Central Composite Rotatable Design Research Articles

Effect of Fermentation Time, pH, and Their Interaction on the Production of Volatile Fatty Acids from Cassava Wastewater

Acidogenic fermentation is a technology that involves halting methanogenesis in the conventional anaerobic digestion process to produce mainly volatile fatty acids (VFAs). VFAs serve as direct precursors to energy-rich or higher value-added products upon undergoing additional processing. In this study, batch reactors were utilized to assess the individual and interaction effects of fermentation time and pH variables on VFA production from acidogenic fermentation of cassava wastewater through the establishment of a completely randomized design and a second-order response surface (rotatable central composite design), respectively. The maximum VFA production observed was 3444.04 mg of acetic acid (HAc)/L (0.58 gCODVFA/gCOD) in a fermentation time of 6 days, with acetic (48.5%), propionic (28.3%), and butyric (13.6%) acids identified as the main metabolites. Additionally, in the assessment of the effect of pH, the maximum VFA production reached 2547.72 mgHAc/L (0.34 gCODVFA/gCOD) at pH 5.9, and acetic acid was identified as the predominant organic acid. Statistically, the fermentation time and pH variables individually affect VFA production from cassava wastewater; however, the interaction between them generated a non-significant effect.

Comparing a polynomial DOE model and an ANN model for enhanced geranyl cinnamate biosynthesis with Novozym® 435 lipase

Central Composite Rotatable Design (CCRD), a type of factorial design of experiment is among the most traditional methods used for optimizing bioprocesses, but, in recent years artificial neural networks (ANNs) have emerged as a promising approach for data modeling in bioprocesses. A comparative study between CCRD and ANN modeling for data treatment in the optimization of geranyl cinnamate biosynthesis using Novozym® 435 lipase was conducted. The most effective ANN architecture identified for predicting and maximizing the enzymatic synthesis of geranyl cinnamate was a 3-3-1 neurons model utilizing logsig activation function in the hidden layer. The ANN was trained using all available experimental data and demonstrated a strong fit to the experimental data, coefficient of determination near 1 (R2 = 0.9948) and low Sum-squared Error (SSE = 43.06). The polynomial model (CCRD; R2 = 0.9806; SSE = 161.56) indicated the same optimal conditions as the ANN model, predicting a temperature of 90.2°C, molar ratio of 1:5.68, and enzyme concentration of 18.6% w/w. Comparison of R2 and SSE values due to lack of fit between both models suggests that ANN predictions closely align with experimental conversion values of geranyl cinnamate. Although the polynomial model is feasible to be applied in enzymatic synthesis, it may be less precise in its predictions than ANN models.

Production of Anthocyanin-Rich Red Rose Petal Extract by Enzymatic Maceration

The use of enzymes to hydrolyze the plant cell matrix is a method known for extracting bioactive substances. The current work used this strategy to produce a rose petal extract rich in anthocyanins that is stable in the presence of marine polysaccharides and has a high antioxidant activity. The process evaluation was carried out sequentially, initially comparing water, ethanol, and their mixtures to anthocyanins extracted in the presence or absence of enzymes. Then, a multi-objective desirability function optimized experimental conditions such as solvent and enzyme concentrations. This study is the first report describing the use of a statistical tool, the central composite rotatable design (CCRD), to optimize anthocyanin extraction from rose petals. This method obtained a maximum extraction of 9.99 mg/g of phenols. The stability of the rose petal extract when using marine polysaccharides retained 60% of the anthocyanins over 28 days without deterioration when protected from sunlight but was practically degraded upon exposure to sunlight. The rose petal extract demonstrated a very high antioxidant capacity of 3.19 μg/mL, close to the literature data for citrus compounds, known to be high in antioxidant compounds for cosmetic food purposes.

Salt slag and rice husk ash as raw materials in zeolite synthesis: Process optimization using central composite rotational design

The growing demand of zeolites for many industrial applications has led to a search for eco-friendly alternatives for their production, in an attempt to reduce costs, save natural resources and alleviate the associated environmental impacts. In the present study, hazardous aluminum salt slag (aluminum source) and rice husk ash (silicon source) were used as secondary raw materials to synthesize sustainable NaP-type zeolites through a hydrothermal process. A central composite rotational experimental design was applied to evaluate the effect of the reaction time and hydrothermal temperature on the obtained zeolites crystallinity. Using the proposed experimental design, temperatures between 85 and 115 °C and different reaction times (2–28 h) were tested. It was found that the interaction between the variables (time and temperature) and both variables, independently, exerted a significant influence on the crystallinity of the zeolites. The optimal experimental conditions (105 °C and 20 h), statistically determined, enabled a high degree of crystallinity (>73%) to be achieved. Thus, the use of hazardous aluminum and agri-food wastes as unconventional precursors for the production of zeolites represents a sustainable alternative to manage these wastes, by transforming them into secondary raw materials.

