Central Composite Experimental Design Research Articles

Detoxification and enhancement of in vitro rumen digestibility of exhausted olive pomace wastes through alkaline hydrogen peroxide treatment

Abstract Background Due to the sharp rise in animal feed costs, funding alternatives to substitute high-cost raw materials used in animal feed is a persistent need. This study investigated the effect of alkaline hydrogen peroxide pretreatment as straightforward non-toxic technology to enhance the in vitro rumen digestibility of exhausted olive pomace (EOP), an abundant agricultural waste, to be suitable as animal feedstock. It examined the efficiency to eliminate the toxic phenolic content and minimize lipid oxidation of EOP. Results The pretreatment was first optimized using a central composite experimental design. Under the optimized conditions (1.6% H2O2, 5% NaOH), the measured phenolic content was 1.51 ± 0.03 mg/100 g dry weight (DW) for treated olive pomace (TOP) versus 4.91 ± 0.06 mg/100 g for the untreated one. The pretreatment showed that approximately 25% of the lignin was removed. Crude proteins, neutral detergent fibers, and acid detergent fibers yields of TOP were, respectively, 3.320 ± 0.05, 75.24 ± 0.23, and 54.05 ± 0.35 g/100 g of DW, significantly more important than those of untreated EOP. The enzymatic hydrolysis with a cellulase-based cocktail (Celluclast15 FPU/gDW), recorded a 48% of reducing sugar yield for TOP against 33% for EOP. When the in vitro organic matter digestibility (IVOMD) was assayed, the potential gas production of TOP (41.371 ml/g DM) was significantly higher than EOP (25.771 ml/g DM). The metabolizable energy of TOP (9.28 kcal/kg DM) was higher than that of EOP (7.78 kcal/kg DM). Conclusions The present study revealed that alkaline hydrogen peroxide (AHP) could be an efficient treatment for the detoxification and enhancement of in vitro rumen digestibility of olive pomace. This straightforward approach demonstrated that treated olive pomace waste may be well valorized as suitable animal feedstock. Graphical Abstract

Development and assessment of rutin loaded transfersomes to improve ex vivo membrane permeability and in vitro efficacy

The melanoma is the most dangerous kind of skin cancer begins in the melanocytes, or cells that make melanin, the pigment that gives your skin its color. Due to the need of local effect topical administration of anticancer drugs could be the best option for clinical therapy. Present study aimed to formulate transfersomes to enhance the skin penetration of rutin (Rtn). Rutin loaded transfersomes (RtnTFs) were formulated by employing central composite design (CCD) of experiment and comprising of various ratios of phospholipid 90H and sodium deoxycholate as independent variables. The assessment of critical parameters suggested higher encapsulation of Rtn and improved stability of formulation with significant drug release (P < 0.05). The RtnTFs shows higher cell inhibition on Murine skin Melanoma cell line (B16–F10). Further, formulated RtnTFs were incorporated in transdermal patches (TPs) to enhance skin deposition. However the higher deposition of about 0.921 ± 0.23 mg/cm3 of Rtn was observed. RtnTFs-TPs exhibited ideal morphological characteristics in scanning electron microscopic images. Ex-vivo skin diffusion studies revealed the sustained release of about 98 ± 0.26 % drug at the end of 36 h (P < 0.05). Skin irritancy study demonstrated the suitability of RtnTFs-TPs for dermal delivery and with higher stability. Hence the topical delivery with delayed release of drug by enhancing the solubility could be the promising strategy for efficient delivery of anticancer agents.

Optimizing the Antimicrobial Activity of Sodium Hypochlorite (NaClO) over Exposure Time for the Control of Salmonella spp. In Vitro.

