Optimal Value Research Articles

Optimization of multiple outputs of electric arc spray coating parameters for EN AW 7020-T6

Electric arc spray coating (EASC) is a method used to protect aluminum materials from corrosion, but there is no optimization in the literature using Al99.99 coating wire for EN AW 7020 alloy. The presented study aims to optimize the EASC process parameters (voltage, amperage, spray distance, and number of passes) for EN AW 7020-T6 aluminum samples. The experimental design of selected factors was made with Taguchi L9(34) orthogonal array and the aftermath of optimum values for coating were obtained with the TOPSIS multicriteria decision-making method. Output parameters respectively; pull-off strengths of coating were determined in compliance with the ASTM D4541 standard, the coating thicknesses were measured with a 3D profilometer, and the porosity values for cross-section were analyzed by optical microscope according to ASTM E2109 standard. After determining the optimum parameters, the substrates were coated and the crystallographic analysis of the coated samples was performed by XRD technique and electrochemical corrosion potential values were determined by galvanostat/potentiostat device in 3.5% NaCl solution. In exfoliation corrosion (EXCO) tests performed according to ASTM G34-1 standard, EXCO damage was detected on the surfaces of uncoated samples and graded as EA. In the EXCO tests with coated samples, no corrosion damages were observed on the coatings and they were rated with an N grade. The Al99.99 coating significantly improved the EXCO resistance of EN AW 7020-T6, reducing the corrosion rate by almost 100%. EXCO tests with uncoated and coated samples proved that the Al99.99 coating acts as a barrier to protect the substrate. Optimized Al99.99 coating offers a promising solution to improve the corrosion resistance of EN AW 7020-T6 aluminum alloys and extend their service life in harsh environments.

Process Optimization for Development of Extruded Snack from Brown Rice-Amaranth-Moringa Seed Powder Blend

The study was aimed at utilizing brown rice, germinated amaranth and moringa seed powder in the development of nutritious extruded product. The extruded product was optimized by employing Response Surface Methodology using Central Composite Rotatable Design (CCRD). The experiment consists of three independent variables each having five different levels. The process variables were selected as feed moisture content (8-16%), blend ratio of brown rice flour: germinated amaranth flour: defatted moringa seed powder (50:45:5, 50:40:10, 50:35:15, 50:30:20 and 50:25:25) and barrel temperature (100-140ºC). Optimization was done on the basis of product responses i.e. bulk density, expansion ratio and hardness. The values of bulk density, expansion ratio and hardness of extruded products ranged between 0.06 to 0.35 g/cm2, 2.30 to 3.34 and 497.48 to 1425.17 g, respectively. The optimum values of extrusion conditions obtained through numerical optimization were blend ratio (50:30:20), feed moisture content (12%) and barrel temperature (1300C). The corresponding predicted values for bulk density, expansion ratio and hardness was 0.0964 g/cm3, 3.33 and 617.16 g, respectively with desirability 0.912. Whereas the corresponding experimental values for bulk density, expansion ratio and hardness were 0.0939 g/cm3, 3.35 and 635.56 g, respectively. Thus, it is concluded that the brown rice, germinated amaranth and defatted moringa seed has potential to be incorporated in the development of nutritious extruded snacks.

Degradation of azo dye (direct red 89) using H2O2/periodate process-parameter optimization and mixture composition evaluation.

As a fast and efficient process, a periodate (PI)-based advanced oxidation process was used to degrade direct red 89 (DR89), wherein hydrogen peroxide (H2O2) was employed to activate PI (H2O2/PI process) to investigate the effect of operating parameters and mixture composition. The PI was efficiently activated by H2O2 to degrade 67% of DR89 within 1min. Acidic pH was more favorable to high-efficiency degradation than the basic pH; at pH 3 degradation rate was 94.31%, while it was only 20.92% at pH 11. The degradation rates were further enhanced with increasing H2O2 and PI dose up to certain optimum values, later it decreased which was dependent upon the amount of hydroxyl (●OH) and iodyl (IO3●) radicals produced. The quenching experiments suggested that IO3●, ●OH, 1O2, and O2●- are the predominant reactive species during H2O2/PI process, while O2●- radicals are the primary precursor of other reactive oxygen species. The results of this study suggested that H2O2/PI is the efficient and rapid treatment method to degrade persistent organic pollutants (POPs) from polluted wastewater sources.

