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The recycling of waste plastics is of considerable significance with environmental and economic benefits, while available separation approaches have been considered as a major bottleneck for its widespread application. Thus, we proposed a simple method, flotation along with surface modification, to separate waste acrylonitrile-butadienestyrene and polyvinylchloride mixtures. Single-factor experiment was conducted to determine the critical parameters in surface modification. Surface response methodology using Box-Behnken Design was performed to optimize separation performance. The quadratic models were generated to predict the floatability of acrylonitrile-butadienestyrene and the difference between the floatability of polyvinylchloride and acrylonitrile-butadienestyrene. The model was also utilized to determine optimized conditions by desirability approaches. The optimized conditions were: concentration = 0.18 M, temperature = 75.00 °C, treatment time = 11.50 min along with stirring rate = 200 rpm. The efficient separation of acrylonitrile-butadienestyrene and polyvinylchloride was achieved, yielding recovery of 98.40% and purity of 98.43%. The experimental responses well agreed with predicted values, demonstrating the accuracy of the prediction model. The formed hydrophilic groups, coated iron oxide, and signs of corrosion were confirmed as the major mechanism for the selective surface hydrophilization of acrylonitrile-butadienestyrene. Consequently, this method is feasible for separation of waste acrylonitrile-butadienestyrene and polyvinylchloride mixtures, and can be expected to promote the sustainable recycling of waste plastics.

The effects of synthesis parameters during the preparation of Ni catalysts for the CO2 methanation reaction via chemical vapor deposition (CVD) were investigated. For this purpose, a central composite design from the design of experiment approach was conducted to identify and investigate the most significant parameters. A surface response methodology was applied to identify promising synthesis parameter combinations that led to highly dispersed Ni catalysts and to understand the interaction of the synthesis parameters. Finally, the methanation activity of a CVD-prepared catalyst was compared with two different Ni catalysts with the same metal loading but prepared with different methods. The CVD preparation herein presented proved to be a promising method to obtain low-loaded Ni catalysts in CO2 methanation.

The determination of the maximum adsorption capacity for a biosorbent is crucial to evaluate the adsorption performance. This parameter is usually obtained from the Langmuir isotherm because it involves very simple and low-cost procedures. Nevertheless, acquisition of adsorption isotherm can be very laborious. Multivariate optimization can be used to improve the determination of the maximum adsorption capacity. In this work, Central Composite Design (CCD) and Surface Response Methodology (SRM) are used for a reliable determination of maximum adsorption capacity of arsenic by a biosorbent of lettuce flour and the result was very close to the value obtained from the Langmuir isotherm.

Optimization of microwave-assisted extraction (MAE) of water-soluble pectin (WSP) from Opuntia ficus indica cladodes was performed using Response Surface Methodology. The effect of extraction time (X-1), microwave power (X-2), pH (X-3) and solid-to-liquid ratio (X-4) on the extraction yield was examined. The optimum conditions of MAE were as follows: X-1 = 2.15 min; X-2 = 517 W; X-3 = 2.26 and X-4 = 2g/30.6 mL. The maximum obtained yield of pectin extraction was 12.57%. Total carbohydrate content of WSP is about 95.5% including 34.4% of Galacturonic acid. Pectin-related proteins represent only the 0.66% of WSP mass. HPSEC and light scattering analyses reveal that WSP is mostly constituted of high molecular pectin and FTIR measurements show that the microwave treatment does not alter the chemical structure of WSP, in which Galacturonic acid content and yield are 34.4% and 4.33%, respectively. Overall, application of MAE can give rise to high quality pectin. (C) 2016 Elsevier Ltd. All rights reserved.

Replacement of wheat flour (WF) by soy protein hydrolysates (SPH) and fructooligosaccharides (FOS) may have beneficial health effects, but they can modify dough rheology performance, and the technological quality of functional breads with health claim. This study aimed to evaluate the rheological properties of premixes by Mixolab™ parameters, using a Central Composite Design (CCD), with WF partially replaced by SPH (X 1 = 0–20 g/100 g) and FOS (X 2 = 0–10 g/100 g) for breadmaking. Mixolab™ results were analyzed by Surface Response Methodology (SRM) and the desirability methodology was applied to select two premixes, suitable and unsuitable for breadmaking, comparing with control bread, made only with WF. The results indicated that Mixolab™ parameters and statistical methods including CCD and desirability were appropriate to predict the WF replacement levels by SPH and FOS, for producing functional bread with specific volume and firmness similar to control bread.

Stainless steels are found in various aerated aqueous electrolytes in a passive state which protects them from corrosion. In many aggressive solutions, stainless steels are easily depassivated, which can lead to different types of corrosion. This paper tested the impact of chloride ions at different concentration, temperatures and pH values on the corrosion and pitting potential of AISI 304 stainless steel. In order to predict the behaviour of AISI 304 stainless steel design of experiment and artificial neural network methods were applied. Results of the developed models showed good agreement with the experimental results and no significant differences between models.

