Box-Behnken Response Surface Design Research Articles

Efficient removal of Eosin Yellow dye using solvothermal synthesised Ni/Al layered double hydroxide and layered double oxide: insights into adsorption kinetics and thermodynamics

ABSTRACT The accumulation of organic pollutants in the environment is swelling steadily and raising the alarm for their redressal. Layered double hydroxides (LDH) and layered double oxides (LDO) are gaining prominence for their potential to address this challenge. This work includes an eco-friendly facile solvothermal synthesis of Ni/Al LDH and their calcination to Ni/Al LDO. The prepared nanomaterials were characterised by XRD, FE-SEM, HR-TEM, FT-IR, BET and TGA techniques, which confirm the highly porous structure of synthesised nanomaterials with a high specific area of 109.94 m2g−1 and 188.94 m2g−1 for Ni/Al LDH and Ni/Al LDO, respectively. A systematic study was conducted to explore the adsorptive potential of these materials towards the removal of organic dye Eosin Yellow (EY). The adsorptive efficiency was found to be 95% and 99% for Ni/Al LDH and Ni/Al LDO, respectively, under the optimised conditions of pH, adsorbent dose, contact time, dye concentration and temperature on adsorptive removal of EY dye, which was analysed by BBD-RSM (Box-Behnken Design Response surface methodology). The adsorption data fits best with the Freundlich isotherm model and pseudo-second-order kinetics. The thermodynamic study confirms the exothermic adsorptive process. The durability and reusability of the synthesised adsorbents were ascertained by their retention of the adsorptive efficiency even after five adsorption-desorption cycles which were as high as 91% and 85% for Ni/Al LDH and Ni/Al LDO, respectively. The mechanism of adsorption involves electrostatic interaction and hydrogen bonding between the surface of adsorbent and adsorbate as well as intercalation of dye molecules.

Optimization of Microbial Fuel Cell Operational Parameters for the Treatment of Brewery Sludge

AbstractThis study investigates the potential of a salt bridge‐mediated microbial fuel cell (MFC) for power generation and wastewater sludge treatment in breweries. Unlike traditional “one‐parameter‐at‐a‐time” methodologies, this study uses a three‐variable Box–Behnken design response surface methodology to optimize critical MFC operational parameters. The effects of parameters such as solution pH, salt bridge molarity, and temperature were studied in the range of 4 to 10, 1 to 5 M, and 20 to 45 g L−1. The optimum operating parameters were found to be solution pH of 5.853, salt bridge molarity of 3.343 M, and temperature of 32.5 °C for chemical oxygen demand and biological oxygen demand removal efficiencies of 92.485 % and 88.51 %, respectively. Temperature was found to be the most significant factor affecting the reactor's performance.

Preparation and Effect of CO2 Response Gel for Plugging Low-Permeability Reservoirs.

In order to solve the problem of gas channeling during CO2 flooding in low-permeability reservoirs, a novel CO2 responsive gel channeling system was prepared by using carrageenan, branched polyethylene imide and ethylenediamine under laboratory conditions. Based on the Box-Behnken response surface design method, the optimal synthesis concentration of the system was 0.5 wt% carrageenan, 2.5 wt% branchized polyethylenimide and 6.5 wt% ethylenediamine. The micromorphology of the system before and after response was characterized by scanning electron microscopy. The rheology and dehydration rate were tested under different conditions. The channeling performance and enhanced oil recovery effect of the gel system were simulated by a core displacement experiment. The experimental results show that the internal structure of the system changes from a disordered, smooth and loosely separated lamellae structure to a more uniform, complete and orderly three-dimensional network structure after exposure to CO2. The viscosity of the system was similar to aqueous solution before contact with CO2 and showed viscoelastic solid properties after contact with CO2. The experiment employing dehydration rates at different temperatures showed that the internal structure of the gel would change at a high temperature, but the gel system had a certain self-healing ability. The results of the displacement experiment show that the plugging rate of the gel system is stable at 85.32% after CO2 contact, and the recovery rate is increased by 17.06%, which provides an important guide for the development of low-permeability reservoirs.

