Box-Behnken Methodology Research Articles

Application of optimized laser surface re-melting process on selective laser melted 316L stainless steel inclined parts

Absract Lower surface quality of selective laser melting (SLM) manufactured parts remains to be a key shortcoming particularly for high performance functional components. In this paper, the authors utilized Box–Behnken methodology to explore the effect of laser surface re-melting process parameters. The process parameters are:laser power, laser exposure time, laser point distance, and shell layer thickness. The experiments were conducted using Renishaw AM-250 machine. SLM manufactured parts with inclination of 45˚ up-skin were treated with a given surface roughness using laser surface re-melting (LSR). The optimization of process parameters was conducted using response surface methodology and the validation tests was carried out utilizing the determined input parameters. The results verified the effectiveness of the integrated approach and the proposed statistical model. The outcomes of this study demonstrated that selective laser melting process followed by the laser surface re-melting process is very likely to become a fast and economic integrated method for improving the inclined surface quality of SLM manufactured parts.

Establishment of Acid Hydrolysis by Box–Behnken Methodology as Pretreatment to Obtain Reducing Sugars from Tiger Nut Byproducts

Carbohydrate-rich byproducts may be used as a growth substrate for microalgae. The tiger nut, compared to other tubers, has higher carbohydrate content, which mostly remain in the byproduct after the production of tiger nut milk (“Horchata”). The aim of this study is the optimization of a hydrolysis pre-treatment in tiger nut byproduct to obtain reducing sugars, objective framed in the European SUSPUFA (Sustainable production of health-promoting n-3 LC-PUFA using agro-food industry by-products through microalgae) Project. Two experimental 4-factor Box–Behnken designs (acid concentration (N), temperature (°C), time (min) and ratio acid/sample) were carried out with 27 experiments to optimize chemical hydrolysis conditions with H2SO4 and H3PO4 in duplicate. The sugars were determined by the Schoorl method and the extracts obtained by the optimal conditions were analyzed by high-performance liquid chromatography (HPLC). Protected designation of origin (PDO) and non-protected designation of origin (n-PDO) tiger nut byproducts were characterized by physicochemical methods. The validity of the experimental designs was confirmed by ANOVA. The optimum sugar values were obtained with H2SO4 2 N at 85 °C, 60 min and ratio 60 and H3PO4 21 N at 90 °C, 60 min and ratio 60. Glucose and xylose were the sugars detected in the hydrolyzed samples. In conclusion, almost 50% of the total carbohydrates present in the tiger nut byproduct were hydrolyzed to reducing sugars.

Electrochemical oxidation treatment of offshore produced water using modified Ti/Sb-SnO2 anode by graphene oxide

To improve Persian gulf severely damaged marine environment and prevent long term exposure risks of toxic chemicals being discharge into the sea, total COD removal of produced water (PW) at a South Pars gas field is proposed by electrochemical oxidation process (EO), using Ti/Sb-SnO2 anode modified with graphene oxide (GO) prepared in a simple and cost effective technique. Comprehensive electrochemical tests, morphological and structural examinations indicated that addition of GO, improved considerably electrocatalytic activity for the fabricated anode, confirmed formation of uniform SnO2 nanoparticles ranging 15−26 nm and presence of reduced GO. Maximum COD removal and energy efficiency for the pre-discharged offshore oxidation process unit was optimized using Box-Behnken methodology in the EO design experiments. For 2 h electrolysis of PW with prepared anodes, software optimized conditions of CD = 10 mA/cm2, pH = 4.00, electrode distances of 10 mm, and predicted 59.96 % COD removal and energy efficiency of 42.83 g/Kwh which were compatible with experimental data of 58.60 % and 42.63 g/Kwh, respectively. COD removal rate equation was a pseudo-first order with a constant rate of 0.006 min−1. Considering offshore platform operational limitations and associated process economics, the optimized EO unit process cost for total COD removal of PW, was estimated at U$5.74/m3.

