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EN
Surface roughness is influenced by various factors with uncertainty characteristic, and roughness reliability can be used for the assessment of the surface quality of CNC milling. The paper develops a method for the assessment of surface quality by considering the coupling effect and uncertainty characteristicsof various factors. According to the milling kinematics theory, the milling surface topography simulation is conducted by discretizing the cutting edge, machining time, and workpiece. Considering thecoupling effect of various factors, a roughness prediction model isestablished by the SSA-LSSVM, and its prediction accuracy reachesmore than 95%. Then, the roughness reliability model isdevelopedby applying the response surface methodology to achieve the assessment of surface quality. The proposed method is verified by the milling experiments. The maximum values of the relative errors between the simulation and experimental results of the surfaceroughness and roughness reliability are 9% and 1.5% respectively, indicating the correctness of the method proposed in the paper.
EN
In this study, a novel method is proposed to optimize the reinforced parameters influencing the bearing capacity of a shallow square foundation resting on sandy soil reinforced with geosynthetic. The parameters to be optimized are reinforcement length (L), the number of reinforcement layers (N), the depth of the topmost layer of geosynthetic (U), and the vertical distance between two reinforcement layers (X). To achieve this objective, 25 laboratory small-scale model tests were conducted on reinforced sand. This laboratory-scale model has used two geosynthetics as reinforcement materials and one sandy soil. Firstly, the effect of reinforcement parameters on the bearing load was investigated using the analysis of variance (ANOVA). Both response surface methodology (RSM) and artificial neural networks (ANN) tools were applied and compared to model bearing capacity. Finally, the multiobjective genetic algorithm (MOGA) coupled with RSM and ANN models was used to solve multi objective optimization problems. The design of bearing capacity is considered a multi-objective optimization problem. In this regard, the two conflicting objectives are the need to maximize bearing capacity and minimize the cost. According to the obtained results, an informed decision regarding the design of the bearing capacity of reinforced sand is reached.
3
Content available remote Synteza materiału katodowego LiMn2O4 dla akumulatorów litowo-jonowych
PL
Spinel LiMn₂O₄ został zsyntetyzowany i wykorzystany do przygotowania materiałów katodowych do baterii litowo-jonowych. Materiały te otrzymano w różnych warunkach syntezy (rodzaj czynników chelatujących, pH, temperatura reakcji, czas reakcji) i badano pod kątem wydajności elektrochemicznej przy użyciu modelu metodologii powierzchni odpowiedzi. Odczyn mieszaniny reakcyjnej odegrał znaczącą rolę w przygotowaniu materiału katody LiMn₂O₄. Zoptymalizowany wskaźnik retencji wyniósł 95,57%.
EN
LiMn₂O₄ spinel was synthesized and used for prepn. cathode materials for Li-ion batteries. The materials were studied for electrochem. performance under varying synthesis conditions (types of chelating agents, pH, reaction temp., reaction time) by using the response surface methodol. model. The pH played a significant role in prepn. of the LiMn₂O₄ cathode material. The optimized retention rate was 95.57%.
EN
The epoxidation process of soybean oil (SBO) and peracid produced by 50 wt% hydrogen peroxide (H2O2) and formic acid (FA) was studied with sulfuric acid (H2SO4) as a catalyst. Three reaction parameters, including reaction temperature, FA-to-SBO ratio, and H2O2-to-SBO ratio, were investigated, along with the combined effect on oxirane value (OV). Based on response surface methodology (RSM), the Box-Behnken design (BBD) was used to optimize the process parameters. According to the results, the calculated OV (7.34%) and the experimental OV (7.31%) were significantly in agreement. The product was con firmed as epoxidized soybean oil (ESO) by IR and NMR characterization methods. These results demonstrated the reliability of RSM to optimize the SBO reaction to produce ESO with high oxygen content.
EN
Flotation separation of galena and chalcopyrite is always a difficult problem in mineral processing. In this paper, the selective preoxidation of galena and chalcopyrite with sulfuric acid was developed, and then the two minerals were completely separated by flotation. The surface oxidation mechanism of galena and chalcopyrite with sulfuric acid was analyzed by Fourier transform infrared spectroscopy (FT-IR) and Atomic Force Microscopy (AFM), and the results showed that hydrophilic oxide film was formed on the galena surface, while the surface of chalcopyrite is still hydrophobic sulfide film, which led to the separation of the two minerals by flotation. In addition, the Response Surface Methodology (RSM) was used to analyze the influence of main preoxidation parameters on the flotation separation of copper-lead concentrate, and the parameters were further optimized, as follows: sulfuric acid concentration of 5.3 mol/L, oxidation temperature of 101.8 °C and time of 48.3 min. The mixed concentrate containing Cu 11.57% and Pb 16.75% was preoxidized under the above conditions, and the flotation separation verification results showed that Cu concentrate with Cu grade of 18.09% and recovery of 95.41%, and Pb concentrate with Pb grade of 44.96% and recovery of 95.94% was obtained respectively. This paper provides a new method of preoxidation combined flotation to achieve high-efficiency separation of copper-lead mixed concentrate.