Identifying Optimal Processing Variables and Investigating Mechanisms of Grain Alignment in Hot-Deformed NdFeB Magnets through Design of Experiments.

This study introduces a novel approach for investigating hot-deformed NdFeB magnets by combining the minimal stress deformation process (MSDP) with the design of experiment (DoE) methodology. This study focused on enhancing the crystallographic alignment, particularly the c-axis alignment of the Nd2Fe14B grains, to optimize the magnetic properties. By utilizing the Box-Behnken design matrix and response surface regression, critical processes and variables were identified, determining that a hot-pressing temperature of 700 °C is crucial for achieving optimal grain alignment. Changing the strain rate to 0.019 mm/s under a stress of 110 MPa led to significant enhancements in the alignment, yielding magnets with a remanence of approximately 13.4 kG and a coercivity of 21 kOe. These findings highlight the effectiveness of combining the MSDP and DoE for predicting and achieving improved magnetic properties. Despite the challenges associated with understanding the complexity of crystal alignment mechanisms, this integrated approach successfully improved magnetic characteristics. The methodology represents a significant advancement in the fabrication of high-performance hot-deformed NdFeB magnets, marking a notable contribution to the field.

Electrospun O-quaternary ammonium chitosan/polyvinyl alcohol nanofibrous film by application of Box–Behnken design response surface method for eliminating pathogenic bacteria

In this study, O-quaternary ammonium chitosan (O-HTCC) containing bicationic antibacterial active groups was synthesized to develop an O-HTCC/PVA porous nanofibrous film to enhance antibacterial activity, leveraging surface modification and nano-porous structure design. Uniform and smooth nanofibrous structures (average diameter: 72–294 nm) were successfully obtained using a simple and feasible electrospinning method. A response surface model via Box-Behnken design (BBD) was used to clarify the interaction relationship between O-HTCC fiber diameter and three critical electrospinning parameters (O-HTCC concentration, applied voltage, feed flow rate), predicting that the minimum O-HTCC fiber diameter (174 nm) could be achieved with 7 wt% of O-HTCC concentration, 14 kV of voltage, and 0.11 mL/h of feed flow rate. Linear regression (R2 = 0.9736, Radj2 = 0.9716) and the Anderson Darling test demonstrated the excellent fit of the RSM-BBD model. Compared to N-HTCC/PVA nanofibrous film, the O-HTCC/PVA version showed increased growth inhibition and more effective antibacterial efficacies against Escherichia coli (E. coli) (~;86.34 %) and Staphylococcus aureus (S. aureus) (~;99.99 %). DSC revealed improved thermal stability with an increased melting temperature (238 °C) and endothermic enthalpy (157.7 J/g). This study holds potential for further development of antibacterial packaging to extend food shelf-life to reduce bacterial infection.

Optimizing Coreopsis tinctoria Flower Extraction and Inhibiting CML Activity: Box-Behnken Design.

Chronic myelogenous leukemia (CML) is an uncommon type of cancer of the bone marrow associated with high mortality. Although several effective therapies have been developed to reduce symptoms in patients with CML, many of these methods are associated with side effects. Coreopsis tinctoria Nutt. (C. tinctoria) is a natural medicinal material that possesses antioxidant and anticancer activities. Yet, its effect in treating leukemia has still not been fully explored. To optimize the C. tinctoria flower extraction process and investigate whether these extracts can impair CML cell survival. The extraction process of C. tinctoria was optimized by the Box-Behnken design response surface method. K562 cells were treated with different volumes (0, 10, 25, 50, and 100 µL) of C. tinctoria flower extracts. The effect of C. tinctoria extract on cell morphology and cell apoptosis was assessed by light microscopy, laser confocal microscopy, and flow cytometry. We established the following optimized C. tinctoria flower extraction conditions: temperature of 84.4 °C, extraction period of 10 mins, solid-liquid ratio of 1:65, and times 4. These conditions were applied for C. tinctoria flower extraction. Pre-incubation of extracts prepared under the aforementioned optimal conditions with K562 cells induced cell cytotoxicity and cell apoptosis. C. tinctoria flower extracts exert obvious anti-leukemia effects in vitro and may be a potential drug candidate for leukemia treatment.