Fish is a nutritionally rich product; however, it is easily contaminated by pathogenic microorganisms, such as Salmonella spp. Therefore, this study aimed to identify the best concentration of sodium hypochlorite (NaClO), exposure time, and water temperature that allow the most effective antimicrobial effect on the viable population of Salmonella spp. Thus, Salmonella Enteritidis ATCC 13076 and Salmonella Schwarzengrund were exposed to different time frames, ranging from 5 min to 38.5 min, temperatures between 5 and 38.5 °C, and NaClO concentrations ranging from 0.36 to 6.36 ppm, through a central composite rotational design experiment (CCRD). The results demonstrated that the ATCC strain exhibited a quadratic response to sodium hypochlorite when combined with exposure time, indicating that initial contact would already be sufficient for the compound's action to inhibit the growth of the mentioned bacteria. However, for S. Schwarzengrund (isolated directly from fish cultivated in aquaculture), both NaClO concentration and exposure time significantly influenced inactivation, following a linear pattern. This suggests that increasing the exposure time of NaClO could be an alternative to enhance Salmonella elimination rates in fish slaughterhouses. Thus, the analysis indicates that the Salmonella spp. strains used in in vitro experiments were sensitive to concentrations equal to or greater than the recommended ones, requiring a longer exposure time combined with the recommended NaClO concentration in the case of isolates from aquaculture.

Decolorisation of textile wastewater using biosynthesised iron oxide nanomaterials and Optimisation by Response Surface Methodology

AbstractIn this study, the bacteria (Pseudomonas sp.) was isolated and cultured for biogenic fabrication of Fe3O4 (synthesised using bacterial cell mass) and Fe3O4@ME (synthesised using bacterial extracts) nanoparticles. The biomolecules of the bacterial extract function as a reducing and capping agent, giving the nanoparticle surface negative charges, according to the FTIR and Z potential analysis. The parameters were optimised and screened for indigo blue (IB) dye adsorption onto Fe3O4 and Fe3O4@ME nanoparticles. This work used the Design of the Experimental (DoE) method rather than the conventional one‐variable‐at‐a‐time method. The central composite design (CCD) experiment consisted of 13 experimental runs, and an analysis of variance (ANOVA) was performed to analyse the results. The models for IB dye removal using Fe3O4 and Fe3O4@ME nanomaterials showed adjusted R2 values of 0.99 and 0.99 and predicted R2 values of 0.97 and 0.99, respectively, indicating good model fit. The optimum conditions required for 70 and 64 % colour removal for Fe3O4 and Fe3O4@ME nanomaterials, respectively, are observed at 0.050 gm sorbent doses at the constant room temperature and contact time of 100 min.

Optimization of Total Phenolic Content from Gynura Procumbens Leaves Under Oven and Microwave Drying

The optimization of the process variable; temperature, power, and drying time, under oven and microwave drying were studied for total phenolic content of Gynura procumbens leaves. The optimization conducted using response surface methodology central composite design of experiment. The optimum drying condition was obtained at 65.61°C at 10 hours with 201.78 mgGAE/g of TPC yield for oven drying while, for microwave drying was 436.19 Watt at 8.37 minutes with 12.24 mgGAE/g of TPC yield. The response surface methodology used in this study was able to predict the optimum drying condition for total phenolic content via linear and interaction mathematical model with higher adjusted coefficient determination , for both oven and microwave drying, 0.9383 and 0.7785, respectively. Hence, the models gave good prediction of the total phenolic content obtained from Gynura procumbens leaves under the experimental conditions used in this study. In addition, these outcomes are also expected to contribute to the production of shelf stable Gynura procumbens leaves which can be used for pharmacological purposes.

Optimization of formulation ratios of geopolymer mortar based on metakaolin and biomass fly ash

