Factorial Design Research Articles

Effects of Italian ryegrass desiccation timing on corn performance: is growth inhibition due to the release of plant allelochemicals or nitrogen immobilization?

Context There is no consensus between farmers and researchers about timing for ryegrass desiccation before corn sowing, considering interactions between ryegrass straw, nitrogen immobilization, and allelochemical release impacting corn growth. Aims This study aims to assess the effects of different desiccation timings of annual ryegrass (Lolium multiflorum Lam.) and nitrogen management on corn. We sought to elucidate whether corn growth inhibition is attributable to allelochemical release or nitrogen immobilization. Methods A two-year field factorial experiment was conducted, with Factor A comprising fallow and three ryegrass desiccation timings before corn sowing, and Factor B involving two nitrogen fertilization methods to evaluate N immobilization. Laboratory experiments assessed allelopathic properties using a 3 (desiccation periods) × 5 (ryegrass extract concentrations) factorial design. Assessments included corn (Zea mays) germination, seedling radicle and coleoptile length, and germination speed. Results Ryegrass desiccation timing of less than 20 days before corn sowing reduced corn stature at the beginning of development and grain yield, due to nitrogen immobilization and allelopathic influences possibly exercised by caffeic acid and epicatechin present in roots and shoots, released as residues decomposed. Non-desiccated ryegrass aqueous extracts reduced germination speed and germinability. Root/shoot extracts reduced seedling elongation. Desiccated aqueous extracts at 15 and 30 days before corn sowing didn’t present inhibitory effects. Conclusion Nitrogen enhances corn growth regardless of ryegrass influence, under these experimental conditions. Ryegrass desiccation timing affects corn yield; and delaying corn sowing post-desiccation mitigates losses. Ryegrass extracts inhibit corn germination and viability, regardless of concentration, possibly due to phytotoxic compounds.

Ethanol Production From Sugarcane Molasses: Effects of Ph, Supplementation, and Refrigeration in Simulated Industrial Conditions at a Microdistillary

Objective: This study aims to evaluate the effects of pH, ammonium sulfate supplementation, and refrigeration on fermentation performance in sugarcane molasses, with the goal of optimizing ethanol production under simulated industrial conditions. Theoretical Framework: The research builds on key concepts in biofuel production, emphasizing the role of pH, nutrient supplementation, and temperature control in influencing yeast metabolism and fermentation efficiency. Theories on enzymatic activity and nutrient absorption (Vidal et al., 2013; Gutierrez, 1993) provide the foundation for understanding the interactions between these factors. Method: A full 2³ factorial design was employed, evaluating the effects of pH (3.5 and 5.0), supplementation (0.0 and 1.0 g/L), and refrigeration (with or without) on fermentation efficiency, process efficiency, ethanol productivity, and substrate-to-cell conversion in a microdistillery. Analytical methods included spectrophotometry, refractometry, and chromatography. Results and Discussion: The results indicate that fermentation conditions with pH 3.5, without supplementation, and with refrigeration yielded the best performance, with significant increases in ethanol productivity and fermentation efficiency. The interaction between variables suggests that these factors should be considered jointly to optimize the process. Research Implications: The findings offer practical insights for improving fermentation in industrial biofuel production, particularly in optimizing conditions for ethanol yield and process efficiency under near-industrial conditions. Originality/Value: This study contributes by using a microdistillery to simulate industrial conditions, providing more accurate data for scaling ethanol production. It adds value by highlighting how specific combinations of pH, supplementation, and refrigeration can improve biofuel sustainability.