Preparation and evaluation of microencapsulated delivery system of recombinant interferon alpha protein from rainbow trout

Diseases caused by viruses pose a significant risk to the health of aquatic animals, for which there are presently no efficacious remedies. Interferon (IFN) serving as an antiviral agent, is frequently employed in clinical settings. Due to the unique living conditions of aquatic animals, traditional injection of interferon is cumbersome, time-consuming and labor-intensive. This study aimed to prepare IFN microcapsules through emulsion technique by using resistant starch (RS) and carboxymethyl chitosan (CMCS). Optimization was achieved using the Box-Behnken design (BBD) response surface technique, followed by the creation of microcapsules through emulsification. With RS at a concentration of 1.27 %, a water‑oxygen ratio of 3.3:7.4, CaCl2 at 13.67 %, CMCS at 1.04 %, the rate of encapsulation can escalate to 80.92 %. Rainbow trout infected with Infectious hematopoietic necrosis virus (IHNV) and common carp infected with Spring vireemia (SVCV) exhibited a relative survival rate (RPS) of 65 % and 60 % after treated with IFN microcapsules, respectively. Moreover, the microcapsules effectively reduced the serum AST levels and enhanced the expression of IFNα, IRF3, ISG15, MX1, PKR and Viperin in IHNV-infected rainbow trout and SVCV-infected carp. In conclusion, this integrated IFN microcapsule showed potential as an antiviral agent for treatment of viral diseases in aquaculture.

Two-response surface design optimization of carboxylated CNCs with super high thermal stability and dye removal capability

Discharging wastewater from industrial dyeing and printing processes poses a significant environmental threat, necessitating green and efficient adsorbents. Cellulose nanocrystals (CNCs) have emerged as a promising option for dye adsorbing. However, the industrial production and commercialization of CNCs still faced low yield, time-consuming, and uneco-friendly. In this study, we proposed a facile hydrochloric/maleic acid (HCl/C4H4O4) hydrolysis method to synthesize carboxylated CNCs using Box-Behnken design and dual response surface design, which can systematically investigate the effect of experimental factors (temperature, time and HCl/C4H4O volume ratio) on the final products. The rod-liked carboxylated CNCs gave the highest yield of 90.50 %, maximum carboxyl content of 1.29 mmol/g, and efficient dye removal ratio of 91.5 %. Furthermore, compared to CNCs obtained by commonly sulfuric acid hydrolysis way (CNCs-S) with a Tmax of 242.6 °C, the CNCs extracted at 5 h exhibited significantly improved thermal stability with Tmax reaching 351.2 °C. The enriched carboxyl content and excellent thermal stability show potential wastewater treatment applications under harsh conditions.

Sodium alginate/gelatin hydrogel spheres loaded with Fructus Ligustri Lucidi essential oil: Preparation, characterization and biological activity

The application of plant essential oils in the food industry is often hindered by their poor water solubility and high volatilize. Encapsulation has emerged as an effective solution to this problem. This study focuses on the preparation of Fructus Ligustri Lucidi essential oil gel spheres (FEOH) based sodium alginate and gelatin. The optimum formulation for FEOH was established by Box-Behnken Design response surface testing, resulting in a composition of 10 % FEO, 5 % TW20 and 2 % CaCl2. This formulation achieved an encapsulation efficiency of 85.56 %. FTIR and SEM results indicated the successful encapsulation of FEO within the gel spheres. Furthermore, DSC and TGA results showed that encapsulation enhanced the thermal stability of the essential oil. At room temperature, the water content of FEOH exceeded 90 %, and it showed the highest swelling ratio of 62.5 % in an alkaline medium at different pH conditions. The in vitro release behavior showed that FEOH was released up to 85.28 % in oil-based food simulants within 2 h. FEOH showed strong antibacterial activity, with a Minimum Inhibitory Concentration (MIC) of 128 mg/mL against Staphylococcus aureus and 256 mg/mL against Escherichia coli. The gel spheres obtained in this research show significant potential as food preservatives in food matrices.