This study investigated the factors affecting the properties of geopolymer (GP) mortars through a two-stage experimental program created through central composite design of experiments. Stage I focused on the effects of SiO₂/Al₂O₃, H₂O/Na₂O, and total water-to-total solids (W/S) ratios on mortars formulated using metakaolin (MK) as the only geopolymerization precursor, while Stage II evaluated the impact of introducing biomass fly ash (BFA) as a second precursor. Most importantly, the SiO₂/Al₂O₃ ratio was defined based on raw materials’ dissolution tests rather than on their starting chemical composition, setting this study apart from most published literature. The mortars’ properties of interest, taken as response variables, were the flow test spreading diameter, and the efflorescence level and compressive strength after 7 days of curing under ambient conditions. The results of Stage I, regarding GP mortars based on MK only, show that SiO₂/Al₂O₃, H₂O/Na₂O, and W/S all had a statistically significant effect on compressive strength. Regarding the efflorescence level, SiO₂/Al₂O₃ had the most significant effect, H₂O/Na₂O showed a small contribution, and W/S effect was not statistically significant. In stage II, the incorporation of BFA led to (MK + BFA)-based mortars with lower spreading diameter and compressive strength, and higher efflorescence levels, with % BFA being the most important factor affecting these three response variables. Based on the developed models, appropriate combinations of factor values that simultaneously maximize the compressive strength while maintaining the spreading diameter and efflorescence levels within suitable limits were found: GP mortars based only on MK with SiO₂/Al₂O₃ = 4.5, H₂O/Na₂O = 19.0, and W/S = 0.17 are expected to achieve 53MPa of compressive strength at 7 days; (MK + BFA)-based GP mortars with % BFA = 39.0, H₂O/Na₂O = 15.5, SiO₂/Al₂O₃ = 4.5 and W/S = 0.17 are expected to achieve 30MPa. These results provide valuable insights into the factors affecting the properties of GP mortars and can be useful for optimizing formulations for different applications.

Comparative characteristics of different methods for electrophoretic determination of mono- and disaccarides using derivatization

The following variants of electrophoretic determination of sugars with prior derivatization are considered in the article: reductive amination using p-aminobenzoic acid ethyl ester (ABEE) and condensation with 1-phenyl-3-methyl-5-pyrazolone (PMP). Derivatization products were separated using capillary electrophoresis in both zone and micellar modes, and comparative estimate characteristics were obtained. The best efficiency (ca. 650 thousand theoretical plates), selectivity (2.1–2.4), and LOD (0.8–2.9 μg/mL) was observed for the separation of reductive amination products using micellar electrokinetic chromatography (MEKC). Optimization of derivatization conditions was performed for the reductive amination using the central composite experiment design. Additionally, LOD was lowered by the sample intracapillary concentration in sweeping mode, and sample enhancement factors (SEF) of 13–19 were achieved. A proof-of-concept possibility of the intracapillary reductive amination ensuring electrophoretic mobility of the derivatization reagent using detergent micelles as carrying agents was demonstrated. Both derivatization methods were applied for the analysis of baby food.

Treatment of Antihypertensive and Cardiovascular Drugs in Supercritical Water: An Experimental and Modeled Approach

Pharmaceutical pollutants are considered emerging contaminants, representing a significant concern to the ecosystem. Thus, this study reports on the degradation of antihypertensive and cardiovascular drugs (atenolol, captopril, propranolol hydrochloride, diosmin, hesperidin, losartan potassium, hydrochlorothiazide, and trimetazidine) present in simulated wastewater through applying the technology of oxidation using supercritical water (SCW). The operational parameters of the treatment process, particularly the feed flow rate, temperature, and concentration of H2O2, were assessed. A central composite design of experiments associated with differential evolution was employed in the optimization. Both liquid and gaseous phase products were submitted to physical–chemical characterization. As a result, the optimized conditions for the treatment were discovered to be a feed flow rate of 13.3 mL/min, a temperature of 600 °C, and a H2O2 oxidation coefficient of 0.65, corresponding to the oxygen stoichiometric coefficient in the carbon oxidation chemical reaction. Under optimal conditions, the total organic carbon (TOC) decreased from 332 to 25 mg/L (92.1%), and the pharmaceutical molecules underwent near-complete degradation. The physical–chemical parameters also met with the main environmental regulations for wastewater disposal. The compounds determined in the gaseous phase were CO2 (97.9%), H2 (1.3%), CH4 (0.3%), and CO (0.5%.). Additionally, a modeling thermodynamic equilibrium of the system was performed, based on the experimental data. The results revealed that SCW technology has a great potential to oxidize/degrade organic matter and can be applied to treat pharmaceutical pollutants.

