Silica Titania Research Articles

Evaluation of the cooling performance of various heat-reflective cool pavement coatings for Urban Heat Island mitigation

Abstract This paper investigates the optimization of heat-reflective cool pavement coatings to address the critical Urban Heat Island (UHI) effect, which significantly increases energy consumption for urban cooling and adversely impacts thermal comfort and public health. With pavements constituting about 30% of urban surfaces, their role in amplifying UHI effects underscores the need for innovative solutions. This study evaluated the cooling effect of heat reflective coatings (HRC) using water-based and oil-based binders, such as Acrylic Emulsions and Epoxy Resins, with the addition of functional fillers and pigments, including Titanium oxide, Iron oxide, and Silicon oxide. The results showed that both waterborne (acrylic emulsion) and oil-based (epoxy resin) HRC significantly reduced pavement surface temperatures, achieving maximum cooling effects of up to 20°C. During nighttime cooling simulations, these coatings maintained lower average temperatures, demonstrating their effectiveness both day and night. Waterborne HRC exhibited a rougher surface texture, resulting in higher skid resistance compared to the smoother epoxy resin HRC, which poses a potential risk for skid resistance and requires anti-skid additives. However, waterborne HRC showed signs of cracking after 24 hours of drying, indicating lower durability. Incorporating SiO2 maintained the cooling performance of epoxy resin HRCs while reducing glossiness, enhancing safety and efficacy. Conversely, SiO2 reduced the cooling effect in acrylic emulsion HRCs, suggesting that their natural matte appearance is already optimal. While yellow and white HRCs have high cooling effects, they may not be suitable for all applications due to potential glare and aesthetic mismatches, particularly in architectural and heritage settings.

The novel incorporation of lignin-based systems for the preparation of antimicrobial cement composites

This paper, for the first time, presents a potential application of titanium(IV) oxide and silicon(IV) oxide combined with lignin through a solvent-free mechanical process as admixtures for cement composites. The designed TiO2–SiO2 (1:1 wt./wt.) hybrid materials mixed with lignin were extensively characterized using Fourier transform infrared spectroscopy (FTIR), electrokinetic potential analysis, thermal analysis (TGA/DTG), and porous structure properties. In addition, particle size distributions and scanning electron microscopy (SEM) were conducted to evaluate morphological and microstructural properties. In the next step, the effect of the TiO2–SiO2/lignin hybrid admixture on the workability, hydration process, microstructure, porosity, mechanical, and antimicrobial properties of the cement composites was evaluated. It was observed that appropriately designed hybrid systems based on lignin contributed to better workability, with an improvement of 25 mm, and reduced porosity of cement composites, decreasing from 14.4 % to 13.3 % in the most favorable sample. Additionally, a higher microstructure density was observed, and with increasing amounts of hybrid material admixture, the mechanical parameters also improved. In addition, the TiO2–SiO2/lignin hybrid systems had significant potential due to their high microbial purity, suggesting their effectiveness in minimizing microbial accumulation on surfaces. The final stage of analysis involved employing response surface methodology (RSM) to ascertain the optimum composition of cement composites. The results obtained indicate that the TiO2–SiO2/lignin admixtures are a promising approach for the valorization of lignin waste flows in the design of cement composites.

Biopolyurethane coatings with silica-titania microspheres (MICROSCAFS®) as functional filler for corrosion protection