Fabrication and optimization of hybrid AA-6082-T6 alloy/8%Al2O3(Alumina)/2%Grp metal matrix composites using novel Box-Behnken methodology processed by wire-sinking electric discharge machining

This work reports the fabrication and studies the influence of Electric discharge machining parameters during machining of the hybrid AA-6082-T6 alloy/8%Al2O3(Alumina)/2%Graphite (Grp) alloy-based metal matrix composite. Experiments were designed & optimized via Novel Box-Behnken technique in Response surface methodology. The pulse off-time, pulse on-time, peak current, and applied voltage used during this research investigation considered as process parameters. These process parameters measured in terms of MRR (Material removal rate) and SR (Surface roughness) using a copper rod of Ø12 mm as an electrode. A scientific model was additionally created to achieve a better performance in optimizing process parameters. From the experimental study, it has concluded that both MRR and SR are directly and mostly influenced using Pulse-on time & peak current. The affected response parameters were also evident by Scanning Electron Microscopy (SEM) & Energy Dispersive Analysis of X-Ray (EDAX) observations. This experimental research study believed that our Novel approach to Design & Optimization plays a vital role for researchers who tend to work in the field of process parameters optimization during machining.

Kinetics and mechanism of the oxidation of vanillic acid using smectite clay

In this study, the oxidation of vanillic acid (VA) into protocatechuic acid (PCA) was investigated using montmorillonite KSF as inexpensive and environmentally benign solid acid, with peroxide hydrogen to afford excellent yields (more than 75%) endowed with high selectivity. To our knowledge, the aforementioned method was used for the first time in green, clean synthesis. The influence of the several operating parameters were performed using an experimental design Box–Behnken methodology. The progress of the concentrations of VA and its oxidation product PCA was accomplished using ultra-high-performance liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (RP-UHPLC-DAD-QTOF-MS) and mass spectrometry. Accordingly, PCA would be advantageous when used in food as well as cosmetic and pharmaceutical industries. Finally, a mechanistic pathway for the VA oxidation was proposed.

Optimization of a Centrifugal Compressor Using the Design of Experiment Technique

Centrifugal compressor performance is affected by many parameters, optimization of which can lead to superior designs. Recognizing the most important parameters affecting performance helps to reduce the optimization process cost. Of the compressor components, the impeller plays the most important role in compressor performance, hence the design parameters affecting this component were considered. A turbocharger centrifugal compressor with vaneless diffuser was studied and the parameters investigated included meridional geometry, rotor blade angle distribution and start location of the main blades and splitters. The diffuser shape was captured as part of the meridional geometry. Applying a novel approach to the problem, full factorial analysis was used to investigate the most effective parameters. The Response Surface Method was then implemented to construct the surrogate models and to recognize the best points over a design space created as based on the Box-Behnken methodology. The results highlighted the factors that affected impeller performance the most. Using the Design of Experiment technique, the model which optimized both efficiency and pressure ratio simultaneously delivered a design with 3% and 11% improvement in each respectively in comparison to the initial impeller at the design point. Importantly, this was not at the expense of sacrificing range, of critical concern in compressor design.

The discrepancy in the prediction of surface temperatures by inverse heat conduction models for different quenching processes from very high initial surface temperature

ABSTRACTIn the current work, an attempt has been made to study the effect of different parameters on the accuracy of the prediction at a very high initial surface temperature by developing two different heat conduction models. The result depicts that MSSE (minimum sum squared error) in the prediction decreases with increasing number of sensors used in the prediction. The accuracy of the prediction enhances with decreasing plate thickness and distance between the thermocouple and quenched surface. Up to a cooling rate of 60 K/s, the selection of model dimension (1-D or 2-D) does not affect, but beyond the previously mentioned cooling rate, 2-D model induces less error than 1-D. Moreover, the inclusion of thermo-physical properties in the model reduces the error in the MSSE. By using Box–Behnken methodology, the optimum conditions (d/D = 0.81, n/Y = 0.5 and Y*/Y = 0.65) for the least MSSE have also been determined.

Design, Optimization and Characterization of Granisetron HCl Loaded Nano-gel for Transdermal Delivery.

