Optimal Parameters Research Articles

Synthesis, structural characterization and in vitro digestion stability of a soluble soybean polysaccharide‑zinc chelate

The chelation reaction of soluble soybean polysaccharide (SSPS) with zinc was investigated. Using response surface methodology, the optimum parameters for SSPS-Zn synthesis were obtained: pH 5.3, SSPS-ZnCl2 mass ratio of 9.44:1, reaction temperature 50.44 °C, and reaction time 1.5 h, with the highest zinc content of 24.73 %. Compared with SSPS, SSPS-Zn increased in rhamnogalacturonan content and decreased in that of neutral monosaccharides (Fuc, Ara, Gal, Glu and Xyl). UV–vis spectra indicated that SSPS-Zn was lower than SSPS in protein content. FTIR spectra indicated that CO group of SSPS was bonded to Zn2+. X-ray diffraction spectra demonstrated that SSPS-Zn had higher crystallinity. Congo red reactions showed that SSPS possessed a triple-helix conformation while SSPS-Zn formed an irregular free-coiled conformation. EDX confirmed SSPS-Zn synthesis successfully. TGA curves exhibited that SSPS-Zn required higher temperature to undergo degradation. AFM revealed that SSPS-Zn was clustered while SSPS was filamentous. SEM micrographs showed the cracked fragments on the surface of SSPS-Zn. By in vitro simulation of gastrointestinal digestion, Zn2+ release reached 68.87 % after 2 h digestion. Consequently, the chelation of SSPS with zinc could change structure and provide a basis for research and application of novel zinc supplements.

Optimization of process parameters in laser cladding multi channel forming using MVBM-NSGA-II method

ABSTRACT Laser cladding multi-channel forming is a complex, nonlinear process characterized by multi-parameter coupling. To determine the technology parameters, an optimization method of multivariate black-box prediction model (MVBM) matching non-dominated sequential genetic algorithm (NSGA-II) was constructed. Multi-channel LC orthogonal experiments were designed. The MVBM was established with process technology parameters as inputs and characteristic parameters reflecting the quality (surface hardness, dilution rate) as responses. The set of optimal solutions for technology parameters by the NSGA-II. The experimental results showed that, under the optimum parameters, the average hardness of the optimized increased by 6.1%, and the dilution rate was reduced by 49.8%. The dilution rate was maintained within the optimal range. The study’s findings can provide theoretical support for optimizing LC multi-objective technology parameters and improving coating quality control.

Osmodehydrofreezing of Tomatoes: Optimization of Osmotic Dehydration and Shelf Life Modeling.

The objective was to review, using an integrated approach, all parameters related to osmotic dehydration, freezing, and frozen storage when assessing the advantages of the osmodehydrofreezing-ODF process. Peeled cherry tomatoes were treated at (T) 25, 35, and 45 °C (t) up to 180 min in glycerol-based OD-solution (50, 60, 70% w/w). OD was studied and optimized by applying the Response Surface Methodology, combined with selected desirability criteria to define the optimum process parameters. Water loss-WL, solid gain-SG, water activity reduction-aw, texture and color changes were monitored during the process. Untreated and OD-treated at optimal OD conditions (C = 61.5%, T = 36 °C; t = 72 min) samples were frozen and stored at isothermal (T, -5, -8, -14, -23 °C) and non-isothermal temperature conditions (Teff, -7.3 °C). OD samples presented acceptable color, increased firmness, low drip loss and high vitamin C/lycopene retention during frozen storage. OD increased the shelf life of frozen cherry tomato (up to 3.5 times based on sensory quality loss). The kinetic models obtained for vitamin and lycopene degradation and sensory quality loss were validated at non-isothermal conditions.

块茎收获物清选机的设计与模拟分析

In this paper, a screening machine was designed to remove the impurities in the tuber harvest, which integrates the functions of vibration screening, air separation, and flexible polishing. Discrete element simulation analysis was carried out to investigate the movement of tuber harvest and soil in the machine and the effect of polishing and removing impurities, the rationality of the structure, and the size were verified. Orthogonal tests were designed and carried out, with the rate of impurity, loss, and crushing as indicators and crank speed, impeller speed, and polishing roller speed as factors. The optimum working parameters were obtained: crank speed 280.12 r/min, impeller speed 1056.27 r/min, polishing roller speed 405.02 r/min, the impurity content was 0.29%, the loss rate was 1.01%, and the breakage rate was 0.11%. Through experimental verification, the actual value and theoretical value are basically the same, which verifies the rationality.