Optimization of the Removal of Hexavalent Chromium Cr(VI) from Aqueous Solution by Moringa oleifera Bark-Derived Activated Carbon (MOBAC) Using Response Surface Methodology (RSM)

This study investigated the removal of hexavalent chromium Cr(VI) ions in an aqueous solution using Moringa oleifera bark-derived activated carbon (MOBAC). The adsorption removal of Cr(VI) was systematically investigated as a function of four experimental factors: pH (1-5), contact time (10-90 min), adsorbent dosage (0.020-0.100 g L-1), and temperature (25-45°C) by following a statistical experimental design. A response surface methodology (RSM)-based central composite experimental design was used to establish an empirical model that assessed factors' effects on Cr(VI) ions adsorptive removal. The model was verified and validated and used to predict optimal adsorption removal of Cr(VI) from aqueous solutions. At optimized conditions, 99.612 % of 1.5 mg L-1 Cr(VI) ions are removed from the aqueous solution. These optimum condition values include a pH of 2.1, contact time of 62.72 min, adsorbent dosage of 0.065 g L-1, and temperature of 39.8°C. The adsorptive mechanism was assessed by conducting isotherm and kinetic studies. The adsorption process of Cr(VI) ions by MOBAC is described by Langmuir isotherm, indicating monolayer adsorption, and the reaction kinetics is described by pseudo-second order kinetics model. The Langmuir monolayer adsorption capacity of Cr(VI) adsorption on MOBAC was found to be 4.577 mg g-1 for Cr(VI) ions. The findings support the use of MOBAC in the removal of Cr(VI) ions from aqueous systems.

Process monitoring by deep neural networks in directed energy deposition: CNN-based detection, segmentation, and statistical analysis of melt pools

The complex interaction between laser and material in Laser Wire Direct Energy Deposition (LW-DED) Additive Manufacturing (AM) benefits from process monitoring methods to ensure process stability and final part quality. Understanding the relationship between process parameters and melt pool geometrical characteristics can be used to effectively monitor and in-process control the process, as the melt pool geometrical characteristics serve as crucial indicators of process stability and quality.This study presents a novel in-situ monitoring approach for LW-DED, utilizing process images for melt pool segmentation, melt pool geometrical characteristics estimation, process stability assessment, and bead geometry prediction. The segmentation of melt pool objects was successfully accomplished using Convolutional Neural Networks (CNN)-based models, enabling the prediction of essential parameters such as melt pool area, height, width, center of area, and the center point of the bounding box enclosing the melt pool. Multiple models were compared regarding the accuracy and processing speed using a controlled central composite design and random experiments. We used an Inconel alloy 625 wire and two distinct substrate materials for deposition, a coaxial laser welding head with a 3 kW fiber laser, and an off-axis welding camera for monitoring.Among the CNN architectures evaluated, YOLOv8l demonstrated superior accuracy with mean Average Precision (mAP) values of 0.925 and 0.853 for Stainless Steel (SS) and low carbon steel (S355) substrates, respectively. Additionally, YOLOv8s exhibited a notable processing speed of over 114 frames per second, which indicates its suitability for real-time process control. Furthermore, the results indicate a significant correlation between process parameters and melt pool geometry variables. Notably, a clear correlation was established between melt pool characteristics and bead geometries obtained through microscopic examinations, including penetration depth and heat-affected zone. The analysis revealed a significant correlation for the bead area and width parameters. In relation to the bead height, while the correlation exhibited a lower magnitude compared to bead area and width, it remained responsive. In addition, the tensor masks derived from the developed models have proven to be highly effective in accurately predicting bead geometries.The results demonstrate the effectiveness of YOLO-based algorithms for detecting and segmenting the melt pool. Statistical analysis confirms the significance of stabilized process data and the accuracy of melt pool geometric models. We demonstrate that integrating advanced monitoring and control techniques using artificial intelligence methods like CNN can facilitate process stability and quality control.

