Showing 111 results for Ali
Muddukrishnaiah Kotakonda, Sajisha V.s, Aiswarya G, Safeela Nasrin Pakkiyan, Najamol A Alungal, Mayoora Kiliyankandi K, Divya Thekke Kareth, Naheeda Ashraf Verali Parambil, Saranya Sasi Mohan, Renjini Anil Sheeba, Sarika Puthiya Veettil, Dhanish Joseph, Nishad Kakkattummal, Afsal Bin Haleem Mp, Safeera Mayyeri, Thasneem Chemban Koyilott, Nasiya Nalakath, Samuel Thavamani B, Famila Rani J, Aruna Periyasamy, Chellappa V Rajesh, Rameswari Shanmugam, Marimuthu Poornima, Tina Raju, Roshni E R, Sirajudheen Mukriyan Kallungal, Lekshmi Ms Panicker, Saranya K G, Shilpa V P,
Volume 21, Issue 3 (September 2024)
Abstract
Biogenic synthesis of papain-conjugated copper metallic Nanoparticles and their antibacterial and antifungal activities Papain metallic conjugated nanoparticles (Papain-CuNPs) were synthesised using Papain and CuSO4.5H2O. Papain-CuNPs were characterized using UV-visible spectroscopy, FT-IR, HR-TEM, XRD, FE-SEM, zeta potential, and a zeta sizer. The antibacterial activity of papain-CuNPs against human infectious microorganisms (Citrobacter spp, Pseudomonas aeruginosa and Candida albicans) was investigated. The mechanism of action of papain-CuNPs was evaluated using FE-SEM and HRTM. UV spectroscopy confirmed the plasma resonance (SPR) at 679 nm, which indicated the formation of papain-CuNPs. The FT-IR spectrum absorbance peaks at 3927, 3865, 3842, 3363, 2978, and 2900 cm-1 indicate the presence of O-H and N-H of the secondary amine, and peaks at 1643 and 1572 cm-1 represent C=O functional groups in Papain-CuNPs. EDAX analysis confirmed the presence of copper in the papain-CuNPs. The zeta potential (-42.6 mV) and zeta size (99.66 d. nm) confirmed the stability and size of the nanoparticles. XRD confirmed the crystalline nature of the papain-CuNPs. FE-SEM and HRTM showed an oval structure, and the nano particles' 16.71244–34.84793 nm. The synthesized papain-NPs showed significant antibacterial activity against clinical P. aeruginosa (15 mm). MIC 125 µg/ml) showed bactericidal activity against P. aeruginosa and the mechanism of action of Papain-NPs was confirmed using an electron microscope by observing cell damage and cell shrinking. Papain-CuNPs have significant antibacterial activity and are thus used in the treatment of P. aeruginosa infections
Ahmad Ostovari Moghaddam, Olga Zaitseva, Sergey Uporov, Rahele Fereidonnejad, Dmitry Mikhailov, Nataliya Shaburova, Evgeny Trofimov,
Volume 21, Issue 3 (September 2024)
Abstract
High entropy intermetallic compounds (HEICs) are an interesting class of materials combining the properties of multicomponent solid solutions and the ordered superlattices in a single material. In this work, microstructural and magnetic properties of (CoCuFeMnNi)Al, (CoCuFeMnNi)Zn3, (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs fabricated by induction melting are studied. The magnetic properties of the HEICs was determined mainly by the nature of the magnetic momentum of the constituent elements. (CoCuFeMnNi)Al and (CoCuFeMnNi)Zn3 displayed ferromagnetic behavior at 5 K, while indicated linear dependency of magnetization vs. magnetic (i.e. paramagnetic or antiferromagnetic state) at 300 K. The magnetization of (FeCoMnNiCr)3Sn2, (FeCoNiMn)3Sn2 and Cu3(InSnSbGaGe) HEICs at 300 K exhibited a nearly linear dependency to magnetic field. Among all the investigated samples, (CoCuFeMnNi)Al exhibited the best magnetic properties with a saturation magnetization of about Ms = 6.5 emu/g and a coercivity of about Hc = 100 Oe.