Optimization of 4-chlorophenol decomposition by H2O2 activate catalytic magnetic iron oxide an activated carbon carrier

Wastewater from chemical plants that produce pesticides always carries a large amount of organic matter that is difficult to decompose. One of them is the compound 4-chlorophenol, which has difficult-to-decompose properties, is durable in the environment, and is also listed in the group of substances that are likely to cause cancer in humans. In this study, the 4-chlorophenol compound was treated with heterogeneous Fenton by H2O2 activated by magnetic iron oxide nanoparticles on activated carbon. Magnetic iron oxide nanoparticles were successfully synthesized and mounted on activated carbon 10-15 nm in size with material surface morphological parameters such as specific surface area 330.28 cm2/g; total pore volume 0.16 cm3/g; magnetization 8.19 emu/g. The optimization of the 4-chlorophenols decomposition reaction with pH parameters, the content of catalytic materials, and the initial concentration of 4-chlorophenol is carried out using the Box-Behnken Design. The results showed that the removal efficiency of 4-chlorophenol was 96.5% achieved with optimum parameters pH 2.9; catalytic concentration 0.32 g/L; initial concentration of 4-chlorophenol 92.3 mg/L. The results of the study show the efficiency of the decomposition of an organic compound using magnetic activated carbon.

Regulating the microstructure and catalytic activity of metal selenides via calcination strategy for lithium-sulfur battery

Metal selenides obtain a series of advantages such as high electronic conductivity, excellent catalytic activity and facile fabrication approach, which are considered as promising catalysts in lithium sulfur (Li-S) battery. Traditional research based on metal selenides focuses on designing novel/complex microstructures or composites, however, the catalytic ability can be greatly affected by internal properties such as defect or vacancy. In this work, hollow nickel-cobalt layered double hydroxide (NiCo-LDH) is first fabricated and applied as a precursor to fabricate NiCoSe, and Se vacancy accompanied with crystal phase, microstructure and catalytic activity can be regulated by simply adjusting selenization atmosphere and temperature. Involving the application of NiCoSe in Li-S battery, the optimum fabrication parameter is perform the selenization at 600 °C under argon/5 % hydrogen, and the battery can exhibit a high discharge specific capacity of 1042.8 mAh g−1, excellent cycling performance of 500 cycles with a decay rate of 0.083 % at 1 C. This work highlights the importance of calcination process and also provides reference for further modifying the microstructure and performance of metal selenides in Li-S battery.

Promising CO2 gas sensor application of zinc oxide nanomaterials fabricated via HVPG technique

Highly effective gas sensors for detecting a range of hazardous and toxic gases were successfully applied in the present study using Zinc oxide (ZnO) nanomaterials. In this work, the horizontal vapor phase growth (HVPG) technique was perfectly capable of the synthesis of zinc oxide (ZnO) nanomaterials. The effect of the growth time with different dwell times was discussed by comparing the SEM-EDX analysis and photoluminescence characterization of the samples. Magnetic field (AMF) was also incorporated to determine the effect of AMF on the synthesis of ZnO nanomaterials. The results showed that the ZnO nanorods and root-like shapes are formed with more than 5 μm length and a few nm diameters. The optimum parameter showed the sensors are shiner than the less effective sensor when applied. The introduction of an external magnetic field led to a reduced energy band gap by a maximum of 15 %. The non-AMF band gap energy value is observed to be between 3.51 and 3.58 eV, while the value obtained using AMF is found to be between 2.94 and 3.22 eV. During the CO2 gas sensor test, AMF ZnO nanomaterial samples exhibited higher voltage and gradient compared to non-AMF samples.