Microalgae Biomass Production from Rice Husk as Alternative Media Cultivation and Extraction of Phycocyanin Using 3D-Printed Ohmic Heating Reactor.

Phycocyanin is a highly valued pigment present in Spirulina platensis biomass with applications in the food industry in terms of biorefinery concepts; specifically, its antioxidant and antimicrobial capacity are an advantage that could be incorporated into a food matrix. This study aims to use rice husk as an alternative culture medium for S. platensis biomass growth and phycocyanin extraction by ohmic heating processing using a 3D-printed reactor. S. platensis was cultivated in rice husk extract (RHE) from 0-100% (v/v). The highest content of microalgal biomass was 1.75 ± 0.01 g/L, with a specific growth rate of 0.125 ± 0.01 h-1. For the phycocyanin extraction under an ohmic heating process, a 3D-printed reactor was designed and built. To optimize phycocyanin extraction, a central composite rotatable design (CCDR) was evaluated, with three factors: time (min), temperature (°C), and pH. The highest phycocyanin content was 75.80 ± 0.98 mg/g in S. platensis biomass grown with rice husk extract. Ohmic heating is a promising method for rapid phycocyanin extraction, and rice husk as a culture medium is an alternative for the growth of S. platensis biomass in the integration of second- and third-generation biorefineries.

Development and optimization of general drying models for cod (Gadus spp.) using supercritical carbon dioxide

This study aimed to investigate the supercritical carbon dioxide (SC-CO2) drying of cod (Gadus spp.) by developing and optimizing a general mathematical drying model. We applied a central composite rotatable design (CCRD) considering the time (180–360 min), temperature (35–45 °C), and CO2 flow rate (15–25 kg/h) as independent factors, aiming at the reduction of moisture and water activity (aw) of Gadus morhua. Time and flow rate (FR) were the main factors affecting the moisture and aw responses. The mathematical models developed were validated with the accuracy and bias factors and generalized using Gadus chalcogrammus samples, resulting in the acceptable range of 1.003–1.121. The optimal parameter values for drying performance were 312.38 min, 45.38 °C, and 27.4 kg/h (R2 = 0.999). Our results suggest a promising application of SC-CO2 as a fish drying technology, describing a generalist-validated and optimized SC-CO2 drying model for Gadus spp. Industrial applicationThe present study collaborates with understanding supercritical carbon dioxide (SC-CO2) as an innovative fish drying technology at a laboratory scale. The optimal variables that were effective in reducing cod fillets water content were 312.38 min, 45.38 °C, and 27.4 kg/h, in which 26.4% moisture and 0.815 aw were predicted. Therefore, SC-CO2 is suggested to be a promising non-thermal food drying technology applied to fish products.

Coffee Extract as a Natural Antioxidant in Fresh Pork Sausage-A Model Approach.

Consumers are increasingly looking for healthy foods without the addition of synthetic additives. The aim of this study was to evaluate the efficiency of coffee extracts as a natural antioxidant in fresh pork sausage. Firstly, the conditions for obtaining coffee green extracts were optimized (Central Composite Rotatable Design 23, variables: extraction time, ethanol-water ratio, and sample-solvent ratio) in an ultrasound bath (70 °C). The response variables were the bioactive compounds levels and antioxidant activity. Valid models were obtained (p ≤ 0.05, R2 > 0.751), with higher bioactive content and antioxidant activity in the central point region. Extracts of Robusta and Arabica coffee green (RG and AG) and medium roast (RR and AR) obtained, and central point (10 min, an ethanol concentration of 30%, and a sample-solvent ratio of 10 g/100 mL) and optimized (14.2 min, 34.2%, and 5.8 g/100 mL) parameters were characterized. The RG presented a significantly (p ≤ 0.05) higher content of caffeine (3114.8 ± 50.0 and 3148.1 ± 13.5 mg/100 g) and 5-CQA (6417.1 ± 22.0 and 6706.4 ± 23.5 mg/100 g) in both extraction conditions, respectively. The RG and RR coffee presented the highest antioxidant activity. Two concentrations of RG and RR coffee extracts were tested in fresh pork sausage. The Robusta coffee extract presented the highest antioxidant activity in both roasted and green states. However, when applied to a meat product, the extract prepared with RG coffee showed better results, with efficiency in replacing synthetic antioxidants (content of malonaldehyde/kg of sample below 0.696 ± 0.059 in 20 days of storage), without altering the sensory attributes of the product (average scores above 7.16 ± 1.43 for all attributes evaluated). Therefore, the RG coffee extract was a suitable alternative as a natural antioxidant applied to fresh pork sausage.

