The durability and strength of acrylic dentures are crucial for patient satisfaction and oral health. However, denture failure rates remain a significant concern. Reinforcing acrylic dentures with nanoparticles such as zirconia improves the mechanical properties of PMMA dentures. This study examines the enhancement of mechanical and physical properties of heat-cured PMMA dentures reinforced with varying amounts (1, 3, 5, 7, and 9 wt.%) of YSZrO2-NP and porcelain particles. The components were fabricated with standard dimensions in a dental flask, compacted using a hydraulic press, and polymerized for 120 minutes in a thermos-stated water curing bath. The properties analyzed included flexural strength, hardness, wear resistance, microstructure, and biocompatibility. The Flexural strength increased significantly with YSZrO2-NP reinforcement (315% at 7 wt.%), whereas porcelain particles reinforcement showed a minimal increase (40% at 9 wt.%). Hardness slightly decreased for all YSZrO2-NP/PMMA compositions (51% at 9 wt.%), while porcelain reinforcement showed a slight increase across all amounts, reaching up to 11% at 9 wt.%. Wear resistance improved with all filler additions in the PMMA. SEM analysis revealed uniformly dispersed particles in the PMMA matrix for 1-5 wt. % porcelain particles and ZrO2NP composites. In contrast, 7-9 wt. % reinforcement showed non-uniform dispersion. Reinforcing PMMA with YSZrO2-NP and porcelain particles enhanced its mechanical and physical properties. Therefore, micro-and nanoparticles of ceramics are a viable option for improving the strength and rigidity of PMMA dentures.

Polymethyl methacrylate (PMMA) has become a staple in dental applications. However, PMMA is inherently fragile and lacks sufficient mechanical strength for specific high stress appl icatio ns. To improve dental restorations and achieve long lasting, appealing results, it is vital to develop denture composites with enhanced mechanical and physical properties. This study explores the mechanical properties of cold cured PMMA denture compo sites reinforced with (1, 3, 5, and 7 wt. %) untreated zirconia (ZrO 2 ) nanoparticles, yttrium stabilized zirconia (YSZ) nanoparticles, and dental porcelain . After the formulated PMMA powder, MMAmonomer, and filler were invested in the mold formed in the d ental flask and compacted with a hydraulic press, flexural strength, impact strength, hardness, and water absorption were evaluated. The results revealed an enhancement in the impact strength for all reinforced PMMA composites, with the highest value obser ved in the composites with 1 wt. % ZrO₂ NPs, YSZ, and porcelain particles marking a 3.50%, 3.04%, and 2.94% increase compared to pure PMMA, respectively. Hardness results for the composites containing 1 wt. % ZrO₂ NPs, 5 wt. %YSZ, and 5 wt. % porcelain par ticles showed the highest increase of 16.48%, 33.4%, and 14.26%, respectively. 7.37% and 64% enhancements in flexural strength were observed for both 1 wt. % ZrO₂ NPs, and YSZ, with a steady decrease for all wt. % of PMMA/porcelain composites when compare d to t he control sample. Generally, water absorption decreased for all reinforced PMMA composites after 48 hours. The best-performing filler overall was YSZ-NP, which exhibited enhanced mechanical properties and water absorption resistance.

Piezoelectric composites offer many advantages compared to piezoelectric ceramics or polymers because of their mechanical flexibility and relatively high stress-induced voltage. In this research, high-molecular weight polyvinylpyrrolidone (PVP) and lead-free piezoelectric (K0.45Na0.51Li0.04) (Nb0.85Ta0.1Sb0.05)O3 (KNNLST) ceramics have been used to produce composites. The possible range of composites from 0 to 100 wt% has been explored. The ceramics were produced using conventional processing methods, while the composites were solution-cast after being mixed with a magnetic stirrer. The composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and dielectric and piezoelectric characterization to determine their properties. The morphology of the composites indicates the homogeneous distribution of the ceramics in the polymer. The XRD patterns show that the dissolved amorphous PVP precipitates and the addition of KNNLST ceramics contributes substantially to the crystalline phase formation. The relative permittivity and loss tangent values increase with an increase in ceramic content. Acceptable polarization and strain hysteresis curves were obtained only for the KNNLST ceramics. The composites produced will be suitable for dielectric applications.