Ultrahigh pressure enhances the extraction efficiency, antioxidant potential, and hypoglycemic activity of flavonoids from Chinese sea buckthorn leaves

Ultrahigh pressure extraction (UHPE) is an emerging non-thermal extraction technology, but whether this technology can be used for extracting flavonoids from sea buckthorn leaves remains unelucidated. This study optimized the processing conditions for flavonoid extraction from Chinese sea buckthorn leaves through UHPE and compared the results obtained with those of ultrasonic-assisted extraction (UAE) and conventional solvent extraction (CSE). The optimum parameters for UHPE were as follows: ethanol concentration, 50%; liquid-solid ratio, 41:1; pressure, 143 MPa; temperature, 44 °C; and holding time, 3 min. Compared with the UAE and CSE extracts the UHPE extracts had a higher content of total flavonoids and flavonol monomers, and the advantages of UPHE were primarily observed in the extraction of flavonoid monosaccharide chain glycosides and flavonoid aglycones. In total, 36 flavonoids were identified in the three extracts, with 33, 30, and 28 flavonoids identified in UHPE, UAE and CSE, respectively. Additionally, the UHPE extracts had a greater ferric reducing antioxidant power (FRAP), oxygen radical absorption capacity (ORAC), α-amylase inhibitory activity, and α-glucosidase inhibitory activity. In conclusion, the efficiency of UHPE to extract flavonoids from sea buckthorn leaves was significantly higher than those of UAE and CSE.

An experimental investigation on copper square electrode wear in electric discharge machining of Hastelloy B2

Hastelloy B2 is a high-performance nickel-molybdenum alloy and has been used in micro reactor, pump, pipe, and corrosion-resistant equipment. Square holes are required in the above application components. Although square holes are easily produced by spending more electrodes wear in Electrical Discharge Machining (EDM). Moreover, the square hole with small electrode wear achieved is a challenging task in thermal machining. Hence, in this work, the effects of EDM process parameters on electrode taper angle, electrode radius, electrode wear length and cutting time of Hastelloy B2 are studied. Taguchi based VišekriterijumskoKompromisnoRangiranje (VIKOR) method is used to find the optimum process parameters and compared with Taguchi based Grey Relational Analysis (GRA) method for validation. The results showed that current and pulse duration greatly affects the electrode wear out surface and edges. The square electrodes with sharp edges and surfaces are fully transformed into hemispherical shapes at electrode ends due to an unstable spark with diffusion of heat. Also, the VIKOR method provides an alternative multi-criteria optimization method that enhances the process performance over the grey relational analysis due to comparability, uniqueness, assessment and prediction.

Design and optimization study of all inorganic based double-absorption- layer CsPbI3/MoS2 heterojunction perovskite solar cells by SCAPS-1D

In recent years, perovskite solar cells (PSCs) continue to be a popular issue due to their high-power conversion efficiency (PCE%) and cost-effective production process. The CsPbI3 absorber layer used to produce PSCs limits the efficiency of the structure because it can absorb low-energy photons. Therefore, in this study, for the first time, CsPbI3 and CsPbI3/MoS2 single and double absorber based inorganic heterojunction PSCs were studied in detail, compared and optimized by using Solar Cell Capacitance Simulator (SCAPS-1D) software package. We discussed how the photovoltaic efficiency changed based on the open-circuit voltage (Voc), circuit current density (Jsc), quantum efficiency (QE), PCE% and fill factor (FF) relies on layer thickness, operating temperature, defect density (Nt), acceptor (NA) and donor density (ND), and heterojunction design. CuSbS2 and PCBM were chosen as the HTL and ETL layers, respectively. Depending on the results obtained from the SCAPS-1D, the optimum parameters for the Au/HTL/CsPbI3/ETL/FTO single layer device were determined as Thickness = 300 nm, Nt = 1011 cm-3, NA = 1013 cm-3, and T = 310 K. Then, the optimum parameters of MoS2 for the Au/HTL/CsPbI3/MoS2/ETL/FTO double layer-based device were determined as Thickness = 600 nm, Nt = 1010 cm-3 and ND = 1018 cm-3. It has been observed that MoS2 increases the light absorption capacity of the PSC device. As a result, the solar cell efficiency of the device with MoS2 has improved from 20.44 % to 40.66 % compared to the single-layer device. Additionally, in this study, presented a new approach for the future development at highly efficient, stable and completely inorganic PSCs integrated with transition metal dichalcogenide(TMDs; MoS2) materials.