Murugesan Suganya, Chembian Kayathiri, Rajavelu Balu, Gandhiraj Vinitha, Zion Delci, Saravanan Chitra Devi, Kaliyamoorthy Devendran, Mathiyalagan Sriramraj,
Volume 21, Issue 4 (December 2024)
Abstract
Perovskite materials are widely studied for their super-conducting, magnetic, catalytic and electro-optic properties. Among them, barium stannate (BaSnO3), finds applications in dielectric and optically active devices, thermally stable capacitors, humidity and gas sensors. In this study, BaSnO3 was synthesized by chemical and greener methods and comparative analyses has been performed on their electrochemical, third order nonlinear, dye deactivation and bacterial suppression properties. Decreased crystallite size was realized for the green synthesized BaSnO3. Energy band gaps were 3.23 and 3.04 eV for BaSnO3 synthesized by normal and greener approach, respectively. The extract mediated sample exhibited increased specific capacitance value. Photocatalytic degradation efficiencies were 78.4% and 89.7%, respectively for BaSnO3 synthesized by normal and greener approach against methyl violet after 90 min of UV light irradiation. Enhanced nonlinear optical parameters were obtained for the extract mediated BaSnO3. Excellent antibacterial efficacy against Proteus vulgaris bacteria was realized for the greener BaSnO3 NPs thanks to the domination of phytochemicals of M. olifera leaf extract.
Zahra Rezayi, Mostafa Mirjalili, Jalil Vahdati Khaki,
Volume 21, Issue 4 (December 2024)
Abstract
Celestite ore, the primary mineral for producing strontium compounds, particularly strontium carbonate, is processed using the black ash method, which involves carbothermic reduction, water leaching, and carbonation. This study aims to investigate the combined effect of mechanical activation and additional graphite on the recovery rate and purity of strontium carbonate. Celestite ore with a strontium sulfate content of 79% was obtained from the Dasht-e-Kavir mine. Acid washing with 10% hydrochloric acid significantly reduced carbonate impurities, resulting in a celestite purity of 96.9%. Mixtures of celestite and graphite with varying amounts of graphite were prepared with and without milling. The mixtures were roasted at 900 °C for 1 hour to form strontium sulfide, followed by hot water leaching. After filtration, sodium carbonate was added to the leachate containing SrS, resulting in the formation and precipitation of white strontium carbonate crystals. The results showed that the addition of graphite increased the recovery rate in unmilled specimens. However, the recovery rate decreased significantly when 1 and 10 hours of milling were applied in the presence of excess graphite. Conversely, in the absence of additional graphite, milling for 1 and 10 hours increased the strontium recovery rate to over 95%. Furthermore, the analysis of strontium carbonate obtained from the sample with the highest recovery rate showed a purity of over 99.9%.
Ahabboud Malika, Gouitaa Najwa, Ahjyaje Fatimazahra, Lamcharfi Taj-Dine, Abdi Farid, Haddad Mustapha,
Volume 21, Issue 4 (December 2024)
Abstract
This paper reports the preparation and characterization of (1-x) PbZr0.52Ti0.48O3 -xBiFeO3 (1-x)PZTxBFO) (x= 0.00, 0.15, 0.30, 0.45, 0.60 and 1.00) multiferroic ceramics which were prepared by a sol-gel method for PZT and hydrothermal reaction process for BFO. The perovskite structure of the composite system was confirmed by X-ray diffraction and Raman spectroscopy, while the composite microstructure w:as char:acterized by scanning electron microscopy. XRD results and Rietveld analysis for the (1-x)PZT-xBFO composites confirm the coexistence of these three phases; rhombohedral (R3m) and tetragonal phases (P4mm) for pure PZT and only the rhombohedral phase (R3c) for pure BFO. Raman spectroscopy of the (1-x)PZT-xBFO composites shows two clear bands around 150 and 180 cm-1. When the BFO content increases, the intensities of Raman modes are decreased. The SEM results suggested a formation of agglomerate and form into large complex clusters as BFO increased and a higher grain size was obtained for the BFO sample compared with the other composites. The EDS spectra of our pellets show that all the characteristic lines of the chemical elements Pb, Zr, Ti, and O and Bi, Fe, and O are present for the PZT and BFO materials respectively. The temperature-dependent dielectric constant shows different behavior dependent on BFO content. Indeed, the dielectric properties are found to be improved with an increase in dopant concentration of BFO in PZT, and novel dielectric behavior, resonance, and antiresonance, were obtained.