In recent times, the demand for innovative, insignificantly invasive diagnostic and therapeutic biomedical tools has reached enhanced attention. Rapid Diagnostic Tests (RDTs) for diagnosis, which are non-invasive, inexpensive, simple, and deliver results accurately in less than 20 minutes, have heightened the accessibility to parasite-based analysis globally. Microneedle (MN) arrays are a fast-developing and promising technology for drug delivery and extraction of Interstitial fluid (ISF) employed for numerous diagnostic and clinical therapies. This review gives a broad overview of the characteristics and history of Microneedles (MNs) patches together with their applications in drug delivery and transdermal rapid diagnostic purposes, classifications, and categories based on the design of fabrication from previous works of literature spanning the period 2018-2023. Utilizing PubMed, Scopus, Google Scholar, and Wiley online library search engines, an online search for scientific publications published between 2018 and 2023 was conducted using the keywords "microneedle patch" and "rapid diagnostic tests." 175 articles in all were found when the search terms were used. The acquired results were then narrowed to 64 citations in this review by applying the inclusion principle. Pictorial and tabular representations highlight the various features of Microneedle patches used in interstitial fluid testing and extraction that have been documented experimentally, including numerous applications of Microneedle patches, showing their dimensions, applications, fabrication methods, and findings made. Finally, research on bio-microneedles and bio-inspired MN are reviewed. The research findings indicate that dissolving microneedles has become increasingly popular since they have several benefits over other microneedles. It is among the most well-known microneedles, and since it degrades naturally, it is a superior option for diagnosis and long-term treatment.

Zeolites being used as builders in detergents are synthesized from expensive chemicals with a cumbersome production process. In this study, zeolite was synthesized from cheaper and readily available kaolin for possible use in detergent production. Kaolin from two sources namely Ajebo, Ogun State and Darazo, Bauchi State, Nigeria was used as starting materials while wet beneficiation followed by acid leaching was used to purify the kaolin and hydrothermal process was used to synthesize the zeolite. The chemical analysis confirms the presence of silica and alumina which are the precursors materials for zeolite synthesis. An increase in the amounts of the desired silica and alumina for both kaolin accompanied by a reduction in the amounts of the undesired oxides present in the kaolin as impurities are clear indications that the acid leaching was successful. The zeolites synthesized from both kaolin shows better water adsorption capacity and ion exchange capacity compared to those reported for zeolite synthesized from pure chemicals, this ability makes zeolite more suitable for the production of detergent. These results are indications that zeolites synthesized from kaolin can serve as a possible replacement for the more expensive zeolite synthesized from chemicals used as builders in detergent production.

Some lead-free piezoelectric ceramics are known to have high dielectric and piezoelectric properties but are limited by their brittle nature. A few amino acids have recently been reported to exhibit rather low dielectric and piezoelectric properties but have the advantage of being biocompatible and flexible. It would therefore be interesting to form a composite that will combine the inherent advantage of high dielectric properties from the ceramics and flexibility from the biomolecule. In this research, the properties of lead-free (K0.45Na0.51Li0.04)(Nb0.85Ta0.1Sb0.05)O3 (KNNLST) ceramics and L-lysine hydrochloride (L-LHCl) have been combined to produce dielectric composites. The samples were produced by mixing the constituents from 0 wt.% to 100 wt.%, pelletising and heat-treating them. Bulk density, X-ray diffraction, scanning electron microscopy, and dielectric characterisation were techniques used to determine the density, phases, morphology, and dielectric properties of the produced composites. The results show an increasing bulk density value from 1.2 g/cm3 for L-LHCl to 4.67 g/cm3 for the KNNLST ceramics. The morphology of the composite shows very tiny grains when small amounts of the ceramics were introduced. The L-LHCl transforms from an amorphous phase to a crystalline phase having the orthorhombic-tetragonal structure with the introduction of the KNNLST ceramics. The dielectric constant values increased with increasing KNNLST ceramics content from 10 @1 kHz to 200 for the composite with 80 wt%. KNNLST content. The dielectric loss values decreased for L-LHCl from 0.9 @1 kHz to 0.2 @1kHz. The electrical conductivity values increased with increasing KNNLST ceramics content. The results show that the composites produced from these constituents may be suitable for dielectric applications.

Glycine exhibits a little piezoelectric response when poled, while lead-free alkaline niobate-based ceramics show much higher responses. This research investigates the synthesis of a dielectric composite from a combination of glycine and (K0.45Na0.51Li0.04) (Nb0.85Ta0.1Sb0.04) O3 (KNNLST) ceramics. The mixed oxide ceramics synthesis method was used to produce the ceramics, while glycine powder was commercially procured. The composition range of the shaped and heat-treated composites is from no ceramics to 100 wt.% ceramics content. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), dielectric studies, and hysteresis measurements were used to characterize the samples. The obtained phases transformed from the monoclinic phase in glycine to a two-phase orthorhombic-tetragonal phase in the ceramics. The samples’ morphology revealed a dense microstructure with some cracks, large porosity, and smaller grain sizes. The dielectric properties showed increasing dielectric constant and loss values with increasing ceramics content, while the ac conductivity also increased with rising ceramics content. Improving the range of ceramics led to polarization hysteresis graphs indicating ferroelectricity in the samples. The properties of the composites show they can be used in electromechanical devices.