The Effect of Various Parameters in the Sulfuric Acid Leaching of Low Grade Zinc Oxide Ore of Niğde-Türkiye

The aim of this study was to investigate the main parameters affecting the leaching of low grade zinc oxide ores with sulfuric acid. The influence of leaching time (5 to 480 minutes), sulfuric acid concentration (25 to 125 g/L), leaching temperature (25 to 90 °C), particle size (-104 µm, -82 µm, -60 µm, -49 µm) and solid/liquid ratio (1/10, 1/7.5, 1/5, 1/4) was investigated. The effects of these process parameters were studied with to achieve maximum zinc extraction with minimum iron extraction and acid consumption. The optimum parameters for sulfuric acid leaching of zinc ore were determined to be 60 min leaching time, 75 g/L sulfuric acid concentration, 80 oC leaching temperature, 1/10 solid/liquid ratio and -60 µm particle size. Under these optimum conditions, Zn extraction (%), Fe extraction (%) and acid consumption (ton H2SO4/ dissolved ton Zn) were obtained 88.68%, 25.83% and 5.47 ton H2SO4/ dissolved ton Zn respectively.

Predicting the Influence of Pulverized Oil Palm Clinker as a Sustainable Modifier on Bituminous Concrete Fatigue Life: Advancing Sustainable Development Goals through Statistical and Predictive Analysis

Currently, the viscoelastic properties of conventional asphalt cement need to be improved to meet the increasing demands caused by larger traffic loads, increased stress, and changing environmental conditions. Thus, using modifiers is suggested. Furthermore, the Sustainable Development Goals (SDGs) promote using waste materials and new technologies in asphalt pavement technology. The present study aims to fill this gap by investigating the use of pulverized oil palm industry clinker (POPIC) as an asphalt–cement modifier to improve the fatigue life of bituminous concrete using an innovative prediction approach. Thus, this study proposes an approach that integrates statistically based machine learning approaches and investigates the effects of applied stress and temperature on the fatigue life of POPIC-modified bituminous concrete. POPIC-modified bituminous concrete (POPIC-MBC) is produced from a standard Marshall mix. The interactions between POPIC concentration, stress, and temperature were optimized using response surface methodology (RSM), resulting in 7.5% POPIC, 11.7 °C, and 0.2 MPa as the optimum parameters for fatigue life. To improve the prediction accuracy and robustness of the results, RSM and ANN models were used and analyzed using MATLAB and JMP Pro, respectively. The performance of the developed model was assessed using the coefficient of determination (R2), root mean square error (RMSE), and mean relative error (MRE). The study found that using RSM, MATLAB, and JMP Pro resulted in a comprehensive analysis. MATLAB achieved an R² value of 0.9844, RMSE of 3.094, and MRE of 312.427, and JMP Pro achieved an R² value of 0.998, RMSE of 1.245, and MRE of 126.243, demonstrating higher prediction accuracy and superior performance than RSM, which had an R² value of 0.979, RMSE of 3.757, and MRE of 357.846. Further validation with parity, Taylor, and violin plots demonstrates that both models have good prediction accuracy, with the JMP Pro ANN model outperforming in terms of accuracy and alignment. This demonstrates the machine learning approach’s efficiency in analyzing the fatigue life of POPIC-MBC, revealing it to be a useful tool for future research and practical applications. Furthermore, the study reveals that the innovative approach adopted and POPIC modifier, obtained from biomass waste, meets zero-waste and circular bioeconomy goals, contributing to the UN’s SDGs 9, 11, 12, and 13.

Stiffness optimization design of wheeled-legged rover integrating active and passive compliance capabilities

Compliance capability is one of the most important properties of suspension systems for rough-terrain robots. This imposes specific requirements on system stiffness design, which directly determines the platform's performance in response to external stimuli. To address the challenge of stiffness optimization design in active and passive compliant systems, this paper proposes a novel and practical method for optimizing stiffness for a terrain-adaptive wheel-legged rover. Firstly, the kinematic model of this multi-degree-of-freedom platform is established. Secondly, the deformation capability coefficient, load capacity coefficient, energy efficiency coefficient, and dynamic stability coefficient are derived as performance indices to assess the behavior of the system. By establishing the relationship between joint configuration variation and system stiffness, stiffness parameters could be evaluated through these performance indices. Ultimately, the global optimum stiffness parameters are selected from the refined intersection of the individual performance optimal domains. Thirdly, the optimum parameters are calculated and applicability verified numerically. The designed parameters are verified experimentally on a wheeled-legged rover. The experimental results demonstrate that the proposed algorithm can find the parameter combination that achieves optimal system performance, thereby enhancing the system's terrain adaptability.