Development of a Genetic Algorithm – Artificial Neural Network model to optimize the Dimensional Accuracy of parts printed by FFF

PurposeFused Filament Fabrication (FFF) is one of the growing technologies in additive manufacturing, that can be used in a number of applications. In this method, process parameters can be customized and their simultaneous variation has conflicting impacts on various properties of printed parts such as dimensional accuracy (DA) and surface finish. These properties could be improved by optimizing the values of these parameters.Design/methodology/approachIn this paper, four process parameters, namely, print speed, build orientation, raster width, and layer height which are referred to as “input variables” were investigated. The conflicting influence of their simultaneous variations on the DA of printed parts was investigated and predicated. To achieve this goal, a hybrid Genetic Algorithm – Artificial Neural Network (GA-ANN) model, was developed in C#.net, and three geometries, namely, U-shape, cube and cylinder were selected. To investigate the DA of printed parts, samples were printed with a central through hole. Design of Experiments (DoE), specifically the Rotational Central Composite Design method was adopted to establish the number of parts to be printed (30 for each selected geometry) and also the value of each input process parameter. The dimensions of printed parts were accurately measured by a shadowgraph and were used as an input data set for the training phase of the developed ANN to predict the behavior of process parameters. Then the predicted values were used as input to the Desirability Function tool which resulted in a mathematical model that optimizes the input process variables for selected geometries. The mean square error of 0.0528 was achieved, which is indicative of the accuracy of the developed model.FindingsThe results showed that print speed is the most dominant input variable compared to others, and by increasing its value, considerable variations resulted in DA. The inaccuracy increased, especially with parts of circular cross section. In addition, if there is no need to print parts in vertical position, the build orientation should be set at 0° to achieve the highest DA. Finally, optimized values of raster width and layer height improved the DA especially when the print speed was set at a high value.Originality/valueBy using ANN, it is possible to investigate the impact of simultaneous variations of FFF machines’ input process parameters on the DA of printed parts. By their optimization, parts of highly accurate dimensions could be printed. These findings will be of significant value to those industries that need to produce parts of high DA on FFF machines.

Optimization of guar gum-based anti-browning coating for prolonging the shelf life of cut potatoes

The impact of guar gum (GG), crude algae ethanolic extract (CAEE), and turmeric essential oil (TEO) incorporated edible coating formulations on the quality of cut potatoes was investigated at room temperature (27 ± 3 °C, 70–85 % RH) storage using a rotatable central composite design. Besides, 30 % glycerol, 5 % calcium chloride, and 3 % ascorbic acid (w/w) were added to the coating solution as additives. The surface color, respiration rate, water vapor transmission rate, visible mold growth, and sensory analysis were assessed after seven days of storage. The inclusion of ascorbic acid and TEO in edible coating demonstrated a more effective delay in browning. The coated potatoes had lower OTR, CTR, and WVTR values for GG concentrations of 0.5 to 1 g/100 mL than the control. Compared to additives, higher concentrations of GG improved response parameters. The WVTR value of coated potatoes was significantly impacted by the interaction between CAEE and TEO with GG. Incorporating CAEE and TEO into the formulations of guar gum led to a reduction in the permeability of the coating to oxygen and water vapor. The seven days of extended shelf life compared to two days of control were observed with the optimized coating formulation. Furthermore, the application of the coating treatment proved effective in preventing enzymatic browning and creating a barrier against moisture and gases, contributing to prolonged freshness during extended storage periods.