In this work, we studied a biopolyurethane (BioPU) coating derived from a bio-based polyol and isocyanate for the protection of carbon steel against corrosion. The direct utilization of polyols obtained from raw biomass represents a novelty in polyurethane coatings production. The protective properties of these coatings were enhanced by incorporating unique silica-titania (ST) MICROSCAFS®, which are microspheres exhibiting interconnected macro- and mesoporosity. They were loaded with tannic acid (TA), an eco-friendly corrosion inhibitor. Confirmation of TA loading into the ST carriers (therefore called ST\\TA) was achieved through Attenuated total reflectance - Fourier-transform infrared spectroscopy (ATR-FTIR) and Thermogravimetric (TG) analyses. TG analysis revealed that ST\\TA particles contain approximately 34 wt% TA, and their average particle diameter is approximately 25 ± 5 μm, observed by SEM. The TGA shows slightly improved thermal resistance of the coatings modified with the filler MICROSCAFS®. Furthermore, it was observed that the fillers strengthened the coating hardness without negatively affecting the adhesion strength. Electrochemical Impedance Spectroscopy (EIS) results demonstrated that all modified coatings exhibited very good to excellent resistance in mild corrosive environments. The coatings maintained a high impedance modulus (|Z|) at low frequencies and phase angle values close to −90° across a wide frequency range, over an immersion period of 80 days in a 0.05 M NaCl solution. After 80 days of immersion, the best coating, BPU-ST\\TA, displayed |Z| of 3 × 1010 Ω cm2. Scanning Vibrating Electrode Technique (SVET) analysis revealed the inhibitory behaviour of TA. For the BPU-ST\\TA sample, inhibition of both anodic and cathodic activities was clearly visible, with a significant reduction of the current densities starting at 1 h and up to at least 24 h of immersion. In summary, the BioPU coatings modified with tannic acid-loaded MICROSCAFS® exhibit improved barrier properties and notable corrosion inhibition capacity in mild corrosive environments.

Exploring the superior mild temperature performance of nickel-infused fibrous titania silica for enhanced dry reforming of methane

Carbon (IV) oxide (CO2) and methane (CH4) contribute significantly to greenhouse gas emissions and global warming. One potential approach for reducing their environmental impact is transforming these gases into synthesis gas (CO + H2). This study illustrates the advancement of catalysts supported by fibrous titania silica (FTS), which have nickel loadings of 1%, 3%, and 5%. The FTS support, a modified variant of silica-titania, has a distinct fibrous structure and exhibits mesoporous material properties such as a type IV isotherm and an H1 hysteresis loop. After 72 h of operation, the 1Ni/FTS catalyst converted over 80% of CH4 and CO2 with low coke deposition, outperforming other catalysts. The bare FTS support had reduced CH4 conversion at 600°C, CO2 conversion at 650°C, and H2/CO ratio at 700°C. However, the 5Ni/FTS and 3Ni/FTS catalysts showed consistent increases in CH4 conversion at 600°C. The 1Ni/FTS catalyst, with a pore size of 7.39 nm, had strong metal-support interaction and moderate basicity sites, which helped with reactant dissociation and coke gasification. Despite the slightly higher CH4 conversion of the 3Ni/FTS catalyst and the high basicity of the 5Ni/FTS catalyst, the 1Ni/FTS catalyst demonstrated superior thermal stability and coking resistance, as evidenced by negligible weight loss during TGA analysis. Raman shifts revealed the presence of carbon synthesis and the buildup of disordered amorphous carbon. The Id/Ig ratios of FTS, 1Ni/FTS, 3Ni/FTS, and 5Ni/FTS were 1.01, 0.98, 1.01, and 1.01, respectively. The lower Id/Ig ratio of 1Ni/FTS suggests less disorder. The FTS support promises mild-temperature, carbon-neutral CH4 reforming with long-term catalytic applications. This study demonstrates the efficacy of FTS-supported catalysts in constructing long-term and efficient systems for converting greenhouse gasses.

Green synthesized metal nanoparticle incorporated titania silica and its application in the photodegradation of Rhodamine B

Photocatalytic activity of Titania has a very intriguing mechanism with numerous potential uses such as air and water cleaning. The inclusion of silica improves its catalytic capabilities. The use of titania silica nanoparticles for photocatalytic activity in environmental applications is limited due to their activity in the UV region rather than the visible range. Titania silica nanoparticles were synthesised using the sol-gel method. Metal nanoparticles of vanadium, manganese and silver were synthesised and integrated into the titania silica using a green method. To clarify the structure property correlations for titania silica materials, several characterisation techniques such as SEM-EDAX, IR analysis, UV-Visible spectroscopy and XRD were applied. The photocatalytic activities of titania alone, titania silica and titania silica including the various metals were studied.