Laser-induced protruded bioinspired texturing of Ti-6Al-4V for controlled wettability in biomedical application

Bioinspired protruded textures with variable surface morphology and characteristics are getting worldwide popularity due to their wider applications. Among them controlled wettability for different materials through bioinspired textures is very essential to reduce the adhesion, bacterial contamination and growth, and drug delivery application. Even, identification and efficient fabrication of favorable bioinspired protrusions with optimum parameters are comparatively complex from normal textures through any material processing methods due to their complex shapes, form accuracy and dimensions. Therefore, this work targets the fabrication of four different types of protruded bioinspired textures namely, fish scale, protruded square, protruded circular, Python scale (snake) textured surface on biomedical grade Ti-6Al-4V titanium alloy for controlling the wettability using femtosecond laser surface texturing (LST). The optimum process parameters for the machining of Ti-6Al-4V were set as a temporal width of 350 fs, output power of 5.5 W, wavelength of 1030 nm, scanning speed of 100 mm/s and pulse rate of 500 KHz and three repetitions for all the texture types. To examine the effect of texture type, perimeter of all the fabricated textures was kept constant. Further, effect of varying perimeters was also analyzed for perimeter ranges from 300 to 500 µm. Surface morphology and characteristics were also analyzed for the measurement of texture consistency, dimensions and composition which was also related to the wettability results examined by static contact angle of the sessile drop method. Wetting of fish scale texture is decreased with increasing perimeter whereas of all other textures, wettability is going to be improved significantly.

Rotor–stator hydrodynamic cavitation reactor for intensification of castor oil biodiesel production

AbstractNowadays, the intensification of the production of biodiesel from non-edible oil crops is mandatory to overcome petrol-fuel depletion and environmental pollution. For the first time, enhanced biodiesel production from castor oil via rotor–stator hydrodynamic cavitation has been studied in this work. Response surface methodology based on one-factor-at-a-time design of experiments was employed for modelling and optimizing the biodiesel yield and the decrease in feedstock viscosity, density, and total acid number (TAN). The predicted optimum parameters of 8.15:1 methanol:oil (M:O), 1499 rpm, 29.38 min, 48.43 °C, and a KOH catalyst concentration of 0.74 wt.% resulted in a 96% biodiesel yield with a concomitant decrease in viscosity, density, and TAN of approximately 95%, 5.12%, and 90.02%, respectively. According to the results of the breakthrough kinetic calculations, the reaction is pseudo-second order, with the activation energy, frequency factor, and reaction rate constant being 0.23 M−1 min−1, 18.77 kJ/mol, and 6.32 M−1 min−1, respectively. The fuel properties of the produced biodiesel and bio-petro-diesel blends were good, comparable to international standards and the marketed Egyptian petro-diesel.

Optimization and Kinetic Study of Manganese Leaching from Pyrolusite Ore in Hydrochloric Acid Solutions with Oxalic Acid

The leaching behavior of pyrolusite minerals was examined in hydrochloric acid solutions, including oxalic acid, to evaluate the influence of various experimental conditions. The optimum parameters for the leaching process were found in the first stage, and the process's kinetics were assessed in the second. The concentrations of oxalic acid, hydrochloric acid, and temperature were chosen as independent variables in the optimization experiments, with the central composite design used to analyze the experimental data. The optimum concentrations for oxalic acid, hydrochloric acid, and temperature were determined to be 0.75 mol/L, 1.2 mol/L, and 60 °C, respectively. The leaching rate was determined to be 97.4% for 120 min of response time in optimum situations. The kinetic assessment experiments studied the effects of solid/liquid ratio, particle size, stirring speed, and temperature on the manganese leaching rate from pyrolusite. In the studies, the leaching rate was shown to rise with increasing temperature and stirring speed, as well as with decreasing particle size and solid/liquid ratio. The kinetic analysis revealed that the leaching kinetics matched the mixed kinetic model, and a mathematical model for the leaching process was developed. This process's activation energy was determined to be 29.05 kJ/mol.Graphical