Effect of Sporosarcina Pasteurii on Rheological and Strength Properties of Bio-Self Compacting Concrete

The study was conducted to evaluate the rheological and strength properties of bio-self compacting concrete. The materials used are cement, fine and coarse aggregates, bacteria (Sporosarcina pasteurii), and superplasticizer. Preliminary tests were conducted on the materials to ascertain its conformity to standard, and a full factorial design of experiment was adopted. The bacteria nutrient was varied at a ratio 1:3 of the bacteria content (i.e. 75% nutrient and 25% bacteria) at 10^5 cell/ml Sporosarcina pasteurii which was added to the fresh concrete at 5-25ml dosage by weight of water at 5ml increment, while the superplasticizer was added into the fresh concrete at 0.2-1.0% at 0.2 % increment by weight of cement which translated to 234 concrete samples. The rheological tests conducted were slump, V-funnel, L-box, and J-ring test, while the concrete strength tests conducted were compressive, flexural, and split tensile strength. Results from the experiment showed that workability of most of the bio-self compacting concrete is very high compared to the control concrete, and are within the range specified by codes, and the 28 days compressive strength of concrete produced by adding 20 – 25 % bacteria and 0.4-0.8% superplasticizer had 28 days compressive strength equal or greater than the control concrete. Also, the 28 days flexural strength of control concrete is significantly higher than flexural strength of all the bio self-compacting concrete, while the split tensile strength of bio self-compacting concrete produced by adding 25% bacteria and 0.4 – 0.8% superplasticizer is higher than the control concrete.

Factorial experiment to identify two-way interactions between temperature, harvesting period, hydraulic retention time, and light intensity that influence the biomass productivity and phosphorus removal efficiency of a microalgae–bacteria biofilm

ABSTRACT This study evaluated the two-way interaction and main effects of four factors on biomass productivity and phosphorus removal efficiency of a microalgae–bacteria biofilm grown in municipal anaerobic digester centrate, with factor levels and operating conditions selected to mimic a pilot rotating algae biofilm reactor (RABR) at a water resource recovery facility (WRRF) in Utah. The two-way interactions of harvesting period × light intensity (LI), harvesting period × temperature, and LI × hydraulic retention time (HRT) had significant effects on biomass productivity: At high temperature and at low LI, highest biomass productivity was achieved with a 14-day harvesting period (25.5 and 10.9 g AFDW/m2/day, respectively), but at medium temperature and at high LI, highest biomass productivity was achieved with a 7-day harvesting period (16.1 and 16.4 g AFDW/m2/day, respectively). At high HRT, highest biomass productivity occurred at low LI (11.9 g AFDW/m2/day), but at low HRT, highest biomass productivity occurred at high LI (19.3 g AFDW/m2/day). Phosphorus removal was strongly influenced by LI (>70% removal at 1,600 μmol/m2/s) and occurred most rapidly during the first 2 days HRT (e.g. 2,270 TP/m2/day for days 0–2 vs. 217 mg TP/m2/day for days 2–4), which, in combination with chemical equilibrium modeling, suggests precipitation contributed significantly to phosphorus removal in this study.

Impact of tool nose size on the performance and wear behavior of carbide tool when boring 1Cr17Ni2 martensitic stainless-steel parts

Purpose This study aims to examine the cutting performance of a coated carbide tool during the boring of 1Cr17Ni2 martensitic stainless steel, with a focus on how the tool’s structural parameters, particularly the nose radius, affect the wear patterns, wear volume and lifetime of the cutting tool, and related mechanisms. Design/methodology/approach A full factorial boring experiment with three factors at two levels was conducted to analyze systematically the impact of cutting parameters on the tool wear behavior. The evolution of tool wear over the machining time was recorded, and the influences of the cutting parameters and nose radius on wear behavior of the tool were examined. Findings The results show that higher cutting parameters lead to significant wear or plastic deformation at the tool nose. When the cutting depth is less than the nose radius, the tool wear tends to be minimized. Larger nose radius tools have weaker chip-breaking but greater strength and wear resistance. Higher cutting parameters reduce wear for the tools with larger nose radius, maintaining their integrity. Wear mechanisms are primarily abrasive, adhesive and diffusion wear. Furthermore, the full-factorial analysis of variance revealed that for the tool with rε = 0.4 mm and 0.8 mm, the factors contributing the most to tool wear were cutting speed (38.76%) and cutting depth (86.43%), respectively. Originality/value This study is of great significance for selection of cutting tools and cutting parameters for boring 1Cr17Ni2 martensitic stainless-steel parts. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2024-0266/