Application of experimental design in the synthesis of 1-butanol from ethanol on mixed oxide catalysts at different mg/al molar ratios

1-Butanol, primarily sourced from petroleum, is currently being considered as a viable alternative to gasoline. Various pathways for synthesizing 1-butanol from renewable raw materials have been explored, with a particular focus on the Guerbet reactions. This study aimed to investigate the synthesis of 1-butanol from ethanol using Mg/Al mixed oxides derived from layered double hydroxides with Mg/Al molar ratios of 3:1, 5:1, 8:1, and 10:1. The catalysts were analyzed through X-ray diffraction, X-ray fluorescence, N2 adsorption, scanning electron microscope and energy-dispersive X-ray spectroscopy. Catalytic reaction tests were performed according to a Central Composite Rotatable Design (CCRD) with three replicates at the central point (CP). Among the catalysts tested at CP, the mixed oxides with Mg/Al molar ratios of 3:1 and 5:1 exhibited the most promising results, displaying similar ethanol conversion, and 1-butanol selectivity. This similarity underscores their well-balanced combination of both acidic and basic sites. However, further assessment through a deactivation test revealed that the mixed oxides with Mg/Al molar ratio of 5:1 held the most potential for long-term 1-butanol synthesis from ethanol, thanks to its superior stability and sustained activity. Using this catalyst, other reaction tests were carried out following the CCRD, varying N2 feed flowrate, ethanol molar content in feed flowrate, and temperature. The results indicated that an increase in ethanol conversion directly correlated with higher temperatures, while the 1-butanol selectivity depended on both the N2 feed flowrate, ethanol molar content in feed flowrate, highlighting the importance of a well-balanced combination of both acidic and basic sites.

Cananga odorata (Ylang-Ylang) Essential Oil Containing Nanoemulgel for the Topical Treatment of Scalp Psoriasis and Dandruff.

This research aimed to evaluate the efficacy of a nanoemulgel (NE) containing Cananga odorata (Ylang-Ylang) oil for managing scalp psoriasis and dandruff through various assessments. The study involved phytochemical screening, characterization, stability testing, in vivo performance evaluation, dermatokinetic analysis, central composite rotatable design (CCRD) optimization, in vitro release profiling, and antioxidant and antimicrobial activity assessment of the NE. The NE exhibited excellent stability and maintained physical parameters over a three-month period. In vivo studies showed no skin irritation, maintenance of skin pH (4.55 to 5.08), and improvement in skin hydration (18.09 to 41.28 AU) and sebum content (26.75 to 5.67 mg/cm2). Dermatokinetic analysis revealed higher skin retention of C. odorata in the NE (epidermis: 71.266 µg/cm2, dermis: 60.179 µg/cm2) compared to conventional formulations. CCRD optimization yielded NE formulations with the desired particle size (195.64 nm), entrapment efficiency (85.51%), and zeta potential (-20.59 mV). In vitro release studies indicated sustained release behavior, and antioxidant and antimicrobial properties were observed. This study demonstrates the stability, skin-friendliness, therapeutic benefits, and controlled release properties of the NE. The NE presents a promising option for various topical applications in treating bacterial and fungal diseases, potentially enhancing drug delivery and treatment outcomes in pharmaceuticals and cosmetics.

Passion fruit by-products (Passiflora edulis f. flavicarpa) as a potential fat replacer in ice cream.

In recent years, people have become interested in consuming low-fat foods as this reduces the risk of obesity and cardiovascular disease. For this reason, this study optimized the incorporation of passion fruit epicarp (PFE) as a partial fat substitute in dairy ice cream. For this purpose, a central composite rotational design 22 was performed and 5 response variables were optimized, of which 4 variables were maximized (percentage overrun, hardness, adhesiveness, and color coordinates L*, a*, b*), while the melting rate was minimized as a function of two factors (% PFE and % fat). The stability of three types of ice cream was then evaluated: experimental ice cream (3% milk fat and 0.97% PFE), commercial ice cream (4% milk fat and 2% vegetable fat) and control ice cream (3% milk fat without PFE added), according to their physicochemical and sensory properties during 57 days of storage (-22 °C, 85% relative humidity). The results showed that it was possible to reduce the milk fat by up to 25% by adding PFE (0.97%), which significantly reduced the melting rate and resulted in higher hardness (N), adhesiveness and increased yellowness compared to the commercial samples. The optical microscopy analysis also showed that PFE keeps the air bubbles immobile due to the increased viscosity in the serum phase during the 57-day storage.