Experiments were performed to investigate optimised operational conditions for the production of recyclable plaster based on plaster waste from construction and demolition projects or the plasterboard industry in a continuous furnace with a mobile helical element on a bench scale. After the definition of the granulometry that provided the reaction conditions with no diffusive effects, a 2 2 rotational central composite design (CCRD) had been used for the experimental planning, where the factors of which were mean reactor temperature (148 °C and 162 °C) and gauge pressure (0.2–0.8 bar). The statistical analysis of the results based on the response surface methodology allowed the identification of the optimised operational conditions (162.4 °C and 0.5 bar). Under these conditions, the Avrami-Eurofe'ev equation was tested and confirmed (n = 2) for the kinetics of the thermal dehydration process. The capacity of the equipment to produce recyclable beta plaster was tested and confirmed by Scanning Electron Microscopy of the plaster crystals.

Flaxseed mucilage (FM) and soluble protein (FSP) were used as wall materials for encapsulating Lactobacillus acidophilus La-05 by spray drying. The effects of the content of FM in the encapsulating solution and drying temperature on the survival of bacterium after drying and its viability during storage were evaluated. Optimal conditions for maximizing the survival of L. acidophilus (78%) predicted by the surface response methodology were 0.2% w/v of FM and 110 °C. These encapsulating conditions permitted almost a 2-fold increase of viability compared to the product encapsulated without FM. A further increase in survival (90%) was obtained by supplementing the encapsulating solution with heat-treated FSP. Moreover, the encapsulation of L. acidophilus enhanced its viability during incubation in simulated gastric acid and bile solutions.

The study examined whether classroom environment moderates the relationship between student personality and student outcomes. Researchers agree that congruence between persons and their environments leads to better outcomes for the individual. Therefore, I hypothesized that the congruence between classroom environment and student personality would have a positive impact on student satisfaction and performance. The sample included 732 undergraduate students enrolled in Introductory Psychology courses. Data was collected at three different times during the semester. Student personality was operationalized using the Five Factor Model and measured during the first two weeks of the semester. A measure was used to assess the classroom environment in weeks ten through twelve. Student satisfaction was assessed during the last two weeks of the semester using a four item measure. Final percentage grades for each participant were used to assess student performance. Data were analyzed using polynomial regression analysis and surface response methodology. Results indicate that classroom environment is a strong predictor of student satisfaction, and personality is a strong predictor of performance. Structure and focus and student competition seem to be important classroom environment dimensions that increase both satisfaction and performance. Some personality and classroom environment combinations were found to increase satisfaction and performance.

The surface roughness of a milled surface is an important response parameter in finishing milling. The quality of injected products, such as cell phones, laptops, digital cameras greatly depends on the finishing of the molds. The Ra parameter is one of the most commonly used criteria to determine the quality of milled steel. In this study, experiments were carried out on work pieces of AISI P20 steel with 20 × 20 × 10 mm. Solid carbide tools with a diameter of 6 mm were used in the experimental tests. The input parameters were the radial depth of cut, feed rate, and contact angle. The contact angle varied using a special device to simulate the several inclinations in a free-form surface. The results showed that the milled surface is a three-dimensional geometry that is influenced by many parameters. The most important input parameter for the surface roughness, however, is the feed rate, and depending on the measuring direction; the feed rate can have a significant influence on the finishing.

A central composite experimental design was used to investigate experimental process conditions (extraction temperature, extraction time and biomass loading) for the supercritical ethanol extraction of bio-oils from German beech wood. The effects of three independent variables and their interactions on the yields of ethanol extracts and biomass conversion were analyzed using response surface methodology (RSM). The most significant variable was found to be the temperature on the yields of ethanol extract and biomass conversion. High correlation coefficients (R2) were obtained and they were 0.93 and 0.95 for ethanol extract and biomass conversion yields, respectively. The consistent matching of predicted values with the experimental values is an indication of validity of the model used in this study. Optimized conditions were in the range of the experimental design which shows the validity of the design. Optimal conditions for the ethanol extract yield were 315.81°C extraction temperature, 123.67min extraction time, and 15.95wt% biomass loading. The bio-oil contained mainly phenolic compounds. The analyses of results show that the linear coefficient of x1 and the quadratic coefficient of x12 are the most statistically significant factors on the ethanol extract and biomass conversion yield. The ethanol extracts (bio-oils) contained greater amounts of carbon and lesser amounts of oxygen than that of the raw material. © 2013 Elsevier B.V., Karabük Üniversitesi: KBÜ-BAP-13/1-DR-008, The authors gratefully acknowledge Karabük University for financial support ( KBÜ-BAP-13/1-DR-008 ). Our special thanks go to Tepe Home Company for providing the raw material.