Our research objective was to design, develop, optimize and characterize Granisetron HCl transdermal gel in order to minimize side effects associated with oral delivery. A statistical design was practically applied for further optimization and preparation of transfersomal gel using Box-Behnken methodology at three levels. The selected independent and dependent variables were Lipoid, surfactant and sonication time and encapsulation efficiency, size and flux correspondingly. The optimized formulation (GTV-16) morphology, shape, size, potential, encapsulation capacity and flux (using Franz-diffusion cell assembly via animal skin barricade medium) were determined. Then, GTV-16 incorporated into gel and during evaluation nano-transformal gel has good particle size of 127.7±1.08 nm, better entrapment efficiency of 83.0 ± 3.22 % and flux of 20.0 ± 1.88µgcm-2/h. The results demonstrated that Granisetron Hydrochloride loaded nano-gel was significantly superior with 8.5 fold enhancement in bioavailability as compared with drug solution.

Study of factors involved in the gravimetric separation process to treat soil contaminated by municipal solid waste

The current research investigated the effectiveness of a gravimetric process (shaking table) to treat soil contaminated by municipal solid waste. A detailed characterization of the inorganic pollutants was performed, followed by concentrating the metals within smaller volumes using the shaking table technology. The densimetric examination of the 1–2 mm and 0.250–1 mm fractions of the contaminated soil showed that lead (Pb), copper (Cu), and tin (Sn) were mostly concentrated in the heavy fraction (metal removals > 50%). Scanning electron microscopy coupled with elemental analysis indicated the relevance of using gravimetric processes to treat this soil sample. The influence of shaking table parameters was determined using a Box–Behnken design. The tilt and washing water flow demonstrated significant effects on the motion of the 1–2 mm soil fraction and on the removal of Pb, Cu, and Sn. The results obtained under the optimal settings of the shaking table defined using the Box–Behnken methodology when treating the 1–2 mm fraction were close to those obtained when using dense media separation. The recovered mass of the concentrate was approximately 20.8% (w.w−1) of the total mass. The removals of Pb, Cu, and Sn were estimated to be 67.3%, 54.5% and 54.6% respectively. The predicted and experimental mass distributions of the medium (1–2 mm) and fine-sized (0.250–1 mm) particles were compared successively under some selected conditions. The mass distribution of both fractions showed similar tendencies in response to the forces applied by each condition. However, lowering the forces induced by the bumping action and the flowing film was recommended so as to efficiently treat the fine fraction (0.250–1 mm). The recovered mass of the concentrate (10%) was slightly lower than that obtained by dense media separation (13%). However, satisfactory removal yields were obtained for Pb, Cu, and Sn (42.7%, 23.6%, and 35% respectively).

Toughening of polyamide 12/nanoclay nanocomposites by incompatible styrene‐butadiene‐styrene rubber through tailoring interfacial adhesion and fracture mechanism

AbstractThe main drawback of polyamide 12 (PA 12)/nanoclay nanocomposites in their wide range of potential engineering applications known as diminished toughness was overcome using incompatible styrene‐butadiene‐styrene block copolymer (SBS) rubber. Applying optimal processing parameters for co‐rotating twin‐screw extrusion resulted in strong interfacial adhesion of matrix and rubber and intercalated and delaminated nanoclay stacks confined in the matrix. The formulation of compatibilized PA 12/SBS/nanoclay nanocomposites was optimized by employing response surface Box–Behnken methodology. A combination of microscopic methods, that is, atomic force microscopy, transmission and scanning electron microscopy, and transmission optical microscopy, along with single‐edge‐double‐notch four‐point‐bending technique, was exploited to exhaustively explore the toughening mechanisms and microstructure. The findings verify that by tailoring the rubber/matrix interfacial strength and nanocomposite morphology, the Izod impact strength of PA 12/nanoclay nanocomposites is noticeably improved even by incorporating an incompatible rubber and tough fracture mechanisms including rubber particle cavitation and large‐scale shear yielding are attained.