An active learning strategy for sequential designs of probabilistic systems with continuous and discrete input variables

This study proposes an active learning strategy for sequential experimental designs of probabilistic systems with mixed continuous and discrete input variables. The proposed method aims to sequentially explore local optima with high aleatory uncertainties along with the global optimum of the system. In complex probabilistic systems, the exploration of both of these regions is needed to build a more robust understanding across different conditions or scenarios. The proposed strategy employs a non-deterministic kriging (NDK) method, capable of handling mixed input variables, to account for aleatory uncertainties. A modified version of the expected improvement concept is used to identify the regions of interest for the sequential experiments. To avoid neglecting local optima with high aleatory uncertainties, subset simulations are used to identify these regions. The methodology was applied to a set of analytical examples and yielded accurate predictions for the optimum values and associated aleatory uncertainties.

Medicine Prescribing Practices and Prescription Errors Evaluations at Outpatient Department in Debre Berhan Comprehensive Specialized Hospital, Amhara Regional State, Ethiopia

Background: Currently, irrational uses of medicines becoming global problem largely in developing countries like Ethiopia. Inappropriate prescribing is a major cause for poor treatment outcome and higher costs. Hence, this study was aimed to investigate medicine prescribing practice and prescription errors using WHO medicine-utilization core indicators. Methods: A hospital based retrospective cross sectional study design was used to evaluate prescribing practices and prescription errors from September to October, 2024 at the OPD pharmacy using systematic random sampling technique while a prospective approach was employed for facility indicators. Presence of potential drug-drug interactions (DDIs) were evaluated using Medscape Online Drug Interaction Checker. Data were analyzed using SPSS version 25 and interpreted as tables and figures. Results: A total of 1019 medicines were prescribed in 524 prescriptions and 81.6% (n = 832) were actually dispensed. The percentage of antibiotic, injections and medicine prescribed from Essential Drug List was 33.9% (n = 345),3.5% (n = 36) and 92.3% (n = 941) respectively. The most frequently prescribed class of medicine were antibiotics 33.9% (n = 345). 65.1% (n = 341) were ≥2 medicines and 8.3% (n = 85) had at least one potential DDIs. Among overall DDIs, the monitor closely and serious level was 60% (n = 51) and 11.8% (n = 10) respectively. The average prescription error was 4.3. Prescription errors due to failure to mention diagnosis was 40.6% (n = 213). Conclusion: Based on findings, the prescribing practices had defects to the optimum value recommended by WHO and showed high prescription errors. Antibiotics prescribing was the major problem in practice. Remarkable DDIs were observed in prescribed medicines. Therefore, designing and implementing policy to improve medicine use practice is highly indispensable.

Numerical analysis of blade height ratio effects on mixing efficiency and energy consumption in triple-blade concentric double-helix static mixers

This work aims to find the optimum value of blade height ratio (R) for improving mixing performance and energy consumption of a Triple-Blade Concentric Double-Helix Static Mixer. In this study, mixing of two fluids at different concentrations subjected to laminar flow conditions is numerically analyzed by using finite element-based Computational Fluid Dynamics simulations. Different values of the R parameter are considered in a wide range of Reynolds numbers (Re = 200–1000). This analysis then carried out an in-depth study of R's effect on mixing performance, strength segregation, mixing index, helicity, velocity profile, pressure drop, pumping power, and efficiency. The findings showed that a blade height ratio of R = 2/3 gave the highest mixing index (MI), with the maximum value of 0.99 at a Re number of 600, which showed the best mixing performance in the channel. Helicity visualization also showed complex helicity patterns with increased vortex interactions for the 2/3 configuration. This geometry gave an improvement in MI by about 17.85% over Triple-Blade Concentric Single-Helix Static Mixer (TB-CSH-SM) with R = 0 at Re = 600. It is also important to mention that increasing the R value leads to an increase in pressure drop and, consequently, an increase in pumping energy consumption. Although R = 2/3 gives the best mixing performance, the energy consumption is relatively higher than that for R = 0, which has the lowest power input but a lower MI. The investigation concludes that R = 2/3 represents a balanced solution since it realizes an optimum mixing performance with a moderate energy consumption and hence is suitable for applications requiring an efficient compromise between mixing quality and energy consumption.

Model-driven engineering of Cutaneotrichosporon oleaginosus ATCC 20509 for improved microbial oil production.