The adsorption of acid blue 25, Cd2+ and Zn2+ on a physically activated bituminous carbon and a phosphoric activated carbon from wood was studied using single and binary (dye/metal) solutions, at 30 °C and pH 5. Results showed a synergic effect of acid blue 25 in the adsorption of Cd+2 and Zn+2. Thus, the amount of metal ions adsorbed on both activated carbons increased with the initial concentration of acid blue 25. The effect was especially remarkable in the case of the adsorption of Zn2+ ions on the wood-based carbon. For this particular system, the metal uptake increased up to 60 times in presence of acid blue 25, when compared to the results obtained for the mono-component (Zn2+-only) solutions. Modeling of the adsorption results showed that a surface response methodology approach was required to attain an adequate description of the multi-component adsorption.

In this study, the use of entrapped activated carbon was proposed for the removal of coloured compounds from vinasses. The operational conditions of the batch adsorption process were optimized by means of an incomplete 33 factorial design. The independent variables studied included the volume of entrapped activated carbon (x1); time of treatment (x2) and speed of agitation (x3), whereas the dependent variables studied were based on the decrease in absorbance at 620, 520 and 420 nm, as well as on the tristimulus values (x, y), based on chromaticity co-ordinates that map all colours in a two-dimensional space, called a chromaticity diagram. CIELAB parameters (L*, a*, b* and C*ab), which map all colours in a three-dimensional space, were also tested as dependent variables. The optimal conditions for removing coloured compounds from vinasses in batch adsorption experiments were: ratio of entrapped activated carbon/vinasses ~ 1; operational time, 75 min and the minimum agitation speed tested (75 rpm). The results obtained demonstrated the potential application of immobilized activated carbon beads in the design of new eco-friendly, efficient and low-cost bioremediation strategies.

The evaluation of the optimum conditions for concentration of the sweet orange essential oil by wiped film evaporator required a planning of experiments. The factors of the selected centered composite plan are the rate of feed, the temperature of the heated fluid and the stirring velocity. The quadratic model obtained required complementary work by simplex method to determine the optimum. The analysis by gas chromatography of the samples revealed a 18.2 times concentrated oxygenated compound in the residue.

An assessment of various limitations in the traditional preparation of boucan e pork indicated that the process and the end-product quality could be enhanced by certain innovations. The overall aim is to improve the quality of the end product while retaining the uniqueness and specific traits of traditional boucan e and also to assess the innovation potential with respect to processing a range of pork-based products. For that reason, a novel technique involving immersion in a complex solution is proposed as an alternative to traditional processing. A predictive model was thus developed, combining a kinetic approach with surface response methodology. Mass transfers and impact on final product quality were discussed. With this innovation, the meat product can be salted, dried, cooked and smoked in a single step.

The endochitinase gene ech42 from Trichoderma harzianum was cloned and expressed in Escherichia coli BL21(D3)pLysS using a pET-19b expression system. The effect of temperature, cell concentrations and inductor concentration on protein expression were evaluated by response surface methodology. Applying a second-order model to describe the amount of endochitinase produced by two selected clones, demonstrated that different optimal conditions of expression were found among clones, indicating that the best environmental conditions for expression among the several isogenic clones differed.

The still-marinating process is a simplified technology used to tenderize and to improve the flavor and succulence of meat to satisfy consumer demand. The objective of this study was to obtain still-marinated chicken breast meat and legs of good quality. To attain this aim, the effects of salt concentration, polyphosphates concentration and marinating time were optimized to increase weight gain, reduce loss of weight during storage and reduce cooking loss, making use of the surface response methodology. The results of this study indicate that marinating times ranging from 8-12 hours, salt concentrations ranging from 3-4% and polyphosphates concentration ranging from 2-3% are recommended for the still-marinating process of chicken breast meat. In additon, marinating times ranging from 4-8 hours, salt concentration ranging from 3-4% and polyphosphates concentration of about 2% can be suggested for the still-marinating process of chicken legs. ©

Various nasal humidifying agents are being promoted for regular use. In this study we compared the effects of three formulations (medium 199, 0.9% saline and a commercially available isotonic sea-water formulation -Rhinomer) on ciliary beat frequency using rat tracheal cilia as a model. Surface response methodology was used to evaluate the effects of pH and osmolality of the formulation on ciliotoxicity. Our results showed that none of the formulations differed in their effects on cilia. Moreover, neither medium 199 nor Rhinomer protected the cilia from the effects of drugs (chlorbutol, xylometazoline, azelastine and lignocaine) known to be ciliotoxic.

Surface response methodology was used to study the effects of three variables, viz. total reducing sugars (116–222 g l −1 ), yeast inoculum concentration (10–30%) and supplemented inorganic nitrogen as (NH 4 ) 2 SO 4 (1–3 g l −1 ) on the production of ethanol. The complete and incomplete factorial designs (3 3 ) were compared through the residual analysis of variance. Since there was no statistically significant difference at the 5% level, on the basis of cost-efficiency and space limitations, it was recommended to use incomplete factorial design constituting 12 treatments with three repetitions in central point totalling 15 experiments which control the batch alcoholic fermentation.

The design of glass molds has been traditionally done based on rules of thumb and trial-and-error procedures. A methodology is given for the optimal design of glass molds based on CAD/CAE and surface response methodology.