Taguchi Experimental Design Research Articles

An investigation on mechanical strength of fused filament fabricated and injection molded ASA parts

The fused filament fabrication (FFF) process is widely used to fabricate components through a layering approach, also referred to as 3D printing. The fabricated component’s mechanical characteristics are influenced by process variables like raster width, build orientation, raster angle, raster gap etc. Therefore, exploring the effect of processing variables on the mechanical behavior of the fabricated components is crucial. The present work focused on investigating the influence of processing variables on the impact and flexural strength of the Acrylonitrile-styrene-acrylate (ASA) component produced through FFF and injection molding (IM). This investigation uses the Taguchi Design of Experiment (DOE) technique along with Gray relational analysis (GRA) in a combination of analysis of variance (ANOVA) to determine the optimum set of processing variables. From the study, it has been found that the flexural and impact strengths of the FFF sample are 1.11% and 44.36% higher than the IM sample, respectively.

Effect of Manufacturing Parameters on Low-Velocity Impact Behavior of Aramid, Carbon and Glass Fiber Reinforced Polymer Composites Using Taguchi Experimental Design

Effect of Manufacturing Parameters on Low-Velocity Impact Behavior of Aramid, Carbon and Glass Fiber Reinforced Polymer Composites Using Taguchi Experimental Design

TIG welding process on IS 2062A steel of 5 mm plate, utilizing a 2.5 mm diameter tungsten solid wire as electrode along with direct current straight polarity and argon inert gas was employed for shielding purpose

The quality as well as efficient welding is crucial to fulfil the consumer satisfaction and getting returns from production, which is mostly depends on weld bead properties for any welding process, which is influence by the selected welding method and its process variables. So, the significant efforts are to choose the appropriate welding process in addition the process parameters as well as their level. In an atmosphere of welding different technique have been developed in last few decades, the demand of Gas Tungsten arc welding (GTAW) or Tungsten inert gas welding (TIG) has been increasing day by day owing to it has potential to fabricate multiple metallic materials (similar/dissimilar), quality joint, smooth modification for industrialization, higher efficiency, and low capital cost. However, published literature regarding research on TIG welding of IS 2062A steel is notably scarce. Detailed discussions on the optimization techniques exploring the impact of process parameters such as welding current, traversing speed, and gas flow rate on both weld quality and bead geometry in TIG welding of mild steel are conspicuously absent in prior works. So it is very crucial for quality joint to applied process optimization on TIG Welding parameters. The study focused on tungsten inert gas welding process on 5 mm thick plate of IS 2062A steel, utilizing a 2.5 mm diameter tungsten solid wire as electrode along with direct current straight polarity and argon inert gas was employed for shielding purpose. To streamline experimentation, a multi-response optimization technique was employed, using Taguchi's L16 experimental design method. Among several welding parameters, the significant parameters like current (I), traversing speed (S), and gas flow rate (Gf) were considered, others parameters were kept constant. The study measured various aspects of bead properties, including penetration, bead width, and depth of HAZ, along with HAZ hardness. The optimized parameter settings, derived from the signal-to-noise (S/N) ratio, has been validated as improved the weldment properties along with possess highest grey relation grade, which highlighting the effectiveness of the Grey-based Taguchi method in enhancing joints properties as product quality together with efficiency in manufacturing. Quantitative assessment via the analysis of variance method was conducted to determine the relative significance of each variable on the overall output characteristics of the weldment.