Amir Hojjati Lemraski, Ali Sedaghat Ahangari Hossein Zadeh, Rahim Naghizadeh, Hudsa Majidian,
Volume 21, Issue 4 (December 2024)
Abstract
Cordierite ceramics are of interest for various applications due to their properties such as low thermal expansion coefficient and high thermal shock resistance. However, due to the narrow range of sintering temperature, attempts have been made to synthesize it using different additives. In this way, titania and tialite have been added in different amounts to the initial raw material mixture (talc, kaolin, and synthetic alumina). In this research, the initial powders (talc, kaolin, and synthetic alumina) were mixed in a planetary ball mill using different amounts of TiO2 and tialite. The mixtures were sintered at 1250, 1300, and 1350 °C for 3 h. X-ray diffractometry and fluorescence, thermal analysis, microstructural observation, density, and cold compressive strength (CCS) were used to evaluate the sintered samples. Phase analysis revealed the presence of the cordierite phase along with small amounts of spinel. With increasing sintering temperature and titania addition, the amount of spinel decreased and the amount of cordierite phase increased. The real density increased with increasing titania additive content, but at higher titania contents, microcracks were observed in the SEM micrographs. By adding 15 wt% of tialite to the initial batch, the compressive strength has been increased by 88% compared to the pure cordierite sample.
Nazli Aharipour, Adrine Malek Khachatourian, Ali Nemati,
Volume 21, Issue 4 (December 2024)
Abstract
Fe3O4 nanoparticles (NPs) with a continuous and mesoporous silica (m-SiO2) shell were synthesized using a one-step method, sourcing silica from rice husk ash (RHA). The rice husk was thermally treated to obtain ash, from which silica was extracted as sodium silicate and precipitated by pH reduction. This silica powder, combined with iron chloride salts, facilitated the synthesis of the core-shell NPs. Mint extract acted as a capping agent to prevent agglomeration, and CTAB (cetyltrimethylammonium bromide) was used to create the porous SiO2 shell. X-ray diffraction (XRD), Field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) characterization investigated the structure, size, and shell formation. Coating integrity and suspension stability were assessed through Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS). DLS analysis showed a relatively narrow particle size distribution with an average hydrodynamic size of 72.6 nm. Small-angle X-ray scattering (SAXS) provided insights into the meso- and nanoscale structure, while BET and nitrogen adsorption-desorption isotherms confirmed the mesoporous nature of the silica shell. Magnetization measurements showed superparamagnetic behavior, with specific magnetization values of 57.9 emu/g for Fe3O4 and 27.5 emu/g for Fe3O4@m-SiO2. These results confirm the successful synthesis of superparamagnetic magnetite NPs with a mesoporous silica coating from RHA.
Zeinab Abbasali Karajabad, Adrine Malek Khachatourian, Mohammad Golmohammad, Ali Nemati,
Volume 22, Issue 1 (March 2025)
Abstract
Hybrid asymmetric supercapacitors using distinct cathode/anode materials offer enhanced energy density by expanding operational potential windows compared to symmetric configurations. In this work rGO/α-Fe₂O₃ and rGO/TiO₂ nanocomposites were synthesized via hydrothermal method for hybrid asymmetric supercapacitors applications. Field emission scanning electron microscope (FESEM) revealed uniform distribution of spherical α-Fe₂O₃ and TiO₂ nanoparticles on rGO sheets. The X-ray diffractometry (XRD) analysis confirmed the presence of the hematite and anatase in the rGO/α-Fe2O3 and rGO/TiO2 nanocomposites, respectively. Additionally, in the XRD spectra of both nanocomposites, a broad peak corresponding to the (002) crystalline planes of rGO was observed. Electrochemical testing showed specific capacities of 130 F/g (rGO/α-Fe₂O₃) and 253 F/g (rGO/TiO₂) at 5 mV/s in 1M KOH. The assembled hybrid asymmetric supercapacitors (rGO/α-Fe₂O₃//rGO/TiO₂) achieved a 1.6 V operational potential window. Power density and energy density of 1066 W kg-1 and 9.7 Wh kg-1 were achieved at a current density of 1 A/g, respectively.
