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BACKGROUND: Prior to soil formation, phosphate liberated by rock weathering is often sequestered into highly insoluble lanthanide phosphate minerals. Dissolution of these minerals releases phosphate and lanthanides to the biosphere. Currently, the microorganisms involved in phosphate mineral dissolution and the role of lanthanides in microbial metabolism are poorly understood. RESULTS: Although there have been many studies of soil microbiology, very little research has investigated microbiomes of weathered rock. Here, we sampled weathered granite and associated soil to identify the zones of lanthanide phosphate mineral solubilisation and genomically define the organisms implicated in lanthanide utilisation. We reconstructed 136 genomes from 11 bacterial phyla and found that gene clusters implicated in lanthanide-based metabolism of methanol (primarily xoxF3 and xoxF5) are surprisingly common in microbial communities in moderately weathered granite. Notably, xoxF3 systems were found in Verrucomicrobia for the first time, and in Acidobacteria, Gemmatimonadetes and Alphaproteobacteria. The xoxF-containing gene clusters are shared by diverse Acidobacteria and Gemmatimonadetes, and include conserved hypothetical proteins and transporters not associated with the few well studied xoxF systems. Given that siderophore-like molecules that strongly bind lanthanides may be required to solubilise lanthanide phosphates, it is notable that candidate metallophore biosynthesis systems were most prevalent in bacteria in moderately weathered rock, especially in Acidobacteria with lanthanide-based systems. CONCLUSIONS: Phosphate mineral dissolution, putative metallophore production and lanthanide utilisation by enzymes involved in methanol oxidation linked to carbonic acid production co-occur in the zone of moderate granite weathering. In combination, these microbial processes likely accelerate the conversion of granitic rock to soil.

Dye-sensitized solar cells (DSSCs) provide a promising alternative to traditional solar technologies, as they offer a unique mix of cost-effectiveness, adaptability, and the possibility of achieving high efficiency. This study aims to investigate the effect of SiO2 purity obtained from coal fly ash on the photoelectric performance of DSSCs. The study focuses on varying the purity of extracted SiO2 from coal fly ash as a counter-electrode material and examining its impact on the efficiency of DSSCs. The efficiency of DSSCs was assessed by evaluating the performance of several various SiO2 purity materials for counter-electrode materials. The performance testing of DSSCs revealed that the counter electrode material, consisting of artificial SiO2 with a purity of 99.9%, achieved the highest efficiency of 0.0113%. Subsequently, DSSCs were fabricated using counter-electrode materials derived from coal fly ash with a purity of 52.91%. These DSSCs demonstrated an efficiency of 0.0076%. DSSCs utilizing SiO2 with a purity of 91.20% exhibited an efficiency of 0.0062%. Dye-sensitized solar cells utilizing a counter electrode material composed of SiO2 with a purity level of 72.54% demonstrated an efficiency of 0.0061%. The results showed that the level of SiO2 purity obtained from coal fly ash has a substantial impact on the photoelectric performance of DSSCs, since higher purity of SiO2 is associated with improved efficiency. [ABSTRACT FROM AUTHOR]

The present opinion is the follow‐up of the conclusions and recommendations of the Scientific Opinion on the re‐evaluation of silicon dioxide (E 551) as a food additive relevant to the safety assessment for all age groups. In addition, the risk assessment of silicon dioxide (E 551) for its use in food for infants below 16 weeks of age is performed. Based on the newly available information on the characterisation of the SAS used as E 551 and following the principles of the 2021 EFSA Guidance on Particle‐TR, the conventional safety assessment has been complemented with nano‐specific considerations. Given the uncertainties resulting from the limitations of the database and in the absence of genotoxicity concern, the Panel considered that it is not appropriate to derive an acceptable daily intake (ADI) but applied the margin of exposure (MOE) approach for the risk assessment. The Panel concluded that the MOE should be at least 36 for not raising a safety concern. The calculated MOEs considering the dietary exposure estimates for all population groups using the refined non‐brand loyal scenario, estimated at the time of the 2018 re‐evaluation, were all above 36. The Panel concluded that E 551 does not raise a safety concern in all population groups at the reported uses and use levels. The use of E 551 in food for infants below 16 weeks of age in FC 13.1.1 and FC 13.1.5.1 does not raise a safety concern at the current exposure levels. The Panel also concluded that the technical data provided support an amendment of the specifications for E 551 laid down in Commission Regulation (EU) No 231/2012. The paucity of toxicological studies with proper dispersion protocol (with the exception of the genotoxicity studies) creates uncertainty in the present assessment of the potential toxicological effects related to the exposure to E 551 nanosize aggregates. [ABSTRACT FROM AUTHOR]

Recycling of waste tires is the goal of many studies, where the chemical dissolution method depends on the recovery of tire rubber (TR) and carbon black (CB) from the waste tires. Petroleum ether was used to dissolve tire powder and a black solution was produced which after refluxed at 140°C for two hours with a mixture of adsorbents including silicon dioxide (SiO2) and aluminum oxide (Al2O3) and then filtered, will give clear rubber filtrate and CB precipitate and the used petroleum ether was totally regenerate. The rubber was recovered with a weight percentage of 24% (w/w), whereas CB was reclaimed with 20% (w/w) from the total waste tire used. The recovered rubber was characterized and its functional groups were studied by 1H-NMR and FTIR spectroscopy which shows the rubber is polyisoprene blended with polybutadiene. The XRD, FESEM, and thermal analyses (TGA, DTA, and DSC) show the recovered rubber is amorphous with an elastic nature, thermally stable with endothermic behavior, and contains some inorganic impurities. On the other hand, the BET (Brunauer-Emmett-Teller) analysis, of carbon black shows it is a mesoporous material with a high specific surface area (as = 149.44m² . g -1) and pores with a mean diameter (13.623 nm). The particle size, structure and surface chemistry of the reclaimed CB which was measured accordingly by XRD, BET, and FESEM and it was emphasized that the CB has excellent adsorption qualities. Keywords: Recycling of tires, rubber, petroleum ether, carbon black, Silicon dioxide, Aluminum oxide. [ABSTRACT FROM AUTHOR]

The negative consequences of fast fashion have heightened concerns about the fashion industry's sustainability. Bacterial Cellulose (BC) has emerged as a promising biomaterial for sustainable applications in textiles and leather. However, dehydrated BC's low thickness and high stiffness pose limitations, reducing its appeal in diverse fields, including fashion, healthcare, etc. To address this challenge, a Plasticized BC-based interpenetrating polymer network (IPN) leatherette is investigated using an innovative 2-in-1 thickening process and a following softening step using Glycerol. The thickening process involves a novel "self-thickening" technique based on cellulosic mercerization and a formation of interpenetrating polymer network structure using BC and Silica skeleton. The fabricated BC-based material exhibits unique IPN structure and significant increase in BC thickness to 1.83±0.10 mm (≈ 16.64 times thicker), areal density to 2034.46±37.58 g/m 2 (≈ 16.33 times denser), moisture content of 31.09±0.48%, moisture regain of 45.12±1.01%, flexural rigidity of 3291.29±100.88 μ Nm, and improved bending modulus of 6.48±0.20 MPa (≈ 1035.27 times lower) compared to those of untreated BC. Furthermore, the durability of the Plasticized BC-based IPN leatherette is evaluated through five washing cycles, with the material retaining approximately 75.96%, 66.61%, 82.98%, and 77.39% of its unwashed thickness, areal density, moisture content, and regain, respectively. This study contributes to the value of BC-based materials in the textile and leather industries, offering a sustainable alternative to existing materials and production processes. Moreover, developing this novel 2-in-1 thickening process establishes a foundation for future research on BC functionalization in various applications, thereby contributing to sustainable development. [ABSTRACT FROM AUTHOR]

