Doehlert Design Research Articles

Enhancing microfiltration membrane efficiency for treating industrial wastewater derived from Sugar Industry waste through Doehlert Design Optimization

To address the challenges of treating industrial wastewater, the scientific community must engineer novel membrane materials that prioritize innovation, cost-efficiency, and environmental sustainability. The present study describes the fabrication and characterization of a newly designed, economically viable planar microfiltration ceramic membrane made from sugar scum and indigenous Moroccan clay. Utilizing the Doehlert design-based Response Surface Methodology, optimization of preparation conditions was conducted to investigate the effects of sugar scum quantity (5-30%), sintering temperature (800-1000 °C), and sintering time (60-180h) on mechanical strength, water absorption, and water porosity. The enhanced membrane displays a compressive strength of 56.10MPa, a porosity of 42.71%, a permeability of 1246Lh-1 m-2 bar-1, and an average pore size of 0.88µm. Additionally, it demonstrates outstanding resistance to chemical corrosion in basic environments. The optimal clay membrane underwent industrial wastewater filtration and performed admirably as a microfiltration membrane. It had impressive removal rates of 98.26% for turbidity, 62.86% for chemical oxygen demand (COD), and 46.14% for electrical conductivity. Furthermore, the cleaning procedure restored 88% of the membrane's original water permeability.

Valorisation of white wine lees: optimisation of subcritical water extraction of antioxidant compounds

This study explored the extraction of antioxidant compounds from white wine lees using subcritical water extraction (SWE). First, SWE was compared to extraction using conventional solvents mixed with water: 50 % methanol, 50 % ethanol and 50 % acetonitrile. The antiradical activity of the extract increased to 12.8 mg TE/g of extract dry matter (DM) using conventional solvents and to 29.2 mg TE/g DM with SWE, compared to the antiradical activity of dried lees, which was 5.7 mg Trolox Equivalent/g of dry matter (mg TE/g DM). Second, SWE conditions were optimised to obtain lees extracts with a high antioxidant activity by applying a Doehlert design and response surface methodology (RSM). The extraction parameters modulated during RSM optimisation were extraction time (t, 15 – 60 min), temperature (T, 100 – 250 °C) and stirring speed (S, 100 – 1000 RPM). Antioxidant activity was assessed using DPPH and FRAP tests, as well as by measuring the Oxygen Consumption Rate (OCR) of lees extracts. Temperature was found to be the main parameter that had a significant effect on antioxidant activity. The results of the RSM showed the optimal conditions (temperature, duration and speed) for attaining maximum antioxidant activity to be: 240 °C, 15 min and 550 RPM respectively. The best-known antioxidant compounds in white wine lees, Total Polyphenol Content (TPC), Glutathione (GSH) and Total Sulfhydryl groups (TSH) were also quantified. Extracts with the highest antioxidant capacity had the highest TPC and TSH concentrations. In conclusion, this study showed (i) that subcritical water extraction is a green process that has potential as an alternative to using conventional solvents for extracting white wine lees, (ii) the chemical components involved in their antioxidant capacity, and (iii) the potential of the lees for oenological and other industrial applications.

Sulfur fractionation using high-resolution continuum source molecular absorption spectrometry with calcium and hydrophobic palladium nanoparticles as chemical modifiers

The unprecedented use of high-resolution continuum source molecular absorption spectrometry (HR-CS MAS) for the fractionation of organic and inorganic sulfur (S) species through monitoring the CS molecule is presented here. Two separate methods for determining organic (CSorg) and inorganic (CSino) sulfur were developed to work sequentially. The optimized temperature program for both methodologies has two pyrolysis steps and one vaporization step (1st Tpyr: 1800 and 2ndTpyr: 800 °C, and Tvap: 2500 °C). The fractionation was achieved by implementing hydrophobic Pd NPs and Ca as chemical modifiers for the CSorg and CSino methods. Method development was performed by applying different statistical models, allowing the definition of optimal conditions for the chemical modifier mass, and minimizing the S species interconversion, i.e., Doehlert design, and central composite design. The limits of detection (LoD) for CSorg and CSino were 2.4 and 2.1 mg L−1, respectively. Recovery tests evaluated the method's specificity and accuracy; over 92 % recovery was found for both CSorg and CSino. Thus, the proposed methods offer a reliable alternative for fractionating organic and inorganic S by using HR-CS MAS.