Optimizing malathion biodegradation by Bacillus cereus via a design of experiment framework

Bacteria have effectively been employed to biodegrade pesticides, and current research was envisioned to investigate malathion degradation by Bacillus sp. isolated from field soils. About 30.87–72.25% biodegradation was observed after 96 h with the Bacillus sp. when malathion was used as sole carbon, which increased to 45.77–100% after 240 h at initial malathion concentrations of 0.005–0.1%, respectively. The influence of co-substrates, pH, pesticide concentration, rpm, temperature, and inoculum doses were examined to further optimize malathion biodegradation, and the effect of these factors was investigated by the Taguchi design of experiments (DOE). The optimal biodegradation conditions were obtained at 0.1% (w/v), glucose and yeast extract, pH − 7, temperature − 40 °C, malathion concentration − 0.03% (v/v), agitation − 150 rpm, and inoculum dose − 2% (v/v). The biodegradation rate was boosted to 98% at optimal conditions within 36 h. Malathion degradation was confirmed by ultra-high performance liquid chromatography (UHPLC) studies, followed by the elucidation of three different biodegradation/transformation pathways through GC/MS analysis. Biodegradation analysis of malathion by GC/MS confirmed the formation of a monocarboxylic acid, malaoxon, mercaptosuccinic acid, and phosphorus moiety. These findings unequivocally corroborate that Bacillus sp. inherits immense potential for biodegrading malathion at a wide range of environmental conditions and provides a workable solution for bioremediation of malathion.

Synthesis, characterization, experimental design and process analysis of heavy metals adsorption on a wheat straw based amidoximated bioadsorbent

In this research, 3-(trimethoxysilyl)propyl methacrylate (MPS) silane agent was applied to modify the extracted wheat straw (WS) cellulose as a natural biopolymer. Polyacrylonitrile (PAN) was attached to the MPS-modified WS (MPS-WS) via in-situ polymerization to form PAN-WS biocomposite. AO-WS amidoximated biocomposite adsorbent was synthesized through amidoxime reaction and the effects of different parameters including agitation speed, metal ion concentration, and adsorbent dosage on its efficiency of Pb(II) removal were investigated using the Taguchi experimental design method. The adsorbent was characterized using FE-SEM, FTIR, XRD, and TGA. The FTIR results confirmed that the alkaline treatment removed the hemicellulose and lignin groups and that the silane agent successfully bonded to the WS cellulose. The thermal stability of WS was enhanced by the MPS-WS composite due to the attachment of acrylonitrile polymer chains. The ANOVA results indicated that increasing the adsorbent dosage and decreasing the pollutant’s initial concentration significantly improved the adsorption efficiency. The optimal conditions (an agitation speed = 400 rpm, C0 = 60 mg/L, an adsorbent amount = 0.1 g) yielded maximum adsorption capacity of 22.26 mg/g for the AO-WS bioadsorbent. The kinetic and isotherm studies revealed that the pseudo-second-order kinetic model and the Dubinin-Radushkevich isotherm fit the experimental data best.

Enhancing printability and sustainability in three-dimensional-printing of challenging polymers by integrating an easy-to-print polymer raft

Extrusion-based additive manufacturing has revolutionized the production of complex polymer parts by offering a wide range of customization options. However, warping is a persistent issue, especially with materials such as acrylonitrile butadiene styrene, which have unique solidification properties. This work presents a new method to reduce warping by using a base material with strong adhesion properties and optimizing two key variables, that is, raft weight and model weight. The experiments were carried out using an open-chamber Cartesian three-dimensional printer and designed based on the Taguchi design of experiments. Polylactic acid was selected as the base (raft) material for its strong adhesion to the build plate. The analysis of variance revealed that raft weight significantly impacts warping, contributing 83.80%, while model weight accounts for 14.82%. The regression model showed a high correlation between these factors and warping, with an “ R2” value of 98.63%. This method enhances the printability of acrylonitrile butadiene styrene by improving the adhesion of the initial layers, leading to a significant reduction in warping. Additionally, energy consumption analysis revealed that this approach reduces energy consumption by 24.11% in comparison to traditional methods and minimizes material waste, promoting more sustainable additive manufacturing practices.