Process Optimization of Pellet Manufacturing from Mixed Materials in Ultrasonic Vibration-Assisted Pelleting

Achieving carbon neutrality and alleviating the rural energy predicament are crucial aspects in rural areas, particularly in the severe cold regions of northeast China. Pellets serve as clean, renewable energy sources and are ideal alternative fuels. This study investigated the influencing factors and effects of mixed raw materials in ultrasonic vibration-assisted pelleting (UV-A pelleting). Rice straw and corn stover were mixed to produce pellets, and a central composite rotatable design (CCRD) was conducted to analyze the variables and their interactions on pellet density and durability. Mathematical regression models for pellet density and durability were established and then validated through ANOVA analysis. The results showed that all variables significantly affected the density and durability of pellets. The mixing ratio had a greater impact on pellet durability compared to density due to differences in ingredients. The optimal combination of process parameters included a mixing ratio of 25%, molding pressure of 4 MPa, pelleting time of 37 s, and ultrasonic power output at 200 W, resulting in a pellet density of 1301.18 kg/m3 with a durability reaching 94.26%. The desirability value (0.997) under these optimal conditions confirmed the validity of the models; further experiments also verified their effectiveness. The combustion of the optimized pellet was analyzed using thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis in an air atmosphere. Four combustion stages and ignition temperature were provided.

Cellulases production optimization and inductors evaluation in pretreated plantain rachis by Penicillium oxalicum

AbstractPretreated lignocellulosic residues are suitable substrates for cellulases production by filamentous fungi. In the current work, plantain rachis was pretreated with sequential acid and alkali and then used as the main carbon source for cellulases production. First, a full 23 factorial design and response surface methodology (RSM), based on central composite rotatable design (CCRD), were carried out to cellulases production media optimization from plantain rachis by Penicillium oxalicum. The cellulases production was evaluated in flasks and bioreactor scale; in parallel, the addition of possible cellulases inductors was evaluated in flasks: molasses, beer bran, oat bran, and wheat bran. Results from statistical analyses with a level of confidence of 95% demonstrated that the concentration of ammonium sulfate must be kept at 1.625 g/L. The optimum urea and yeast extract concentrations were 0.560 g/L and 0.250 g/L, respectively. Cellulases volumetric productivities were higher in instrumented bioreactor than in flasks: 78.03% for exoglucanase, 10.87% for endoglucanase, 1.58% for β‐glucosidase, and 44.36% for FPU. Therefore, P. oxalicum was able to produce cellulases from plantain rachis in flasks and bioreactor, and molasses was the additional inductor that presented an increment in cellulases activities: endoglucanase 15%, exoglucanase 81%, and β‐glucosidase 55%.

Eugenia uniflora (pitanga) juice as a new alternative vehicle for Limosilactobacillus fermentum ATCC 23271: evaluation of antioxidant and anti-infective effects.

Probiotic-containing foods are among the most appreciated functional foods; however, probiotic-based dairy products cannot be consumed by people who are lactose intolerant, allergic to milk, or vegetarian or vegan individuals. Thus, new non-dairy matrices have been tested for probiotics delivery. This study evaluated the growth and viability of Limosilactobacillus fermentum ATCC 23271 and Lacticaseibacillus rhamnosus ATCC 9595 in Pitanga juice (Eugenia uniflora L.). The effects of the fermentation on the antioxidant and anti-infective properties of the juice were also analyzed. The E. uniflora juice allowed lactobacilli growth without supplementation, reaching rates around 8.4 Log CFU/mL and producing organic acids (pH values < 4) after 72h of fermentation. The strain remained viable after 35 days of refrigerated storage. Fermentation by these bacteria increases the antioxidant capacity of the juice. The central composite rotational design was employed to evaluate the effects of bacterial inoculum and pulp concentration on growth and organic acids production by L. fermentum ATCC 23271. The strain was viable and produced organic acids in all tested combinations. L. fermentum-fermented juice and its cell-free supernatant significantly increased the survival of Tenebrio molitor larvae infected by enteroaggregative Escherichia coli 042. The results obtained in this study provide more insights into the potential of Pitanga juice to develop a functional non-dairy probiotic beverage with antioxidant and anti-infective properties.