Folate-chitosan Coated Quercetin Liposomes for Targeted Cancer Therapy.

Although quercetin exhibits promising anti-tumor properties, its clinical application is limited due to inherent defects and a lack of tumor targeting. This study aimed to prepare and characterize active targeting folate-chitosan modified quercetin liposomes (FA-CS-QUE-Lip), and its antitumor activity in vitro and in vivo was also studied. Box-Behnken Design (BBD) response surface method was used to select the optimal formulation of quercetin liposomes (QUE-LP). On this basis, FA-CS-QUE-LP was obtained by connecting folic acid chitosan complex (FA-CS) and QUE-LP. The release characteristics in vitro of QUE-LP and FA-CS-QUE-LP were studied. Its inhibitory effects on HepG2 cells were studied by the MTT method. The pharmacokinetics and pharmacodynamics in vivo were studied in healthy Wistar mice and S180 tumor-bearing mice, respectively. The average particle size, zeta potential and encapsulation efficiency of FA-CS-QUELP were 261.6 ± 8.5 nm, 22.3 ± 1.7 mV, and 98.63 ± 1.28 %, respectively. FA-CS-QUE-LP had a sustained release effect and conformed to the Maloid-Banakar release model (R2=0.9967). The results showed that FA-CS-QUE-LP had higher inhibition rates on HepG2 cells than QUE-Sol (P < 0.01). There was a significant difference in AUC, t1/2, CL and other pharmacokinetic parameters among QUE-LP, FA-CS-QUE-LP, and QUE-Sol (P < 0.05). In in vivo antitumor activity study, the weight inhibition rate and volume inhibition rate of FA-CS-QUE-LP were 30.26% and 37.35%, respectively. FA-CS-QUE-LP exhibited a significant inhibitory effect on HepG2 cells, influenced the pharmacokinetics of quercetin in mice, and demonstrated a certain inhibitory effect on S180 tumor-bearing mice, thus offering novel avenues for cancer treatment.

Study on the total flavonoid content and antioxidant activity of Morus nigra Linn. from different origins in Xinjiang

Optimization of the extraction process of total flavonoids from Morus nigra Linn. based on response surface design, to compare the differences in total flavonoid content of Morus nigra Linn. from different origins in Xinjiang and its relationship with antioxidant activity. A one-way test was used to investigate the effects of ethanol volume fraction, material-liquid ratio, ultrasonic power and ultrasonic time on total flavonoid content analysis of Morus nigra Linn. , Box-Behnken response surface design optimisation was used to derive the optimal extraction process parameters. Meanwhile, the in vitro antioxidant activity of Morus nigra Linn. was evaluated by antioxidant activity indexes such as hydroxyl radical scavenging capacity and ferric ion reducing capacity. The optimal extraction condition was 45% ethanol by volume, 1∶20 g/mL material-liquid ratio, 300W ultrasound power and 60 min ultrasound time. The total flavonoid content of Morus nigra Linn. s from six origins was detected and the result showed that Kuche &gt;Kashgar &gt;Kuche Wuqia Town&gt;Hetian &gt;Ying jisha &gt;Yutian, in which the total flavonoid content of mulberry in Kucha city was(27.159±0.091)mg/g. The difference in the total flavonoid content of Morus nigra Linn. s in different origicns was statistically significant(P&lt;0.05). In vitro antioxidant activity analysis showed that the antioxidant activity of mulberry from Kuche and Hetian was stronger, and the hydroxyl radical scavenging capacity, ferric ion reducing capacity, and total antioxidant capacity of mulberry from various origins were statistically significant(P&lt;0.05). The correlation analysis showed that the total flavonoid content of Morus nigra Linn. was correlated with the antioxidant capacity to improve the scavenging of hydroxyl radicals. The ultrasonic-assisted method of extracting total flavonoids from Morus nigra Linn. is simple, and the model constructed has a high degree of fit, which can better compare the total flavonoids content of Morus nigra Linn. from different origins in Xinjiang.