How effective is AI augmentation in human–AI collaboration? Evidence from a field experiment

PurposeCompanies increasingly leverage artificial intelligence (AI) to enhance human performance, particularly in e-commerce. However, the effectiveness of AI augmentation remains controversial. This study investigates whether, how and why AI enhances human agents’ sales through a randomized field experiment.Design/methodology/approachThis study conducts a two-by-two factorial randomized field experiment (N = 1,090) to investigate the effects of AI augmentation on sales. The experiment compares sales outcomes handled solely by human agents with those augmented by AI, while also examining the moderating effect of agents’ experience levels and the underlying mechanisms behind agents’ responses.FindingsThe results reveal that AI augmentation leads to a significant 5.46% increase in sales. Notably, the impact of AI augmentation varies based on agents’ experience levels, with inexperienced agents benefiting nearly six times more than their experienced counterparts. Mediation analysis shows that AI augmentation improves response timeliness, accuracy and sentiment, thereby boosting sales.Originality/valueThis study highlights the role of AI augmentation in human–AI collaboration, demonstrates the varying impacts of AI augmentation based on agents’ experience levels and offers insights for organizations on how to regulate AI augmentation to enhance agent responses and drive sales.

Assessing the Drying Sensitivity of Alkali-Activated Binders Through Mechanical Reliability: Effect of Particle Size and Packing

Despite the steady progress of research on the alkali activation of wastes or subproducts from established industrial processes, the brittleness of the hardened alkali-activated materials frequently results in questionable mechanical reliability, particularly in industrial applications beyond construction materials. This work used a 33 factorial Design of Experiments to examine the effect of three different particle size distributions on the compressive strength and mechanical reliability (Weibull modulus) of a sodium silicate-activated blast-furnace slag under the same processing conditions. As expected, curing temperature and time were strongly correlated, and the corresponding response surfaces showed that, for all studied particle sizes, compressive strengths above 60 MPa with mechanical reliability above 5.0 could be obtained by curing at ~60 °C for ~40 h. The particle size differences caused no significant changes in the extent of alkali activation, as seen in the infrared-spectroscopy results. However, the intersection of the response surfaces showed that a coarser and narrower particle size distribution extended the working area (time × temperature) and favored mechanical reliability. Thus, the precursor’s particle size distribution, which governs particle packing and viscosity during processing, also determines the permeability of the set binder, which affects water removal during drying and the dried binder’s mechanical performance.

Probiotication of Plum Pulp and Conditions Effects Freeze-Drying in Cell Viability, Functional Properties and Antioxidant Activity

This study investigated the effects of fermenting plum pulp with Bifidobacterium animalis ssp. lactis (BAL) on its physicochemical and bioactive properties, as well as the optimization of the freeze-drying (FD) process to develop a fruit-based probiotic delivery system. Fermentation significantly reduced the pH and total acidity of the pulp, achieving a cell viability of 11 log CFU/mL. The FD process was optimized using a factorial design, with maltodextrin concentration (3, 5, and 7%) and freezing temperature (−150, −100, and −50 °C) as variables. The P2 experiment, which used 7% maltodextrin and freezing at −150 °C, showed the best results in terms of yield (25.67%), cell viability (8 log CFU/g), and probiotic survival rate (97.66%). Samples P5, P6, and P7, prepared with 5% maltodextrin and freezing at −100 °C, exhibited the highest levels of bioactive compounds and antioxidant activity (p < 0.05). During 28 days of storage, all samples maintained cell viability without significant logarithmic reduction. In summary, probiotic plum powders offer an excellent plant-based alternative for probiotic consumption, providing safe levels of beneficial bacteria and bioactive compounds with antioxidant action, meeting health and nutrition needs.