Improving the extraction yield of essential oil from Pimenta dioica (L.) Merr. using Aspergillus niger ATCC 1004 enzyme blend.

The objective of this work was to optimize the application of an enzymatic blend produced by Aspergillus niger ATCC 1004 on the Pimenta dioica fruits for essential oil extraction. The enzyme blend was obtained from the fermentation of cocoa bean shells, an agro-industrial residue. The effects of the enzymatic pre-treatment on the extraction yield, the chemical composition of the oil through gas chromatography, and the fruit structure through scanning electron microscopy (SEM) were assessed. A Doehlert design was used to optimize the process conditions, resulting in an extraction with 117mL of enzyme during 77min, which increased the extraction yield by 387.5%. The chemical composition was not altered, which proves that the enzyme blend preserves the quality of the essential oil extracted. The content of eugenol (70%), the major compound in the P. dioica essential oil, had a great increase in its concentration (560%). The enzyme activity analyses showed the presence of endoglucanase (0.4U/mL), exoglucanase (0.25U/mL), β-glucosidase (0.19U/mL), and invertase (135.08U/mL). The microscopy analyses revealed changes in the morphology of fruit surface due to the enzymatic action. These results demonstrate the great potential of using enzyme blends produced by filamentous fungi from agro-industrial residues for the essential oils extraction of interest for the pharmaceutical and food industries.

Electrolyte Formulation By Design of Experiments: The Hidden Correlations in the Li-Mediated Nitrogen Reduction Reaction for Ammonia Production

Ammonia, a fundamental building-block for fertilizers and other many commodities, is responsible, through the Haber-Bosh (HB) process, of around 1.4% of the global greenhouse gas emissions. Indeed, HB operates in severe conditions (200 atm), and is fossil fuel dependent, since the few huge, centralized plants are combined with steam reforming for H2 production. To find a renewable-driven and delocalized electrochemical process for NH3 production, complementary to HB, could be a key solution for our society that is facing climate change crisis and that is demographically growing [1].In view of process electrification, the Li-mediated (Li-m) pathway represents the most promising solution in the N2 reduction reaction (NRR) challenging field. Exploiting the unique reducing power of this alkali metal, this strategy achieves the highest Faradic efficiency (FE) and NH3 production rate [2,3,4].Li+ ions from the aprotic electrolyte are electrodeposited on the cathode, where N2 is reduced and protonated into NH3 thanks to a proton donor or a proton shuttle, as EtOH. On the plated Li, a solid electrolyte interphase (SEI) unavoidably forms, and its nature and morphology are straightly dependent on the electrolyte composition. The different diffusion rate of Li+, N2, and H+ trough the SEI layer determines the selectivity towards NH3 formation. The correct reactant ratio at the electrode surface is essential to hinder both the hydrogen evolution reaction and an excessive Li plating, maximizing the FE [5,6].Design of experiment (DoE) together with response surface methodology (RSM) are a powerful tool that can reveal, with a restricted number of experiments (e.g. 9), the optimal composition of the electrolyte towards the highest FE and the hidden intercorrelations among variables. In particular, we aimed at studying two key variables, i.e. EtOH and Li-salt concentration; to this purpose, the Doehlert design with two factors and three replicates of the central point was chosen and RSM was employed to model the response and determine the optimal conditions.The study was repeated with two different fluorinated Li-salt, LiBF4 and LiFOB. LiBF4 has recently shown an improved stability and FE for the Li-m NRR process, correlated to the LiF presence in the SEI layer. The optimal combination of the electrolyte components obtained from the DoE for LiBF4 is in accordance with previous study, validating the statistical methodology applied. The newly proposed salt showed an increase of the 25% in the FE with respect to LiBF4 in the same conditions [7,8]. Experiments was conducted under 20 bar N2 in an autoclaved glass cell with a proper gas purification. As in previous study with this Li-m strategy in this set-up, even in this case the total NH3 amount obtained overcame the amount of possible impurities coming from the N2 gas, moreover controls tests with Ar instead of N2 were performed.