Investigation of oligomeric proanthocyanidins extracted from Rhodiolae Crenulatae Radix et Rhizomes using deep eutectic solvents and identified via data-dependent-acquisition mass-spectroscopy

In this study, 34 deep eutectic solvents were successfully prepared for the extraction of proanthocyanidin from Rhodiolae Crenulatae Radix et Rhizomes. The extraction process was optimized using single factor exploration and Box-Behnken design-response surface analysis. The extraction rate was significantly improved when the molar ratio of choline chloride to 1,3-propanediol was 1:3.5 and the water content was 30% (V/V) in deep eutectic solvents. AB-8 macroporous resin and ethyl acetate were used for separation and refining, and the oligomer-rich proanthocyanidin components were eventually obtained. The ultraviolet (UV) and infrared spectrometer (IR) spectra showed that the proanthocyanidins were mainly composed of catechin and epicatechin. To further clarify the chemical composition of proanthocyanidin, an ion scan list containing 156 proanthocyanidins precursors was obtained by constructing a proanthocyanidins structural library and mass defect filtering algorithm, combined with the Full mass spectrometry (MS)/dd-MS2 scan mode that turns on the “if idle pick others” function. By using Ultra high performance liquid chromatography & High-resolution mass spectrometer (UHPLC/Orbitrap MS), the analysis used both targeted and non-targeted methods to detect proanthocyanidins. Finally, 50 oligomeric proanthocyanidin compounds were identified, including 7 monomers, 22 dimers, 20 trimers, and 1 tetramer, most of which were procyanidins of proanthocyanidins (84%), and a small amount of prodelphinidin (14%) and other types of proanthocyanidins (2%), which enabled the systematic characterization of proanthocyanidin components from Rhodiolae Crenulatae Radix et Rhizomes. Meanwhile, the comparison with the grape seeds oligomeric proanthocyanidins standard (United States Pharmacopoeia) revealed that the proanthocyanidins in Rhodiolae Crenulatae Radix et Rhizomes were more abundant, suggesting that the proanthocyanidins in Rhodiolae Crenulatae Radix et Rhizomes has promising applications.

Optimization of extracting technology of iridoid glycosides and phenylethanoid glycosides from Pedicularis decora Franch. by G1-entropy-coupled response surface methodology and rapid identification by UPLC-Q/TOF-MS

Quality control and clarifying ingredients are the foundation of pharmacodynamic material basis research. Pedicularis decora Franch. (P. decora) is clinically used to treat Alzheimer’s disease and exerts significant antioxidative, anti-inflammatory and neuroprotective effects. However, there is little systematic research on the extraction and composition and the current research on P. decora focused on the quality control and extraction with aucubin as only quality marker. It reported that Iridoid glycosides (IGs) and phenylpropanoid glycosides (PeGs), which are characteristic components of the Pedicularis species, have been reported to have various anti-Alzheimer’s activity. This study focused on the extraction and rapid qualitative analysis of IGs and PeGs in P. decora. First, HPLC-UV method was established to detect five IGs and PeGs analytes simultaneously and assess the effect of the extraction technology. Then, the G1-entropy method with the Box-Behnken response surface design methodology was used to optimized extraction technology. The optimum conditions were determined to be reflux with 55% methanol aqueous solutions, at 75 °C for 50 min. Finally, by establishing UPLC-Q/TOF-MS, 15 IGs and 15 PeGs in P. decora were rapidly identified and characterized for the first time. The results will provide a reverence of a higher quality standard and the pharmacodynamic material basis research.