Increasing demand for palm oil has drastic effects on the ecosystem as its production is unsustainable. C. oleaginosus is a yeast with great potential for microbial oil production and is a sustainable alternative to palm oil. Herein we deployed the Design-Build-Test-Learn approach to establish C. oleaginosus as an efficient fatty acid production platform. In the design step, we combined transcriptome data analysis and metabolic modeling and selected gene overexpression targets (ATP-citrate lyase, acetyl-CoA carboxylase, threonine synthase, and hydroxymethylglutaryl-CoA synthase) and media supplements (biotin, thiamine, threonine, serine, and aspartate). Characterization of transformants at various C/N ratios, and medium supplements provided up to 56% (w/w) lipid content and a 1.4-fold increase in lipid yield on glycerol (g/g). Additionally quadratic regressions suggested C/N ratio of 240 as the optimum value. These results and introduced pipeline for strain and medium optimization establish C. oleaginous as a sustainable alternative to palm as an oil source.

Green adsorbents for water remediation: Removal of Cr(vi) and Ni(ii) using Prosopis glandulosa sawdust and biochar

Abstract Potentially toxic elements like Cr+6 and Ni+2 cause severe health hazards. Therefore, the current work was aimed at cleaning water using Prosopis glandulosa raw sawdust (SD) and its derived biochar (AC). Both the adsorbents were characterized via SEM, FTIR spectroscopy, EDX, and TGA and were applied for the effective removal of Ni(ii) and Cr(vi) at optimum values of experimental conditions, and the mechanism was assessed via adsorption isotherm and kinetic models. The correlation coefficient R 2 confirmed pseudo-second-order kinetics and preferred Freundlich isotherm model. Maximum removal of Cr(iv) was obtained at a pH of 4.0, a bio-sorbent concentration of 0.8 g·L−1, and a temperature of 50°C for 50 min with a metal concentration of 110 ppm, while maximum removal of Ni(ii) was obtained for a contact time of 70 min with a metal concentration of 130 ppm in the above-mentioned experimental conditions. The results of the isotherms and kinetic model revealed that metal adsorption processes involved multilayer formation on the biosorbent’s heterogeneous surface. Also, their thermodynamic investigation showed that the adsorption process is spontaneous and exothermic and, therefore, can be effectively utilized to remove Cr and Ni from water.

Effect of Single Point Incremental Forming (SPIF) Process Parameters on Surface Roughness of Dissimilar Tailor Welded Blanks using the Taguchi Method

In the present paper, the Taguchi method is implemented to figure out which set of process parameters is optimal for forming dissimilar aluminum alloy blank joints together using friction stir welding. In single-point incremental forming (SPIF), four process parameters were taken into consideration: rotational speed, feed rate, step size, and wall angle. Measurements were made on both sides, inner and outer of each surface of the formed part due to dissimilar material of tailor welded blanks (TWBs) to see the pattern and relationship. The results show that step size is the most important parameter, then the wall angle. The rotating speed and feed rate had the least impact on surface roughness. The optimal parameters are a 0.2 mm step size, a 55-degree wall angle, a 1500 rpm rotational speed, and a 1000 mm/min feed rate for the inner and outer surfaces of AA5052. While the AA6061 gives the optimum values of 0.2 mm step size, a 55-degree wall angle, and a 1000 mm/min feed rate on the inner and outer of the measured surface, the slightly different optimum values on the rotational speed are 1250 rpm and 1750 rpm for the inner and outer surfaces, respectively. On Analysis of Variance (ANOVA) showed the step size has a greater percentage contribution effect on the surface roughness of formed TWBs than any other parameter. Furthermore, confirmation test results using optimal conditions showed good agreement wit experimental findings.

Soil fertility management on sesame (Sesamum indicum L.) production in Northern Ethiopia: A review.

Sesame (Sesamum indicum L.) is an important cash crop and plays a vital role in many people's livelihoods in Ethiopia. However, its production is low due to many constraints, and low soil fertility is among the major. The previous fertilizer recommendation was a blanket recommendation regardless of the soil fertility status. Hence, the objective of this review is to synthesize the different recommendations and forward to the sesame growing areas. R statistical software and Python programming language used to analyze the chemical and physical soil properties, association among the chemical and physical soil properties and association with soil depth. The organic carbon, total N (Nitrogen), available P (Phosphorus), S (Sulfur) and Zn (Zinc) are below optimum value while K is sufficient in the soil and moderately alkaline soil. The soil particle size is dominantly clay (58.5%). The clay particle size and pH increased while the sand and silt particle sizes, organic carbon, total N, available P and S decreased as the soil depth increased. 204,558.8 ton of sesame stack residue are burned every year, and from this, 7360.03 ton of NPK is lost every year in Western Tigray. The recommended N, P and S for sesame are: (i) 64 and 41kgha -1N for low N content areas and for medium N content areas respectively; 46 and 23kgha -1 P2O5 for low and medium P content areas; (iii) 60 and 30kgha -1S for low medium S content areas may be recommended to boost sesame production.