Supported heterogeneous catalyst of the copper oxide nanoparticles and nanozeolite for binary dyes mixture degradation: Machine learning and experimental design

The present work aims to evaluate the photocatalytic activity of an alternative supported nanocatalyst (nANA@CuO-NPs) for a binary dye mixture (Crystal Violet and Methylene Blue, labeled CV:MB) under visible light and study to propose a model to predict the reaction pathway for the process. An experimental design (Central Composite Rotational Design with 3 factors and 2 levels – CCRD 23) was proposed to evaluate the ideal condition of the CV/MB photodegradation and four machine learning algorithms (Decision Tree, Random Forest, Xtreme Gradient Boosting and Artificial Neural Network-Multilayer Perceptron) were used to predict the main degradation products. The supported nanocatalyst was characterized by X-ray diffraction (XRD), Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy, N2 porosimetry, Diffuse Reflectance Spectroscopy (DRS), Field Emission Gun – Scanning Electron Microscope (FEG-SEM), Scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX), zeta potential (ZP) and zero charge point (pHZCP). XRD diffractogram of the nANA@CuO-NPs showed the tenorite and analcime phases with crystallite size and microstrain ranging from 0.319 to 22.35 nm and 6.48–454 × 10−3. ATR-FTIR spectra indicated the presence of functional groups characteristic of copper oxide nanoparticles (CuO-NPs) and nanozeolite analcime (nANA) on the supported catalyst, confirming the impregnation method. SEM micrographs indicated a heterogeneous surface with clusters (CuO-NPs and nANA@CuO-NPs) and homogenous surface for nANA, while the EDX showed the nANA with Si/Al < 2 (low-silica nanozeolite) and nANA@CuO-NPs with the presence in the elemental composition of the catalytic support (nANA) and the photoactive phase (CuO-NPs). Supported nanocatalyst showed physio-chemical stability due to the electrostatic interactions (ZP = 51.5 ± 0.5 mV) and band gap energy (Eg) of the 1.67 eV allowing its applicability under visible radiation. XGB algorithm resulted in the best predictive model (R2 equals 0.8106 and 0.9880 for training and testing, RMSE < 6.0), confirming the obtention of carbon dioxide (m/z = 44), water (m/z = 18) and low-molar mass compounds at the final of the binary dye mixture degradation reaction. The ideal condition for the by CCRD 23 for the degradation of the dye mixture was [CV:MB] = 135 mg/L, [nANA@CuO-NPs] = 1 g/L and pH = 7 with 82.84 % (k = 0.0089 min−1). Therefore, the synthesized nanocatalyst proved its good photocatalytic activity toward a cationic dye mixture of CV and MB dyes. Furthermore, this work confirms the potentiality of machine learning algorithms to develop predictive models for the elucidation of the degradation reaction pathway of organic dyes.

Introduction of an electrospun nanofibrous membrane incorporated by metal-organic framework-199 (MOF-199) with Lewis acid property for efficient extraction of sulfonamides in on-chip electromembrane extraction

In this study, a new supporting polymeric membrane having Lewis acid nature was introduced for immobilizing organic solvent in on-chip electromembrane extraction (on-chip EME). For this aim, a polymeric nanofibrous membrane incorporated by a copper based metal-organic framework (MOF-199), with coordinatively unsaturated metal sites and Lewis acid property, was prepared by electrospinning a mixture of polycaprolactone (PCL) and MOF-199. Based on the field emission scanning electron microscopy images, the obtained polymeric membrane consisted of intertwined nanofibers having empty space between the fibers which could provide a suitable place for immobilizing the organic solvent. To demonstrate remarkable extractability of the proposed membrane (PCL/MOF-199 nanofibers) via executing Lewis acid-base interactions, three sulfonamide drugs was selected as anionic polar analytes with Lewis base feature. The parameters affecting the extraction efficiency of the method were optimized through the experimental design method using the orthogonal and rotatable central composite design (CCD). Under optimum conditions, the extraction recoveries ranging from 35.5 to 71.2 %, the relative standard deviations (RSD%) less than 6.45 %, and the detection limits in the range of 0.2–0.5 μg L−1 were achieved. The comparison of the extraction efficiency of the on-chip EME method using the electrospun PCL/MOF-199 nanofibers and PCL nanofibers membranes indicated that the proposed membrane was more efficient for extraction of sulfonamides because of the significant Lewis acid-base interactions of sulfonamides with copper uncoordinated open sites in MOF-199. Finally, the performance of the proposed method for extraction and determination of sulfonamides in three real samples was assayed.