Enhancing H2O2 production with a self-breathing gas diffusion electrode fabricated via ultrasonic impregnation and vacuum filtration

In this study, an electro-Fenton gas diffusion electrode featuring air self-respiration was fabricated by incorporating carbon nanotubes, carbon nitride, and polytetrafluoroethylene onto graphite felt. The fabrication process involved a synergistic approach of ultrasonic impregnation and vacuum filtration, establishing a gas–liquid-solid tri-phase interface both on the surface and within the electrode. This preparation method facilitates autonomous air intake, diffusing it to the tri-phase reaction interface, thereby eliminating the necessity for aeration and reducing operational costs. The optimal electrode preparation conditions were determined through Box-Behnken Design response surface experiments, leading to the enhancement of H2O2 production conditions. Under the optimized conditions, H2O2 accumulation reached 45.83 mg L−1 cm−2h−1, surpassing the performance achieved with conventional ultrasonic impregnation and vacuum filtration methods. Furthermore, the performance of self-breathing and the impact factors are explored. Finally, the electrode’s efficacy was demonstrated through the degradation of phenol and bisphenol A with concentrations of 100 mg L−1 exhibiting degradation rates of 92 % and 95 %, respectively, within 60 min.

Optimizing the quality of bran-fortified stewing noodles using extruded wheat bran and improvers

Aimed to improve the tensile properties, color, and sensory quality of bran-fortified stewing noodles using bran extrusion and improvers. A single-factor experiment and Box–Behnken design response surface experiment were designed, and the multi-index comprehensive weighted scoring method was applied. The single-factor experiment indicated high-quality bran-fortified stewing noodles when wheat gluten, glucose oxidase, and guar gum contents were 10%, 40 mg/kg, and 0.3%, respectively. The response surface experiment showed that the comprehensive weighted score in the response surface optimal group was maximum (86.33 points) when wheat gluten, glucose oxidase, and guar gum contents were 5%, 40 mg/kg, and 0.2%, respectively. The verified model experiment showed that the average comprehensive weighted score was 89.31±0.49 points, indicating that the model was feasible to improve the quality of bran-fortified stewing noodles. The optimal formula involved wheat gluten, glucose oxidase, and guar gum contents of 6.67%, 28 mg/kg, and 0.22%, respectively. Bran extrusion and improvers can improve the quality of bran-fortified stewing noodles. The findings may serve as a reference for the quality improvement and industrial production of fiber-rich stewing noodles.

Simultaneous Extraction and Decaffeination Process Optimization of Green Coffee Bean-Based Beverages Using Response Surface Methodology

Simultaneous Extraction and Decaffeination Process Optimization of Green Coffee Bean-Based Beverages Using Response Surface Methodology

The Optimization of the Steam-Heat-Treated Process of Rattan (Calamus simplicifolius) Based on the Response Surface Analysis and Its Chemical Changes

The objective of this study is to investigate the impacts of steam heat treatment parameters (e.g., temperature, time, and pressure) on the impact toughness of rattan (Calamus simplicifolius). The Box–Behnken design response surface analysis was employed to optimize the steam heat treatment parameters. Impact toughness was selected as the evaluation index, with single-factor tests conducted as a baseline for comparison. Changes in chemical composition, cellulose crystallinity, and pyrolysis properties were analyzed using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectra, Thermogravimetry–Fourier transform infrared (TG-FTIR) spectra, and wet-chemistry methods for both untreated control samples and the heat-treated samples. The results show that a 1 h steam heat treatment at 160 °C under 0.1 MPa pressure has the optimal process parameters for the rattan. The achieved impact toughness value closely matches the predicted value at 71.29 kJ/m2. After the steam heat treatment, hemicellulose and cellulose contents decrease, whereas relative lignin content increases significantly, leading to improved toughness characteristics in Calamus simplicifolius samples. The TG results indicate that maximum weight loss occurs at temperatures of 352 °C, 354 °C, and 361 °C, respectively, for three different samples. This suggests that the thermal stability is enhanced as a result of the heat treatment. These findings will help optimize the heat treatments of the rattan material.

"UHPLC-Q-TOF/MS-chemometrics-network pharmacology" integrated strategy to discover quality markers of raw and stir-fried Fructus Tribuli and process optimization of stir-fried Fructus Tribuli.