Optimization of heat transfer properties in micropolar ternary (Al2O3 + TiO2 + SiO2/water) nanofluid with porosity and magnetic field effects

Decades of study provide substantial evidence supporting that nanofluids possess improved heat transmission capabilities. Optimal qualities of nanoliquids may be achieved by manipulating the volume concentration of the nanoparticles. Nevertheless, this method has constraints due to the balance between negative and positive viscosity. A recent advancement has been produced in creating and thoroughly examining a particular form of hydraulic fluid that incorporates three solid nanoparticles scattered inside an existing fluid. This improvement aims to tackle this limitation. This study investigates the characteristics of a micro-rotational incompressible micropolar ternary hybrid nanofluid in a porous media. It considers the influence of magnetohydrodynamics, Darcy-Forchheimer, and linear thermal radiations on a stretched surface. The nanofluid consists mostly of water, which is blended with titanium oxide, aluminum oxide, and silicon oxide nanoparticles. Using dimensionless similarity transformations, the collection of higher-order non-dimensional partial differential equations is converted into higher-order ordinary differential equations. The BVP4C technique in MATLAB software is used to solve these equations and assess the graphical and tabular outcomes. The graphical analysis examines the influence of various physical characteristics. The heat transfer of a ternary hybrid nanofluid is significantly affected by many factors, including the Forchheimer coefficient, Prandtl number, thermal radiation parameter, and magnetic field parameters, as seen. The research demonstrates that an increase in the magnetic field and Darcy-Forchheimer parameters reduces linear momentum. Conversely, increased porosity, magnetic field, and radiation parameters increase the temperature profile.

Fabrication of Silica–Titanium Composite Film on Wood Surface and Optimization of Its Structure and Properties

In this thesis, wood loaded with a silica–titanium (Si-Ti) composite film was prepared using the sol–gel method in order to achieve improved wood with high hydrophobicity and photocatalytic activity under visible light. The factors affecting the structure and properties of the composite film, as well as the optimization process, were discussed. Infrared analysis revealed that the vibrational intensity of Si-O-Si, Ti-O-Ti, and Ti-O-Si telescopic vibration peaks increased with an increase in vinyltriethoxysilane (VETS). Additionally, the number of Ti-O-Ti telescopic vibration peaks also increased with an increase in VETS. Furthermore, the intensity of -NO3, Si-O-Si, and Ti-O-Ti telescopic vibrational peaks was enhanced with a higher dosage of nitric acid. Conversely, the intensity of -OH telescopic vibrational peaks decreased with an increase in drying temperature. XRD analysis showed that nitric acid could promote the transformation of TiO2 from amorphous to anatase, while SiO2 would reduce the grain size of anatase TiO2 and promote the growth of rutile TiO2. Additionally, wood surfaces loaded with Si-Ti composite film changed from hydrophilic to hydrophobic, with significant differences observed between different levels of each factor. The photocatalytic activity of surface-loaded Si-Ti composite films on wood was most affected by the amount of nitric acid, which influenced crystallinity of TiO2 and thus impacted the photocatalytic activity. Furthermore, changes in VTES dosage not only affected the crystalline phase of TiO2 and the grain size of Si-Ti composite film but also influenced the crystallinity of TiO2 through generating SiO2. Finally, based on optimal preparation process (titanium–alcohol ratio of 1:5, titanium–silicon ratio of 1:0.2, titanium–acid ratio of 1:0.5, and drying temperature of 100 °C), wood surfaces loaded with Si-Ti composite film achieved a contact angle up to 125.9° and exhibited a decolorization rate for rhodamine B under UV light reaching 94% within 180 min.