Amirreza Bali Chalandar, Amirreza Farnia, Hamidreza Najafi, Hamid Reza Jafarian,
Volume 22, Issue 1 (March 2025)
Abstract
This study investigates the microstructural evolution and variations in the mechanical properties of pre-cold worked Nimonic 80A superalloy, subjected to two levels of deformation (25% and 50%) and welded via Gas Tungsten Arc Welding (GTAW) and Pulsed Current Gas Tungsten Arc Welding (PCGTAW) techniques using ER309L filler wire. The objective is to evaluate the effect of the initial microstructure on the welding behavior of Nimonic 80A and compare the weldments produced using GTAW and PCGTAW. Microstructural characterization was conducted using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). XRD analysis demonstrated that the welding pulsed current mode, compared to the continuous current mode and at equal heat input, led to a refined microstructure, suggesting improved welded mechanical properties of the weld. It also showed a potential reduction in grain refinement with a higher level of cold work. Tensile testing demonstrated that fractures consistently occurred within the weld zone (WZ), with the PCGTAW sample achieving the highest tensile strength (766 MPa). Microhardness analysis indicated a notable reduction in hardness within the heat-affected zone (HAZ) and WZ, particularly in the 50% pre-cold worked sample. However, PCGTAW retained higher hardness due to its refined microstructure. The weld metal primarily consisted of an austenitic microstructure characterized by dendrites and interdendritic precipitates. Microstructural analysis revealed that welding induced significant changes in the weldment, with the PCGTAW sample exhibiting a more uniform microstructure and smoother transitions at the weld interface. Fractography confirmed ductile fracture in all specimens, with smoother and more uniformly distributed dimples in the PCGTAW sample. These findings highlight the advantages of pulsed current welding in optimizing the mechanical performance of Nimonic 80A welds and suggest its potential application in industries requiring superior weld quality.
Mohammad Derakhshani, Saeed Rastegari, Ali Ghaffarinejad,
Volume 22, Issue 1 (March 2025)
Abstract
In this research, the morphology of the Ni-W coating was modified by adding graphene oxide (GO) nanosheets in such a way that a foam-like structure with high porosity and holes in the form of intertwined tunnels was obtained. Different amounts of GO nanosheets were added to the plating bath and the resulting coating was examined. In order to estimate the electrochemically active surface area, the cyclic voltammetry (CV) test was used. Moreover, the linear polarization test (LSV) and chronoamperometry in 1 M NaOH were conducted to investigate the electrocatalytic activity for the hydrogen evolution reaction (HER). It was found that by adding 0.4 g/L GO to the electroplating bath, the electrocatalytic properties are doubled and the active surface of the electrode is significantly increased.
Divya Bajpai Tripathy, Anita Kushwaha, Smrita Singh, Smriti Dwivedi, Anjali Gupta, Lalit Prasad, Ashutosh Chauhan,
Volume 22, Issue 2 (JUNE 2025)
Abstract
Organosilicon compounds represent a fascinating class of molecules with diverse structures, unique bonding characteristics, and wide-ranging applications across various fields. The structural diversity of organosilicon compounds arises from the versatility of silicon, which can form a variety of chemical bonds, including single, double, and triple bonds with carbon, as well as bonds with other heteroatoms such as oxygen, nitrogen, and sulfur. This diversity enables the synthesis of an extensive range of organosilicon molecules, including silanes, siloxanes, silanols, silazanes, and silsesquioxanes, among others. The unique properties of these compounds, such as thermal stability, chemical inertness, and flexibility, make them valuable building blocks for the design of advanced materials.Organosilicon compounds find applications in diverse fields, including materials science, pharmaceuticals, electronics, and agriculture. In materials science, they are used as coatings, adhesives, sealants, and modifiers to impart desirable properties such as water repellency, thermal resistance, and biocompatibility. In the pharmaceutical industry, organosilicon compounds serve as drug delivery agents, imaging agents, and synthetic intermediates due to their biocompatibility and tunable properties. In electronics, they are employed as dielectric materials, insulators, and encapsulants in semiconductor devices. Current review aims to unlock new opportunities for the development of innovative materials and technologies with enhanced performance and functionality.