Zeolites are microporous materials that find applications in different fields due to their numerous interesting properties. This research investigated the effect of leaching on unheated Ifon kaolin in dilute hydrochloric acid and sulphuric acid. The hydrothermal method synthesized zeolite-X type, and the resulting sample was characterized using different techniques. The silica/alumina ratio in the synthesized sample was approximately 5.6, while Infrared spectra confirmed that the synthesized material was Zeolite-X. Based on the X-ray diffraction patterns, other phases were also formed in addition to zeolite-X crystals. Thermogravimetry results indicated that the synthesized zeolite was relatively stable below 500(degrees)C, so its weight loss was only 13% after heating to about 200(degrees)C. A differential thermal analyzer confirmed this amount of weight loss, and endothermic and exothermic reactions were also observed for the samples calcined respectively at 700 and 900(degrees)C. Based on Brunauer-Emmett-Teller (BET) analyses, samples at 700(degrees)C showed slower adsorption -desorption isotherms, pore volume, and sizes than those at 900(degrees)C. These results have shown that leaching and calcination temperature significantly affect the type of zeolite produced.

This research investigated the development of biodegradable bioplastic as a possible replacement for petroleum-based plastics, which constitute a serious environmental hazard. These hazards include but are not limited to flooding resulting from blocked sewage and danger to aquatic life in marine environments. The solution casting method was used to blend inhomogeneous kaolinite clay nano-particles with distilled water, starch, dilute acetic and nitric acids to produce different compositions of thermoplastic starch (TPS)/Clay composites with clay reinforcements ranging from 2.5 to 10 wt.%. The composites were characterized using an X-ray diffraction (XRD), and the mechanical and water absorption properties were determined. The result revealed a 9-fold improvement in the tensile strength (0.72 MPa), flexural strength increased 5-fold (3.34 MPa), and hardness increased 2-fold (23.56 HVN) as well as a reduction in water absorption by 3-fold (6.63%) when compared to the control. Furthermore, the 10 wt.% clay content composite showed the highest mechanical properties. The significant improvement in the listed properties was attributed to a reduction in crystallinity and the formation of new chemical bonds between the thermoplastic starch and the nano-clay. It was observed that the properties of the composites can be further enhanced if a synchronized machine blender (such as an extruder) is employed.

This study proposes the utilization of kaolin as an alternate resource for alumina production due to the decreasing availability of bauxite ores in Nigeria. This project covers the procedures and operations required to produce a high surface area γ-alumina using kaolin, a refractory material. The kaolin used in this study was sourced from Ajebo in Ogun State, Nigeria. The mineral processing of kaolin was the initial step involving removing inherent impurities from the clay. Subsequently, calcination was performed to eliminate crystallised water and impurities and activate the kaolin's limited alumina content. This activation process facilitated the subsequent acid-leaching reactions. At 90oC, 5M HCl acid was used to leach meta-kaolin, which was then filtered. The filtrate was mixed with 5M NaOH at 900oC and was transformed into sodium aluminate. This reaction also facilitated the removal of magnesium and iron hydroxides. Subsequently, HCl was introduced to adjust the pH of the solution. The resulting aluminium hydroxide was then calcinated at temperatures of 700oC and 900oC for 2 hours each to produce γ-alumina. Ultimately, the calcined material was cooled to ambient temperature inside the furnace. The produced γ-alumina was further characterised using X-ray Fluorescence (XRF), Fourier Transform Infrared spectrometer (FTIR), and Scanning Electron Microscopy (SEM).

This study investigated the physical, mechanical and thermal characteristics of insulating refractory bricks produced from Nigerian clay blended with melon seed husk. The aim is to reduce the cost of production which arises from importation. This is due to lack of high-quality domestic insulating refractory bricks in most high temperature industries in Nigeria. The test samples were produced by mixing clay and melon seed husk having grain sizes of 212 - 300 μm. The samples were oven dried and fired at temperatures 950℃ to 1150℃ at 50℃ intervals. Physical, mechanical, thermal tests, chemical compositions, Mineralogical and Microstructural analysis were conducted. The results showed that, clay with 25 and 30 wt.% melon seed husks possessed the required refractory properties with cold crushing strength above the recommended ASTM Standard of 1000 kN/m2.