Fructus Tribuli, the dried ripe fruit of Tribulus terrestris L., has various beneficial effects, including liver-calming and depression-relieving effects. Raw Fructus Tribuli (RFT) and stir-fried Fructus Tribuli (SFT) are included in the Chinese Pharmacopoeia 2020 edition (Ch. P 2020). However, owing to the lack of specific regulations on SFT-processing parameters in Ch. P 2020, it is difficult to ensure the quality of commercially available SFT. The present study aimed to screen the quality markers (Q-markers) of RFT and SFT and optimize the processing technology of SFT based on the identified Q-markers. First, the ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) technology as well as multiple statistical analysis along with network pharmacology was used to comprehensively identify the Q-markers of RFT and SFT. Then, based on single-factor experiments, the Box-Behnken design (BBD) response surface methodology (RSM) was used to optimize the processing technology of SFT and perform process validation. A total of 63 components were identified in RFT and SFT extracts. Terrestrosin D and Terrestrosin K were initially considered the Q-markers of RFT and SFT, respectively. The optimum processing technology conditions were 208°C, 14 min, and 60 r·min-1. Three batches of process validation were performed, and the mean composite score was 56.87, with a relative standard deviation (RSD) value of 1.13%. The content of steroidal saponin components in RFT was significantly different before and after stir-frying. Terrestrosin D and Terrestrosin K were validated as the Q-markers of RFT and SFT, respectively. The identification of Q-markers for RFT and SFT offered a clear index for optimizing the SFT-processing technology and provided a basis for the quality control of RFT and SFT decoction pieces.

Ultrasonic–microwave synergistic liquid–liquid microextraction based on solidified floating organic droplets for extraction of histamine in beer and fish and exploration of the extraction process

It is important to detect the presence of histamine (His) for indicating food quality. To improve the precision and accuracy of histamine detection, this study developed a novel ultrasonic–microwave synergistic liquid–liquid microextraction based on solidified floating organic droplets (UMS-SFO-LLME) to determine His in beer and fish combined with visible spectrophotometry. Through single-factor experiments and response surface Box–Behnken design, the key extraction conditions affecting UMS-SFO-LLME were systematically optimized. The results for the extraction kinetics and thermodynamics indicated that UMS-SFO-LLME is a spontaneous endothermic diffusion extraction process. The linear range of this method in combination with visible spectrophotometry for the determination of His in beer and fish is 0.3–15 mg L−1 and 1–300 mg kg−1, limit of detection is 0.1 mg L−1 and 0.3 mg kg−1, the intra-day precision is 0.86%–1.22% and 0.98%–2.11%, and the inter-day precision is 0.81%–1.75% and 1.45%–2.32%, respectively. UMS-SFO-LLME is an efficient, green and economical sample pretreatment method for determination of His in beer and fish samples.

Optimization of mix proportions for hybrid fiber engineered cementitious composites based on Box-Behnken design response surface model

In this paper, basalt fiber (BF) and polyethylene fiber (PE) were mixed into cement matrix to prepare a new hybrid fiber Engineered Cementitious Composite. The Box-Behnken experimental design method within the Response Surface Methodology (RSM) was employed, the effects of water-binder ratio, sand-binder ratio and fiber content on compressive strength, flexural strength and equivalent bending toughness of hybrid fiber ECC were studied. Analysis of variance (ANOVA) was used to verify and optimize the model equation, and the ratio of water-binder ratio 0.2, sand-binder ratio 0.35, BF content 1.25%, PE content 1% was obtained. The results show that the synergistic effect of PE and BF has a favorable effect on the mechanical properties of hybrid fiber ECC. PE can achieve high energy absorption and maintain high strain capacity of matrix. BF increases the strength of the specimen. When the BF content increases from 0.9% to 1.2%, the compressive strength increases by 9.6%. The fiber content is highly sensitive to flexural strength and equivalent bending toughness, and the significance level of each factor is more than 95%. The significance level of each factor is BF content > sand-binder ratio > water-binder ratio. The experiment verified that the established prediction model has high accuracy, and the relative error between the optimized RSM value and the experimental value is less than 5%. To provide a certain reference for the design of ECC mix proportions for preparing multi strength and multi toughness series.