Study on performance of machine learning models in predicting surface roughness when turning of hardened AISI 4340 steel using CERMET cutting tool

This study investigates the effectiveness of machine learning models in predicting surface roughness (Ra parameter) during the hard turning of AISI 4340 steel using CERMET cutting tools, an area with limited prior research. The experiments were conducted on a CNC lathe under dry conditions, with surface roughness measured using a profilometer. The Taguchi design of experiments was utilized to structure the data, incorporating factors such as cutting speed, feed rate, and depth of cut. Three machine learning algorithms-Linear Regression (LR), Random Forest (RF), and Support Vector Regression (SVR)-were employed to develop predictive models. The models' performance was evaluated using the root mean square error (RMSE) and R-squared (R²) metrics. The RF model demonstrated superior predictive accuracy with an RMSE of 0.0758 μm and an R² value of 0.9814 for the testing dataset. The performance of the LR model (RMSE = 0.0783 μm, R² = 0.9791) and the SVR model (RMSE = 0.0779 μm, R² = 0.9798) were close to that of the RF model. Overall, all the algorithms demonstrated good potential for model development in this study.

Investigation of the Ιmpact of HVOF Spraying Parameters on the Abrasion Resistance of Tungsten Carbide Coatings

For components operating under high pressure and high values of friction conditions, rapid wear is a common issue. Surface treatment measures are often employed to enhance the working lifespan of such components by improving their resistance to abrasion. This paper utilizes the Taguchi experimental design method in conjunction with Analysis of Variance (ANOVA) to assess the impact of spraying parameters on the abrasion resistance of the coating when applying the HVOF method. The sprayed material is WC HMSP1060-00+60% 4070, primarily consisting of Nickel and Tungsten Carbide, whereas the material for manufacturing the pressing screws is 1045 steel. The investigated spraying parameters include the spray Flow Rate (F), Spray Distance (D), and Oxygen/Propane Ratio (R). The experimental results are analyzed to determine the most suitable spraying parameters to achieve the highest abrasion resistance, and thereby improve the working lifespan of the components.

Low-Velocity Impact Analysis in Composite Plates Incorporating Experimental Interlaminar Fracture Toughness.

Reliable performance of composite adhesive joints under low-velocity impact is essential for ensuring the structural durability of composite materials in demanding applications. To address this, the study examines the effects of temperature, surface treatment techniques, and bonding processes on interlaminar fracture toughness, aiming to identify optimal conditions that enhance impact resistance. A Taguchi experimental design and analysis of variance (ANOVA) were used to analyze these factors, and experimentally derived toughness values were applied to low-velocity impact simulations to assess delamination behavior. Sanding and co-bonding were identified as the most effective methods for improving fracture toughness. Under the identified optimal conditions, the low-velocity impact analysis showed a delamination area of 319.0 mm2. These findings highlight the importance of parameter optimization in enhancing the structural reliability of composite adhesive joints and provide valuable insights for improving the performance and durability of composite materials, particularly in aerospace and automotive applications.

Bonding performance optimization of homogeneous and hybrid hardwood CLT using the Taguchi experimental design method

The favorable properties of the available hardwood resources in Appalachia make them predestined for various high-value-added products. Between them we find mass timber products also, however, the utilization of hardwood species for such construction products comes with several new challenges. Among these, one of the most crucial issues to overcome is ensuring adequate bonding strength and durability. This research aims to optimize the bonding performance of red oak (RO) and red oak-yellow poplar (RO-YP) hybrid Cross-Laminated Timber (CLT), utilizing a one-component polyurethane (1-C PUR) adhesive an surface pretreatment with a primer. For optimization, the Taguchi method was utilized to quantify the effect of four factors, the primer ‘s concentration, adhesive spread rate, clamping pressure buildup time, and clamping pressure on delamination and shear strength across various layup combinations. The focus predominantly rests on mitigating delamination, as the analysis revealed that shear strength and wood failure manifested no notable variance across the investigated settings. Optimal manufacturing parameters’ setup values were identified, significantly diminishing the delamination rates below established thresholds for both YP and RO-YP hybrid panels. The homogenous RO CLT specimens alone remained above the desired level after optimization. The research concludes by outlining specific optimal settings for each wood combination, offering valuable insights for improving CLT bonding efficacy. These findings not only enhance the understanding of adhesive behaviors in hardwood CLTs but also propose practical guidelines for manufacturing, potentially aiding in the broader adoption and application of such materials in construction.