Effect of increased basalt fibre dosage on hybrid basalt fibre reinforced concrete's strength properties

Natural, eco-friendly fibers are increasingly being used as reinforcement in the creation of lightweight, low-effort polymer composites on a global scale. Because it is intelligent and has unique properties above glass fibers (GF), basalt fiber (BF) is one such material of interest that is currently in widespread use. Among these composites' clear advantages are their high specific mechanic properties, biodegradability, and non-grating nature. In this paper, basalt fibers used as reinforcement for composites are surveyed. The study also addresses how concrete's strength is affected by curing. In addition to this, an attempt is made to highlight the growing trend in research dissemination and activity in the area of basalt fibers. Further segments talk about the improvement in mechanical, warm and synthetic safe properties accomplished for applications in specific enterprises. The results of this study reveal that the optimum value of strength at 28th day of curing is obtained for a mix made with 5% of chopped basalt fiber 50% 6mm Long BF and 50% 12mm Long BF.

Predictive ability of systemic coagulation-inflammation index on early fistula failure after radiocephalic arteriovenous fistula creation.

To the best of our knowledge, a possible predictive relationship between the systemic coagulation-inflammation index (SCI) and arteriovenous fistula (AVF) failure following AVF creation has not yet been examined. We therefore designed this study to examine the predictive ability of SCI on postoperative early AVF failure in patients undergoing primary radiocephalic AVF operation. A total of 189 patients who underwent primary radiocephalic AVF operation for hemodialysis access were included in this retrospective observational cohort study, and then divided into two groups according to whether AVF failure occurred within the first 3 months after the operation; as failed AVF group (n = 44) and non-failed AVF group (n = 145). The patients' baseline clinical characteristics and laboratory parameters were recorded and then compared between the groups. Patients in failed AVF group were significantly older and had higher smoking rate than those in non-failed AF group. The median values of fibrinogen, platelet-to-lymphocyte ratio and SCI were significantly higher in failed AVF group than in non-failed AVF group. With regards to other clinical characteristics and laboratory parameters, no significant differences were detected between the groups in the univariate analyses. Only age and SCI maintained their significances in the multivariate logistic regression analysis, and were therefore considered as the independent predictors of AVF failure. ROC curve analysis revealed that SCI of 37.9 constituted the optimum cut-off value with 97.7% sensitivity and 94.5% specificity rates for predicting AVF failure. The present study demonstrated for the first time in the literature that SCI significantly and independently predicted early AVF failure following radiocephalic AVF creation.

Spectrophotometric and computational characterization of charge transfer complex of selumetinib with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and its utilization in developing an innovative green and high throughput microwell assay for analysis of bulk form and pharmaceutical formulation

For paediatric patients suffering from neurofibromatosis, Selumetinib (SEL) is the only approved drug. Here an original ecofriendly and high pace method is introduced using 96- microwell spectrophotometric assay (MW-SPA) to measure SEL content in bulk and commercial pharmaceutical formulation (Koselugo® capsules). This assay was relied on in-microwell formation of a coloured charge transfer complex (CTC) upon interaction of SEL with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The complex was fully characterized by spectrophotometric and computational studies. The CTC exhibited an absorbance maximum (λmax) at 440 nm. The ease of reaction occurrence, complex stability and its high absorptivity were proved by measuring its association constant (0.63 × 102 L/ mol), standard free energy change (-10.31 KJ/mol), molar absorptivity (ε) (3.78 × 103 L/mol/cm), and the SEL: DDQ stoichiometric ratio (1:1). Establishments of the optimum values of the applied conditions in 96-well assay plate were refined regarding DDQ concentration, reaction time, temperature, and solvents. Validation of the assay was according to the ICH guidelines. The assay was linear in SEL’ concentrations ranged from 10 to 200 µg/well, with limits of detection and quantitation of 4.1 and 12.5 µg/well, respectively. Then, the assay was efficaciously adapted to accurately and precisely determine SEL content in bulk form and Koselugo® capsules. The assay environmental safety was documented by three different comprehensive metric tools. Additionally, assessment of the assay’s rate demonstrated its high throughput, enabling the processing of large number of samples in pharmaceutical quality control laboratories. The successful development of this assay provides a valuable fast and green analytical tool for ensuring the quality control of SEL’s bulk form and capsules.