Stimuli-responsive drug release of polyacrylic acid-coated silica–titania hollow nanoparticles

Inorganic hollow nanoparticles have received a great deal of attention as nanocarriers for drug delivery system, but it is still challenging to control the drug release time and achieve high drug delivery efficiency. In this study, we intend to build a controllable smart drug delivery system that delivers drugs to a desired location for a desired time using a stimulus-responsive material. Polyacrylic acid (PAA), a pH-responsive material, is coated on the silica–titania hollow nanoparticles (HNPs) to acquire stimulus-responsive material for controlled drug release.

Enhanced CO2 conversion with CH4 for greenfuel generation using coke-neutral nickel-loaded fibrous silica titania catalysts

This study reveals a groundbreaking advancement in utilizing carbon dioxide (CO2) for syngas production through methane (CH4) dry reforming using Fibrous Silica Titania (FST) as a support, loaded with different (1%, 3%, and 5%) nickel dosages. FST is distinguished by its fibrous structure, maintains a stable temperature, facilitates the confinement and dispersion of active metal, and is exceptionally effective at preventing carbon deposition. For a thorough examination of the new catalysts, characterization methods including XRD, FESEM, EDX mapping, N2 physisorption, FTIR-KBr, H2-TPR, and CO2-TPD were employed. Importantly, TEM lattice fringes verified the existence of XRD peaks and planes of Ni (111), Ni (200), and TiO2 (101). Aspects such as O-H stretching, Si-O-Si asymmetry, vibrations caused by external Si-OH groups, and Si-O-Si bending were identified using FTIR-KBr analysis. The study ingeniously identified the superior (3Ni/FST) catalyst, which exhibited moderate basicity sites on the CO2-TPD at approximately 350 °C. The catalyst converted nearly 100% CH4 at 750 °C with minimal coke production and 80% CO2 at 850 °C. Surprisingly, the 3Ni/FST catalyst demonstrated remarkable stability during a 72 h TOS stability test at 650 °C, effectively preventing coke-forming side reactions such as CO disproportionation, CO hydrogenation, CO2 and CH4 cracking with syngas ratio around unity and little coke production. The FST support exhibited exceptional attributes for low temperature carbon neutral CH4 reforming.

Tunning of catalytic performance in coupling, reduction and oxidation of hydrothermal assisted mixed metal oxides of Pd and Cu loaded over mesoporous nanostructure titania coated N‐doped silica using rice husk

Silica–titania‐based mesoporous nanomaterials due to their widespread availability and inexpensive cost have been employed in an extensive range of applications, including heterogeneous catalysis. This research article discusses the hydrothermal synthesis of highly efficient heterogeneous nanocatalyst, that is, mixed metal oxides of Pd and Cu immobilized over silica–titania mesoporous nanostructure and its application in coupling, reduction and oxidation reactions. It was characterized by Fourier transform infrared spectroscopy (FTIR), powder X‐ray diffraction (P‐XRD), field emission gun–scanning electron microscopy (FEG‐SEM), energy‐dispersive X‐ray analysis (EDX), high‐resolution transmission electron microscopy (HR‐TEM), X‐ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), UV–visible spectroscopy (UV–VIS), Brunauer–Emmett–Teller (BET), X‐ray resonance fluorescence (XRF), photoluminescence (PL) and inductively coupled plasma–atomic emission spectroscopy (ICP‐AES) studies to assemble information regarding various structural features. XPS analysis successfully confirmed the presence of mixed oxidation state of Pd and Cu, that is, Pd(0), Pd(II), Cu(0), Cu(I) and Cu(II) over the nanocatalytic support. TEM images showed that the PdCu alloy had spherical shape with average size between 3 and 4 nm. BET analysis indicated that the catalyst has specific surface area of 57.296 m2 g−1 with average pore diameter of 1.84 nm. The results of TGA and DTA analysis demonstrated that the maximum temperature up to which PC‐TNS can catalysed organic reactions was 170°C. The average crystallite size of PC‐TNS was came around 16.08 nm calculated using Scherrer's equation. Moreover, synthesized heterogeneous nanocatalyst was highly recyclable and FEG‐SEM, P‐XRD and XPS findings confirmed the structural disruption after sixth or seventh catalytic run resulted in decrease in yield of products. In general, nanocatalysts can be convincingly more superior to other heterogeneous nanocatalyst due to their unique features such as high specific surface area, high reusability, high reactivity, high product yield and environmentally friendly.