Composite zirconium–titanium–silica sorbents with SiO2 content of 10–30 wt % were synthesized on the basis of products of hydrochloric acid decomposition of eudialyte concentrate and their surface modification into H+ and Na+ forms was carried out. All samples were studied by methods of chemical, X‑ray phase, Brunauer–Emmett–Teller (BET), and Barrett–Joyner–Halenda (BJH) analyses. It is shown that all obtained samples of silica-containing Zr–Ti–SiO2 sorbents are mesoporous. The pores are predominantly wedge-shaped with open ends, and pores with a diameter of 10–50 nm (~50% of the total pore volume) have the maximum volume. Based on the obtained values of the specific capacity of the adsorption monolayer of the surface of SiO2 samples and the value of Gibbs energy change (ΔG°) in the process of nitrogen sorption, it was concluded that the surface modification of synthesized Zr–Ti–SiO2 sorbents does not affect the physicochemical properties of their surfaces and the mechanism of nitrogen sorption. The sorption activity of synthesized samples towards Cu2+, Co2+, and Sr2+ ions was studied by the static method. It was found that modification of the obtained samples into the H+ form has less influence on their sorption capacity than their conversion into the Na+ form, does not depend on their SiO2 content in the range of 10–30%, and decreases in the Cu2+ → Co2+ → Sr2+ series. [ABSTRACT FROM AUTHOR]

A passive daytime radiative cooling thin film material has been developed to provide the cooling source which requires no input, sustainable, and no pollutants or greenhouse gases emission. The thermally induced phase separation method and simple compression were used to prepare the compressed composite silica dioxide/polyethylene(SiO2/PE) aerogel films. The impact of SiO2 particle sizes and additions on the optical properties of composite films was investigated, and the internal microstructures and optical properties of the films were characterized. The optical properties of the films were enhanced by controlling the degree of compression. The results indicate that the addition of micro SiO2 is more favorable for increasing reflectance and nano SiO2 is more favorable for increasing emissivity, and the densification could result in emissivity enhancement and reflectance reduction. The optimal sample is achieved when the mass ratio of nano SiO2 to micro SiO2 to polyethylene is 0.5∶1∶1 and the compression ratio is one-ninth. This sample has a thickness of 0.5 mm, with 96.4% average reflectance of the solar spectrum and 95% average emissivity of the atmospheric window. The practical application performance of the sample was evaluated by testing its radiative cooling performance, antifouling and mechanical stability abilities. The experimental results show that the optimal sample achieves a significant temperature reduction of up to 6.5 ℃ compared to the sub-environment. This indicates that the SiO2/PE aerogel film has the ability to passively cool the sub-environment during both day and night, and that it has a contact angle with water of 127°, providing water resistance and potential self-cleaning properties in practical applications. [ABSTRACT FROM AUTHOR]

This research paper explores the impact of electrical discharge machining process parameters, including current, pulse‐on time (Ton), and pulse‐off time (Toff), on the material removal rate (MRR) and surface roughness (SR) during the fabrication of aluminum silicon dioxide (Al7075–SiO2) composites. The Al7075–SiO2 composites were produced through stir casting, incorporating 10% by weight of SiO2 reinforcements with an average particle size of 54 µm. To systematically investigate the process parameters' effects, Taguchi's L9 orthogonal array was implemented in the design of experiments. Subsequently, the experimental data underwent analysis of variance (ANOVA) for thorough analysis. The response table for MRR and SR demonstrated that the current significantly influenced both responses (MRR and SR). The ANOVA results provided valuable insights into the percentage contribution of each parameter to the responses. Through the analysis, the optimal control variable settings for achieving the highest MRR were identified as a current of 3 A, a pulse‐on time of 1500 µs, and a pulse‐off time of 1 µs. Conversely, to attain the lowest SR, the ideal control variable settings were determined to be a current of 1 A, a pulse‐on time of 500 µs, and a pulse‐off time of 1 µs. Results also suggest that the error was within admissible range of 5% and the percentage contribution of the current (70.19%) had the largest effect on MRR. [ABSTRACT FROM AUTHOR]

To improve the stability of vitamin C(Vc) in cosmetics, Vc was coated with silica dioxide (Vc@SiO2), modified by silane (Vc@s-SiO2) and dispersed in decanoyl/octanoyl-glycerides (GTCC) oil phase system. The experimental results show that the encapsulation rate and drug loading rate are 68.2% and 13.6%, respectively, when Vc is encapsulated into silica dioxide. After modification, the surface of Vc@s-SiO2 is hydrophobic and the contact angle increases from 33.6° to 130.7°. When Vc is maintained at 50 or exposed to ultraviolet light, Vc@s-SiO2 exhibits an increase in antioxidant activity by 11.4 times and 27.7 times, respectively, compared to free Vc. This study reveals that silica dioxide coated Vc and dispersed in GTCC can isolate the adverse factors such as water oxygen, reduce the activity loss and improve the stability of Vc. [ABSTRACT FROM AUTHOR]

A perfect metamaterial absorber (MMA) using a SiO2 substrate has been designed. The suggested absorber model was created by implementing graphene as a metallic layer for the structured patch and copper in the ground plane of the design. The geometry of the prescribed absorber was finalized by cutting the rectangular and circular slots and loading the open-ended dual rings on the structure. Furthermore, the approach based on equivalent circuit modeling (ECM) with mathematical analysis for the proposed MMA is thoroughly discussed. The simulation outcome (S11) obtained with the help of CST software has been compared with the ECM analysis result. The proposed absorber shows a perfect absorbance of 99.97% at the operating frequency of 6.15 THz. The absorption characteristics of the suggested structure have been parametrically investigated as a function of oblique incidence and polarization angles. Furthermore, the designed structure has been analyzed by using various substrates and conducting materials to achieve the optimal value of the absorption peak as a percentage. Overall, the compact, ultra-thin, simple geometry of the prescribed MMA with a high absorption peak and polarization-insensitive nature makes it a suitable choice for utilization in sensing, imaging, and detection in the terahertz regime. [ABSTRACT FROM AUTHOR]

The use of household bleach cleaning products results in emissions of highly oxidative gaseous species, such as hypochlorous acid (HOCl) and chlorine (Cl2). These species readily react with volatile organic compounds (VOCs), such as limonene, one of the most abundant compounds found in indoor enviroments. In this study, reactions of HOCl/Cl2 with limonene in the gas phase and on indoor relevant surfaces were investigated. Using an environmental Teflon chamber, we show that silica (SiO2), a proxy for window glass, and rutile (TiO2), a component of paint and self-cleaning surfaces, act as a reservoir for adsorption of gas-phase products formed between HOCl/Cl2 and limonene. Furthermore, high-resolution mass spectrometry (HRMS) shows that the gas-phase reaction products of HOCl/Cl2 and limonene readily adsorb on both SiO2 and TiO2. Surface-mediated reactions can also occur, leading to the formation of new chlorine- and oxygen-containing products. Transmission Fourier-transform infrared (FTIR) spectroscopy of adsorption and desorption of bleach and terpene oxidation products indicates that these chlorine- and oxygen-containing products strongly adsorb on both SiO2 and TiO2 surfaces for days, providing potential sources of human exposure and sinks for additional heterogeneous reactions.