Green Ammonia Electrosynthesis from Nitrate-Polluted Waters

Ammonia (NH3) is the basis of all nitrogen fertilisers constituting one of the pillars of modern society, without which nearly half of the population would not be present on Earth.1 Moreover, due to its high energy content and density, it has recently emerged as a potential fuel on the route to decarbonisation.2 However, contemporary NH3 is mainly produced via the energy-intensive and fossil fuel-dependent Haber-Bosch process so to meet the future NH3 demand, the development of new green synthesis techniques is crucial.3 Conversely, due to its high solubility, nitrate (NO3 -) is considered one of the most widespread pollutants in groundwaters.4 Increasing NO3 - concentrations in water sources represent an environmental concern and a risk to human health, requiring the development of novel and efficient techniques to remove them5,6 To this end, electrochemical nitrate reduction reaction (E-NO3RR) has received considerable attention since, among other advantages, it permits the utilization of electricity from renewables. Besides, taking into account that molybdenum and sulphur play key roles in nitrogenase-based nitrogen fixation, molybdenum disulphide (MoS2) is expected to be active toward E-NO3RR, even if it has already demonstrated good catalytic activity toward hydrogen evolution reaction (HER, the main competitor of E-NO3RR).6 In this work, MoS2 has been tested for E-NO3RR in combination with K2SO4 0.1 M as electrolyte. Experiments have been performed employing a flow cell with a gas diffusion electrode (GDE), on which the catalyst is immobilized through air-brushing technique. The design of the experiment and surface response methodology (DoE/RSM) were used to gain further insight onto the influence of three operational variables (i.e. operating potential, catalyst loading and salt concentration in the electrolyte) on the Faradaic efficiency and NH3 yield of the NO3RR, as well as the possible interaction between those variables. Concretely a 3-factors Doehlert design with 3 replicates of the central point was employed. To select the proper range for every variable, screening experiments were first performed. Results reveal operational potential and salt concentration at the electrolyte as main parameter controlling the efficacy of the process Valve, H., et al. in Handbook of the Circular Economy (Edward Elgar Publishing, 2020).Smith, C., et al. Energy Environ. Sci. 13, 331–344 (2020).MacFarlane, D. R., et al. Joule 4, 1186–1205 (2020).Abascal, E., et al. Sci. Total Environ. 810, 152233 (2022).Garcia-Segura, S., et al. Appl. Catal. B Environ. 236, 546–568 (2018).Ingle, J., et al. J. Water Process Eng. 49, 103082 (2022).Zhang, L., et al. Adv. Mater. 30, 1800191 (2018).

Advancing reinforcement of sustainable gypsum composites: High-performance design by reusing waste materials

This study tends to optimize and develop an innovative gypsum material by incorporating hybrid waste compounds. Using a Doehlert design, this work explores the effects of introducing paper (X1), polystyrene (X2), and polyester fibers (X3), as well as their interactions, on gypsum's thermophysical and mechanical behavior. Bulk density, thermal conductivity, flexural strength, compressive strength, and the fire resistance test were performed on the developed formulations. Statistical analysis emphasizes the significant influence of all process variables on gypsum properties. Polyester fibers notably enhance flexural strength when combined with the cooperative effect of paper and polystyrene wastes, which strike a balance between physical and mechanical characteristics. The optimum formulation parameters lead to a significant 33% decrease in bulk density, a 43% reduction in thermal conductivity, a notable 42% increase in flexural strength, and a significant reduction in compressive strength of around 50%, but still meet the 2 MPa standard. The new samples show ductile behavior, highlighting gypsum's potential as a load-bearing material with excellent thermal insulation properties and impressive fire resistance. This research significantly improves our understanding of the effectiveness of a gypsum compound incorporating waste in a hybrid manner, bringing this approach into line with sustainable development objectives.