Enhancement of dissolution and oral bioavailability by adjusting microenvironment pH in crocetin ternary solid dispersions: Optimization, characterization, in vitro evaluation, and pharmacokinetics.

The most promising active ingredient of Crocus sativus L., crocetin (CCT), has been demonstrated to possess many biological activities. However, only a few studies have been conducted on CCT formulation, especially in oral formulation, mainly due to its insolubility in water, which limits its application for oral administration. This article reports an equilibrium saturation solubility and single-pass intestinal perfusion studies conducted to classify the biopharmaceutics classification system (BCS) of CCT. To enhance in vitro dissolution and in vivo oral bioavailability, ternary solid dispersions of CCT (CCT-SDs) with soluplus (SOL) as hydrophilic carrier and meglumine (MEG) as alkalizer were optimized using response surface methodology (RSM) with central composite design (CCD) experiments. Four different preparation methods were evaluated using the optimal formulation, including solvent evaporation, ball milling, spray drying, and freeze-drying. Prepared formulations were characterized by TG-DSC, FTIR, X-RPD, and SEM; the pharmacokinetic studies were performed in rats after oral administration. The cumulative dissolution rate of CCT-SDs containing SOL and MEG prepared by the ball milling method was 97.1% at 15min and remained at 95.6% at 480min, which was significantly higher than that of untreated CCT. The lower crystallinity, smaller particle size, and higher microenvironment pH (pHM) were observed in CCT-SDs prepared by the ball milling method. In vivo absorption of CCT-SDs (Cmax = 52.789 ± 12.441μg/mL and AUC0-12 = 191.748 ± 35.043μg/mL·h) was greater than untreated CCT (Cmax = 5.918 ± 1.388μg/mL and AUC0-12 = 44.309 ± 7.264μg/mL·h). In conclusion, the current study provides ternary solid dispersion formulation of CCT to increase the in vitro dissolution and in vivo bioavailability, which will benefit the commercial production and future clinical applications of CCT.

Enhancing the formation of eco-friendly CO2 adsorbent through utilizing the RSM technique and implementation of PAN/PU electrospinning and radiation-grafted approaches

In this research, the original, efficient, novel NF-PAN/PU-GMA-EA nanocomposite was fabricated and used as an adsorbent to remove carbon dioxide from methane. For this purpose, two cheap polymers, including industrial polyacrylonitrile (PAN) and industrial polyurethane (PU) were used to prepare NF-PAN nanofibers under the electrospinning method. Then, the synthesis procedure was performed by grafting glycidyl methacrylate (GMA) onto NF-PAN nanofibers and ethanolamine (EA), diethylamine (DEA), and triethylamine (TEA) as the modified agents. In addition, the response surface methodology based on the central composite design experiments was developed to predict adsorption capacity. The aforementioned approach determined the impacts of GMA monomer (10–30%); gamma radiation at doses (10–50 kGy); and amine concentrations (40–100%). The results showed that ethanolamine was the best amine to modify the surface of NF-PAN/PU nanofibers. The highest adsorption was obtained equal to 2.95 mmol CO2/g adsorbents at a radiation dose of 28.03 kGy, 25.77% GMA and 66.45% EA. The results described that the variation from micro to nanoscale increases the adsorption capacity. Also, a significant increase in the adsorption capacity in the radiation-grafted adsorbent was observed equally to be 73.15% higher than the non-irradiated adsorbent. The adsorption capacity was decreased by about 9% after four adsorption and desorption cycles (regeneration at 80 °C and 15 min), indicating the proper performance of the novel eco-friendly synthesized adsorbents.

