounds less than 10 wt.%, the diffraction patterns show only reflections characteristic of poorly crystallized aluminum oxide. However, the electron paramagnetic resonance (EPR) spectra of these samples clearly show intense signals characteristic of superpara/ferromagnetic particles of iron and manganese oxides, as well as EPR signals from isolated Fe3+ substituting Al3+ ions in the aluminum oxide structure. EPR spectra most of the iron and manganese is stabilized on the surface of poorly crystallized aluminum oxide in the form of nanostructured iron and manganese oxides.

Physical and chemical characteristics and activity of nickel-modified cobalt-iron-containing catalysts in the reaction of dry reforming of methane

In the process of dry reforming of methane (DRM), the activity of low-percentage catalysts based on cobalt and iron oxides and their modification with nickel oxide was studied. It has been established that the addition of nickel oxide into the Fe2O3/γ-Al2O3 catalyst increases the degree of methane conversion from 14 to 89%, and also increases the yield of target reaction products H2 to 43.0 vol.%, CO to 46.1 vol.% at 850 °C. On a Co3О4-NiО/γ-Al2O3 catalyst at 850 °C, methane conversion reaches to 88.1%, the yield of H2 and CO is 44.8%. TPR-H2 analyzes showed that the introduction of nickel oxide into Fe2O3/γ-Al2O3 composition, in contrast to the Co3O4/γ-Al2O3 catalyst, the temperature peaks of Fe2O3-NiО/γ-Al2O3, reduction shift towards lower temperatures and weaken the interaction of metals with the support - γ-Al2O3 and thereby the amount of active reduced particles of iron and nickel oxides increases, which ensures good catalytic activity of Fe2O3-NiО/γ-Al2O3. According to the XRD results, spinel-like form - NiFe2O4, NiAl2O4 and CoAl2O4, also phase as Fe2O3 were obtained on the Fe2O3-NiО/γ-Al2O3 catalyst. This indicates that the developed catalysts form new phases that are active at high temperatures to produce synthesis gas in reduction-oxidation processes during the DRM reaction.

Fine carbonyl iron particles grafted with poly(2-isopropenyl-2-oxazoline): A potential embolization agent for cancer therapy

Despite the significant success of clinical trials on cancer patients using the therapy with carbonyl iron (CI) particles, this topic laid dormant for over two decades. In this context, we developed a CI particle-based embolization agent via polymer surface engineering and tested its biocompatibility and behavior in contact with human blood. The finest grade of the CI particles was controllably grafted with poly(2-isopropenyl-2-oxazoline) (PiPOx) using surface-initiated atom transfer radical polymerization (ATRP) to achieve a system combining the properties of suitable size, high magnetization, and advantages at the cellular level connected to the presence of PiPOx. The cell viability of 3T3 fibroblasts and P388.D1 macrophages was investigated after treatment with particle extracts and was found to be concentration-dependent but generally demonstrated no or mild cytotoxicity. The PiPOx-grafted particles showed negligible effect on the breakdown of human erythrocytes and significantly improved hydrophilic-hemophilic properties when compared to bare CI. The magnetorheological (MR) activity of the particles dispersed in human blood was studied in vitro under shear mode conditions showing slightly decreased shear stresses but improved sedimentation stability. Moreover, the effect of PiPOx molecular weight on the studied parameters was monitored across the whole range of tests. The study demonstrates the potential of prepared core-shell structures in biomedical and related fields of application.