Impact of PECVD deposition on dielectric charge and passivation for n-GaN/SiO[formula omitted] interfaces

Controlling properties of GaN/dielectric interfaces is crucial for determining the characteristics of MOS-HEMT devices and their stability. Interface properties are largely affected by the techniques and specific conditions of dielectric deposition. In this work, a Taguchi design of experiment was applied to study the effect of plasma parameters during deposition of SiOx by PECVD for passivation of n-GaN. SiOx/GaN MIS capacitors were fabricated and characterized by capacitance measurement at a high probing frequency of 1 MHz. The interface states density, hysteresis and flatband voltage were analyzed and modeled in relation with the flow of SiH4, plasma power, chamber pressure and temperature. Excellent fits could be obtained on a single model including linear terms for all studied parameters and quadratic terms for the flow of SiH4 and temperature. We show that it is possible to obtain some control of the flatband voltage while maintaining a good interface quality. Positive flatband voltages are potentially of interest to enable normally-off operation for MOS-HEMTs and this could be obtained mainly by using a high SiH4/N2O ratio. To the contrary, negative flatband voltage values often ensure the most stable operation of MOS-HEMTs and this was achieved with a low SiH4/N2O and high plasma power. MIS capacitors with near-zero flatband voltage were also obtained with low SiH4/N2O ratio and low plasma power. Hysteresis and interface states density in relation with deposition plasma conditions are also analyzed in order to offer the best trade-offs depending on the end applications of MOS-GaN devices. By demonstrating the great impact of plasma conditions during dielectric deposition on electronic properties of MIS devices, we show that the process of gate insulation can be optimized to simultaneously control the density of defects and fixed charge at the interface.

Statistical optimisation of enzymatic pre-treatment process of marigold flower waste for enhanced hydrolysis and complete release of lutein ester through Taguchi orthogonal design

ABSTRACT The lutein ester of the marigold flower is entrapped in the matrix of pectin, cellulose, hemicellulose and lignin which cannot be released by moderate acidic, alkaline treatment or enzymatic treatment with a single enzyme. Five different parameters are optimized in the current study for two response factors: lutein ester extraction (LEEP) and floral solid hydrolyzed percentage (FSHP). Three commercially available enzymes, namely pectinase, cellulase, and xylanase, at various temperatures and time intervals were utilised to optimise the enzymatic hydrolysis of flower biomass. An L27 orthogonal Taguchi experimental design was employed, investigating temperature (25–35 °C), time (10–30 days), and enzyme levels (pectinase, cellulase and xylanase at 0–1 mL). The optimal conditions for 100% lutein ester extraction from marigold flower waste were: temperature 35 °C, 20 days, and enzymes 1 mL/200 g each of pectinase (2600 µPG/g), cellulase (20000 CMC U/g), and xylanase (300000 U/g). Thus, it could be concluded that optimisation by the Taguchi method could be used to develop an enzyme cocktail for the hydrolysis of marigold flowers to obtain the best yield of lutein ester. The aim is to enhance the yield of lutein ester through the optimisation of the enzymatic pre-treatment of the marigold flower.