Finishing of additively manufactured stainless steel features by the eco-friendly electrolyte: Plasma and surface interaction science

Many industries, including the chemical, food, medical, and aerospace sectors, use complex-shaped components fabricated by additive manufacturing. The usage of additively manufactured components in end-user applications is challenging due to their higher surface roughness. Finishing processes are necessary to reduce the surface roughness. Electrolytic hot plasma polishing is a newly developed finishing process. For this process, an eco-friendly electrolytic solution is prepared and used to finish any shape of the component that is to be conductive. Salts and distilled water are used while preparing the eco-friendly electrolytic solution, which is used to finish stainless steel. Initially, the prepared solution was used to finish cast stainless steel components, and subsequently, it was employed for finishing additively manufactured stainless steel components. Voltage–current characteristics of the cast and additively manufactured components resulted in a similar pattern. As a result, the range of the input process parameters for cast components was chosen for the input of central composite rotatable design to finish the additively manufactured stainless steel components. The surface roughness of additively manufactured stainless steel features was reduced to 95.6 % of the original surface roughness of 12.45 μm. Scanning electron microscopy was used to examine surface morphology and material removal mechanisms.

Optimization of Power Tiller Operated Pneumatic Planter under Laboratory Conditions for Enhancing Cotton Planting Efficiency

Aim: The study aimed to optimize the operational parameters viz. orifice diameter, suction pressure and forward speed of operation of a power tiller operated pneumatic planter specifically for cotton crops in laboratory condition, focusing on improving planting operation. Study Design: A Central Composite Rotatable Design (CCRD) was employed to optimize the operational parameters. Place and Duration of Study: The study was conducted in a Soil test bin (sand bed test) in the Tillage and Traction Laboratory in the year 2023 to evaluate the effect of various operational parameters on seed uniformity. Methodology: Based on the study of engineering properties of cotton seed, the size of the orifice on the seed drum was determined. The effect of operational parameters was examined by evaluating mean seed spacing, precision in spacing (coefficient of variation), miss index, multiple index, and quality of feed index. Results: The study found that for achieving singulation of seeds, optimal parameters included a metering drum with an orifice size of 3 mm, a suction pressure of 2.78 kPa, and a forward speed of 1.36 km/h. Corresponding actual values of miss index, multiple index, quality feed index, and precision index were found 7.6±2.5, 6.8±1.6, 82.4±2.5 and 4.1±1.2 against predicted values of 4.40, 4.56, 90.1, and 3.90, respectively. Conclusion: The findings suggest that optimizing operational parameters such as orifice size, suction pressure, and forward speed can significantly improve the performance of power tiller operated pneumatic planters for cotton seed planting. These results contribute to enhancing planting accuracy and efficiency in cotton sown areas.

Optimization of conditions for production of pectinase in solid-state fermentation with Aspergillus flavus using dried Assam lemon peel powder as substrate

The culture conditions for pectinase production with Aspergillus flavus by solid-state fermentation (SSF) using dried Assam lemon peel were optimized and the pectinase was used for clarification of grape juice. A central composite rotatable design (CCRD) was used for optimization experiments with moisture content (50-90%), incubation temperature (20-60 ℃), incubation time (96 h–192 h), and urea concentration (0–1%) as independent variables, and pectinase activity as dependent variable. The optimum conditions for pectinase production obtained were moisture content of 60%, incubation temperature of 50 ℃, incubation time of 96 h, and urea concentration of 0.30% with a pectinase activity of 3.68±0.20 U/mL where one unit of pectinase activity corresponds to number of µmole of galacturonic acid released in one minute in 1% pectin solution at 37°C and 4.8 pH. The crude pectinase was found to have maximum activity at a temperature of 40 ℃ and pH 4 and had an apparent Vmax and Km of 6.10 U/mL and 6.62 mg/mL respectively. The grape juice clarified using the crude pectinase showed decreased optical density (1.45±0.06 to 1.17±0.07) and viscosity (1.76±0.10 to 1.46±0.07 mPa.s) and increased reducing sugar content (13.90±0.10 to 16.96±0.06 g/100 mL juice), and total soluble solids (17.77±0.16 to 18.50±0.30 °Brix).