Zainab Dhyaa Fawzy, Saja Ali Muhsin, Taha Hassan Abood,
Volume 22, Issue 2 (JUNE 2025)
Abstract
Ceramics in dentistry have been mainly recommended from a cosmetic perspective. Yet, the hardness behaviour may limit the application in many cases. Although amber glass is used for medications and chemicals, no studies focus on using amber glass for dental purposes as an additive material. This study aims to investigate the dark amber glass behaviour as a new additive material for dental ceramics. The amber glass powder was prepared using the ball mill technique. For the amber glass powder characterization, the SEM/EDX, particle size, DSC, Ion release, and XRD analysis were tested compared to VITA Lumex® AC ceramic. In addition, the Vickers hardness test was applied for ceramic and ceramic amber with an addition of 0.01g, 0.03g, and 0.05g amber glass powder following the DIN EN ISO 6872/ 2019. Statistically, the ANOVA (post hoc- Tukey) test was used for hardness testing analysis at a significant P-value of (P≤0.05). The results show that the amber glass behaviour and composition elements seem similar to VITA ceramics. The addition of amber glass powder to ceramic shows an increase in the HV hardness of specimens. Overall, it was concluded that the amber glass powder could be a promising material for ceramics to use as an additive powder.
Seyed Hossein Razavi, Amirhossein Riazi, Alireza Khavandi, Mostafa Amirjan, Mohsen Ostad Shabani, Hossein Davarzani, Yazdan Shajari,
Volume 22, Issue 2 (JUNE 2025)
Abstract
Additive manufacturing (AM) of metallic parts has gained significant attention in recent years due to its ability to produce components without traditional tooling such as molds, melting furnaces, or extensive raw material preparation. Its unique capability to fabricate complex geometries has revolutionized part design and enabled substantial weight reduction. This review first outlines the development trajectory of metal-based AM, with a particular focus on laser-based fusion methods, including Laser Powder Bed Fusion (LPBF) and Direct Laser Deposition (DLD). Understanding this evolution helps researchers identify both the capabilities and limitations of AM technologies, thereby enhancing their application in areas such as prototyping, mass production, and repair. Each metal possesses unique physical and chemical properties, which often make traditional manufacturing methods more challenging—especially for alloys with high strength, hardness, or temperature resistance. In this context, the review then focuses on nickel-based superalloys (NBSAs), which are widely used in high-temperature and high-stress environments but are particularly difficult to process using conventional techniques. Their application serves as a representative case study for evaluating the performance and feasibility of AM techniques for advanced materials. Furthermore, the future prospects of AM are discussed, including advancements in monitoring systems, integration of machine learning, and the development of AM-specific alloys. As a novel aspect, this work compares LPBF and DLD in terms of their advantages, limitations, and resulting material properties, along with a comparison to traditional manufacturing methods such as casting and wrought processing.
Ali Keramatian, Mohammad Hossein Enayati, Fatemehsadat Sayyedan, Sima Torkian,
Volume 22, Issue 2 (JUNE 2025)
Abstract
The aim of this study was to investigate the effect of current density on the microstructure of electrodeposited Ni–WC–TiC composite coatings on 304 stainless steel and compare the corrosion resistance of the coating and substrate in a 3.5 wt.% sodium chloride solution. A Watts nickel bath was employed under direct current (DC) conditions. Microstructure, elemental composition, and phase composition analyses were conducted using scanning electron microscopy (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The results revealed that the coating formed at a current density of 40 mA/cm² exhibited a denser microstructure with higher cohesion and uniformity compared to coatings produced at other current densities. The corrosion resistance of the coating and substrate was evaluated using Tafel and electrochemical impedance spectroscopy (EIS) analyses. The corrosion test results indicated that the substrate exhibited superior corrosion resistance compared to the coating. Based on the dynamic polarization test plots, the corrosion mechanism of the substrate is active-quasi passive, with a pseudo-passive layer forming on the sample which remains stable within the potential range of -0.17 to 0.17 V. Beyond this potential range, the sample becomes susceptible to pitting. In the coated sample, the corrosion behavior is similar to that of the substrate, with the exception that the pseudo-passive layer remains stable within a narrower potential range of -0.19 to 0.08 V.