Assessment of simultaneous removal of salt and dye by utilizing capacitive deionization and UV-electro oxidation hybrid process in saline wastewater treatment

In this research, the goal was simultaneous elimination of salt (NaCl) and dye (C·I Acid Orange 7 or AO7) through integration of capacitive deionization (CDI) technique with UV-based electrochemical advanced oxidation process (UV-EAOP). To optimize salt adsorption capacity (SAC) of MnO2 electrode, Taguchi's experimental design methodology was employed to fine-tune synthesis parameters, including bath temperature, current density, and precursor concentrations. BiOCl was synthesized and implemented as an anode to bolster AOP's effectiveness. Several experiments were conducted to analyze the effects of applying the combined AOP and CDI. The findings revealed that parameter optimization improved SAC, and the application of UV irradiation decreased electrode's SAC. Furthermore, it was observed that AO7 could enhance SAC while lowering salt adsorption rate (SAR). More importantly, the combined application of CDI and AOP resulted in superior pollutant removal efficiency and improved SAC, despite reduced SAR. Finally, color was entirely eliminated after 90 min, and the generated species were recognized by GC–MS. Additionally, a possible pathway for AO7 degradation was suggested based on the generated species.

Electrophoretic deposition of LiFePO4 and carbon black: A numerical study to explore longitudinal trends using Taguchi design

Developing Electrophoretic Deposition (EPD) for Composite Structural Batteries (CSBs) could revolutionise energy storage technology. CSBs offer an innovative solution by seamlessly integrating batteries into structures and effectively reducing weight and space constraints. Despite its successful implementation across various fields, EPD method still lacks comprehensive understanding of the underlying physical and chemical processes due to the number of variables involved. In this study the effects of key parameters associated with the process are investigated with a coupled FEM and analytical approach to find correlations with the deposition process. A Taguchi Design of Experiment with five parameters, namely voltage, concentration, relative weight ratio of LiFePO4 – carbon black particles, length and perimeter of the electrodes is implemented to identify the correlations with mass deposited, thickness of the coating and yield rate when LiFePO4 and Carbon Black particles in ethanol suspension are used. In order to capture the variation over time, each parameter is studied at six different time of deposition. A concentration that optimises yield rate resulting in thickness and mass deposition is identified. The resistivity of the suspension dictates the yield rate dynamics, allowing it to be designed within a specific range to meet requirements of different applications.

Cavitation erosion behaviour of MAB-CU4 alloy: influences of cavitation number, attack angle, time, and stand-off distance

Abstract The present study comprehensively examines the cavitation erosion behaviour of a manganese aluminium bronze alloy (MAB-CU4 alloy) as a function of several parameters (i.e., cavitation angle, cavitation number, time, and stand-off distance), particularly focusing on the influences of cavitation angle on the surface morphology and topography of the alloy. According to the design of experiment (Taguchi experimental design) analysis, mass loss increased with cavitation number and attack angle, while increasing the stand-off distance resulted in a decrease in mass loss and an increase in the surface area affected by cavitation erosion. Cavitation erosion behaviour was most affected by the cavitation attack angle, with the cavitation attack angle contributing 69.1% to total erosion, according to variance analysis. At 90° cavitation attack angle, MAB-CU4’s erosion rate was 64% greater than that at 30°. Scanning electron microscopy and optical profilometry revealed that cavitation erosion damage at 90° occurred mostly in the grain interiors as cavitation pits due to severe plastic deformation and surface corrosion, whereas pit formation was restricted around the hard secondary phases at the grain boundaries. At 30°, deep cavitation pits were limited, the erosion crater expanded, and the number of pits was reduced. Overall, finer microstructures with more grain boundaries and secondary phases may improve cavitation erosion resistance at 90°. The present study is the first to comprehensively capture erosion damage at the microstructural scale and analyse the impact of microstructural features on the erosion damage during the cavitation erosion of MAB-CU4 alloy.

Optimization of docetaxel-loaded cholesterol nanostructured lipid carriers for improving cancer treatment using Taguchi experimental design