Modeling and Optimization of Electrochemical Advanced Oxidation of Clopidogrel Using the Doehlert Experimental Design Combined with an Improved Grey Wolf Algorithm

In this research, the optimization of the electrochemical advanced oxidation treatment for the degradation of Clopidogrel was investigated. This study examined the influence of various experimental parameters including applied current, initial Clopidogrel concentration, and ferrous ion concentration by the use of the Doehlert design within a response surface methodology framework. The improved grey wolf optimizer was applied in order to define the optimum operating conditions. The monitoring of clopidogrel concentration during treatment revealed that complete disappearance of clopidogrel was achieved under an initial clopidogrel concentration of 0.02 mM, current intensity of 0.55 A, Fe2+concentration of 0.7 mM, and a reaction time of 20 min in a solution containing 50 mM Na2SO4 at pH 3. A quadratic polynomial model was developed, and its statistical significance was confirmed through the analysis of variance, demonstrating a high level of confidence in the model (R2 = 0.98 and p-value < 0.05). Furthermore, following electrolysis treatment for 480 min, the synthetic clopidogrel solutions underwent mineralization, achieving a 70.4% removal rate of total organic carbon. Subsequently, the applicability of the optimized process was tested on real pharmaceutical wastewater, and mineralization was investigated under the identified optimal conditions, resulting in a total organic carbon removal rate of 87% after 480 min of electrolysis time. The energy consumption for this system was calculated to be 1.4 kWh·kg−1 of the total organic carbon removed. These findings underscore the effectiveness and potential applicability of the electrochemical advanced oxidation for industrial wastewater treatment.

Investigating Cd2⁺ ion sensing with palygorskite-carbon paste electrodes: optimizing performance through Doehlert design

Investigating Cd2⁺ ion sensing with palygorskite-carbon paste electrodes: optimizing performance through Doehlert design

Harnessing Brewery Spent Grain for Polyhydroxyalkanoate Production

The utility of brewery spent grain (BSG), a byproduct of the beer production process, for the synthesis of polyhydroxyalkanoates (PHAs), is a significant advancement towards sustainable and cost−effective biopolymer production. This paper reviews the upcycling potential of BSG as a substrate for PHA production, utilizing various biotechnological approaches to convert this abundant waste material into high−value biodegradable polymers. Through a comprehensive review of recent studies, we highlight the biochemical composition of BSG and its suitability for microbial fermentation processes. This research delves into different methodologies for PHA production from BSG, including the use of mixed microbial cultures (MMCs) for the synthesis of volatile fatty acids (VFAs), a critical precursor in PHA production, and solid−state fermentation (SSF) techniques. We also examine the optimization of process parameters such as pH, temperature, and microbial concentration through the application of the Doehlert design, revealing the intricate relationships between these factors and their impact on VFA profiles and PHA yields. Additionally, this paper discusses challenges and future perspectives for enhancing the efficiency and economic viability of PHA production from BSG. By harnessing the untapped potential of BSG, this research contributes to the development of a circular economy model, emphasizing waste valorization and the creation of sustainable alternatives to conventional plastics.

A novel g-C3N4@La:Y2O3 nanocomposite fluorescence sensor for simultaneous determination and photocatalytic degradation of Ulipristal acetate and Tacrolimus using Doehlert design optimization

Graphitic carbon nitride nanocomposite doped with La:Y2O3 was used as a new sensor for detection and determination of two hazardous active pharmaceutical compounds, Tacrolimus and Ulipristal acetate, by fluorescence spectrophotometry. This novel nanosensor has a fantastic ability to detect these drugs quickly, accurately, and simultaneously. The effect of Tacrolimus on this nanosensor is the quenching of fluorescence emission intensity at the wavelength of 369 nm while the Ulipristal acetate increases the fluorescence emission at 433 nm. Doehlert design was used to optimize the effective factors to reach the maximum fluorescence emission intensity of the nanosensor. Factors including pH, buffer solution concentration and the ratio of La:Y2O3 dopant in the nanocomposite structure. Under optimal conditions, the limit of detection of 17 nM and the limit of qualification of 58 nM for Tacrolimus and the limit of detection of 11 nM and the limit of qualification of 36 nM for Uipristal acetate were obtained with good accuracy. The prepared g-C3N4@La:Y2O3 nanocomposite has a reasonable ability to photodegrade these two drugs. In this regard, the process of photocatalytic degradation of Tacrolimus and Ulipristal acetate was investigated under visible light irradiation. The effect of active species in photocatalytic degradation was evaluated in order to determine the exact degradation mechanism, and the effect of Fenton factors on analytes degradation was also investigated.