Dye-sensitized solar cells (DSSCs) provide a promising alternative to traditional solar technologies, as they offer a unique mix of cost-effectiveness, adaptability, and the possibility of achieving high efficiency. This study aims to investigate the effect of SiO2 purity obtained from coal fly ash on the photoelectric performance of DSSCs. The study focuses on varying the purity of extracted SiO2 from coal fly ash as a counter-electrode material and examining its impact on the efficiency of DSSCs. The efficiency of DSSCs was assessed by evaluating the performance of several various SiO2 purity materials for counter-electrode materials. The performance testing of DSSCs revealed that the counter electrode material, consisting of artificial SiO2 with a purity of 99.9%, achieved the highest efficiency of 0.0113%. Subsequently, DSSCs were fabricated using counter-electrode materials derived from coal fly ash with a purity of 52.91%. These DSSCs demonstrated an efficiency of 0.0076%. DSSCs utilizing SiO2 with a purity of 91.20% exhibited an efficiency of 0.0062%. Dye-sensitized solar cells utilizing a counter electrode material composed of SiO2 with a purity level of 72.54% demonstrated an efficiency of 0.0061%. The results showed that the level of SiO2 purity obtained from coal fly ash has a substantial impact on the photoelectric performance of DSSCs, since higher purity of SiO2 is associated with improved efficiency.

Introduction. The production of plasticizing additives using nanoparticles for the construction industry represents a promising sector in the development of advanced building materials. By incorporating nanoparticles, such as silicon dioxide, into complex additives, it is possible to significantly enhance the structural and mechanical characteristics of cement-based systems, resulting in increased strength, durability, and resistance to external forces. This study aims to investigate the process of synthesizing silicon dioxide nanoparticles in aqueous media and creating a complex organic-mineral additive comprising phloroglucinol- furfural oligomers with silicon dioxide nanoparticles. Materials and methods of research. A modifier based on phloroglucinol-furfural oligomers was used as an organic component of the complex additive. To synthesize silicon dioxide nanoparticles, which are the mineral component of the additive, liquid glass (sodium silicate solution) was used. Additionally, Aerosil, with a specific surface area of 2,000 m3 /kg, was used as the dispersed phase in the organic mineral additive to study the compatibility of the components and the mechanism of their interaction. The particle and size distribution were determined using laser light diffraction on the Malvern Mastersizer 3000 device and dynamic light scattering on the Microtrac S3500 device. Microscopic analysis of the complex additive was performed on a TESCAN MIRA 3 LMU scanning electron microscope. The chemical structure and composition of the obtained additive were monitored by UV and IR spectrophotometry on Specord 200 Plus and Alpha Bruker Optics devices, respectively. Results and discussion. The article presents the results of the development of a method for the synthesis of silicon dioxide nanoparticles and creating an organic-mineral additive based on phloroglucinol-furfural oligomers containing these nanoparticles. The additive is designed for use in mineral suspensions in construction additive technologies. It has been shown that it is possible to obtain nanoscale particles of silicon dioxide through the hydrolysis of sodium silicate. It has been demonstrated that as the concentration of sodium silicate increases, the number of silica particles increases significantly, the number of silicon dioxide particles increases significantly. This leads to faster coagulation of the particles, resulting in the formation of larger aggregates. It has been shown that silicon dioxide particles smaller than 10 nm can be obtained through acid titration. During the maturation period, particles increase in size by about 7 times over a period of 1 to 7 days. The optimal ratio for particle synthesis should be considered to be a 2:1 ratio of reagent solutions (sodium silicate to hydrochloric acid) by volume. It is shown that the introduction of the specific additive at the stage of particle formation can help to stabilize their growth. Conclusion. The complex organic-mineral additive based on a phloroglucinol-furfural oligomer and silicon dioxide nanoparticles has been developed. It has been established that the introduction of the specific additive in the process of synthesis of silicon dioxide particles contributes to an increase in the aggregate stability of the dispersed system of the complex additive, reduces the tendency of particles to enlargement and sedimentation

1H NMR spectral features of hydrogen molecules in the stacking interstices of silicon dioxide (SiO2) microspheres with different sizes are studied in the present article. The chemical shift of hydrogen molecules is observed to gradually shift towards higher fields as the size of the stacking interstices decreases. Combined with experimental results of variable temperature hydrogen spectroscopy, self-diffusion coefficients measurement, and scanning electron microscopy, the observed phenomenon is attributed to two factors, namely, 1) the microsphere size-dependent local magnetic field inhomogeneity in the stacking interstices caused by the diamagnetic SiO2 microspheres; and 2) the rapid exchange among hydrogen molecules experiencing different local fields within the microsphere interstices. The results of this study demonstrate the potential of hydrogen gas as a probe molecule for measuring micro- and nano-scale pore sizes.

Soft tissue adhesion and sealing around dental and maxillofacial implants, related prosthetic components, and crowns are a clinical imperative to prevent adverse outcomes of periodontitis and periimplantitis. Zirconia is often used to fabricate implant components and crowns. Here, we hypothesized that UV treatment of zirconia would induce unique behaviors in fibroblasts that favor the establishment of a soft tissue seal. Human oral fibroblasts were cultured on zirconia specimens to confluency before placing a second zirconia specimen (either untreated or treated with one minute of 172 nm vacuum UV (VUV) light) next to the first specimen separated by a gap of 150 µm. After seven days of culture, fibroblasts only transmigrated onto VUV-treated zirconia, forming a 2.36 mm volume zone and 5.30 mm leading edge. Cells migrating on VUV-treated zirconia were enlarged, with robust formation of multidirectional cytoplastic projections, even on day seven. Fibroblasts were also cultured on horizontally placed and 45° and 60° tilted zirconia specimens, with the latter configurations compromising initial attachment and proliferation. However, VUV treatment of zirconia mitigated the negative impact of tilting, with higher tilt angles increasing the difference in cellular behavior between control and VUV-treated specimens. Fibroblast size, perimeter, and diameter on day seven were greater than on day one exclusively on VUV-treated zirconia. VUV treatment reduced surface elemental carbon and induced superhydrophilicity, confirming the removal of the hydrocarbon pellicle. Similar effects of VUV treatment were observed on glazed zirconia specimens with silica surfaces. One-minute VUV photofunctionalization of zirconia and silica therefore promotes human oral fibroblast attachment and proliferation, especially under challenging culture conditions, and induces specimen-to-specimen transmigration and sustainable photofunctionalization for at least seven days.

Owing to environmental friendliness, waterborne coatings have attracted considerable attention for the protection of mechanical equipment. Herein, polyaniline (PANI)‐aniline modified silicon dioxide (ANSiO2) composite was prepared to improve the corrosion resistance of waterborne epoxy coatings through the modification of SiO2 nanoparticles by aniline‐methyl‐triethoxysilane and the subsequent in situ polymerization of aniline (AN). When the molar ratio of AN to ANSiO2 was 6:1, the obtained PANI‐ANSiO2 composite appeared spherical‐planar shape and was able to obviously improve the anticorrosive performance of the epoxy coatings. The impedance value of the PANI‐ANSiO2 composite modified coatings maintained above 108 Ω cm2 after being immersed in 3.5 wt% NaCl solution for 30 days, and the surface of the coating had no corrosion spread after 30 days of salt spray erosion test. The excellent anticorrosive effect of the PANI‐ANSiO2 was mainly attributed to not only the filling of the defective parts of the coatings by hydrophobic ANSiO2 but also the formation of passivation layer on the coating surface by PANI to impede electrochemical corrosion reaction. The preparation method in this work is facile, low‐cost, and easy produced on a large scale, and the environment friendly high‐anticorrosion coating shows great application potential in the field of metal protection. [ABSTRACT FROM AUTHOR]