EN
In this article, the potential use of banana bunch waste (BBW) as a source of bioenergy through hydrothermal carbonization (HTC) was investigated. BBW, a byproduct of banana production, is difficult to use as a fuel due to its low density and carbon ratio. However, its high lignocellulose content indicates its potential as a bioenergy source. To determine the optimal HTC conditions, an experiment was conducted using temperature, water to feedstock ratio, and processing time, with the RSM Box-Behnken method used to produce 15 trial formulations. Energy value and mass yield data were collected to determine the optimal values for both. The main parameter affecting energy yield was found to be the water to feedstock ratio, and the optimal conditions were determined to be a temperature of 180 °C, a water to feedstock ratio of 1.5:1, and a processing time of 15 minutes. The highest energy yield of 99.7% was observed under these conditions, while the lowest mass yield of 25.30% was observed at a temperature of 200°C with a water ratio of 2 and a time of 15 minutes. The heating value of the HTC solid product ranges from 17–27 MJ/kg, which is comparable to low-grade sub-bituminous coal, indicating potential for co-firing with coal and other hydrothermal products as a fuel.
EN
Electrocoagulation (EC) can be defined a method utilized to remove pollutants from wastewater by applying an electric current to sacrificial electrodes. Many experimental variables like NaCl content (0–4 g/l), current density (5–25 mA/cm2), time (30–90 mins), and pH (4–10) that influence the removal efficiency regarding COD were considered. In the presented research, three distinct configurations related to electrodes, i.e. Al-Al, Fe-Al, and Fe-Fe, have been utilized to determine which was the most effective. RSM depending on BBD was utilized for optimizing various operational parameters with regard to HWW by use of EC. Maximum COD removal (97.9%) was reached at Fe-Al electrodes, NaCl (3.2 g/l), current density (24.7 mA/cm2), time (81.7 mins), and pH (7.4). COD removal (91.3%) was achieved at the Al-Al electrodes, NaCl (3.8 g/l), current density(23.5 mA/cm2), time-86.3 min, and Ph (7.7). At the Fe-Fe electrodes, the removal of COD (89.5%) was obtained at NaCl (2.3 g/l), current density (24.6 mA/cm2), pH 8.5, and time (86.9 min). This indicates that EC could remove pollutants from different types of wastewaters under many operating parameters and with arrangements of electrodes.
EN
This study aimed to determine the performance of modified slow sand filter (SSF) media with blood clam shells (Anadara granosa) and activated carbon to remove turbidity, TSS, TDS, and FOG on the food court wastewater. The concentration of water pollutant parameters processed by SSF was determined based on Indonesia water quality standards, as well as knowing the optimum operational parameters of intermittent slow sand filter with Response Surface Methodology (RSM). The research data was processed using the Optimal type (custom) design which consisted of independent factors including the type of filter media, the addition of bacteria to the grease trap pre-treatment unit, and running time, as well as the research response in the form of the effectiveness of removing turbidity, TSS, TDS, and FOG. The reactor was operated intermittently (48 hours) for a maximum of 22 days and the concentration of pollutant parameters was calculated using the Standard Methods. The results of the Analysis of Variance (ANOVA, p<0.05) in the 2FI model of the study showed that there was a significant effect of all independent factors on the effectiveness of removing all water pollutant parameters. The most optimal operational parameters were achieved with the type of activated carbon media, the addition of Bacillus sp. in the grease trap pre-treatment unit in the amount of as much as 1%, and the detention time of 4 days, with the effectiveness of removing turbidity reaching 39.53%; TSS 45.25%; TDS 19.30%; FOG 61.35%.
EN
Electrodialysis has been proven effective due to its high selectivity for separating monovalent and divalent ions. This study statistically evaluated the simultaneous electrodialytic recovery of mineral ions from bittern wastewater. The objective was to investigate the effect of cell number, anode materials, and applied voltage to optimize mineral ion recovery. A D-optimality design response surface methodology was performed to estimate the model parameter and identify the factors contributing to mineral ions recovery. The effects of independent variables and their interactions on the responses were investigated using ANOVA. All developed models were highly significant, with a p-value of <0.0001. The applied voltage was considered very important for the recovery process of all mineral ions as it affects the driving force of ion migration through the ion-exchange membrane. The optimization analysis (desirability value of 0.967) revealed 12% Cl–, 14% SO4 2–, 0.7% Mg2+, and 21% Ca2+ recovery at the combination of 5-cells configuration, graphite electrode, and 9 V.