Determination of critical operational conditions favoring sulfide production from domestic wastewater treated by a sulfur-utilizing denitrification process

The aim of this study was to determine the critical operational conditions leading to the generation of sulfide in a domestic wastewater treated by a sulfur-utilizing denitrification process. The influence of various important parameters on the reduction of the sulfates present in denitrified domestic wastewaters to sulfide was studied. Experiments were carried out in batch mode with denitrified domestic wastewaters containing various amounts of both organic matter and sulfates. Preliminary results showed that aqueous sulfide was generated for DOC and sulfate contents higher than 56 mg/L and 371 mg/L, respectively, while DOC and sulfate contents of 77 mg/L and 412 mg/L, respectively, were required to allow the release of gaseous H2S. Good correlations were also observed between gaseous sulfide production and the values of ORP and DOC, while the amounts of dissolved sulfide produced seemed to be correlated with the ORP values and the concentration of sulfates. Additional experiments were conducted using a Box-Behnken methodology to determine if the production of aqueous or gaseous sulfide can be predicted depending on the DOC (from 50 to 90 mg/L) and sulfate contents (from 160 to 380 mg/L) at various temperatures ranging from 5 to 25 °C. The highest sulfide generation (H2S(g) = 84.8 ppm and H2S(aq) = 2.42 mg/L) occurred at 25 °C with DOC and sulfate concentrations starting from 90 mg/L and 270 mg/L, respectively, indicating that the production of sulfides from denitrified domestic wastewaters required conditions not likely to occur at the effluent of a sulfur-based denitrification unit following secondary treatment.

PHENOL TOLERANCE AND BIODEGRADATION OPTIMIZATION OF Serratia marcescens NSO9-1 USING PLACKETT-BURMAN AND BOX-BEHNKEN DESIGN

The phenol degradation capacity of Serratia marcescens NSO9-1 isolated from olive mill wastewater was evaluated and optimized in this study. Plackett-Burman design coupled with Box-Behnken methodology was used to evaluate the effects of medium components and significant parameters on phenol degradation by this relevant strain. According to Plackett-Burmanbased statistical screening, seven of the eleven components of the medium had a significant effect on the metabolism of phenol degradation. The most important factors were MgSO4, NaCl, CaCl2, and molybdenum salt, which had an effective contribution of 90.12%. Additionally, Box-Behnken methodology using a quadratic model was adopted to investigate the mutual interactions between process parameters. The analysis results indicated that interactions between pH and temperature, pH and inoculum amount, and incubation time and inoculum amount critically affected the response variable. The experimental results showed that under the determined conditions, 41.66% of the maximum removal efficiency of phenol was achieved. The optimal conditions were 8.94, 30.22 C, 4.19 days, and 4.68% (v/v) for pH, temperature, incubation time, and inoculum amount, respectively. The validity and practicability of this statistical optimization strategy confirmed the relation between predicted and experimental values. Using a selective isolation method, the performance of this indigenous strain isolated from olive oil mill wastewater, which contained polyphenolic compounds, is comparable to the reported literature at higher phenol concentrations.

Evaluation of combined lignite cleaning processes, flotation and microbial treatment, and its modelling by Box Behnken methodology

In this study, first, the physicochemical cleaning of Cayirhan region’s low-quality lignites was investigated by flotation to reduce ash content. In the flotation experiments, the effects of collector dosage, frother dosage, dispersant dosage, pulp density and air flow rate on ash content and combustible recovery in the concentrate fraction were optimized. Flotation tests were designed with Box Behnken design (BBD) which is a response surface method (RSM). The effective parameters and their interactions in lignite flotation are described with a mathematical model. After physicochemical cleaning, further desulfurization studies were carried out through biological treatment. Alternaria sp. Cf1 strain which was isolated from the same region lignites was used in microbial treatment for desulfurization studies. Sulfur emission values (EV) of studied sample, flotation and microbial treatment’s concentrates were calculated and compared. After flotation and microbial treatments, sulfur emission values reduced from 12.76 to 1.01 to 0.34 for head sample, flotation and microbial treatment’s concentrates, respectively that accounts for 97.37% total reduction in terms of dry ash free basis.