One of the obstacles that arise in optimal design is the non-linear model. The relationship between temperature factors and the temperature increase rates with the purity of silicon dioxide (SiO2) forms a non-linear pattern. Determining the optimal design for a non-linear model is relatively more complex than a linear model because it requires additional information in its information matrix. Therefore, this issue necessitates further research on optimal design in non-linear models. This study uses the polynomial Taylor approach to approximate the non-linear equation through a linear equation using the appropriate optimal design methods, namely A-Optimal and I-Optimal criterion. The point search algorithm used was variable neighborhood search, this algorithm searches for design points by exploring several different neighborhood structures. These two methods were chosen to compare the characteristics and performance of the designs produced, aiming to obtain an optimal design to improve SiO2 purity (non-linear case) using the same algorithm, VNS. The research results showed that the design pattern produced by the A-Optimal design formed three temperature groups, namely the minimum temperature of 800°C - 820°C, the middle temperature of 850°C, 860°C, and the maximum temperature of 900°C, with varying temperature increase rates in the design area. The design pattern produced by the I-Optimal design formed a full quadratic pattern, namely the minimum temperature of 800°C and the maximum temperature of 900°C, with varying temperature increase rates in the design area. The I-Optimal design demonstrated the best performance (most optimal) in the aspect of prediction variance compared to the A-Optimal design across all alternative points in this study to improve SiO2 purity.

Abstract Infectious coryza (IC) is an acute upper respiratory disease of chicken caused by Avibacterium (A.) paragallinarum. This disease results in an increased culling rate in meat chicken and a marked decrease in egg production (10% to more than 40%) in laying and breeding hens. Vaccines were first used against IC and effectively controlled the disease. Nanotechnology provides an excellent way to develop a new generation of vaccines. NPs have been widely used in vaccine design as adjuvants and antigen delivery vehicles and as antibacterial agents; thus, they can be used as inactivators for bacterial culture. In this research, the antibacterial effects of several nanoparticles (NPs), such as silicon dioxide with chitosan (SiO2-CS), oleoyl-chitosan (O.CS), silicon dioxide (SiO2), and iron oxide (Fe3O4), on A. paragallinarum were studied. Additionally, different A. paragallinarum vaccines were made using the same nanomaterials at a concentration of 400 µg/ml to help control infectious coryza disease in chicken. A concentration of 400 µg/ml of all the NPs tested was the best concentration for the inactivation of A. paragallinarum. Additionally, this study showed that the infectious coryza vaccine adjuvanted with SiO2 NPs had the highest immune response, followed by the infectious coryza vaccine adjuvanted with Fe3O4 NPs, the infectious coryza vaccine adjuvanted with SiO2-CS NPs, and the infectious coryza vaccine adjuvanted with O.CS NPs in comparison with the infectious coryza vaccine adjuvanted with liquid paraffin (a commercial vaccine).

Aim: Agar-based phantoms are popular in high intensity focused ultrasound (HIFU) studies, with magnetic resonance imaging (MRI) preferred for guidance since it provides temperature monitoring by proton resonance frequency (PRF) shift magnetic resonance (MR) thermometry. MR thermometry monitoring depends on several factors, thus, herein, the PRF coefficient of agar phantoms was estimated. Materials and Methods: Seven phantoms were developed with varied agar (2, 4, or 6% w/v) or constant agar (6% w/v) and varied silica concentrations (2, 4, 6, or 8% w/v) to assess the effect of the concentration on the PRF coefficient. Each phantom was sonicated using varied acoustical power for a 30 s duration in both a laboratory setting and inside a 3T MRI scanner. PRF coefficients were estimated through linear trends between phase shift acquired using gradient sequences and thermocouple-based temperatures changes. Results: Linear regression (R2 = 0.9707–0.9991) demonstrated a proportional dependency of phase shift with temperature change, resulting in PRF coefficients between −0.00336 ± 0.00029 and −0.00934 ± 0.00050 ppm/°C for the various phantom recipes. Weak negative linear correlations of the PRF coefficient were observed with increased agar. With silica concentrations, the negative linear correlation was strong. For all phantoms, calibrated PRF coefficients resulted in 1.01–3.01-fold higher temperature changes compared to the values calculated using a literature PRF coefficient. Conclusions: Phantoms developed with a 6% w/v agar concentration and doped with 0%–8% w/v silica best resemble tissue PRF coefficients and should be preferred in HIFU studies. The estimated PRF coefficients can result in enhanced MR thermometry monitoring and evaluation of HIFU protocols.

The study concerns the behavior of optical and colorimetric properties of cadmium telluride semiconductor colloidal quantum dots covered with silica shell (CdTe/SiO2, core/shell) in an external constant electric field has been studied. To date, the electric field is known to lead mainly to quenching and red shift of the luminescence spectra of quantum dots; however, in most of the corresponding studies only the behavior of band-edge luminescence is considered. In this work, in addition to the luminescence due to interband transitions, the effect of the electric field on the trap-related luminescences of core/shell quantum dots is studied. Semiconductor nanocrystals were synthesized by colloidal chemistry methods. The product mixture was a solution of quantum dots in an aqueous medium. To investigate the optical properties of CdTe/SiO2 nanoparticles in an external electric field, a series of samples was fabricated on the basis of an optically passive cellulose film, in the pores of which quantum dots were embedded. The final sample was a cellulose film with quantum dots sandwiched between two glasses with transparent indium tin oxide electrodes. The strength of the constant electric field applied to such structures reached 140 kV/cm. Photoluminescence spectra of the investigated nanostructures were recorded using a CCD spectrometer. As a result of the experiments it was found that the presence and subsequent increase of the external electric field leads to quenching of the intensity of both band-edge and traprelated photoluminescence of quantum dots. This fact is associated with a decrease in the overlap between electron and hole wave functions under the action of the electric field. It is also shown that at moderate field strength there is a slight increase in the total photoluminescence intensity. This observation can be related to impeded charge carrier trapping. The demonstrated quenching of luminescence intensity is also consistent with the results of other authors who have shown a decrease in the absorption of quantum dots in external electric fields. The stability of colorimetric characteristics of the spherical nanoparticles in an external electric field has been demonstrated. The results of the study can be used for development of optoelectronic devices based on CdTe/SiO2 nanoparticles.

The evolution of a multilayer sample surface during focused ion beam processing was simulated using the level set method and experimentally studied by milling a silicon dioxide layer covering a crystalline silicon substrate. The simulation took into account the redeposition of atoms simultaneously sputtered from both layers of the sample as well as the influence of backscattered ions on the milling process. Monte Carlo simulations were applied to produce tabulated data on the angular distributions of sputtered atoms and backscattered ions.Two sets of test structures including narrow trenches and rectangular boxes with different aspect ratios were experimentally prepared, and their cross sections were visualized in scanning transmission electron microscopy images. The superimposition of the calculated structure profiles onto the images showed a satisfactory agreement between simulation and experimental results. In the case of boxes that were prepared with an asymmetric cross section, the simulation can accurately predict the depth and shape of the structures, but there is some inaccuracy in reproducing the form of the left sidewall of the structure with a large amount of the redeposited material.To further validate the developed simulation approach and gain a better understanding of the sputtering process, the distribution of oxygen atoms in the redeposited layer derived from the numerical data was compared with the corresponding elemental map acquired by energy-dispersive X-ray microanalysis.