Hydrophobic Modification of Bi2O3-Doped Si-Ti Composite Film on a Wood Surface

In order to improve the hydrophobicity of the composite film on the wood surface, the wettability of the wood surface and its morphology, chemical structure, roughness and free energy changes were investigated in this paper after modification treatments with different volume fractions of octadecyltrichlorosilane (OTS) and polydimethylsiloxane (PDMS). It can be found that the water contact angle and surface roughness of the hydrophobically modified wood increased with the increase in volume fraction, but the overall effect of OTS hydrophobic modification was better than that of PDMS, and a maximum water contact angle of up to 140.8° could be obtained at a volume fraction of 2% of OTS. In addition, the intensity of the stretching vibration peak of -OH was weakened after the modification, while the intensity of the stretching vibration peak of -CH2- was enhanced, resulting in an increase in hydrophobicity. At the same time, it can be found that the surface free energy of the modified wood specimens was reduced, which shows that OTS and PDMS improve the surface hydrophobicity of the wood by increasing the surface roughness and decreasing the surface free energy together. Finally, the hydrophobically modified Bi2O3-doped silica–titanium composite film still possessed high photocatalytic degradation activity for rhodamine B and gas formaldehyde, and the degradation rate could reach more than 90%.

Synthesis of Monodisperse Silica Nanospheres and Titania Beads from Rotating Cylinder System

Economic raw materials such as low-grade ethanol and Tetraethyl Ortosilicate (TEOS) were adopted as reactants for the synthesis of monodisperse silica nanospheres using a Taylor Vortex flow reactor with a rotating cylinder system. Factors affecting the mean diameter and size distribution of the silica grains were investigated by changing the rotating speed of the inner cylinder and the composition of reactants. In the case of titania beads, grain diameter size was adjusted by changing the amount of precursor (titanium (IV) isopropoxide, TIP), hexadecylamine (HDA) or Potassium Chloride (KCl) and reaction temperature as well as the rotation speed of the cylinder. As a demonstrative application, titania beads could be used for the removal of organic dye as a model contaminant dissolved in an aqueous medium using a photocatalytic decomposition system.

PH-Triggered Controlled Release of Chlorhexidine Using Chitosan-Coated Titanium Silica Composite for Dental Infection Prevention.

Peri-implantitis is a growing pathological concern for dental implants which aggravates the occurrence of revision surgeries. This increases the burden on both hospitals and the patients themselves. Research is now focused on the development of materials and accompanying implants designed to resist biofilm formation. To enhance this endeavor, a smart method of biofilm inhibition coupled with limiting toxicity to the host cells is crucial. Therefore, this research aims to establish a proof-of-concept for the pH-triggered release of chlorhexidine (CHX), an antiseptic commonly used in mouth rinses, from a titanium (Ti) substrate to inhibit biofilm formation on its surface. To this end, a macroporous Ti matrix is filled with mesoporous silica (together referred to as Ti/SiO2), which acts as a diffusion barrier for CHX from the CHX feed side to the release side. To limit release to acidic conditions, the release side of Ti/SiO2 is coated with crosslinked chitosan (CS), a pH-responsive and antimicrobial natural polymer. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDX) and Fourier transform infrared (FTIR) spectroscopy confirmed successful CS film formation and crosslinking on the Ti/SiO2 disks. The presence of the CS coating reduced CHX release by 33% as compared to non-coated Ti/SiO2 disks, thus reducing the antiseptic exposure to the environment in normal conditions. Simultaneous differential scanning calorimetry and thermogravimetric analyzer (SDT) results highlighted the thermal stability of the crosslinked CS films. Quartz crystal microbalance with dissipation monitoring (QCM-D) indicated a clear pH response for crosslinked CS coatings in an acidic medium. This pH response also influenced CHX release through a Ti/SiO2/CS disk where the CHX release was higher than the average trend in the neutral medium. Finally, the antimicrobial study revealed a significant reduction in biofilm formation for the CS-coated samples compared to the control sample using viability quantitative polymerase chain reaction (v-qPCR) measurements, which were also corroborated using SEM imaging. Overall, this study investigates the smart triggered release of pharmaceutical agents aimed at inhibiting biofilm formation, with potential applicability to implant-like structures.