Amin Rezaei Chekani, Malek Naderi, Reza Aliasgarian, Yousef Safaei-Naeini,
Volume 22, Issue 2 (JUNE 2025)
Abstract
This paper presents the novel fabrication method of a three-dimensional orthogonally woven (3DW) C/C-SiC-ZrB2 composite and the effects of ZrB2 and SiC particles on microstructure and the ablation behavior of the C/C–SiC–ZrB2 composite are studied. C/C–SiC–ZrB2 composite was prepared by isothermal-chemical vapor infiltration (I-CVI), slurry infiltration (SI), and liquid silicon infiltration (LSI) combined process. Pyrolytic carbon (PyC) was first infused into the 3DW preform by I-CVI at 1050°C using CH4 as a precursor in order to form a C/C preform with porous media. The next step was graphitization at 2400°C for 1hr. Then ZrB2 was introduced into 3DW C/C preform with a void percentage of 48 by impregnating the mixture of ZrB2 and phenolic resin, followed by a pyrolysis step at 1050°C. A liquid Si alloy was infiltrated, at 1650 °C, into the 3DW C/C composites porous media containing the ZrB2 particles to form a SiC–ZrB2 matrix. An oxyacetylene torch flame was utilized to investigate The ablation behavior. ZrB2 particles, along with the SiC matrix situated between carbon fiber bundles, form a compact ZrO2-SiO2 layer. This layer acts as a barrier, restricting oxygen infiltration into the composite and reducing the erosion of carbon fibers. The findings were supported by FESEM imaging and further confirmed through x-ray diffraction and EDS analysis. The addition of ZrB2 to the C/C-SiC composite resulted in a lower mass and linear ablation rate; 2.20 mg/s and 1.4 µm/s respectively while those for C/C-SiC composite were 4.8 mg/s and 6.75 µm/s after ablation under an oxyacetylene flame (2500°C) for 120 s.
Sara Ahmadi, Bijan Eftekhari Yekta, Alireza Mirhabibi,
Volume 22, Issue 3 (September 2025)
Abstract
The crystallization behavior and photocatalytic properties of the sol-gel derived glass ceramic coatings in the TiO2-SiO2-B2O3 system were studied. the prepared sol was sprayed on a glazed ceramic wall. Following drying, the coated specimens were fired at 900°C for 1 h. The impact of boron oxide content in the composition was explored in terms of anatase stability and glass maturing temperature. The thermal and crystallization behaviors of the dried gels were studied by the STA, XRD, and FESEM. The photocatalytic property of the coated layer was examined using methylen blue degradation. Based on the results, the sample containing 15 wt% of boron oxide demonestrated about 30% dye removal efficiency, after only 60 min of UV-irradiation. Additionally, this particular sample exhibited the greatest magnitude of the anatase phase in comparison to the other samples.
Mohammad Abdullah Al Asad, Hasan Ridoy, Md. Shuzon Ali, Mst. Jeba Maimuna,
Volume 22, Issue 3 (September 2025)
Abstract
Perovskite materials have accumulated considerable attention in recent years for their exceptional electro-optical properties, creating them rising candidates for various uses in the fields of photovoltaics, light-emitting devices, and beyond. Among these perovskite materials, CsPbI3 stands out as a notable example due to its remarkable stability, tunable bandgap, and efficient light-emitting properties. The crystal structure, composition, and introductory properties of CsPbI3 perovskite using density functional theorem (DFT) being focused. In detailed exploration of Electronic property, Elastic property, Optical property, Population analysis, and shedding light on the unique attributes of this material highlighted this study. To do above computation we have used CASTEP in Material Studio.