To produce a better connection and greater electron transfer efficiency between the TiO2 particles, as well as to eliminate agglomeration and increase the dispersion of TiO2 powders, a silicon dioxide/titanium dioxide (SiO2/TiO2) nanocomposite has been used as a photoanode in this study. An attempt was made to construct dye‐sensitized solar cells (DSSCs) at a low cost with reasonable efficiency by replacing the highly costly platinum counter electrode with polypyrrole/sodium dodecyl sulfate (PPy + SDS) as Counter Electrode 1 (C1) and PPy/SDS/multiwalled carbon nanotube (PPy + SDS + MWCNT) as Counter Electrode 2 (C2), using Ru‐based dyes Z907, pomegranate (Pom) dye, arugula (Aru) dye, and hibiscus dye as photosensitizers. The working electrode composite was deposited on fluorine‐doped tin oxide (FTO) glass using a thermal chemical spraying approach, while the counter electrodes were produced using an electropolymerization method. The structural and optical characteristics are fully examined using several characterization techniques such as X‐ray diffraction (XRD), Raman scattering, field‐emission scanning electron microscopy (FESEM), and atomic force microscopy (AFM). The photovoltaic properties of the constructed DSSCs were assessed under light irradiation (100 mW/cm2). When compared to the reference cell based on the Pt counter electrode, which has an efficiency of 8.4%, the measured current–voltage (I–V) curve shows that the efficiency of DSSC in the case of Z907 dye with C1 and C2 was 3.037% and 3.743%, respectively. This suggests that the low‐cost prepared DSSCs have good efficiency. Natural dyes show an efficiency range of 1.317%–0.66%, which indicates a moderate level of sensitivity. [ABSTRACT FROM AUTHOR]

Water pollution with heavy metals owing to industrial and agricultural activities have become a critical dilemma to humans, plants as well as the marine environment. Therefore, it is of great importance that the carcinogenic heavy metals present in wastewater to be eliminated through designing treatment technologies that can remove multiple pollutants. A novel green magnetic nano-composite called (Carbonized Chitosan-Fe3O4-SiO2) was synthesized using Co-precipitation method to adsorb a mixture of heavy metal ions included; cobalt (Co2+), nickel (Ni2+) and copper (Cu2+) ions from aqueous solutions. The novelty of this study was the synthesis of a new nano-composite which was green with magnetic properties to be more sustainable and environmentally friendly. Its magnetic properties made it separated easily from solutions after accomplishment of the adsorption process using a magnet. Extended Freundlich isotherm was the best fitted model with maximum adsorption capacity of the metal ions mixture 2908.92 mg/g. Different experimental parameters have been studied included the initial concentration for a mixture of nickel, cobalt and copper metal ions (0.05–0.1 molar), dosage of adsorbent (0.5–3.5 g/L) and contact time (6–90 min) to investigate their changing effect on the removal percents of the heavy metal ions mixture from aqueous solutions. The experimental adsorption percent of cobalt ion ranged from 1.58 to 64.28%, nickel ion adsorption percent ranged from 10.68 to 94.12% and copper ion adsorption percent ranged from 4.41 to 76.23% at pH = 9 were based on the combination of the adsorption process parameters. [ABSTRACT FROM AUTHOR]

To demonstrate the effect of silicon dioxide, citric acid and sodium selenite combination vaginal gel (DeflaGyn®) on critical parameters in carcinogenesis in vitro HeLa cell culture medium. Various parameters including cell viability, intracellular reactive oxygen species, genotoxicity, apoptosis, mitochondrial membrane potential and glutathione levels were evaluated by applying varying doses of vaginal gel to HeLa cell culture medium. The vaginal gel showed a dose-dependent cytotoxic effect on HeLa cells. The IC50 (half maximal inhibitory concentration) gel concentration for HeLa cells at 24 h was calculated on the concentration-response curve and was found to be 80.15% of DeflaGyn®. Increasing DeflaGyn® concentrations (12.5–100%) increased iROS (intracellular reactive oxygen species) levels 1.3-fold on average compared to the control (0.1% DMSO (dimethyl sulfoxide)). DNA damage and apoptosis levels increased significantly with concentration in a dose-dependent manner. Similarly, a decrease was observed in the mitochondrial membrane potential (MMP levels decreased statistically significantly up to 70.14%) and intracellular glutathione levels, and all changes were proportional to the dose. Although it is known that the combination of vaginal gel facilitates the regression of cervical dysplasia and clearance of high-risk HPV (Human Papilloma Virus) types, there is no detailed information on the mechanism by which it provides these effects. In the present study, we found that the specific vaginal gel had a dose-dependent effect on various parameters thought to be important in the process of cervical carcinogenesis. Further studies are needed to reveal the pathways through which the gel is effective and whether it has similar effects in vivo. [ABSTRACT FROM AUTHOR]

In order to enhance the stability of VO2(M) while reducing its phase transition temperature, the hydrothermal synthesis process of VO2(M) was optimized in this paper using vanadium pentoxide (V2O5) as the vanadium source and hydrazine hydrate (N2H4·H2O) as the reducing agent. By doping W6+ and depositing SiO2 on the surface, stability is improved while phase transition performance is guaranteed. The results show that there is a VO2(A)-VO2(M) mutual transformation process during the hydrothermal process, and the adjustment of the hydrothermal reaction conditions can lead to VO2(M) with good crystallinity, a phase transition temperature of 66.3 ℃ and a thermal hysteresis width of 9.2 ℃. With the increase of W doping amount (expressed by atomic fraction), the Tc of W-VO2(M)@SiO2 decreases, and ΔT=7.2 ℃ when W doping amount is 1.0 at%. After accelerated test, the VO2 of W-VO2(M)@SiO2 composite still exists as V4+, which has good thermal stability. [ABSTRACT FROM AUTHOR]

Phase change nanocapsules (NEPCM) with n-octadecane (C18) phase change material as the core material and silica (SiO2) as the shell material were prepared by sol-gel method. A silane coupling agent, 3-Aminopropyltriethoxysilane (APTES), was added to functionalize the SiO2 surface. In addition, the addition of APTES promoted the hydrolysis and condensation of Tetraethyl orthosilicate (TEOS) to form a dense SiO2 shell layer. The effects of different core/shell mass ratios on the microscopic morphology and phase change enthalpy of NEPCM were investigated. Meanwhile, the properties of NEPCM, such as thermal cycling stability, leakage prevention, thermal stability, and temperature regulation of the interior of the building, were also studied in detail. The results showed that the phase change enthalpy of NEPCM changed with the change of core/shell mass ratio. At the core/shell mass ratio of 1/1.3, the phase change enthalpy of the prepared nanocapsules was the highest, reaching 140.57 J/g, with an encapsulation rate of 61.6%. Meanwhile, due to the protection of dense SiO2 shell material, NEPCM had good leakage prevention compared with pure C18. Its enthalpy only decreased by 0.13% after 150 heating-cooling cycles, which exhibited excellent thermal cycle stability and durability. In addition, when NEPCM was used in building thermal management, it effectively delayed the time for the indoor temperature to reach the peak temperature by 385 s and reduced the peak temperature by 9 ℃, which indicated that NEPCM had excellent thermal storage and thermoregulation performance. Meanwhile, the addition of APTES functionalized the NEPCM shell, and the efficient interactions between the surface amino groups and the functional groups of the organic polymer provided a broad application prospect for the efficient preparation of nanocomposites. [ABSTRACT FROM AUTHOR]