Effects of Desilication Conditions on the Formation of Wollastonite during the Autoclave Leaching of Silica–Titanium Concentrates

Effects of Desilication Conditions on the Formation of Wollastonite during the Autoclave Leaching of Silica–Titanium Concentrates

Enhanced visible-light photocatalytic degradation of organic pollutants using fibrous silica titania and Ti3AlC2 catalysts for sustainable wastewater treatment

Visible light photocatalysis offers a green and sustainable approach to wastewater treatment and environmental remediation.

Sintesis Komposit Titatnia-Silika dengan Proses Sol Gel

Sintesis komposit titania silika telah berhasil dibuat dari geothermal sludge dengan menggunakan metode sol gel dan sonikasi. Sonikasi digunakan untuk mengecilkan partikel TiO2 dengan bantuan alat sonikator dengan larutan asam sulfat sebagai pelarut TiO2. Sedangkan metode sol gel digunakan untuk mengkompositkan antara silika dari geothermal sludge yang diektraksi menggunakan NaOH menjadi larutan natrium silika dengan larutan TiO­2 yang sudah disonikasi sehingga tebentuk komposit titania silika. Untuk mempelajari pengaruh komposisi dari komposit digunakan TiO2 dengam berat 4-8 gram dan pH gelling dari proses sol gel dengan pH 4-8. Komposit titania silika yang tebentuk akan dikarakterisasi menggunakan X-Ray fluorescence (XRF), X-Ray Diffraction (XRD), dan Spektroskopi Fourier Transform Infrared (FTIR). Dari analisa yang dilakukan didapatkan hasil bahwa, dengan penambahan berat TiO2 yang berbeda dan pH gelling yang berbeda didaptkan rasio silika/titania dengan rentang 0,3113-1,5268.Gugus yang menunjukkan adanya ikatan titania silika dapat dilihat pada bilangan gelombang 965,1 dan 967,03 cm-1. Pola XRD dari komposit menunjukkan adanya silika amorf dan kristal titania sehingga terdapat titania dan silika dalam produk. Komposit titania silika dapat digunakan pada proses adsorpsi jika komposisi silika lebih banyak dibanding titania, sedangkan jika komposisi titania lebih banyak digunakan pada proses oksidasi.

Effects of micro and nano fillers on the mechanical and thermal properties of hydroxyl‐terminated polybutadiene‐polyurethane based rocket motor liner

AbstractCase bonded solid rocket motors hold significant importance in both the defense and aerospace industries which typically consist of an insulating layer, a solid propellant, and a liner layer serving as an adhesive between the insulator and solid propellant. In this investigation, the aim was to assess the critical mechanical properties of five different HTPB based liner formulations under ambient conditions, as well as at elevated and reduced temperatures. The liner formulations incorporated micro carbon black, nano carbon black, nano silica, and nano titania as fillers. A comprehensive characterization study encompassing mechanical and thermal properties was conducted to evaluate the performance of these potential rocket motor liners. Mobility reduction of polymer chains and bond strengthening at lower temperatures led to the enhancement in mechanical properties of all filled and unfilled liners with decline in temperature. All mechanical properties of filled liner formulations increased significantly compared to unfilled formulation at all temperatures. Enhancements in mechanical properties were more pronounced with carbon blacks as fillers. Thermal analyses of each formulation revealed that there were improvements in the thermal properties of filled liners compared to unfilled one.