New Hybrid Approaches Based on Swarm-Based Metaheuristic Algorithms and Applications to Optimization Problems

Metaheuristic algorithms are favored for solving a variety of problems due to their inherent simplicity, ease of implementation, and effective problem-solving capabilities. This study proposes four new hybrid approaches using swarm-based metaheuristic algorithms. Two of these new approaches are HHHOWOA1 and HHHOWOA2, based on the hybridization of Harris Hawks Optimization (HHO) with the Whale Optimization Algorithm (WOA), and the others are HHHOWOA1PSO and HHHOWOA2PSO, based on the hybridization of HHHOWOA1 and HHHOWOA2 with particle swarm optimization (PSO). An evaluation of these four innovative approaches is conducted on 23 benchmark functions, and their results are compared to those reported in the literature under equivalent parameter settings. Among the four approaches, HHHOWOA1 and HHHOWOA2PSO have demonstrated more favorable results. According to the literature, the HHHOWOA1 and HHHOWOA2PSO approaches achieve the most optimal results, either better or with the same average fitness values in 15 of the 23 functions and in 18 of the 23 functions, respectively. Moreover, the proposed approaches have been applied to three engineering problems, and the optimum values obtained are compared to the literature. Ultimately, the proposed approaches have proven effective in providing competitive solutions for the majority of optimization problems.

Applicationof Full Factorial Planning to Control Nitrogen in a Water Resource

Objective: The aim of this work is to show the application of Full Factorial Planning to an environmental problem. Theoretical framework: Design of experiments is defined as a set of statistical techniques applied to the planning, conduct, analysis and interpretation of controlled tests, seeking to find (define) the factors that influence the values of a parameter or a group of parameters. Its basic principle makes it possible to vary all the levels of all the discrete or continuous variables (called factors) at once, for each experiment, in a programmed and rational way (Peixoto et al., 2008). Method: Experiments were carried out in an industrial plant in the south of Rio de Janeiro and the data was treated using Full Factorial Design. Final Considerations: It can be concluded that full factorial design is a very viable option for obtaining the optimum values or the optimum range of values to obtain the best possible response variable in a study. In this specific case of the company, it can be concluded that Line 1 and Line 3 are the most responsible for the concentration of nitrogen oxide discharged into the river and, therefore, the n-waste should be pre-treated. Implications of the research: The use of Factorial Planning is multiplying in the scientific literature and is proving to be highly effective in dealing with data where the assumptions of Normality are not confirmed. Originality/value: Despite being well-known statistical tools, Factorial Designs are widely used and can bring innovations to their application, as in the case of the company in question.

{110} Surface-Exposed Bi3.15Nd0.85Ti3O12 Ferroelectric Nanosheet Arrays on Porous Ceramics as Efficient and Recyclable Piezo-Photocatalysts.

Bismuth-layered ferroelectric nanomaterials exhibit great potential for piezo-photocatalysis. However, a major challenge lies in the difficulty of recovering the catalytic powders, raising concerns regarding secondary pollution of water. In this work, a novel hierarchical porous ferroelectric ceramic containing {110} surface-exposed Bi3.15Nd0.85Ti3O12 (BIT-Nd) nanosheet arrays is grown on a porous ceramic matrix for efficient and recyclable piezo-photocatalysis. By controlling the BIT-Nd loading level of the nanosheets, the piezo-photocatalytic degradation efficiency of a Rhodamine B(RhB)(C0 = 10 mgL-1) solution reached an optimum value of 97.1% in 100 min with a first-order kinetic rate constant, k, of up to 0.0321 min-1 in Bi3.15Nd0.85Ti3O12-20 (BITNd-20) with a mass ratio of hydrothermal products to ceramics of 20%. In the presence of BITNd-20, a surprising H2 yield rate of 130 µmol·h-1 is achieved without using anycocatalyst or scavenger. Specially, the beneficial role of snowflake structures on piezoelectric potential amplification and introducing nanosheets with exposed {110} surfaces on hydrogen evolution reaction (HER) activity, piezoelectric potential output, and catalytic performance of porous ceramics has been revealed. This unique design strategy provides a new approach to enhance the piezo-photocatalytic activity by addressing environmental issues and enhancing catalytic performance to yield cleaner energy.