The combination of nanoparticles and endophytes boosts Thyme (Thymus vulgaris L.) resistance to drought stress by elevating levels of phenolic compounds, flavonoids, and essential oils

BackgroundAs climate change and water scarcity increasingly threaten agricultural productivity, enhancing plant resilience to drought has attracted great attention. This study explored the potential of combining Fe2O3 nanoparticles (FeNPs), endophytic bacteria (EB), and endophytic fungi (EF) to boost drought tolerance in Thymus vulgaris. The research aimed to assess how these combined treatments affect the plant’s physiological responses and chemical composition under drought stress.ResultsA factorial experiment was designed using completely randomized design (CRD) method, incorporating four irrigation levels [100%, 75%, 50%, and 25% field capacity (FC)], four FeNPs concentrations (0, 0.5, 1, and 1.5 mg L−1), and three endophyte types (control, bacteria, and fungi). After extracting, purifying, identifying, and screening EB and EF from nine Lamiaceae species, the endophytes Azospirillum lipoferum and Aspergillus oryzae isolated from Salvia mirzayanii exhibited the highest drought resistance. The highest amounts of TFM (45.45 g) and TDM (21.56 g) were obtained using the combination of EB and FeNPs at 1 mg L−1 under irrigation with 100% FC. At 25% FC, EB treatment increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL) by 62.12% and 18.23% compared to the control, respectively. In addition, under optimal humidity conditions, FeNP concentrations were higher than 0.5 mg L−1 leading to a decrease in PPO activity. At 25% FC, the highest content of total phenols was observed with a 37.5% increase under EB treatment using 1 mg L−1 of FeNPs, while the highest content of total flavonoids showed a 62.72% increase under EF treatment with 0.5 mg/L of FeNPs. The highest level of p-coumaric acid was obtained under EF (34.27% compared to control). At 25% FC, EB and FeNPs (1 mg L−1) increased the level of caffeic acid in thyme plants by 24.70% and 10.08%, respectively. In addition, inoculation with EB increased (11.9%) the content of ferulic acid in plants and the application of FeNPs as a foliar spray decreased the level of ferulic acid in thyme plants. The highest essential oil percentage at 25% FC was observed after inoculation with EF and FeNPs (0.5 mg L−1), resulting in significant increases of 14.7% and 82.12%, respectively, compared to the control. A decrease in irrigation level led to an increase in the percentage of essential oil in thyme plants while decreasing dominant essential oil compounds, thymol, and carvacrol. The levels of thymol and carvacrol in the essential oil were not affected by the interaction effects of drought stress, endophytes, and FeNPs. EF and FeNPs (1.5 mg L−1), respectively, caused significant increases of 17.44% and 29.87% compared to the control in the amount of thymol and significant increases of 13.75% and 31.01% in the amount of carvacrol. All FeNPs concentrations decreased the concentrations of ferulic acid, FeNPs (1.5 mg L−1) and PPO; these particles act as abiotic stressors at sub-toxic levels and become phytotoxic at higher concentrations.ConclusionsIt seems that combining endophytes with FeNPs showed promise in enhancing drought tolerance in T. vulgaris. These treatments have significantly contributed to the production of enzymatic antioxidants, flavonoids, and phenolic compounds, leading to a reduction in the amounts of oxidants. At the same time, they have improved both the quality and quantity of essential oils. This highlights the importance of establishing an effective antioxidant system in response to environmental stresses.Graphical

SAMBILOTO LEAF NANOEMULSION AS A PHOTOPROTECTIVE AGENT: OPTIMIZATION OF TWEEN 20 AND PEG-400 CONCENTRATION USING THE REGULAR TWO-LEVEL FACTORIAL DESIGN

Objective: This study aims to determine the optimum concentration of Tween 20 and Polyethylene Glycol 400 (PEG-400) in Sambiloto leaf extract nanoemulsion. Methods: The formula of sambiloto leaf nanoemulsion was developed using the regular two-level factorial design based on responses of pH values, density, viscosity, and transmittance percentage. The optimum formula was tested for stability and photoprotective activity by determining the Sun Protection Factor (SPF) value and antioxidant activity. Results: Sambiloto leaf extract contains andrographolide at 3.397%. The optimum formula for nanoemulsion preparations was obtained at 10% of tween 20 and 10% of PEG-400. The optimum nanoemulsion had a distinctive green extract aroma, a transmittance percentage of 86.7±0.170, a globule size of 130.43±54.056 nm, a polydispersity index of 0.318±0.043, and a zeta potential of-26.5±0.544 mV. The optimum formula's photoprotective activity resulted in an SPF value of 42.944±0.026 and an IC50 of 103.611±1.085 ppm. There was no significant change in pH or transmittance percentage based on the stability test (p<0.05). Conclusion: The results show that the optimum formula of sambiloto leaf nanoemulsion could be a photoprotective agent that is also stable.