Thermal conversion of solar radiation for possible applications in industrial heat convertors

The proposed solar thermal absorber consists of sandwich structure-inspired Ti–SiO2–Ti (Titanium–Silicon Dioxide -Titanium) Metal-insulator-Metal (MIM) material. Here proposed thermal absorber has materials, Ti as ground, SiO2 as substrate and Ti as resonator. The design of solar thermal absorber is well-versed with the modern theory of absorption and made up on a nanometre basis with each parameter being less than 500 nm. An average absorption of 96.34 % has been achieved throughout the wavelength range of 0.2–3 μm including various regions including UV, Visible, NIR, and MIR with an average absorptance 92.72 %, 93.81 %, 96.58 %, 98.55 % respectively. The proposed nanoscale solar absorber also has 1920 nm of wavelength range above 95 % with an average absorptance of 97.985 % and 2730 nm of wavelength range above 90%with an average absorptance of 96.6 %, although transverse electric (TE) and magnetic (TM) modes achieved an average absorptance of 96.34 % and 94.1 % respectively. We also have noticed characteristics like large angular and polarization-independent in the proposed solar energy absorber structure which eventually benefitted the applications of optoelectronics.

Racetrack Ring Resonator Integrated with Multimode Interferometer Structure Based on Low-Cost Silica–Titania Platform for Refractive Index Sensing Application

In this work, a racetrack ring resonator (RTRR) integrated with a multimode interferometer (MMI) structure based on a silica–titania (SiO2:TiO2) platform is projected for refractive index sensing application. The typical ring resonator structure requires a gap of ~100 nm to 200 nm between the bus waveguide (WG) and the ring structure which makes it challenging to fabricate a precise device. Thus, the device proposed in this paper can be considered a “gapless” ring resonator structure in which the coupling of light between the ring and bus WG can be achieved via an MMI coupler. A minor change in the refractive index in the vicinity of the MMI structure can trigger a shift in the resonance wavelength of the device. Thus, this simple and fascinating structure can be employed as a refractive index sensor. The device’s sensitivity is ~142.5 nm/RIU in the refractive index range of 1.33 to 1.36 with a figure of merit (FOM) of 78.3. This simple device structure can potentially be fabricated via a low-cost and highly efficient sol–gel process and dip-coating method combined with the nanoimprint lithography (NIL) method.

Bayesian regularization networks for micropolar ternary hybrid nanofluid flow of blood with homogeneous and heterogeneous reactions: Entropy generation optimization

This study aims to analyze a Bayesian regularization backpropagation algorithm for micropolar ternary hybrid nanofluid flow over curved surfaces with homogeneous and heterogeneous reactions, Joule heating and viscous dissipation. The ternary hybrid nanofluid consists of nanoparticles of titanium oxide (TiO2), copper oxide (CuO), and silicon oxide (SiO2), with blood as the base fluid. The governing partial differential equations for the fluid flow are converted into ordinary differential equations using a group of self-similar transformations. The ordinary differential equations are solved using an appropriate shooting algorithm in MATLAB. The effects of physical parameters including curvature, micro-polar, radiation, magnetic, Prandtl, Eckert, Schmidt, and homogeneous and heterogeneous chemical reaction parameters are analyzed for velocity, micro rotational, temperature, and concentration profile. Physical quantities of engineering interest like heat transfer rate, mass transfer rate, skin friction coefficient, couple stress coefficient, and entropy generation are also discussed in this study. A Bayesian regularization backpropagation algorithm is also designed for the solution of the ordinary differential equations. The obtained network is analyzed using training state, performance, error histograms, model response, Error autocorrelation, and input-error correlation plots. It is observed that the entropy generation and the Bejan number increase for enhancing Brinkman and radiation parameter. Clinical researchers and biologists may use the results of this computational study to forecast endothelial cell damage and plaque deposition in curved arteries, by which the severity of these conditions can be reduced.