Study into surface integrity aspects in single point incremental forming of AA 7079 sheet: experimental investigation and evolutionary parametric optimization

ABSTRACT Aluminum alloys have been used for the Single Point Incremental Forming (SPIF) process due to their formability, corrosion resistance, less weight and its isotropic mechanical properties. The proposed research work aims to experimentally investigate the optimisation of the process inputs affecting the quality of the SPIF incrementally formed surface. The experimentation was performed to optimise parameters under varying conditions, focusing on various process factors. The surface roughness (SR) has been found most significantly affected by the tool diameter, followed by vertical step size, side wall angle, feed rate, and rotational spindle speed. Experimentation result shows the outstanding values of the experimental set-up for surface finish found on the base of the ANOVA at 70° cone angle under the test setting of a TD of 13.0 mm, a VSS of 0.50 mm, RSS of 1000 rpm, and a FR of 2500 mm/min. The parametric optimisation for SR with Desirability approach, TLBO (Teacher learner-based optimisation), and ACO (ant colony optimisation) methods has been attempted, out of which the best optimum value (with ACO) for SR was achieved as 0.162 µm at the optimal parametric settings of TD = 14.75 mm, VSS = 0.660 mm, RSS = 521.70 rpm, FR = 2760 mm/min, and WA = 76.56°.

Examination of mechanical properties of 3D printed geopolymer mortar using the Taguchi method

This study examined the strength features of 3D printed fly ash-based geopolymer mortar with silica fume using the Taguchi and ANOVA methods. This study used the Taguchi L18(21 × 32) orthogonal array. Silica fume was used in the mixtures at 0% and 10% of the binder weight. 40 × 40 × 160 mm specimens were manufactured by a 3D printer. After the specimens were produced, they were cured at 80 °C for 24, 48, and 72 h. Then, these specimens were kept at 20 ± 2 °C for 3, 7, and 28 days. Lastly, the microstructural features, compressive strength, and flexural strength of the samples were determined. The ANOVA results found that the most affecting parameter for the strength properties of geopolymer mortars was found to be silica fume. Also, the Taguchi method found that optimum values of silica fume, curing time, and curing day for strength properties of geopolymer mortar were 10%, 48 h, and 28 days, respectively.

Optimisation of Permanent Magnet Eddy Current Braking System using Aluminum Discs by Taguchi Technique

In this work, an attempt has been made to understand the suitability of various positions of permanent magnets, the optimum thickness and speed of Aluminum discs, and Taguchi parameter optimisation. L9 orthogonal array was chosen for the analysis. From Signal to Noise (S/N) ratio calculations it was observed that 3000 rpm, 4mm thick disc and solo magnet with swift application situation were optimum values. SS% from ANOVA indicated that the position of magnets has the greatest influence on brake parameters. The permanent magnet used is a Neodymium – Iron – Boron (NdFeB) magnet. The brake parameters recorded are speed reduction percentage, time consumed and negative acceleration. In solo magnet condition and solo magnet with swift application, better brake parameters were observed in a 4mm thick disc. Solo magnet condition with a 4mm thick disc may be suitable for elevated-speed train applications. Solo magnet with swift application situation may be suitable for high-speed automotive applications.

Optimization Using Central Composite Design of the Response Surface Methodology for the Compressive Strength of Alkali-Activated Material from Rice Husk Ash

Alkali-activated materials are promising alternatives to cement. This study investigated the effects of the silica content, particle size, and replacement ratio of rice husk ash (RHA) on the compressive strength and the optimization of these parameters. Seventeen mixtures with different materials were tested to evaluate their compressive strengths. Three levels of particle size, silica content, and RHA replacement ratio were used. The effects of RHA characteristics on the compressive strength were investigated based on Archimedes porosity, pH, ignition loss, and X-ray diffraction. The experimental results reveal that the replacement ratio of RHA was p-values < 0.002, which affected the compressive strength compared with the particle size (p-values < 0.450) and silica content of the RHA (p-values < 0.017). It was confirmed that the optimum values of particle size, silica content, and replacement ratio of RHA were 50 µm, 90%, and 15 wt.%, respectively. After re-testing, the compressive strength of mortar made with the optimum values was 49.8 MPa. This increase in compressive strength was also found to be closely related to the porosity, pH, and ignition loss of the paste. It was confirmed that the replacement ratio of RHA increased with decreasing porosity and pH and increasing ignition loss, which was related to the formation of calcite and C-S-H.