EN
This study goal to the ability of using low cost materials representing thermestone and aluminum solid wastes in water filtration by using a pilot plant constructed in wastewater treatment plant to remove cadmium ions (Cd(II)). Response Surface Methodology (RSM) used to optimize the optimal parameters that affecting the performance of filter units, these parameters are time, Cd(II) concentration, and filtration rate. These optimized parameters were 9 hr., 5 ppm, 10 l/hr. with removal efficiency of Cd(II) for A-Filter, T-Filter, S-Filter, and A-T-S-Filter was 94%, 95%, 86.8% and 90%, respectively. The result shows that the T-filter has higher cadmium removal efficiency than A-filter, S-filter and S-T-A- filter. While A-filter has a higher removal efficiency of cadmium than the S-filter and S-T-A- filter. While the S-T-A- filter has higher efficiency than S- filter. The result obtained from RSM was good Agreement with the result of experiments. As a result, the optimized process in this paper can be widely utilized with high removal ratio of Cd(II) ions from wastewater samples.
EN
The abundant availability of waste oil palm trunks is one of the potential fibers for new thermal insulation materials. While focusing on the manufacturing of thermal insulation materials, the main points to be considered are particle size, reinforcement fiber ratio, and press durations, besides binders type and temperature. This study aimed to optimize the manufacturing process of hybrid bio panels based on oil palm trunks as thermal insulation material. The response surface methodology (RSM), with a Box-Behnken Design (BBD), was used to model and optimize the manufacturing process variables. A total of 17 hybrid bio panels were in operation and the independent variables used were particle size, ramie ratio, and press duration. The dependent variables were water absorption, thickness swelling, MOR, and thermal conductivity. The hybrid bio panel obtained under the optimum conditions was characterized by thermogravimetric analysis to observe thermal stability. On the basis of analysis of variance and the contour plot, it was discovered that the interaction between particle size and ramie fiber ratio was a significant variable to optimize hybrid bio panel manufacture. The thermal resistance and modulus of rupture of hybrid bio panels also improved with higher particle size and ramie fiber ratio. The optimum manufacturing process was obtained at OPT particle size of 0.248 mm, ramie fiber ratio of 19.775, and press duration of 25 min. This condition produces a thermal conductivity of 0.079 W/mK, modulus of rupture of 17.702 MPa, water absorption of 54.428%, and thickness swelling of 21.974%. In addition, the hybrid bio panel resulted in thermal stability of 341 °C.
EN
As a result of rapid industrialization and population development, toxic chemicals have been introduced into water systems in recent decades. Because of its excellent efficiency and simple design, the three-dimensional (3D) electro-Fenton method has been used for the treatment of wastewater. The goal of the current study is to explore the efficiency of phenol removal by the 3D electro-Fenton process, which is one of the advanced oxidation processes (AOPs). In the present work, the effect of the addition of granular activated carbon (GAC) particles to the electro-Fenton system as the third electrode would be investigated in the presence of graphite as the anode and nickel foam as the cathode, which is the source of electro-generated hydrogen peroxide (H2O2). The influence of operation parameters (current density, electrolysis time, and GAC) on catalytic performance will be studied, which will be adjusted by the response surface methodology (RSM). The pH was adjusted to 3, and the airflow was set to 10 L/h. According to the results the nickel foam was an excellent cathode material choice. The best conditions for phenol elimination were at current density of 3.56 mA/cm2, FeSO4.7H2O dosage of 0.1 mM, GAC of 30 g, and a time of 3 h to attain the removal rates of phenol and chemical oxygen demand (COD) of 98.79% and 93.01%, respectively. The results showed that time had a higher effect on the phenol and COD removal efficiency, while the impact of current density was lower. The model equation’s high R2 value (97.90%) demonstrates its suitability.