Production, characterization and application of polygalacturonase produced by Lentinus tigrinus CCMB 553

Polygalacturonases can be used to improve the processing of fruit juices and wines. This study aimed to produce, characterize and evaluate the potential application of polygalacturonase obtained from Lentinus tigrinus CCMB 553 in mango juice clarification. The fungal was isolated from the northeastern semi-arid region and fermented using Passiflora cincinnata bark as a substrate for solid state fermentation. The optimal conditions for enzyme production were obtained by applying the three-level factorial experimental design and were defined as 9 days and 30 °C for time and temperature, respectively. The optimal pH and temperature were determined by applying the Doehlert design and the results showed higher production between 45 and 60 °C and 4.0 and 5.5 for temperature and pH respectively. Km and Vmax of polygalacturonase from Lentinus tigrinus were 2.7 mg/mL and 12.86 μmol/min. The enzyme maintained 40 % residual activity after 30 min at 80 C. The influence of cations on enzyme activity was studied, and calcium ions seem to have a positive influence on enzyme activity, while Fe2+ ions have a negative influence. K+, Na+ and NH4+ salts showed little influence on the polygalacturonase activity of Lentinus tigrinus. The application in the clarification of mango juice (Mangifera indica) using optimal conditions obtained resulted in a reduction of 45% of the viscosity and the clarification by about 79%. The results show that the polygalacturonase produced by Lentinus tigrinus CCMB 553 was efficiently applied in mango juice, improving the quality of the juice.

Development and validation of an efficient approach for extracting essential oil, scutellarin, and rosmarinic acid from Perilla frutescens leaves using vacuum microwave-mediated rotary hydrodistillation and extraction in situ and a choline amino acid ionic liquid

In this study, an efficient vacuum microwave-mediated rotary hydrodistillation and extraction in situ (VMRHDE) device was used for extracting essential oil, scutellarin, and rosmarinic acid from Perilla frutescens leaves with choline amino acid ionic liquid solution. The extracted products were then analyzed through GC–MS and HPLC. The optimal parameters were determined through a Doehlert design matrix and desirability function, resulting in the use of 10 % choline glutamate ionic liquid ([Ch][Glu]), a liquid–solid ratio of 15 mL/g, a microwave irradiation time of 20 min, a microwave irradiation power of 540 W, and a rotary speed of 24 r/min. Under optimal operating conditions, the yields of essential oil, scutellarin, and rosmarinic acid were 0.41 % ± 0.02 %, 0.39 % ± 0.01 %, and 0.36 % ± 0.01 %, respectively. GC–MS analysis revealed that adding [Ch][Glu] significantly increased the content of perilla aldehyde and oxygenates in the essential oils. Methodological validation confirmed that the established method met the detection requirements, with recoveries of 99.20 % for scutellarin and 99.83 % for rosmarinic acid, demonstrating high accuracy. The linear relationship of scutellarin and rosmarinic acid was good in the concentration range, with R2 values of 0.9999 for both.

Optimizing the Vanillin-Acid Sulfuric Method to Total Saponin Content in Leaves of Yerba Mate Clones.

Yerba mate (Ilex paraguariensis) is a forest species consumed in the form of non-alcoholic beverages in South America, with applications in foods, cosmetics, and pharmaceutical industries. The species leaves are globally recognized for their important bioactive compounds, including, saponins. We adjusted the vanillin-acid sulfuric method for determining spectrophotometrically the total saponin in yerba mate leaves. Seeking to maximize the extraction of saponins from leaves, a Doehlert design combined with Response Surface Methodology (RSM) was used, considering ethanol:water ratios and ultrasound times. In addition, the same methodology was used for the analysis of times and temperatures in the vanillin-sulfuric acid reaction heating. The contents of total saponin in mature leaves were compared in four yerba mate clones. The extraction was maximized using 40 % ethanol:60 % water and 60 minutes of ultrasound assisted extraction (UAE) without heating. For the reaction conditions, 70 °C for 10 minutes heating is recommended, and UV/Vis reading from 460 to 680 nm. Using the optimized methodology, total saponin contents ranged from 28.43 to 53.09 mg g-1 in the four yerba mate clones. The significant difference in saponin contents between clones indicate great genetic diversity and potential for clones' selection and extraction of these compounds from yerba mate leaves.