Corrosion is a material removal process in which a refined metal is converted into a chemically stable oxide. This process is the gradual deterioration of materials by chemical or electrochemical reactions with their environment. Corrosion is heavily influenced by environmental factors such as air, moisture, water, and temperature. This study aims to minimize corrosion resistance by applying silicon dioxide nanocoating to mild steel. Silicon dioxide nanomaterials are synthesized with a precursor using the sol–gel method and coated on a mild steel substrate using a spin coater. A corrosion test is conducted on the sample to determine inhibition efficiency and corrosion rate. The nanocoated substrate is tested in a NaCl solution. The characterization techniques of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) tests are conducted on the substrate. SEM results show the morphology and structure of the coated and uncoated substrates. Nanomaterials are distributed uniformly on the substrate in the third and fourth layers of coating. The absence of cracks in the third and fourth layers of coating can be attributed to the uniform deposition of nanomaterials and the required amount. EDS results indicate the presence of elements or compositions in the nanocoating. The corrosion test result reveals that corrosion rate decreased and inhibition efficiency increased up to three coatings. If more than three coatings are present, then the corrosion rate is increased due to micelle formation. [ABSTRACT FROM AUTHOR]

A method of sequential spraying of polyvinyl alcohol with carbon quantum dots (PVA@CDs) aqueous suspension and SiO2 aqueous suspension is proposed to rapidly prepare multicolor dual-mode anti-counterfeiting labels. With the optimization of the concentration (15%) of colloidal microspheres in the SiO2 aqueous suspension as well as the spraying process parameters (spray distance of 10 cm, spray duration of 3 s, and assembly temperature of 20 °C), different-sized SiO2 microspheres (168 nm, 228 nm, and 263 nm) were utilized to rapidly assemble red, green, and blue photonic crystals. Furthermore, the tunable fluorescence emission of carbon quantum dots endows the labels with yellow, green, and blue fluorescence. The constructed dual-mode labeling was used to develop an anti-counterfeiting code with dual-channel information storage capabilities and also to create dual-mode multicolor anti-counterfeiting labels on various packaging substrates. This work provides a novel solution for anti-counterfeiting packaging and information storage. [ABSTRACT FROM AUTHOR]

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We have developed and simulated a high electron mobility transistor (HEMT) operating in the 5 nm regime. This HEMT uses hafnium oxide (HfO2), a high-k dielectric material, to create an undoped region (UR) beneath the gate. While the gate and undoped regions share equal thickness, the channel length differs. This innovative undoped under the gate dielectric HEMT design mitigates the maximum electric field (V) within the channel area, leading to a significant increase in drain current. The utilization of a high-k dielectric in the HEMT structure results in a saturated Ion current that is 60% higher compared to conventional structures. Specifically, we use an AlGaN/GaN/SiC-based HEMT with an intrinsic section below the gate, using HfO2 as the high-k dielectric substantial, for applications requiring high power and high-frequency power amplifiers. Compare this advanced HEMT design to conventional HEMTs and you will see improved conductivity, a greater drain current (Id), a 54% increase in transconductance (Gm), and a lower on-resistance (Ron). Additionally, advancements in the electric field in the Y direction are seen. This HEMT structure exhibits superior performance compared to alternative materials analyzed. The integration of AlGaN/GaN materials in HEMTs opens up extensive opportunities in the realms of radio frequency very large-scale integration (VLSI) and power electronics. [ABSTRACT FROM AUTHOR]

The present work deals with analyzing the effect of silicon dioxide on mechanical and thermal stability of hybrid polymer composite. Compression molding is adopted to develop the hybrid composite with constant 0.5 wt.% of graphene and varying wt.% of silicon dioxide (2, 4 & 6 wt.%). Modified hummers method is used to synthesis graphene by chemical exfoliation of graphene from graphite flakes. Mechanical properties of developed composite is investigated using tensile, flexural, impact and interlaminar shear testing follow by fracture surface analysis of tested samples. Thermal stability is examined by thermogravimetric analysis and functional group confirmation is carried out using Fourier transform infrared spectroscopy (FTIR). Investigation over mechanical properties of fabricated composite reveals that addition of silicon dioxide up to 4 wt.% depicted higher flexural and tensile strength. Increment in silicon dioxide percentage improves the toughness of composite. FTIR results confirms the presence of asymmetric stretching vibrations due the after effect of hybrid fillers. Thermogravimetric analysis results depict that incorporation silicon dioxide increases the activation of energy of matrix from ~ 24.2 to 31.5 kJ/mol. [ABSTRACT FROM AUTHOR]

Interactions at high temperatures between thin films and the Si substrate limit materials discovery using combinatorial processing platforms (CPPs). To overcome this, a diffusion and reaction barrier, SiO2, by thermal oxidation of Si tips is developed. The application of this diffusion barrier in CPPs for atomic‐scale investigations of new materials in atom probe tomography is reported. Thermal SiO2 layers (20 and 50 nm thick) are examined as barriers to separate coatings from Si tips. Pt is chosen as it easily forms silicides. CPPs are sequentially annealed in vacuum at 400 °C for 10 h, 600 °C for 2 h, and 800 °C for 2 h. The thermal SiO2 diffusion barrier remains stable and prevents intermixing at least up to 800 °C. Moreover, it provides improved film adhesion as dewetting of Pt on the oxide surface occurred at 800 °C instead of 600 °C without a thermal diffusion barrier. A comprehensive structural and chemical analysis of the Pt film, the thermal SiO2 layer, and their interfaces is performed using scanning and transmission electron microscopy, and atom probe tomography. As a result, the thermal SiO2 forms a stable barrier, even at the lowest thickness of 20 nm, avoiding the formation of Pt silicides, even at 800 °C. [ABSTRACT FROM AUTHOR]

Nowadays Alternaria is considered one of the main fungi causing damage in cereal crop such barley. This work was designed to assess the potential role of silicon dioxide nanoparticles (SiO2 NPs) in enhancing barley's tolerance against A. alternata attack. For this purpose, twenty day-olds, seedlings were irrigated either with tap water or with SiO2 NPs solutions at 20 and 200 ppm for one week. After that, different group of seedlings were exposed to fungus inoculation and the others serve as control. The results showed that the fungi attack reduced seedlings biomass, hydration status, transpiration, stomatal conductance, total antioxidant activity, and DPPH levels compared to non-inoculated seedlings. Meanwhile, there was an increase in total phenolic compounds and flavonoid contents. The application of SiO2 NPs in absence of inoculation, resulted in an increase in seedling shoot length, shoot and root biomass, and water content at any NPs concentrations. Furthermore, when applied prior to inoculation at both concentrations (20 and 200 ppm), SiO2 NPs mitigated the effects of pathogen attack by enhancing net CO2 assimilation rate, internal CO2 concentration, transpiration, and stomatal conductance and increasing total antioxidant activity and DPPH antioxidant profiles compared to inoculated plants. The shoot exhibited a significant increase in zinc, iron, manganese, and potassium with SiO2 NPs at 200 ppm, regardless of the presence of fungi. The substrate's pH and conductivity remained unchanged compared to the control. However, there was a notable increase in nitrogen, manganese, potassium, and iron contents. On the other hand, levels of zinc and copper slightly decreased. This exploratory work highlights the protective role of SiO2 NPs in barley seedlings under pathogen attack conditions possibly due to the Si-mediated protection against oxidative stress and photosynthesis modulation. Using SiO2 NPs as a supplement offers a cost-effective and an eco-friendly and avenue for sustainable agriculture. They aid in nutrient delivery, help plants combat biotic stress, and enhance plant tolerance. [ABSTRACT FROM AUTHOR]

Several organisms are able to polycondensate tetraoxosilicic(IV) acid to form silicon(IV) dioxide using polycationic molecules. According to an earlier mechanistic proposal, these molecules undergo a phase separation and recent experimental evidence appears to confirm this model. At the same time, polycationic proteins like lysozyme can also promote polycondensation of silicon(IV) dioxide, and they do so under conditions that are not compatible with liquid‐liquid phase separation. In this manuscript we investigate this conundrum by molecular simulations. [ABSTRACT FROM AUTHOR]