An Experimentally Designed Sertaconazole Sensor for Selective and Enhanced Potentiometric Response: Determination in Cream, Plasma & in Presence of Other Imidazoles

AbstractA two‐step experimental design was followed to develop a potentiometric solid contact ion‐selective electrode for sertaconazole (STN) determination. A full factorial design was first employed in screening for the best cation exchanger, ionophore and conducting polymer. Amounts of the selected cation exchanger; tetrakis[3,5‐bis(trifluoromethyl)phenyl] borate (TFPB), and ionophore; calix[6]arene (CX6), incorporated in STN sensing membrane were then optimized with the aid of face centered composite design. Calibration slope, detection limit and electrode selectivity in presence of another imidazole‐classified drug; econazole, were the selected responses in both designs. The optimized ion‐sensing membrane, containing 1.0 mg TFPB and 9.9 mg CX6, showed enhanced responses compared to the primarily screened ones. This optimized electrode exhibited a linear response over a concentration range of 1.0×10−6‐−1.0×10−3 M with a Nernstian slope of 57.50 mV/decade. The detection limit was lowered by about one order of magnitude via this optimization to equal 3.16×10−7 M. The proposed electrode was successfully challenged for STN determination in the presence of other imidazoles. It was then used for STN determination in cream and spiked plasma as an example of biological fluid. Our proposed potentiometric method was finally compared to the reported chromatographic ones in terms of sensitivity, and greenness evaluation by the widely applicable Analytical GREEnness (AGREE) tool. The comparison revealed the superiority of our method in terms of sensitivity and sustainability.

Self-assembled latanoprost loaded soluplus nanomicelles as an ophthalmic drug delivery system for the management of glaucoma

Glaucoma, a leading cause of blindness due to elevated intraocular pressure (IOP), is managed with medications like latanoprost (LAT), a prostaglandin analogue, to enhance aqueous outflow. Despite the challenge posed by eye anatomy and tear dynamics, effective ocular bioavailability via topical administration remains elusive. This study aims to optimize self-assembled nanomicelles incorporating LAT, an anti-glaucoma drug, belonging to BCS Class II (low solubility and high permeability) via a two-level, two-factor full factorial design, the nanomicelles were formulated via direct dissolution method and validated using design of expert. The optimized nanomicelles exhibited a spherical morphology, with a size of 69 nm and encapsulation efficiency of 77.5%, demonstrating a sustained LAT release over 12 h. In normotensive rabbits, the nanomicelles elicited a substantial reduction in intraocular pressure (IOP) by up to 40% for a duration of three days, that was significantly longer than the IOP-lowering efficacy of XALATAN eye drops (24 h). These findings indicated that self-assembled nanomicelles hold promise for enhancing the ocular bioavailability and extending the therapeutic duration of LAT, while providing the physical stability.

Effect of nitrogen/potassium combination on irrigated wheat cultivation

With the expansion of wheat cultivation into areas with low natural fertility such as the Brazilian Cerrado, studies aimed at determining the appropriate amounts of nutrients supplied in fertilization are crucial. In this context, the objective was to evaluate the effects of applying doses of nitrogen combined with doses of potassium in the fertilization of irrigated wheat cultivar BRS 254 grown in a Cerrado environment. The experiment was conducted in the experimental area of the Federal University of Rondonópolis, Brazil, in randomized blocks with a 5x5 split factorial design with four replications. The treatments were five doses of nitrogen (0, 70, 140, 210 and 280 kg ha-1) and five doses of potassium (0, 50, 100, 150 and 200 kg ha-1). For grain yield, the application of 168 kg N ha-1 and 200 kg K ha-1 provided maximum grain yield (2,828 kg ha-1). Nitrogen fertilization does not benefit the technological quality aspects of wheat and the use of 200 kg K ha-1 provides the best results. Nitrogen is the nutrient that most limits the development of the BRS 254 wheat cultivar.