Preparation, statistical optimisation and in vitro characterisation of poly (3-hydroxybutyrate-co-3-hydroxyvalerate)/poly (lactic-co-glycolic acid) blend nanoparticles for prolonged delivery of teriparatide

The purpose of this study was the preparation, optimisation and in vitro characterisation of PHBV and PLGA blend nanoparticles (NPs) for prolonged delivery of Teriparatide. Double emulsion solvent evaporation technique was employed for the fabrication of NPs. The nanoformulation was optimised using the Box–Behnken methodology. The morphological properties of NPs were assessed by both SEM and transmission electron microscopy (TEM). Encapsulation of Teriparatide within the NPs and lacking of chemical bonds between drug and copolymers were proved by XRPD, FTIR and DSC. The structural stability of Teriparatide after processing was confirmed by fluorescence spectrometry. The average size of optimised NPs was 250.0 nm with entrapment efficiency (EE) of 89.5% and drug loading (DL) of 5.0%. Teriparatide release from optimised NPs led to 64.4% release over 30 days and it showed a diffusion-based mechanism. Based on the favourable results, PHBV/PLGA blend NPs could be a promising candidate for designing a controlled release formulation of Teriparatide.

Understanding wetting phenomena in membrane distillation and how operational parameters can affect it

Direct contact membrane distillation experiments were carried out under this work to study the influence of operational variables on membrane wetting. In the first part of this work, experiments were designed according to a Box-Behnken methodology and results were analyzed statistically using Pearson correlation coefficients, principal component/factor analysis and cluster analysis. The independent operational parameters were the temperatures of both the hot and cold streams (Tf, Tc) and their flow rates (Ff, Fc). The analyzed responses were the time and rate of wetting along with distillate flux. Statistical analysis showed strong evidence of a relationship between the selected variables and the wetting patterns. In general, parameters enhancing flux production led to suppression of wetting (both delayed wetting and reduced wetting rate). The second part of the work focused on reversing the wetting with minimal operation disruption by varying the operational parameters. The data generated helped in understanding the salt passage and wetting mechanisms. The wetting hypothesis developed herein is based on water bridging as a consequence of the weak hydrophobicity of the PVDF membrane and a net absolute transmembrane pressure. Data were analyzed through the Peclet number, the Poiseuille flow and a mass balance in order to understand the interplay between diffusion and convection/advection. High transmembrane temperature (ΔT) (ΔT=Tf−Tc) counteracts the build-up of a net absolute transmembrane pressure and reduces the viscous liquid flux. In this case, the diffusion of salt through the stagnant water layer in the membrane pores (a much slower mechanism) becomes more important and the wetting rate can be reduced and further reversed.

Modeling and Analysis of Drilling Induced Damages on Hybrid Composites

Background/Objectives: To investigate the damages that occurs during drilling on newly prepared hybrid composites. Methods/Analysis: Composites have been prepared by using randomly oriented steel wool and woven jute as reinforcements and polyester as the matrix resin. Drilling experiments have been carried out on the developed composite by adopting Box-Behnken methodology. Speed, feed rate, point angle and tool diameter are taken as the input factors and the damage at entrance and exit surfaces have been measured as output responses. Findings: The output factors have been analyzed and optimized to yield a set of optimum conditions on the basis of desirability approach. The results showed that speed, feed rate and tool angle have significant influence on the entrance and exit damages but tool diameter does not have any influence. A speed of 500 rpm-970 rpm, a constant feed of 0.1 mm/rev, a tool angle of 900-1200, and selection of 8 mm and 10 mm as tool diameter are found to be the optimum input conditions for drilling. Confirmatory experiments have been conducted for the set of optimum conditions and the responses have been measured. The developed model is validated by an error analysis between the model and confirmatory runs. The observed errors between the model and confirmatory runs are meagre and hence the optimization using Box-Behnken design is satisfactory. Novelty/Improvement: Machining associated failures must be resolved in order to improve the productivity. This research made an attempt to optimize drilling associated damages on new composites made by using metal and natural fibers as reinforcement.

Synergistic removal of Cu(II) and nitrazine yellow dye using an eco‐friendly chitosan‐montmorillonite hydrogel: Optimization by response surface methodology

ABSTRACTA comprehensive feasibility study on adsorption of Cu(II) and a water‐soluble nitrazine yellow (NY) dye by chitosan‐montmorillonite (CS‐MMT) hydrogel as the biosorbent was investigated as a function of biosorbent dosage, initial concentration, pH, temperature, and the presence of salts. Box–Behnken methodology was applied to optimize the adsorption experiments. Maximum adsorption values were determined as 132.74 mg/g and 144.41 mg/g at pH = 5.0, for Cu(II) and NY dye, respectively. Equilibrium isotherms of Langmuir and Freundlich were analyzed by the non‐linear regression model. The equilibrium data were well described by Freundlich model and the adsorption process well fitted pseudo‐second order kinetics. The enthalpy change of adsorption (ΔH°) were calculated as −3.78 kJ/mol and −5.75 kJ/mol for Cu(II) and NY dye, respectively, indicating that the adsorption processes were exothermic. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43664.