Infectious coryza (IC) is an acute upper respiratory disease of chicken caused by Avibacterium (A.) paragallinarum. This disease results in an increased culling rate in meat chicken and a marked decrease in egg production (10% to more than 40%) in laying and breeding hens. Vaccines were first used against IC and effectively controlled the disease. Nanotechnology provides an excellent way to develop a new generation of vaccines. NPs have been widely used in vaccine design as adjuvants and antigen delivery vehicles and as antibacterial agents; thus, they can be used as inactivators for bacterial culture. In this research, the antibacterial effects of several nanoparticles (NPs), such as silicon dioxide with chitosan (SiO2-CS), oleoyl-chitosan (O.CS), silicon dioxide (SiO2), and iron oxide (Fe3O4), on A. paragallinarum were studied. Additionally, different A. paragallinarum vaccines were made using the same nanomaterials at a concentration of 400 µg/ml to help control infectious coryza disease in chicken. A concentration of 400 µg/ml of all the NPs tested was the best concentration for the inactivation of A. paragallinarum. Additionally, this study showed that the infectious coryza vaccine adjuvanted with SiO2 NPs had the highest immune response, followed by the infectious coryza vaccine adjuvanted with Fe3O4 NPs, the infectious coryza vaccine adjuvanted with SiO2-CS NPs, and the infectious coryza vaccine adjuvanted with O.CS NPs in comparison with the infectious coryza vaccine adjuvanted with liquid paraffin (a commercial vaccine). [ABSTRACT FROM AUTHOR]

The study included the use of technogenic ore formations from the metallurgical industry of the Republic of Armenia for hydrometallurgical treatment in laboratory conditions. In the course of the study, a new complex pyrohydrometallurgical technological method was proposed, which is designed to effectively extract metals in the form of concentrates from technogenic ore formations, and produce technical silicon dioxide from materials resistant to chemical reagents. Within the framework of this method, raw materials obtained from technogenic formations are melted using certain chemical reagents, after which the resulting melt is dissolved in an aqueous solution of hydrochloric acid in specially created gel-like conditions. The reduced silicic acid then undergoes a purification process by dissolving in a weak aqueous solution of hydrochloric acid to remove impurities, and then undergoes heat treatment in atmospheric air to convert into silicon dioxide. The metals contained in technogenic ore formations are separated into solid and liquid concentrates. [ABSTRACT FROM AUTHOR]

Recycled soda-lime glass powder is a sustainable material that is also often considered a filler in cement-based composites. The changes in the surface properties of the glass particles due to the treatments were analyzed by X-ray photoelectron spectroscopy (XPS) and optical spectroscopy. We have found that there is a relatively high level of carbon contamination on the surface of the glass particles (around 30 at.%), so plasma technology and thermal annealing were tested for surface cleaning. Room temperature plasma treatment was not sufficient to remove the carbon contamination from the surface of the recycled glass particles. Instead, the room temperature plasma treatment of recycled soda-lime glass particles leads to a significant enhancement in their room temperature photoluminescence (PL) by increasing the intensity and accelerating the decay of the photoluminescence. The enhanced blue PL after room-temperature plasma treatment was attributed to the presence of carbon contamination on the glass surface and associated charge surface and interfacial defects and interfacial states. Therefore, we propose blue photoluminescence under UV LED as a fast and inexpensive method to indicate carbon contamination on the surface of glass particles. [ABSTRACT FROM AUTHOR]

Silicon nanoparticles (Si NPs) have an eminent role in improving plant yield through improving yield. The present study was conducted to find the effect of Si NPs on plant yield, biochemical attributes, and minerals of different cucumber cultivars. The greenhouse experiment with foliar application of Si NPs (100, 200, and 300 mg L-1) was carried out on cucumber cultivars (Emilie, Mirsoltan, Mitio, and Viola). The application of Si NPs at 300 mg L-1 led to the highest fruit yield, with a 17% increase in fruit production compared to the control. Fruit firmness differed by 31% between Emilie and Si NPs at 100 mg L-1 and Mito at 300 mg L-1. Plants experiencing Si NPs at 300 mg L-1 had the greatest chlorophyll (Chl) a+b. Compared to the other cultivars, Mito had a greater fruit yield and Chl content. The Si NPs increased TSS by 11% while lowering TA by 24% when compared to the control at 300 mg L-1. Foliar application of Si NPs reduced the value of TSS/TA. The largest value of K was reached in the Mito cultivar with Si NPs at 200 mg L-1, with a 22% increase in comparison to the control, indicating that Si NPs considerably boosted the K content. The Si NPs at 200 mg L-1 significantly increased leaf N and P in the Mito cultivar by 16 and 50%, respectively. By using agglomerative hierarchy clustering (AHC), Emilie and Mito were located in two separate clusters, whilst Viola and Mirsoltan were grouped in one cluster. In conclusion, Si NPs at 200-300 mg L-1 enhanced fruit yield, and Mito showed the highest yield when compared to other cultivars. [ABSTRACT FROM AUTHOR]

Electrospun nanofibers have been used as wound dressings to protect skin from infection and promote wound healing. In this study, we developed polyvinylpyrrolidone (PVP)/silicon dioxide (SD) composite nanofibers for the delivery of probiotic Saccharomyces cerevisiae (SC), which potentially aids in wound healing. PVP/SD composite nanofibers were optimized through electrospinning, and bead-free nanofibers with an average diameter of 624.7 ± 99.6 nm were fabricated. Next, SC, a wound-healing material, was loaded onto the PVP/SD composite nanofibers. SC was encapsulated in nanofibers, and nanofibers were prepared using SC, PVP, SD, water, and ethanol in a ratio of 3:4:0.1:4.8:1.2. The formation of smooth nanofibers with protrusions around SC was confirmed using SEM. Nanofiber dressing properties were physicochemically and mechanically characterized by evaluating SEM, DSC, XRD, and FTIR images, tensile strength, and elongation at break. Additionally, a release test of active substances was performed. The absence of interactions between SC, PVP, and SD was confirmed through physicochemical evaluation, and SEM images showed that the nanofiber dressing contained SC and had a porous structure. It also showed a 100% release of SC within 30 min. Overall, our study showed that SC-loaded PVP/SD composite nanofibers prepared using the electrospinning method are promising wound dressings. [ABSTRACT FROM AUTHOR]

This study investigates the mechanical and tribological properties of Kevlar-based composites filled with varying weight percentages (5%, 10%, and 15%) of nano fillers, specifically nanographene oxide (GnO) and silicon dioxide (SiO2), intended for automotive applications. The composites were fabricated using the conventional hand layup method. To assess the mechanical performance, including tensile, flexural, interlaminar shear strength (ILSS), and hardness, tests were conducted to evaluate material strength. Tribological characteristics were examined through wear and frictional tests carried out under different temperature conditions, ranging from 50 °C to 250 °C, with a sliding speed of 0.261 m/s, loads varying from 156 N to 315 N, and a test duration of 120 min. Comparative results revealed that the composite containing 10 wt% SiO2 exhibited superior mechanical properties, with a tensile strength of 372.45 MPa, flexural strength of 339.92 MPa, ILSS of 56.38 MPa, and a hardness rating of 92 HRB. These improvements were attributed to the inherent hardness and effective dispersion of SiO2, enhancing matrix-fiber bonding. In comparison to nano GnO, the Kevlar fibers loaded with 10 wt% nano SiO2 demonstrated the highest capacity for reducing wear (0.554 × 10−3m3/Nm) and frictional coefficients (0.083). Because SiO2's stiff and strong structure offers a firm surface against the opposing material, it lowers friction and resists wear. The friction rate of the nano-fillers-loaded materials gradually increased with rising temperatures up to 200 °C and exhibited a significant increase from 200 to 250 °C. Conversely, Kevlar composites with 15 wt% SiO2 and 15 wt% GnO displayed higher wear rates, accompanied by pronounced fiber breakage and surface degradation, attributed to intense frictional forces generating thermal effects during sliding. Microstructural and structural characteristics of the hybrid composites were analyzed using high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM), electron diffraction (ED), and X-ray diffraction (XRD). In summary, Kevlar composites with 10 wt% SiO2 filler demonstrated exceptional wear resistance, positioning them as promising candidates for automotive components prone to wear and friction, such as clutch systems, brakes, and engine parts. [ABSTRACT FROM AUTHOR]