Synergistic Effects of Mannan Oligosaccharides and Onion Peels on In Vitro Batch Culture Fermentation of High Concentrate and Forage Diets

The current study evaluated the effect of combining mannan oligosaccharide (MOS) and onion peel (OP) on ruminal in vitro total gas (GP), greenhouse gas emissions, dry matter and fiber fraction digestibility, partitioning factor (PF24; mg degradable DM per mL gas), microbial mass, and volatile fatty acids using two dietary substrates: high forage (HF) and high concentrate (HC) diets. The study was arranged as a 2 × 2 × 6 factorial design with two dietary substrates, two time points (6 and 24 h), and six treatments. The treatments included a control group with no MOS or OP administration and groups administered with 2% of a mixture containing MOS and OP in the following ratios: 1:0 (MOS), 0:1 (OP), 1:1 (MOS:OP), 1:2 (MOS:2OP), and 1:3 (MOS:3OP). No significant diet × treatment interactions were observed for any of the measured parameters. However, treatments decreased (p < 0.05) the undegraded portion of HC, and treatment × substrate interactions were significant (p < 0.05) for PF24 and microbial mass. The treatments in the HC diet produced higher GP (p < 0.001) at 6 h compared to the treatments in the HF diet. Administration of MOS:2OP to the HC diet increased GP at 24 h of incubation, while the lowest GP was observed with the OP in the HF diet. The administration of MOS, OP, and MOS:2OP to the HC diet decreased methane production at 24 h of incubation. Additionally, MOS:2OP and MOS:3OP increased (p < 0.001) degradable acid detergent fiber (dADF) in the HC diet at 6 h of incubation. Both OP and MOS:3OP decreased the degradability of acid detergent lignin in the HC diet (p < 0.001). The OP also resulted in the lowest DM disappearance (p < 0.001) at 24 h of incubation in the HF diet, while the MOS:3OP had the highest dADF. At the end of incubation, the highest productions of total volatile fatty acids and acetate were observed (p = 0.002) with the MOS:OP administration in the HC diet, whereas the lowest values were observed with MOS and OP administration to the HF diet. The inclusion of mannan oligosaccharide and onion peel combinations as additives improved substrate (HC and HF) fermentation, leading to higher GP and volatile fatty production, and modulated fiber degradability by improving the breakdown of acid detergent fiber and acid detergent lignin.

Environmental Factors in Oryctes rhinoceros (Coleoptera: Scarabaeidae) Breeding

ABSTRACTThe Oryctes rhinoceros (Scarabaeidae: Coleoptera) is a common coleopteran insect in tropical and subtropical areas with many potential uses. Its larvae are commonly found in dead coconut trees and hay piles in the wild and are widely distributed in the northern hemisphere. This study investigates the environmental factors influencing the growth of Oryctes rhinoceros beetle larvae and provides valuable insights into their breeding conditions versus their potential applications. The research examined three key affecting factors of larval development over time, namely, moisture content, growth space and soil content. Results of a pretest run revealed that moisture content, but not the soil content, affected the larval survival greatly. A reasonable confinement on feed moisture (i.e., 30%–60%) was included in the later conducted three‐factor factorial experiment. At last, results of the factorial run suggested that: (1) for a consistent and massive larval breeding, environmental factors, setting moisture content at 60%, larval space at 100 cm3/larva and no soil addition, are deemed appropriate, (2) for nutritional purpose, setting moisture content at 60%, larval space at 300 cm3/larva and no soil addition are recommended, and (3) for soil pollution remediation, setting moisture content at 60%, larval space at 100 cm3/larva and a soil‐to‐feed (S/F) ratio of 2:1 is concluded. This study marks the first engineering breeding exploration of Oryctes rhinoceros larvae, offering practical recommendations for various research purposes and applications.