EN
In this study, the effectiveness of using natural bio-coagulants and bio-flocculants to treat textile wastewater through the coagulation-flocculation method was examined. These bio-based agents have several advantages over chemical agents, including biodegradability, natural abundance, low toxicity, and low cost. A bio-coagulant (holm oak acorn (HOA)) and a bio-flocculant (cactus juice) were used to investigate the capacity for turbidity removal and decolorization of textile wastewater. The UV spectrophotometer was used to characterize the discharges before and after treatment, and the chemical oxygen demand (COD) and biological oxygen demand (BOD5) levels were calculated. Box-Behnken design (BBD) coupled with response surface methodology (RSM) were utilized to optimize the process and reduce turbidity and decolorization in textile wastewater. The obtained results show that under the optimal conditions (0.5 g·L-1 of HOA, 15 mL·L-1 of cactus juice, and a pH of 7), decolorization and turbidity removal were achieved at 69% and 90%, respectively. This study demonstrates the potential of using bio-coagulants and bio-flocculants in the treatment of textile wastewater.
EN
In this manuscript, an attempt has been made to predict and improve the overall equipment effectiveness of core drill rigs. A combined Box– Jenkins and artificial neural network model was used to develop a three parameter model (drill pushing pressure, drill penetration rate & average pillar drill pit cycle time) for predicting effectiveness. the overall equipment efficiency of core drill rigs. The values of mean average percentage error, root mean square error, normalized root mean square error, men bias error, normalized mean biased error and coefficient of determination values were found to be 9.462%, 17.378%, 0.194, 0.96%, 0.0014 and 0.923. Empirical relationships were developed between the input and output parameters and its effectiveness were evaluated using analysis of variance. For attaining 74.9% effectiveness, the optimized values of pushing pressure, penetration rate and average pillar drill pit cycle time were predicted to be 101.7 bar, 0.94 m/min and 272 min, which was validated. Interactions, perturbations and sensitivity analysis were conducted.
EN
In the present work, Response Surface Methodology (RSM) was utilized to optimize process variables and find the best circumstances for indirect electrochemical oxidation of mimicked wastewater to remove phenol contaminants using prepared ternary composite electrode. The electrodeposition process is used for the synthesis of a ternary composite electrode of Mn, Co, and Ni oxides. The selected concentrations of metal salts of these elements were 0.05, 0.1, and 1.5 M, with constant molar ratio, current density, and electrolysis time of 1:1:1, 25 mA/cm2, and 2 h. Interestedly, the gathered Mn-Co-Ni oxides were deposited at both the anode and cathode. X-ray diffraction (XRD) and scanning electron microscopy (SEM) facilitated the qualitative characterization of surface structure and morphology of the accumulated oxides. The energy dispersive X-ray (EDX) provided a semi-quantitative analysis of deposit composition. The atomic force microscopy (AFM) apparatus quantified the roughness. We examined the efficiency of composite electrodes in coinciding with the removal of Chemical Oxygen Demand (COD) under current densities of 40, 60, and 80 mA/cm2, pH values of 3, 4, and 5, and NaCl concentrations of 1, 1.5, 2 g/l. RSM covered the optimization of process parameters in conjunction with Central Composite Design (CCD). The COD represented the response function in the optimization procedure. The optimal current density, NaCl concentration, and pH magnitude were 80 mA/cm2, 1.717 g/l, and 3, respectively. The efficiency of COD elimination of 99.925% attained after 1 hour of indirect electrochemical oxidation with an energy consumption of 152.380 kWh per kilogram of COD. The COD elimination model is significant based on the correlation coefficient (R2) and F-values, and the experimental data fitted well to a second-order polynomial model with R2 of 98.93%.
EN
The research conducted here will hopefully lead to the creation of a practical, inexpensive method for purging aqueous solutions of contaminating phenolic chemicals. A biosorbent system comprised of eggshells and iron was studied for its potential to effectively detoxify phenol. Both the eggshell and the iron systems were used in the preparation of the adsorbents in order to achieve the desired result of having the properties of both systems. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) were used for characterisation. Batch tests were conducted to evaluate the adsorption capacity of eggshells and iron under the influence of different operating parameters (shaking speed, pH, initial phenol content, and contact time). In the design-expert modelling, the optimisation conditions were found to be a pollutant concentration = 30.0 mg . L–1, pH of 3.00, adsorbent dose = 0.11 mg . L–1, shaking speed = 150 rpm, and time = 120 min for an phenol reduction rate of 94.4 % which it was extremely near to the experimentally value (96.6 %). The CCD modelling that was performed in the RSM verified the findings that were predicted. On the basis of laboratory results, the prediction proved accurate.