Performance optimization of an air-assisted electrostatic spraying unit using response surface methodology

An air-assisted electrostatic spraying unit along with a set-up to measure the spray current was developed. Response surface methodology was used to optimize the performance of the developed electrostatic spraying unit. The optimum parameters such as electrode diameter, electrode voltage, electrode position and target distance for maximizing charge-to-mass ratio (CMR) were determined to be 30 mm, 2000 V, 0 mm and 400 mm, respectively Predicted CMR under optimal conditions was experimentally validated. Furthermore, charged spray demonstrated 1.5 to 4.6 times higher droplet deposition with lower uniformity coefficient (2.13–2.14) and relative span factor (0.84–0.9) compared to uncharged spray.

Study on Mechanical and Electrical Properties of High Content CNTs/Cu Composites.

It is expected that composites made of carbon nanotubes (CNT) and copper (Cu) display both mechanical and electrical properties, but the low damage dispersion and high-quality composite of high-content CNTs have always been research difficulties. In this paper, high-content CNTs/Cu composites were prepared. The effects of the sintering method, sintering temperature, directional rolling and the CNTs' content on the relative density, hardness and electrical conductivity of the composites were studied. The uniform dispersion of high-content CNTs in Cu matrix was achieved by ball milling, sintering and rolling, and the processes did not cause more damage to the CNTs. The properties of composites prepared by spark plasma sintering (SPS) and vacuum hot pressing sintering (HPS) were compared, and the optimum process parameters of SPS were determined. When the CNTs' content is 2 wt.%, the hardness is 134.9 HBW, which is still 2.3 times that of pure Cu, and the conductivity is the highest, reaching 78.4%IACS. This study provides an important reference for the high-quality preparation and performance evaluation of high-content CNTs/Cu composites.

Parametric study and optimization of H-type finned tube heat exchangers with honeycomb arrangement using Taguchi method

Enhancing the efficiency of flue gas waste heat utilization is an important way to achieve carbon peaking and carbon neutrality goals. In this paper, a three-dimensional numerical model of an H-type finned tube heat exchanger with honeycomb arrangement is developed. Firstly, the effects of five parameters are analyzed using the control variable method, including the oblique tube pitch, the ratio of fin height to oblique tube pitch, fin pitch, fin thickness and slit width. Then, the Taguchi method was used to investigate the interaction effects of the five geometric parameters. Numerical simulations of 27 cases with different parameter combinations were carried out and the heat transfer and flow friction characteristics and their overall performance were discussed in detail. The results show that oblique tube pitch has the most significant effect on heat transfer capacity, fin pitch has the most significant effect on overall performance, and slit width has the least effect on both. Finally, the optimum parameter combinations were obtained. When inlet velocity ranges from 5 m/s to 10 m/s, heat transfer performance is increased by 46.3 %-52.1 %, pressure drop is increased by 5.7 % − 11.3 %, and the overall performance PEC is improved by 63.5 %-105.9 %. The results of the study contribute to the development and optimization of new flue gas heat exchangers.

Ziziphus nummularia leaves extract mediated CuO nanostructures for photocatalytic degradation of Methylene Blue

In this study, Ziziphus nummularia leaves extract was applied for the synthesis of CuO nanostructures. The material was characterized by various techniques such as Infrared (IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray (EDX) and scanning electron microscope (SEM) analysis. The characteristic peaks in powder XRD pattern of nanostructured of CuO at 2θ of 32.33, 35.57, 38.71, 46.11, 48.80, 51.50, 58.22, 61.58, and 68.08◦, correspond to (110), (−111), (111), (−112), (−202), (112), (202), (−113), and (220), respectively, match with diffraction patter of standard monoclinic phase of CuO (JCPDS: 01–080-1916). Tauc plot was plotted and band gap energy was calculated, and found to be 2.4 eV. The material was tested as photocatalyst for degradation of MB, and worked well at optimum parameters such as dosage of catalyst 25 mg, concentration of MB 20.0 mg L−1, pH 7 and time 120 min. The proposed method worked very well on synthetic solutions with degradation efficiency (%) ≥ 83.51 and an RSD (%) of ≤ 4.0.