Optimization of Cultural Conditions for Vinegar of Litchi ( Litchi chinensis Sonn.) in Liquid State Fermentation

In order to enhance the value of industry application of litchi, fermentation experiment of litchi vinegar was conducted to optimize process parameters. The technology of alcohol fermentation was carried out to investigate the effects of parameters such as original sugar content, yeast inoculation amount, pH value and fermentation temperature. A Box-Behnken experimental design of 3-factor and 3-level was used to build the secondary multivariate regression model related to the yield of acid including inoculation amount, original alcohol content and fermentation temperature, and explore the effect of process parameters of acetic acid fermentation above on the yield of acid in the light of response surface plots. Finally the fermentation process of its acetic acid fermentation was optimized using Box-Behnken methodology. Results were as follows. The optimal process of its alcohol fermentation was as follows: original sugar content, 16%; yeast inoculation amount, 5%; pH value, 3.5 and fermentation temperature, 30~32 °C. The optimal process of its acetic acid fermentation optimized by response surface methodology was as follows: inoculation amount, 10%; original alcohol content, 7.0% and fermentation temperature, 30 °C, in the optimal condition the yield of acetic acid was 52.45 g/L. The secondary multivariate regression model showed as follows. The effects of inoculation amount and original alcohol content were non-significant, and that of fermentation temperature extremely significant. The interaction of inoculation amount and original alcohol content was extremely significant. In conclusion, the regression model was accurate and reliable; the optimal fermentation technology of litchi vinegar was advisable.

Evaluation of mechanical membrane cleaning with moving beads in MBR using Box–Behnken response surface methodology

Incorporation of moving beads into membrane bioreactor (MBR) has been suggested as an effective membrane fouling control because moving beads can mechanically remove bio-cakes on the membrane surface without additional equipment and energy input. As the efficiency of fouling control is dependent on factors associated with moving beads, however, the design of experiment was applied to find optimum condition for the effective mechanical cleaning with moving beads in MBR. Bead diameter (mm), bead number, and aeration rate (m3/h) were selected as independent design parameters. Based on batch test results, the correlation between the detachment efficiency of bio-cakes and three design parameters was established using Box–Behnken methodology. When all three design parameters at their optimal conditions (beadopt) were extended to the continuous lab-scale MBR, membrane filterability increased by three times, compared with that in the control MBR without bead. On the other hand, each of five experimental sets with two optimal and one random parameter (beadrandom) showed less membrane filterability by 9–80%, respectively, compared with beadopt. The parameter C (aeration rate) affected most significantly as it is associated with not only bead movement but also shear induced by air bubbles.

Box-Behnken methodology for Cr (VI) and leather dyes removal by an eco-friendly biosorbent: F. vesiculosus.

This study focused on leather industrial effluents treatment by biosorption using Fucus vesiculosus as low-cost adsorbent. These effluents are yellowish-brown color and high concentration of Cr (VI). Therefore, biosorption process was optimized using response surface methodology based on Box-Behnken design operating with a simulated leather effluent obtained by mixture of Cr (VI) solution and four leather dyes. The key variables selected were initial solution pH, biomass dosage and CaCl2 concentration in the pretreatment stage. The statistical analysis shows that pH has a negligible effect, being the biomass dosage and CaCl2 concentration the most significant variables. At optimal conditions, 98% of Cr (VI) and 88% of dyes removal can be achieved. Freundlich fitted better to the obtained equilibrium data for all studied systems than Temkin, Langmuir or D-R models. In addition, the use of the final biosorbent as support-substrate to grown of enzyme producer fungi, Pleurotus ostreatus, was also demonstrated.