Surface finishing operation is a very vital aspect of the manufacturing process and would not fully be achieved without abrasives such as emery paper. Some materials used in the production of abrasives like alumina (Al2O3), and Boron Carbide (B4C) are expensive thereby limiting their usage. This work is aimed at producing abrasive materials from snail shells, silica (SiO2), and epoxy resin while melamine formaldehyde acts as a hardener. The raw materials used were sieved according to ASTM E11-20 standard to obtain an average particle size of 400 µm. The composites were produced by varying different amounts of the epoxy resin as well as the other materials. The samples were analysed using physical, mechanical, and microstructural characterization techniques. An analysis of the results showed that as the content of the epoxy resin in the composite increased, the hardness values increased. The wear rate of the samples containing snail shell powders are higher than those containing only silica. The morphology of the samples obtained through microstructural tests revealed that the silica-based abrasive has better interfacial bonding which helped to confer strength. Therefore, silica can be used to produce abrasives with the required mechanical properties comparable to those of conventional abrasives.

Dental porcelain was produced by mixing feldspar, silica, kaolin and bone ash by varying the contents of feldspar and silica. The processing steps include milling, sieving, pressing/shaping, drying, and sintering while the characterisation techniques were Hardness, Compressive strength, X-ray diffraction, Scanning electron microscopy and Fourier Transform Infrared (FTIR). The mixture was subjected to temperatures of 1100 and 1200 oC in a sintering furnace. The chemical composition was determined using X-ray fluorescence and they confirm that SiO2 and Al2O3 are the two major constituents in feldspar and kaolin while CaO is the major constituent in bone ash. For samples sintered at 1200oC, the X-ray diffraction showed that some glass phase possibly consisting of hedenbergite, ilmenite and silica were formed while crystalline phases namely microcline and sanidine were obtained for samples sintered at 1100°C. The morphology of the grains revealed that samples sintered at 1200oC had some hexagonal silica crystals while flakes of different sizes were obtained for samples sintered at 1100oC. Hardness values between 262 and 536 BHN, compressive modulus values ranging from 219 MPa to 324 MPa and linear shrinkage values between 6.34 and 7.6% were obtained. The batches of different compositions with ranges: quartz (silica) (15-25%), feldspar (70-80%), kaolin (Edda/Bauchi) (4%) and bone ash (1%) were fired at 1100, 1200oC, and the developed properties were tested. The sample with 70 wt.% of feldspar, 25 wt.% silica, 4 wt.% of Bauchi clay, and 1 wt.% bone ash sintered at 1200oC gave the best properties and has the potential to be used in dental restoration.

The computational studies of a predictive mathematical model for the extraction of interstitial (ISF) for transdermal and non-invasive diagnosis using biodegradable and hollow microneedle patch is presented in this paper. Rapid Diagnostic Tests diagnosis, which is non-invasive, affordable, straightforward, and provides results promptly and reliably, has increased access to parasite-based analysis on a global scale. Microneedle arrays are a rapidly evolving and promising technology for transdermal interstitial fluid extraction, which is used for many clinical diagnostic procedures. Hence, a developed mathematical predictive model used to optimize the design of microneedle patch for transdermal ISF extraction and subsequent diagnosis using dissolvable microneedle arrays was applied in this study. The model's solutions were obtained using the Differential Transform Method. The numerical Runge-Kutta method of fourth order was used to validate it. An experimental test result was also used to further validate the analytical results in the absence of the extracted velocity parameter. And there was a good agreement among them. Influence of dissolution rate constant, microneedle height, diffusion coefficient, velocity of ISF, microneedle ISF drug load, and density of the microneedle; were investigated. Increase in diffusion coefficient and density led to an increase in concentration of ISF extracted over time, an increase in dissolution rate led to a decrease in concentration extracted, while decrease in drug load and height, led to increase in ISF concentration extracted. A negligible effect was observed by varying the velocity of ISF extracted. The approximate analytical approach utilized in the current work has given us a more precise strategy for creating a mathematical model that predicts how ISF will be extracted from skin for use in transdermal and non-invasive rapid diagnostic tests.

Zeolites are microporous materials that find a lot of applications in today’s world due to their different properties. In this research, the effect of different calcination temperatures (700oC and 900oC) and acid leaching (7% and 15% dilution) on zeolite-X crystals has been investigated using the hydrothermal method. The results from the different sample characterization show that the SiO2/Al2O3 ratio is approximately 5.6 while the Infrared spectra indicate that Zeolite-X was produced with slight shifts in the wavenumbers. The diffraction patterns show that in addition to the formation of zeolite-X crystals, other phases were also obtained. The thermal analysis indicates that the zeolite is stable below 500oC. Thermogravimetric study shows that after about 200oC, only about 13% of the mass was lost. The differential thermal analyzer indicates that the samples followed the same trend until a temperature of 300oC where the samples calcined at 700oC had a positive heat loss while the samples calcined at 900oC had a negative heat loss. The BET analyses show that the zeolite from samples calcined at 700oC had lower adsorption-desorption isotherms compared to those at 900oC. The pore volume and sizes of the former were also lower than those of the latter. These results have shown that leached kaolin is effective in producing zeolite-X samples.