The aim of the study is to determine factors affecting cast iron metallurgical quality in casting mass production using new modifiers. Results of studying mechanical properties, microstructure and thermal analysis are presented. Mechanical tests are performed on specimens cut from a stepped casting, and microstructural studies are conducted using a light microscope and a scanning electron microscope. Results of thermal analyses show that introduction of modifiers increases the eutectic minimum solidification temperature and therefore increases the likelihood of forming a vermicular form of graphite within cast iron. An increase in nucleation potential may be achieved by adding modifiers obtained from silicon production waste. Modifiers obtained from silicon production waste containing silicon dioxide and carbon nanoparticles appear to be the most advantageous final modifiers in terms of obtaining the best gray cast iron microstructure parameters and ductility properties. [ABSTRACT FROM AUTHOR]

This work aims to study the production of hydrogen peroxide gas (H2O2) through photocatalysis. It consists of two main parts. In the first part, we explore the optimal conditions for synthesizing H2O2 gas from humidity using a gas system photoreactor. Through experimentation, we discovered that the fabricated photoreactor, equipped with three series of coated photocatalyst-supporting plates, can synthesize H2O2 gas up to 3 ppmv. The photoreactor incorporates key components, including a photocatalyst material, UV light source, ventilation fan, and air filter. The identified optimal conditions included a relative humidity of 60‒65% RH and an air flow rate of 12.0 m/s. The TiO2/1%SiO2 photocatalyst, composed of SiO2 particles smaller than 63 μm, yielded the most favorable results. The second part focused on studying the role of SiO2 in TiO2/SiO2. We observed that modifying the TiO2 morphology with SiO2 created a pore structure on the surface. This structural modification leads to the formation of Ti‒O‒Si bonds, which facilitate electron and hole trapping on the photocatalyst surface. Furthermore, the presence of hydroxyl groups on the surface enhanced the attraction of reactant molecules. XRD results reveal a mixed-phase structure of TiO2 (anatase‒rutile)/SiO2 amorphous, contributing to improved electron and hole pathways within the photocatalyst. [ABSTRACT FROM AUTHOR]

A High-K Dielectric Dual Metal Gate FinFET (DMG-FinFET) is proposed in this work to improve the drain current and electrical characteristics of the device. The proposed device employing dielectric materials such as Silicon dioxide, Hafnium oxide and Titanium oxide and investigated in 10 nm technology. The architecture represents a critical advancement in transistor design, addressing challenges posed by traditional high-K gate dielectric materials being HfO2 and TiO2. This work employs a comprehensive approach, incorporating simulation techniques to evaluate the performance metrics of DMG FinFET. This investigation encompasses key aspects being transistor characteristics, power consumption, and reliability. This high-k dielectric (HfO2) Dual material Gate -FinFET device achieving improved performance parameters such as Ion= 32.12 mA, Ioff= 33 μA, Gm(max) = 0.045 S, Gds(max) = 0.024 S and Ron(max) = 32.87 kΩ. Therefore this work is suitable for designing high performance devices with high-k dielectric materials being HfO2 and TiO2. The impact of dual metal gate materials on Ion, Ioff, Gm (max), Gds(max) and Ron(max) is calculated and improved 64% compared to conventional device. [ABSTRACT FROM AUTHOR]

This investigation relates to the production of materials with noiseproof and vibration-absorbing properties, in the manufacturing of which a number of by-products are formed that require for safe disposal. When solving the production problems connected with wastewater treatment from toxicants, the concentration of which exceeds permissible values, it is proposed to use structured materials based on silicon dioxide as an adsorbent. In the course of conducting research, two experimental samples with a highly developed surface containing an extensive network of pores have been obtained and tested. The experimental testing of adsorbents has shown that such adsorbents are able to provide the removal of toxicants up to attaining a safe concentration level thereof. [ABSTRACT FROM AUTHOR]

As a kind of low temperature bulk heat storage material, calcium chloride hexahydrate has a great application prospect in heat storage and energy saving. However, the single calcium chloride hexahydrate phase change heat storage material has the disadvantages of low thermal conductivity and easy leakage when melting. Mesoporous silicon dioxide with large inner core and interpenetrating mesoporous channel structure can solve the above problems. Mesoporous silicon dioxide has the advantages of low density, low thermal expansion coefficient, low refractive index and large specific surface area. However, it has low thermal conductivity and needs to be combined with other materials with good thermal properties to enhance its thermal conductivity. MXene was used as the thermal conductivity enhancement material, mesoporous silicon dioxide was grown on its surface, and then the phase change material calcium chloride hexahydrate was loaded into it. By means of synchronous thermal analyzer and infrared thermal imager, it is proved that the heat storage performance, thermal stability and heat transfer rate of the composite phase change materials are significantly improved. The leakage of calcium chloride hexahydrate in the oven was also obviously inhibited by the carrier material. A kind of composite phase change heat storage material with excellent thermal properties and stability was successfully prepared. [ABSTRACT FROM AUTHOR]

Over the last few decades, researchers have devoted significant consideration to the use of nanoscale elements in concrete. Silicon dioxide nanoparticles (SDNs) have been a popular subject of study among the several types of nanoparticles. This article describes the findings of a laboratory investigation that examined the properties of ultra-lightweight foamed concrete (ULFC) including different proportions of SDNs. Wide range of the properties was evaluated specifically the slump flow, density, consistency, flexural strength, modulus of elasticity, compressive strength, split tensile strength, thermal properties, porosity, water absorption, sorptivity, intrinsic air permeability, and chloride diffusion. Additionally, the scanning electron microscopy (SEM) and pore distributions analyses of different mixes were done. Results confirmed a noticeable increase in the mechanical properties of ULFC, with respective improvements in the 28-day compressive, split tensile, and flexural strengths of up to 70.49%, 76.19%, and 51.51%, respectively, at 1.5% of the SDNs inclusion. However, further increases in the SDNs percentage did not result in remarkable enhancements. As the SDN percentage increased from 1.5% to 2.5%, the ULFC's sorptivity, porosity, water absorption, intrinsic air permeability, and chloride diffusion showed substantial improvements. When compared to the control sample, ULFC with SDNs demonstrated higher thermal conductivity values. The reason for this occurrence was determined to be the smaller pore size observed in the ULFC specimens containing SDNs. A great adjustment in the distribution of pore diameters was witnessed in the ULFC mixes when the percentages of SDNs were adjusted. The ULFC specimens, which included SDNs at the percentages of 0.5%, 1.0%, and 1.5%, indicated a reduction in the total number of large voids measuring 500 nm or more, compared to the control ULFC specimen. The findings of this study highlight the potential benefits of incorporating SDNs into ULFC, which may improve its overall properties.