Pengaruh Dosis Pupuk Kandang Kambing terhadap Pertumbuhan dan Hasil pada Dua Varietas Kacang Panjang (Vigna unguiculata L.)

Poor choice of varieties and the decrease in soil fertility are among the few variables that can affect long peanut productivity. The aim of this research is to study how the dose of goat fertilizer and long bean varieties affects the growth and yield of long beans. The research was a factorial experiment with two factors and three replications using the Randomized Blok Design (RBD) method. The first factor, the dose of goat manure 0 ton ha-1(k0), 10 ton ha-1(k1), 20 ton ha-1(k2), 30 ton ha-1(k3), and 40 ton ha-1(k4). The second factor was long bean varieties Kanton Tavi (v1) and Katrina (v2). Data were analyzed using analysis of variance (ANOVA) at the 5% level. The results of the experiment showed an interaction in the parameters of plant height 7 DAP and 14 DAP, number of leaves 14 DAP, 21 DAP, 28 DAP, number of pods per plant, and pod weight per plot. A dose of 30-ton ha-1 (k3) goat pen fertilizer produced a healthy amount of beans on the cantonese Kanton Tavi variety (v1) with X optimum (v1) = 29,08 ton ha-1 and Y maximum (v1) = 21,86 ton ha-1 and on Katrina variety (v2) X optimum (v2) = 25,15 ton ha-1 and maximum y (v2) = 20,56 ton ha-1.

Analysis of 3k Experiments Applied to Railway Braking: Influence of Contaminants and Train Speed

The presence of contaminants influences braking efficiency in the railway system because it alters the adhesion at the wheel–rail interface. It is essential to study this phenomenon, as contaminants reduce the friction between wheels and rails, which impacts braking and transport safety. In addition, these contaminants increase the risk of derailments. The objective of the research was to determine the impact of different contaminants and operating speeds on the critical braking system’s responses. Using the 3k full factorial experimental design methodology, with analysis of variance (ANOVA) and linear and quadratic regressions, visualized using surface graphs, the effects of three operating conditions were studied: clean rails, with sand and sawdust, and driving the train at three operating speeds. These conditions gave rise to variations in braking distances, maximum creep, wheel slip times, and maximum peaks of electric current when braking in each experiment. The tests were carried out on the straight section of a β-shaped track and a railway vehicle, designed at a scale of 1:20. The analysis reveals that the braking distance increases significantly with surface roughness (clean track < sawdust < sand). At 0.75 m/s, the sawdust track reduces braking distance by 21% compared with the clean track; at 1.00 m/s, the reduction is 19%; and at 1.30 m/s, it is 35%.

Multivariate Optimization of a Green Microwave-Assisted Hydrogen Peroxide Digestion of Vegetable Oils and Subsequent Elemental Determination Via Inductively Coupled Plasma–Optical Emission Spectrometry

AbstractA microwave-assisted digestion technique based on dilute hydrogen peroxide (MW-AHPD) was developed for multielemental determination in vegetable oils. The determination of ten trace elements (As, Cd, Cr, Cu, Fe, Pb, Ni, Sn, V, and Zn) was conducted via inductively coupled plasma optical emission spectroscopy (ICP-OES) after digestion. The most influential parameters were investigated by using multivariate optimization tools (two-level full factorial and central composite design) with percent recovery as the chemometric response. The optimum conditions were 2.0 mol L−1 (H2O2]), 156 °C (digestion temperature), 0.1 g (sample mass) and 50 min (digestion time). Under the optimized conditions, the efficiency of digestion was evaluated based on the residual carbon content (RCC) of the final digests. The RCC values were very low, ranging from 0.84 to 1.60% (m/m). The greenness of the technique was evaluated using the Analytical Eco-scale, and the proposed method was considered an excellent green analysis method with a final score of 90. The accuracy of the optimized MW-AHPD was evaluated by spiking sunflower, olive, and peanut oils at concentrations of 2.5 and 5.0 μg L−1, and excellent recoveries between 90.3 and 107.3% were reported. The accuracy of the MW-AHPD method was compared with that of microwave-assisted digestion using concentrated HNO3, and there was no significant difference between the two methods. The limits of detection ranged from 0.026 to 14.6 μg L−1. On the other hand, the interday and intraday precisions were less than 6.67 and 6.96%, respectively. The method was successfully applied to determine the concentrations of trace elements in 5 vegetable oils on the South African market. Thus, MW-AHPD-ICP–OES is applicable for the determination of trace elements in vegetable oils.