Today's diets boost breast, head, neck, ovarian, and lung cancer risk. This has prompted researchers to study active compounds against these slow killers. Docetaxel (DTX) loaded onto cholesterol nanostructured lipid carriers (NLCs) with elaidic acid appears promising. Carriers were made using solvent emulsification-diffusion. This study used Taguchi's experimental design and analysis with the L16 orthogonal array. The design was utilised to analyse NLC particle size and zeta potential data. These trials considered process factors like elaidic acid percentage (15–30 %), emulsifier concentration (1–4 %), agitation duration (2–8 min), and blending speed (800–1400 rpm). Controlled experimental design plays an important role in pharmaceutical research, as does the privilege of a comprehensive technique aimed to maximize the creation of NLCs loaded with DTX for cancer treatment. Blending speed had a substantial influence on particle size, as the lowest and maximum particle sizes were 170.54 and 190.90 nm. In the zeta potential research, values ranged from 5.88 to 30.72 mV. These data show how important blending speed is in determining particle size. This research supports the sustainable development goals of 3, 9, 12, and 17.

Enhanced cationic/anionic dyes removal in wastewater by green nanocomposites synthesized from acid-modified biomass and CuFe2O4 nanoparticles: Mechanism, Taguchi optimization and toxicity evaluation

This article addresses the nanoadsorption mechanisms of rhodamine B (RB), crystal violet (CV), and Congo red (CR) using acid-treated C.edulis (ATCE)/CuFe2O4 (ATCE@CuFe2O4) from an aqueous solution. The physical and chemical characterizations of nanobiomass were studied using different techniques. The specific surface areas of the ATCE and ATCE@CuFe2O4 composites were 15.88 and 337.81 m2/g, respectively, indicating a significant specific surface area of ​​the ATCE@CuFe2O4 nanocomposite. A number of functional groups were determined, which promote the binding of the dye to the adsorbent. The SEM also shows that the adsorbent has a homogeneous texture with deep voids and significant porosity, which likely explains the retention and binding of dye ions on the surface of the adsorbent. In fact, the Langmuir isotherm with a correlation coefficient of 99 % for CV, RB and CR, respectively, represents the most suitable model to explain the adsorption mechanism. The maximum adsorption amount is 666.6 mg/g for CV, 645.16 mg/g for RB and 434.71 mg/g for CR at 308 °K. The adsorption kinetic processes were predicted by the pseudo-second order kinetic model. The thermodynamic properties showed that the adsorption on ATCE@CuFe2O4 was possible and spontaneous. The ATCE@CuFe2O4 recycling and elimination CV, RB, and CR were 74.23 %, 72.75 %, and 67.84 %, respectively, after seven cycles. The design, modeling and optimization of the adsorption parameters were carried out using the Taguchi experimental design. The maximum removal efficiency of CV, RB and CR dyes in optimal operating conditions were 99.96, 98.29 and 97.76 %, respectively. Which at the optimal conditions of 1 g/L, 90 min, 20 mg/L, 298 °K, pH 10 for CV and RB dyes and 1 g/L, 90 min, 20 mg/L, 308 °K, pH 4 for CR. This research demonstrated the performance of ATCE@CuFe2O4 in bean seed germination test and its effectiveness in removing dyes from wastewater.

Optimising the acquisition conditions of high information quality low-field NMR signals based on a cutting-edge approach applying information theory and Taguchi's experimental designs – Virgin olive oil as an application example

BackgroundDeveloping a new spectrometric analytical method based on a fingerprinting approach requires optimisation of the experimental stage, particularly with novel instruments like benchtop low-field NMR spectrometers. To ensure high-quality LF-NMR spectra before developing the multivariate model, an experimental design to optimise instrument conditions is essential. However, difficult-to-control factors may be critical for optimisation. Taguchi methodology addresses these factors to obtain a system robust to variation. This study uses the Taguchi methodology to optimise instrument settings for acquiring high-quality 1H and 13C LF-NMR signals in a short time from virgin olive oil (VOO). ResultsTwo experimental trials (for 1H and 13C signals, respectively) were carried out and analysed to find an optimal and robust combination of instrument settings against changes in two difficult-to-control factors: ambient temperature and small deviations of the NMR tube volume (700 ± 50 μL). The responses to be optimised, run time and spectral information quality, were analysed separately and jointly, as some factors showed opposite behaviour in the effect on the responses. Multiple response analysis based on suitable desirability functions yielded a combination of factors resulting in desirability values above 0.8 for 1H LF-NMR signals and almost 1.0 for 13C LF-NMR signals.In addition, a novel approach to assess the information quality of an analytical signal was proposed, addressing a major challenge in analytical chemistry. By applying information theory and calculating information entropy, this approach demonstrated its potential for selecting the highest quality (i.e. most informative) analytical signals. SignificanceThe acquisition instrument conditions of LF-NMR were successfully optimised using Taguchi methodology to acquire highly informative 1H and 13C spectra in a minimum run time. The importance lies in the future development of non-targeted analytical applications for VOO quality control. In addition, the innovative use of information entropy to a priori assess the signal quality represents a significant advance and proposes a solution to a long-standing challenge in analytical chemistry.