Study on the preparation and use of edible coating of fish scale chitosan and glycerol blended banana pseudostem starch for the preservation of apples, mangoes, and strawberries

Agro-industries and the fish processing sector generate large amounts of waste, which may be converted into useful ingredients for preserving fruit. Studies show that starch-based edible film still needs some improvement because it’s brittle and weaker, which might be improved by adding chitosan. The study aimed to investigate the optimal composition of edible film-forming material prepared from banana pseudostem starch and fish-scale chitosan to preserve the selected fruits. In the current study, chitosan and starch were extracted from the waste of Nile tilapia fish scale and Dwarf cavendish banana pseudostem as found to be 29.66 ± 0.46 % and 4.26 ± 0.21 %, respectively. Central composite response surface experimental design combined banana pseudostem starch, chitosan, and glycerol to prepare the edible films. Using the Design-expert program, the ideal film-forming composition with an overall acceptability of 0.968 was identified based on the physico-mechanical characteristics of the created composite edible films. It comprised 15 mL of 1 % banana pseudostem starch, 3.2 mL of 0.5 % chitosan, and 0.6 mL of 30 % glycerol. The persistence of the microbial load on coated and uncoated fruits throughout the storage was also assessed in the study. The microbial and fungal growth was significantly lower (>37 %) in optimal edible film-coated fruits than in the control fruits. After 28 days of storage of fruits at room temperature, the microbial count (in CFU/mL) on the edible coated surfaces of apples, mangoes, and strawberries was found to be 2.04 ± 0.32x103, 2.71 ± 0.29x103, and 2.5 ± 0.51x104, respectively. Also noticed the fungus counts of 1.86 ± 0.48x03 (in apples), 1.09 ± 0.11x104 (in mangoes), and 1.56 ± 0.04x104 (in strawberries) in the studied coated fruits after 28 days of storage. Furthermore, the film-coated fruits had a significantly lower weight loss than uncoated fruits. Thus, the studied banana pseudostem starch-chitosan-glycerol composite edible coating potentially preserves by inhibiting the development of natural microbes when storing apples, mangoes, and strawberries, and it is adequate to extend their shelf life.

Xanthan gum and pectin as beverage stabilizers reduce the digestive enzyme hydrolysis of antioxidant and antihypertensive peptides obtained from a brewery byproduct

An acidic beverage was formulated with xanthan gum (XG), pectin (P) and brewer spent grain (BSG) peptides with antioxidant and antihypertensive properties. The impact of hydrocolloids levels on peptide bioaccessibility was studied. Peptides were obtained from BSG using Purazyme and Flavourzyme enzymes. BSG peptides were fractionated by ultrafiltration (UF) and four fractions were obtained: F1 (>10 kDa), F2 (10–5 kDa), F3 (1–5 kDa), and F4 (<1 kDa). F3 showed the highest protein purity, ferulic acid content, proportion of amphipathic peptides, and bioactive properties (ABTS+ radical scavenging and ACE-I inhibitory activity). The identified peptides from F3 by tandem mass spectrometry were 138. In silico analysis showed that 26 identified peptides had ABTS+ inhibitory activity, while 59 ones presented good antihypertensive properties. The effect of XG and P levels on bioaccessibility of F3 peptides in the formulated beverages was studied by a central composite experimental design. It was observed that F3 peptides interacted with hydrocolloids by electrostatic forces at pH of formulated beverages. The addition of hydrocolloids to formulation modulated the release of the antioxidant peptides and protected the degradation of ACE-I inhibitory peptides from F3 during simulated gastrointestinal digestion. Finally, the level of hydrocolloids that produced intermediate viscosities in the formulated beverages improved the bioaccessibility of the F3 peptides.

Key Fabrications of Chitosan Nanoparticles for Effective Drug Delivery Using Flow Chemistry Reactors.