Effects of Dietary Fiber and Copper on the Performance and Gut Microbiota of Finishing Pigs

This study aimed to investigate the effects of dietary fiber (DF) levels and copper concentrations on the production performance and cecal microbial diversity of finishing pigs. A 2 × 2 factorial experimental design was used, with different levels of dietary fiber (low [23% DF]: L and high [30% DF]: H) and copper concentrations (normal [25 mg/kg]: N and supplemented [45 mg/kg]: S) resulting in four diets (LN, LS, HN, and HS). Forty-eight hybrid barrows (Duroc × Landrace × Yorkshire), with an initial body weight of 76 kg ± 1.5 kg, were randomly assigned to four groups: LN, LS, HN, and HS, with 12 replicates per group and one pig per replicate. There was a 7-day adaptation period followed by a 56-day feeding trial, after which all pigs were slaughtered for sampling. Results indicated that in finishing pigs, the low dietary fiber group exhibited a higher final weight, a higher average daily gain, and a lower feed-to-gain ratio compared to the high fiber group (p < 0.05). The LS group showed higher digestibility of dry matter, crude protein, crude fiber, ash, neutral detergent fiber, and DF than the HN and HS groups (p < 0.05). Blood total protein levels were higher in the high fiber group, whereas blood Cu levels were higher in the supplemented copper group (p < 0.05). High dietary fiber increased the activities of colonic carboxymethylcellulase and β-glucanase (p < 0.05). Concentrations of acetic acid, propionic acid, and total volatile fatty acids were elevated in the high fiber group (p < 0.05). Microbial α-diversity indices (observed species, Chao 1, and Shannon indices) increased with fiber but decreased with copper supplementation (p < 0.05). The Firmicutes/Bacteroidetes ratio increased with fiber levels, with a higher relative abundance of Lactobacillus in the LS group. In conclusion, appropriate copper supplementation in diets can mitigate the negative effects of high fiber levels on finishing pig production performance by enhancing nutrient digestibility, fiber-degrading enzyme activity, regulating the microbial community, and its metabolic products.

The Effect of Interaction between Training Methods and Eye-Hand Coordination on the Accuracy of the Forehand Groundstroke of Court Tennis

This study aims to determine the Effect of Training Methods on the Accuracy of Court Tennis Reviewed from Eye Hand Coordination. This study uses a 2x2 factorial design experiment, which is an experimental design method that combines several independent variables while still considering the potential impact of factorials. Moderator variable on the outcome or independent variable. This research was carried out at the Kentoeng Tennis Academy Sukoharjo Field, Pojok, Mulur, Bendosari District, Sukoharjo Regency. There was no effect of interaction between eye hand treatment and coordination on the improvement of accuracy Groundstroke forehand . This is evidenced by the results of the anova statis tical test with a probability value of 0.841 > 0.05. The test results with 2-way anova statistics were obtained in the interaction test, a calculated f value of 0.042 and a probability of 0.841. Based on the criteria mentioned above, the probability of > 0.05 means that the interaction factor does not affect the improvement of the accuracy of the forehand groundstroke of the court. The interaction factor means that the training method and eye-hand coordination do not work together to improve the accuracy of the forehand groundstroke court tennis. So, Hypothesis 3 which states: there is an interaction between training methods and eye-hand coordination on improving the accuracy of the forehand groundstroke of the tennis court, is rejected.