Degradation of antibiotic sulphamethoxazole by application of modified photo-Fenton processes: kinetics, degradation pathways and toxicity

ABSTRACT Degradation of antibiotic sulphamethoxazole (SMX) was studied by applying modified photo-Fenton reactions (MPF) with the novel choice of using sodium tripolyphosphate (STP) and sodium hexametaphosphate (SHP) complexing agents. STP and SHP have a strong ability as complexing agents because they can sequester and complex with different ions. Process optimisation was performed using Doehlert design at pH = 6. This study presented higher performance for MPF using STP and SHP complexing agents than conventional photo-Fenton and H2O2 + UV process. The best yields were associated with the formation of a smaller number of intermediates with high degradation efficiency and low oxidative stress, environment-friendly and promising processes.

Response surface methodology for low-energy consumption electro-Fenton process for xanthene dye electrochemical degradation

Erythrosine B (EB) is a dye widely used in the food and textile industries. Despite many studies that have been proposed in the literature about the electrochemical oxidation of dyes, few studies considered such recalcitrant xanthene compound, although it has been recognized as a threat to health and the environment. Then, this study investigates the oxidation of EB by a homogeneous electro-Fenton process using iron (II) sulfate heptahydrate as a catalyst, carbon felt cathode, and Ti/RuO2 anode. The treated synthetic wastewater contains 100 mg L−1 of EB and has a pH = 3. The effects of three independent variables have been considered for process optimization, such as applied current intensity (0.1–0.5 A), iron concentration (1–10 mM), and stirring rate (100–1000 rpm). Their interactions were investigated considering response surface methodology (RSM) based on Doehlert design as optimization method. EB removal efficiency and energy consumption were considered as model responses after 30 min of electrolysis. Analysis of variance (ANOVA) revealed that the quadratic model was adequately fitted to the experimental data with R2 (0.9819), adj-R2 (0.9276), and low Fisher probability (< 0.0181) for the EB removal model, and R2 (0.9968), adj-R2 (0.9872) and low Fisher probability (< 0.0014) relative to the energy consumption model, suggesting a robust statistical significance. The energy consumption model significantly depends on current density, as expected. The foregoing results obtained by RSM led to the following optimal conditions for EB degradation: current intensity of 0.2 A, iron concentration of 9.397 mM, and stirring rate of 500 rpm, which gave a maximum decolorization rate of 98.15% with a minimum energy consumption of 0.74 kWh m−3 after 30 min of electrolysis. The competitiveness of the electro-Fenton process has been confirmed by the literature analysis proposed as well as by the preliminary economic analysis proposed in the second section of the study.Graphical abstract

Analysis of Volatile Hydrocarbons (Pentene Dimers and Terpenes) in Extra Virgin Olive Oil: Optimization by Response Surface Methodology and Validation of HS-SPME-GC-MS Method.

A head space-solid phase microextraction-gas chromatography-mass spectrometery (HS-SPME-GC-MS) method for the simultaneous analysis of pentene dimers from lipoxygenase (LOX) pathway, monoterpenes, and sesquiterpenes in extra virgin olive oil (EVOO) was proposed. A Doehlert design was performed; the conditions of the HS-SPME preconcentration step (extraction temperature, extraction time, sample amount, and desorption time) were optimized by response surface methodology, allowing defining the method operable design region. A quantitative method was set up using the multiple internal standard normalization approach: four internal standards were used, and the most suitable one was selected for area normalization of each external standard. The quantitative method was successfully validated and applied to a series of monocultivar EVOOs. This is the first paper in which a quantitative method using commercial standards has been proposed for the analysis of an important class of molecules of EVOO such as pentene dimers. The optimized method is suitable for routine analysis aimed at characterizing high quality EVOOs.