Chitosan nanoparticles have garnered considerable interest in the field of drug delivery owing to their distinctive properties, including biocompatibility, biodegradability, low toxicity, and ability to encapsulate a wide range of drugs. However, the conventional methods (eg, the drop method) for synthesizing chitosan nanoparticles often face limitations in regard to controlling the particle size, morphology, and scalability, hindering their extensive application in drug delivery systems. To overcome these challenges, this study explores using a novel flow chemistry reactor design for fabricating clindamycin-loaded chitosan nanoparticles. By varying two critical operating parameters of flow chemistry, namely, the flow rate ratio and total flow rate, the impact of these parameters on the properties of chitosan nanoparticles is investigated using a central composite experimental design. The optimized conditions for nanoparticle preparation yielded remarkable results, with chitosan nanoparticles exhibiting a small size of 371.60 nm and an extremely low polydispersity index of 0.042. Furthermore, using novel design flow chemistry reactor, the productivity of chitosan nanoparticles was estimated to be 25,402.17 mg/min, which was ~12.71 times higher than that obtained via batch synthesis. The findings of this study indicate that the use of novel design flow chemistry reactor is promising for synthesizing clindamycin-loaded chitosan nanoparticles and other polymeric nanoparticles intended for drug delivery applications. This is primarily attributed to their ability to produce nanoparticles with a considerably reduced particle size distribution and smaller overall size. The demonstrated high productivity of this technique suggests the potential for industrial-scale nanoparticle manufacturing.

Green RP-HPLC methods for assay and related substances in rivaroxaban tablets

AbstractIn this study, two different ethanol-based RP-HPLC methods for assay and quantification of rivaroxaban related substances in tablets were developed, based on green analytical chemistry (GAC) principles, using the design of experiments approach. The chromatographic separation was performed on X-Bridge C18 column (250 × 4.6 mm, 5 µm particle size), using isocratic elution with ethanol : water (35:65, % v/v) for the assay and gradient elution with ethanol/water mobile phase, for related substances, with a flow rate of 1.0 mL min−1. The gradient method was optimized for the separation of three specified impurities (impurity G, impurity H, and impurity 14) and the selectivity was further confirmed using forced degradation studies. Both methods were validated in accordance with ICH guidelines. The robustness of the methods was confirmed with the Central Composite Face Design of Experiments. Analytical Eco-scale approach and AGREE metrics confirmed that both methods are in accordance with the GAC principles. The proposed ethanol-based RP-HPLC methods were applied for assay and determination of related substances in rivaroxaban 10 mg tablets obtained from three different manufacturers available on the Macedonian market.

Guadua angustifolia Kunth leaves as a source for bioactive phenolic compounds: Optimization of ultrasound-assisted extraction using response surface methodology and antioxidant activities

This study evaluated the ultrasound-assisted extraction of phenolic compounds from Guadua angustifolia leaves, along with their optimization using response surface methodology. The effects of two sonication process conditions were determined using a central composite experimental design, with three levels (low, medium, and high) evaluated for time (10, 20, and 30 min) and temperature (20 °C, 35 °C, and 50 °C). A total of 12 experiments with four replicates were conducted at the central point, with the total phenol and flavonoid contents determined using the Folin-Ciocalteu colorimetric method and complexation with AlCl3, respectively. The optimized extract was analyzed using ultra-performance liquid chromatography (UPLC), and the antioxidant capacity of the optimized extract was determined by DPPH• (2,2-Diphenyl-1-Picrylhydrazyl) and ABTS•+ (2,2′-Azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) assays. Extraction at 50 °C for 20 min was found to favor the extraction of phenol and total flavonoids. The experimental validation of the total phenol and flavonoid content produced values of 7.39 mg gallic acid equivalents per gram of dry matter and 1.55 mg quercetin equivalents per gram of dry matter, respectively. These values suggest that the extraction process is reproducible, with a relative standard deviation of 22.9 % and 14.1 %, respectively. The chromatographic profile showed that optimization favored the visualization of phenolic compounds compared to the non-optimized extract. The optimized extract had higher antioxidant capacity than the non-optimized extract, with values of 209.23 and 144.76 μmol Trolox per gram extract for the DPPH• and ABTS•+ techniques, respectively. Thus, the conditions evaluated in the ultrasound-assisted extraction were an efficient technique capable of extracting the maximum amount of phenolic compounds with antioxidant activity from the leaves of G. angustifolia, showing its potential application in various industries.