Manufacturing and processing industries usually consume large quantities of materials and energy in the course of their operations. The energy supplied for high-temperature processes are used partially for the actual technical process and between 30 to 40% of the energy escapes through the walls of the reactor into the atmosphere, leading to a high degree of thermal inefficiency and fuel consumption. This paper studies the thermal behaviour of insulating refractory bricks produced from a blend of fireclay and agroforestry wastes. The fireclays used were obtained from Ukpor deposit in Anambra State (Latitude 5.95°N, Longitude 6.92°E), Osiele deposit in Abeokuta, Ogun State (Latitude 7.18°N, Longitude 3.45°E) and Kankara Katsina State (Latitude 11.93°N, Longitude 7.41°E), all of which are in Nigeria. Samples were prepared with various weight percentages (60–100 wt.%) clays and (0–40 wt.%) of agroforestry waste, with grain sizes between 212 and 600 µm. Raw materials and the developed refractory bricks were characterised using appropriate standard techniques. The chemical, mineralogical constituents and phases present in the microstructure were examined. Physical and thermo-mechanical properties were investigated. The insulating refractory bricks developed have porosity of 78.83% , cold crushing strength (CCS) 3.144 kN/m2 and thermal conductivity 0.04–0.046 W/(m∙K) that compare favourably with imported bricks 75–85%, 2.756 kN/m2 and 0.049 W/(m∙K) in both physical, mechanical and thermal properties respectively. The reason is that the agroforestry waste used (coconut shell), served to create the pores that improve insulation after burning. Also the ash that remains serves as reinforcement to improve the mechanical properties. The thermal behaviour of the bricks was studied using Finite Element Method and shows a strong correlation with the experimental findings. This indicates that the produced insulating bricks have the thermal properties required for insulation of furnaces.

A micro-macro model based on deterministic continuum mechanics and the modified source term method has been used to study the solidification problems involving binary Al-4.0 wt% Cu eutectic system. The model is further tested with other equiaxed eutectic binary aluminium alloys that include Al-3.0 wt% Si, Al-6.0 wt% Mg and Al-3.0 wt% Zn. All the heat transfer regimes including convection and radiation at the open top surface of the mould are considered. The nucleation steps are accounted for by considering continuous nucleation and growth kinetics. Information such as undercooling, nucleation rate, recalescence, growth rate, solid fraction, cooling curve, grain size and volumetric grain density which directly link to mechanical properties of cast components are accurately predicted. The model result is validated against the experimental data obtained from the current study and others published in the literature. From the results predicted in the current work, it is observed that the model gives the actual cooling history instead of a rough estimation of cooling curves as obtained from previous models. Among the aluminium-based alloys analysed, the Al–Cu alloy has the fastest nucleation and solidification rates. The predicted volumetric grain density suggests that magnesium has a more grain refinement effect on the aluminium matrix than copper, zinc and silicon. The model results are in agreement with the physical metallurgy of alloy theory and can be used by alloy manufacturers to improve the mechanical properties of alloy castings.

Mathematical developments and computer simulation have greatly aided the modern day study of solidification phenomena. This work presents a numerical modelling of the effect of cooling conditions and mould size during solidification of Al-Cu eutectic binary alloy in static casting process. The numerical method adopted for the current work is the finite volume method and the mathematical problem was formulated according to the classic continuum energy conservation equation for the transient solidification problems. The latent heat evolution was accounted for using the modified source-based method. The boundary conditions included all the modes of heat transfer between the solidifying system and its surrounding. Two cases were simulated to study the effect of cooling conditions and mould size on the solidification system. In case I, a Dirichlet boundary condition with a known temperature (373 K) value was imposed on the bottom of the mould surface. An adiabatic condition was imposed on the bottom of the mould in case II. It was observed that the different boundary conditions and mould sizes have significant influence on the rate and pattern of solidification. Cooling curve results and temperature contours from these models showed reasonable deviations due to various cooling conditions and mould sizes. Larger thermal and solid fraction layers were predicted for the case II with slower cooling rate. It was also observed that temperature distribution along the horizontal distance within the casting increases monotonically as mould size was increased.