Cocultivo de calos in vitro como estratégia na prospecção de reguladores de crescimento para indução da enxertia in vivo da videira

Abstract The use of growth regulators (GRs) in a mechanized bench grafting system is essential for the final quality of grafted grapevine plants. In Brazil, the GRs used (commercial waxes) are imported, increasing the production cost for nurseries. This work aimed to test the in vitro callus co-cultivation technique as a strategy for prospecting effective doses and mixtures of GRs for in vivo graft union on grapevines. Two genotypes were used as scions (‘Bordo’ and ‘Riesling Italico’) and two as rootstocks (‘SO4’ and ‘P1103’). Callus from different scion/rootstock combinations were co-cultivated, varying the doses (0.25 to 20 mg l-1) of auxins (DBA, IAA and IBA) and cytokinin (BAP), following the Doehlert design. The best in vitro treatments were validated in vivo, in plants grafted with an ‘omega’ cutter machine. Multivariate and non-parametric methods were applied to integrate the results. In vitro prospecting combined with the in vivo validation strategy allowed us to select effectively the IAA(2.50 mg l-1) plus BAP(1.00 mg l-1) formulation with the potential to induce graft callus union similar to commercial waxes. The induction intensity varied among the genetic combinations but was similar in the in vitro and in vivo conditions.

APLICATIVO GAMMA-GUI: UMA INTERFACE GRÁFICA AMIGÁVEL PARA PLANEJAMENTO DE EXPERIMENTOS NO MATLAB

GAMMA-GUI APP: A FRIENDLY GRAPHICAL USER INTERFACE FOR THE MULTIVARIATE DESIGN OF EXPERIMENTS IN MATLAB. We present to users unfamiliar with the programming language a user-friendly interface for the multivariate design of experiments (DoE) in Matlab®. The interface of the GAMMA app - Grupo de Análise Multivariada em Matrizes Alimentares, in Portuguese-BR, is available for free download on GitHub https://github.com/appGAMMA, and has a YouTube channel https://www.youtube.com/@appGAMMA with a series of tutorial videos. In this tutorial, some practical demonstrations are made using the DoE interface with real applications: (i) screening design for variable selection; (ii) optimization by Box-Behnken design; (iii) optimization by central composite design; (iv) factorial design for variable selection following by optimization with Doehlert design; (v) optimization by mixture design; (vi) optimization by mixture design with pseudocomponents; (vii) optimization by mixture design with process variable; and (viii) multiple-response optimization; also reproduced in the software Statistica v.13, StatSoft® for comparison. The GAMMA-GUI is constantly developing; suggestions for improvements or new ideas are welcome and can be directed to the developers.

Engineering properties and optimization of the dehulling process for hairless canary seed.

This work aimed to determine the engineering properties of hairless canary seeds (Phalaris canariensisL.) of the variety "CDC Maria" and the optimum combination of operating conditions of the dehulling process with a pilot-scale centrifugal dehuller. The engineering properties analyzed in this study were the principal dimensions, length (4.8mm), width (1.95mm) and thickness (1.41mm); geometric mean diameter (2.36mm); the sphericity (49.2%); apparent and true densities (752 and 1191.47kg/m3, respectively); the porosity (0.37); 1000 grains weight (7.28g); angle of repose (15.89°) and the static coefficient of friction (galvanized steel, 0.325; plywood, 0.372; aluminium, 0.316). For the process optimization, a two-variable Doehlert design was used, analyzing the effect of impact dehuller rotor speed (peripheral speed 30.4 to 47.1m/s) and seed moisture content (10 to 14% d.b.) by maximizing the dehulling ability (DA) and maintaining the production of fines by 3%. Under the experimental conditions of 36.7m/s (peripheral speed) and 10% d.b. (seed moisture), with a double pass through the dehuller, the optimum value of DA (94%) was obtained, with a fine production of 3%. The optimized dehulling process allows removing a large percentage (98%) of the canary seed hull.