Effect of Delignification on Reducing Sugar Recovery from Crocodile Gourd for Bioethanol Production

A central composite experimental design was used to optimize the key parameters affecting biomass delignification process of crocodile gourd for maximum reducing sugar recovery. The effects of temperature (70 oC to 90 oC), residence time (2 hrs. to 6 hrs.), concentration of sodium chloride (0.05 g/dm3 to 0.1 g/dm3) and volume of acetic acid (0.50 mL to 3 mL) were studied. The result obtained showed that optimum reducing sugar yield for crocodile gourd was achieved at temperature, time, sodium chloride and acetic acid of 70 oC, 6 hrs. 3 g and 3 mL respectively. The results indicate that X3, X4, X1 2 interactions and X2X4 interaction has linear effect on reducing sugar yield for crocodile gourd. The result of the proximate analysis showed moisture content of 6.50+ 0.50 %, Ash Content 11.00+ 0.28 %, Carbohydrate 64.40+0.62 %, Organic carbon 12.95+0.13 (%), Nitrogen 2.10+ 0.02 (%), Carbon/Nitrogen 6.16+0.08 %, Potassium 14100+23 mg/kg, Sodium 228+ 29 mg/kg, and Fixed carbon 7.4+0.80 %. The result of proximate analysis and compositional analysis revealed that the substrate could be utilized for biofuel production.

Optimized electrocatalytic degradation of ciprofloxacin using Co3O4 coated stainless steel electrodes

Ciprofloxacin (CIP) is a fluoroquinolone antibiotic that is widely used across the globe and its release is a serious concern due to its persistent nature, partial degradation, and simple transport through different environmental matrices. Pharmaceuticals have been degraded effectively by electrochemical oxidation. Exploring ways to increase the mineralization of these compounds while maintaining low power consumption is important. In this study, the treatability and degradation of CIP were investigated by using cobalt oxide-coated stainless steel (SS) electrodes in a lab-scale electrochemical (EC) reactor. The performance of the electrochemical reactor was determined under various operational conditions. The feed wastewater was synthetically prepared in the laboratory with varying concentrations of CIP ranging from 8 to 41 mg/L and the EC reactor was operated with an applied voltage and airflow rate of 2.6–9.3 volts and 1.6–3.5 L/min, respectively. A 3-factor central composite experimental design (CCD) was developed by using response surface methodology (RSM) in Design-Expert software. At a residence time of 27 min, initial concentration of 25 mg/L, airflow rate of 2.5 L/min, and applied voltage of 6 volts, the EC reactor achieved a removal efficiency of 70.8% for CIP with SS electrodes. On the contrary, the removal efficiency was increased to 91.5% at a reduced residence time of 21 min with cobalt oxide (Co3O4) coated over SS plates. The results indicated that Co3O4@SS electrodes resulted in better removal efficiency of CIP at a lower residence time. This system can be used as a robust benchmark for a single or consortium of antibiotics present in domestic and hospital wastewater.

Calibration of Small-Grain Seed Parameters Based on a BP Neural Network: A Case Study with Red Clover Seeds

In order to enhance the accuracy of discrete element numerical simulations in the processing of small-seed particles, it is essential to calibrate the parameters of seeds within the discrete element software. This study employs a series of physical tests to obtain the physical and contact parameters of red clover seeds. A discrete element model of red clover seeds is established. Plackett–Burman Design, steepest ascent, and Central Composite Design experiments are sequentially conducted. The simulation deviation of the resting angle of red clover seeds is employed as the evaluation criterion for parameter optimization. The results indicate that the coefficients of static friction between red clover seeds, the coefficients of rolling friction between red clover seeds, and the coefficients of static friction between red clover seeds and the steel plates significantly influence the resting angle. Modeling was performed using a backpropagation neural network, a genetic algorithm–optimized BP network, particle swarm optimization, and simulated annealing. It was found that GA-BP ensured both accuracy and stability. Compared to the traditional response surface methodology, GA-BP showed better fitting performance. For the optimized red clover seed simulation, the error between the angle of repose and the physical experiment was 0.98%. This research provides new insights into the calibration of small-grain seed parameters, demonstrating the value of GA-BP for precision modeling.