EN
Treatment of Municipal wastewater by Electrocoagulation (EC) process using punched aluminium and zinc electrodes was studied in a batch EC cell reactor. Response surface methodology (RSM) based on Central Composite Design (CCD) was utilized to optimize the operating parameters for the removal of % Total Suspended Solids (TSS) and % Chemical Oxygen Demand (COD) from Municipal Sewage. Effect of operating parameters such as Electrode Distance (x1), Electrolysis Time (x2) and Voltage (x3) has been optimized for the removal of TSS and COD. The prediction of removal percentage of TSS and COD in various Operational circumstances is done by using Quadratic model. The significance of each operating parameter was computed by Analysis of variance (ANOVA). To achieve the maximum removal of % TSS and % COD, the optimum conditions were Electrode distance(x1)-3 cm, Electrolysis Time (x2)-70.299 minute and Voltage (x3)-6.5V. It was observed that the performance of electrocoagulation process increased up to 61.45% for COD removal, and 73.73% for TSS removal using punched electrode compared to plane electrodes.
EN
It is an underlying fact for the case of the joining process especially welding to have optimized parameters to achieve joints with outstanding mechanical characteristics. In the current article, using stir-cast aluminum-based alloy (Al 6061) is stir-cast with Al 6061/5%wt. silicon carbide, Al 6061/10%wt. silicon carbide, and Al 6061/18%wt. silicon carbide was welded using an underwater friction-stir welding process. Optimum welding parameters [namely, tool rotating speed (N), welding speed (S), and silicon carbide (SiC)] are investigated using analysis of variance (ANOVA) and response surface methodology (RSM) statistical approaches. High ultimate tensile strength and microhardness were set as required characteristics of quality welds. Since there are two responses and two objectives, multiple-criteria decision-making approach-response surface methodology was performed alongside ANOVA. Optimal parameters from these statistical approaches are converged to a tool rotating speed of 1,736.36 rpm, a welding speed of 11.58 mm/min, and a SiC of 16.67%, respectively. For the current inquiry, the computed ultimate tensile strength and microhardness are 984 MPa and 89.9 HV, respectively, and these values are congruent with the findings of effectiveness studies. It is deduced from this study that the optimal parameters are convergent irrespective of the two used techniques for the investigated experimental data.
EN
The current study focuses on the performance of a solar greenhouse dryer for drying of potato chips in Solar Dryer and Open sun conditions in Western Maharashtra. Potato chips is a value added product that can be effectively used during throughout the year as snacks, a side dish or an appetizer. It can be either deep dried or backed for consumption. The dried potato contains a high fiber content and it helps to lower the cholesterol level in blood reducing the risk of blood pressure if consumed backed. Potato chips can effectively be stored for one year to six months and consumed as snacks. The experiment was conducted for drying of potato chips in Solar Greenhouse Dryer and open sun conditions on 1st of April 2021 for 6 hours. The initial weight of the potato chips to be dried was 500 grams both for the solar greenhouse dryer and open sun drying conditions. The experiment was conducted at Bahe, Borgaon, Tal-Walwa, Dist-Sangli, Maharashtra, India located at 17.115°N and 74.33°E. The experimental observations collected during the tests were set as input data for the Design of the Experiments (DoE) i.e., for Response Surface Modelling (RSM). The main aim of using DoE i.e., Response Surface Modelling, is to obtain an optimum region for drying of potato chips in the Solar Greenhouse Dryer, from the surface plot; the region of maxima and minima was obtained. The contour plot obtained during modeling resembles the optimum region of drying; the optimum region for drying of potato chips is 47 to 50°C respectively. The Moisture Removal Rate (MRR) for drying of potato chips in the Solar Greenhouse Dryer and Open sun drying is 83% and 78% respectively. The drying rate observed during the experiment has a better resemblance with simulated Response Surface Modelling.
EN
Water pollution and the lack of access to clean water are general global problems that result from the expansion of industrial and agricultural activities. Petroleum refinery wastewaters are considered as a major challenge to the environment and their treatment is mandatory. The present work investigated the removal of chemical oxygen demand (COD) from petroleum refinery effluents generated from the Al-Dewaniya petroleum refinery plant located in Iraq by utilizing a novel graphite–graphite electro-Fenton (EF) system. The electrochemical reactor was a tubular type with a cylindrical cathode made from porous graphite and concentric porous graphite rode acts as an anode. By adopting the response surface methodology (RSM), the impacts of different operating variables on the COD removal were investigated. The optimal conditions were a current density of 25 mA/cm2, FeSO4 concentration of 1.4 mM, and electrolysis time of 90 minutes, which resulted in the COD removal efficiency (RE%) of 99% at a specific energy consumption (SEC) of 10.34 kWh/kg COD. The results indicated that both current density and concentration of FeSO4 have a major impact on the elimination of COD, while time has a minor effect. The adequacy of the model equation was demonstrated by its high R2 value (0.987). The present work demonstrated that the graphite–graphite EF system could be considered as an effective approach for removing of COD from petroleum refinery wastewaters.
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