Farzaneh Sadat Teimoory Toufal, Alma Kalali, Arvin Attari Navab, Mohadeseh Reyhani, Hamidreza Rezaie, Jafar Javadpour,
Volume 22, Issue 3 (September 2025)
Abstract
Glass ionomer cements (GICs) are widely utilized in clinical restorative dental applications, which suffer from poor mechanical strength. Recent research shows that GIC achieves optimal performance when modified with lower percentage of filler materials, particularly when using nanoparticles, due to the resultant increase in surface area and packing density of the cement. Notably, while some modifications show promise, others fail to deliver improvements in material characteristics. This study addressed a gap in the literature by investigating the impact of acidic/basic additives, such as Diopside (CaMgSi2O6) and Zirconia (ZrO2), on the properties of the cement. The reactivity of zirconia and Diopside differ distinctly from traditional calcium-aluminosilicate glass when exposed to acidic conditions in GICs. Also, to clarify the impact of acidity/basicity on filler reactivity during cement setting, the potential mechanical enhancement effects by using nano-sized particles is limited to submicrons. This research incorporated Diopside at concentrations of 2, 4, and 6 wt.%, and zirconia at 8, 10, and 12 wt.% into a glass powder component. Results demonstrated that adding 8 wt.% Zirconia led to a 49% enhancement in compressive strength, also improve microhardness by 16 wt.%, attributed to its non-reactive nature, minimal dissolution, and high inherent strength of ZrO2. In contrast, Diopside had a detrimental effect due to its basic nature compared to that of glass powder. These findings highlight the potential of zirconia as a valuable reinforcing material for the successful mechanical performance of glass ionomer cements. Conversely, basic fillers like diopside appear unsuitable for achieving improved mechanical performance in these systems.
Ali Azari Beni, Saeed Rastegari,
Volume 22, Issue 3 (September 2025)
Abstract
Aluminide coatings are widely used in high-temperature applications due to their excellent corrosion resistance and thermal stability. However, optimizing their composition and thickness is crucial for enhancing performance under varying operational conditions. This study investigates the optimization of aluminide coatings through a data-driven approach, aiming to predict the coating thickness based on various composition and process parameters. A comparative analysis of six machine learning models was conducted, with the k-nearest neighbors regressor (KNNR) demonstrating the highest predictive accuracy, yielding a coefficient of determination R² of 0.78, a root mean square error (RMSE) of 18.02 µm, and mean absolute error (MAE) of 14.42. The study incorporates SHAP (Shapley Additive Explanations) analysis to identify the most influential factors in coating thickness prediction. The results indicate that aluminum content (Al), ammonium chloride content (NH4Cl), and silicon content (Si) significantly impact the coating thickness, with higher Al and Si concentrations leading to thicker coatings. Zirconia (ZrO2) content was found to decrease thickness due to competitive reactions that hinder Al deposition. Furthermore, the level of activity in the aluminizing process plays a crucial role, with high-activity processes yielding thicker coatings due to faster Al diffusion. The pack cementation method, in particular, produced the thickest coatings, followed by gas-phase and out-of-pack methods. These findings emphasize the importance of optimizing composition and processing conditions to achieve durable, high-performance aluminide coatings for high-temperature applications.
Khashayar Zamani, Majid Tavoosi, Ali Ghasemi,
Volume 22, Issue 4 (December 2025)
Abstract
The present work, set out with the aim of studying the effect of in-situ precipitation of TiO2 form Ti3C2Tx MXene phase on the electromagnetic (EM) behavior of Ti3C2/TiO2 composites. In this regard, Ti3C2Tx MXene phase was synthesized using HF acidic etching of Ti3AlC2 MAX phase and the in-situ precipitation of TiO2 phase within Ti3C2 sheets was followed by controlled annealing in temperature range of 500-800 oC for 2 h. The phase and structural characteristics of prepared composites were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and differential thermal analysis. The electromagnetic behavior of samples was also analyzed using vector network analyzer (VNA). The results showed that by performing the controlled annealing process of Ti3C2Tx MXene phase, it is possible to in-situ formation of TiO2 phase and form the Ti3C2/TiO2 composites. The electromagnetic behavior of Ti3C2/TiO2 composites is in direct relation with the percentage of TiO2 phase deposited within Ti3C2 sheets during annealing process. The reflection loss (RL) changed from -7.98 to -21.28 dB (within frequency range of 1-18 GHz) with increasing in annealing temperature from 500 to 800 oC as well as increasing the size and percentage of formed TiO2 particles.