Properties of foam glass produced with the use of soot from a cement factory as a foaming agent: A study based on Taguchi design of experiments

Cellular glass is a lightweight, porous medium with excellent heat transfer resistance that can be used in a variety of industries. This study investigated the use of soot from cement plants as a new foaming agent for producing foam glass. The experiments were designed using the Taguchi Design of Experiments (DOE) method. By applying this approach, instead of creating and testing 27 different groups of samples, only 9 groups were produced. The properties of the remaining 18 sample groups were then predicted based on Taguchi analysis. Soot and silicon carbide were used simultaneously (at weight ratios of 2 % and 3 %) as foaming agents in the samples. Alumina was also used as a modifier with weight ratios of 4 %, and 8 %. Mechanical strength, water absorption, density, and thermal resistance were evaluated. The findings indicated a direct correlation between elevated soot content and increased water absorption (open porosity), coupled with a reduction in compressive strength and overall density of the foam glass. Electron microscopy observations revealed a wide range of crystallite morphologies in the resulting foam glass, which results in diverse properties in the material. The developed glass foams exhibit a density spanning from 125 to 700 kg/m3, with compressive strength varying between 1.2 and 6.7 MPa, and thermal conductivity in the range of 0.08–0.5 W/m·K. The samples with 3 % soot, 0 % alumina, and 3 % SiC exhibited exceptional thermal insulation properties. In contrast, the samples containing 1 % soot, 8 % alumina, and 1 % SiC demonstrated the highest compressive strength. Overall, this study found that soot from cement plants is a viable foaming agent for producing foam glass with desirable properties. The use of soot from cement plants can not only reduce the dispersion of pollution in the environment but also produce a wide range of foam glass with different properties at a lower cost.

Enhancing Compressive Strength of Cement by Indigenous Individual and Co-Culture Bacillus Bacteria

Using a Taguchi experimental design, this research focuses on utilizing indigenous bacteria from the Danube River to enhance the self-healing capabilities and structural integrity of cementitious materials. Bacillus licheniformis and Bacillus muralis were used as individual bacterium or in co-culture, with a concentration of 8 logs CFU, while the humidity variation involved testing wet and wet–dry conditions. Additionally, artificial neural network (ANN) modeling of the compressive strength of cement samples results in improvements in compressive strength, particularly under wet–dry conditions. By inducing targeted bacterial activity, the formation of calcium carbonate precipitates was initiated, which effectively sealed formed cracks, thus restoring and even enhancing the material’s strength. In addition to short-term improvements, this study also evaluates long-term improvements, with compressive strength measured over periods extending to 180 days. The results demonstrate sustained self-healing capabilities and strength improvements under varied environmental conditions, emphasizing the potential for long-term application in real-world infrastructure. This study also explores the role of environmental conditions, such as wet and wet–dry cycles, in optimizing the self-healing process, revealing that cyclic exposure conditions further improve the efficiency of strength recovery. The findings suggest that autochthonous bacterial co-cultures can be a viable solution for enhancing the durability and lifespan of concrete structures. This research provides a foundation for further exploration into bio-based self-healing mechanisms and their practical applications in the concrete industry.