Level Factorial Design Research Articles

Fast Pyrolysis of Residues from Paper Mill Industry to Bio-oil and Value Chemicals: Optimization Studies

Biomass is a renewable energy and had been recognized as a promising feedstock for producing bio-fuels. In this work, pyrolysis of black wattle residues was investigated with the aim to study the product distribution and their chemical composition and predicting the optimal condition for maximized bio-oil especially aromatics content by using a two level factorial design of experiment. The pyrolysis were performed at temperature of 380 – 580 oC, Under screw feeder carried the biomass residues and weight of dolomite as catalyst of 1-5 wt% inside pyrolyzer with nitrogen gases flow rate of 20 to 80 cm3/min The detention time was controlled by reactor screw feeder at feeding rate of 120 to 240rpm. Based on the analysis from a design-expert program to determine the appropriated condition of experiment was 515.18 oC, 120.01rpm of feed rate and 20.00 cm3/min of nitrogen flow rate using 5.00wt% of dolomite catalyst. The elemental and physicochemistry analysis of bio-oil were determined, the chemical composition also investigated using gas chromatography-mass spectrometry and 1H NMR. The composition of bio-oil mainly oxygenated compound with high molecular weight and phenol. The results show that the biomass residual can be considered as a potential alternative fuels and relevant to valuable chemical feedstock.

Influence of surfactant and processing conditions in the stability of oil-in-water nanoemulsions

This work evaluates the influence of the type of surfactant (Tween 20, SDS and DTAB) and processing conditions on the stability of oil-in-water nanoemulsions, measured in terms of hydrodynamic diameter (Hd), polydispersity index (PdI) and zeta potential (Zp). Nanoemulsions were prepared using high-pressure homogenization based on a 24 level factorial design. Results show that processing parameters such as homogenization pressure, surfactant concentrations and oil:water ratio significantly affected the values of Hd and PdI of nanoemulsions. The value of Hd of anionic nanoemulsions decreased (from 177 to 128nm) with the increase of the homogenization pressure. The increase in the surfactant concentration and the decrease of the oil:water ratio lead to a decrease of Hd for the cationic nanoemulsions (from 198 to 135nm). The increase of the oil:water ratio lead to a decrease of Hd for the non-ionic nanoemulsions (from 341 to 171nm); this is contrary to the usual assumption that higher content in oil results in higher values of Hd. Those nanoemulsions showed a good kinetic stability (evaluated after centrifugation, heating–cooling cycles and thermal stress) upon measuring the Hd during 28 and 35days of storage, without visual evidence of creaming and phase separation. After one year of storage the nanoemulsions produced with the anionic surfactant remained kinetically stable, without visual evidence of creaming and/or phase separation.

Biogenic synthesis of Iron oxide nanoparticles via optimization of nitrate reductase Enzyme using statistical experimental design

Statistically designed experiments were proceeded to evaluate nutritional and environmental parameters that affect nitrate reductase enzyme (NR) activity in Achromobacter sp. KT735046. Plackett-Burman design was performed for screening and identifying efficiently the significance of 15 culture conditions influencing NR activity. FeCl3·6H2O, Na2MoO4·2H2O and CuSO4.5H2O were the most significant variables positively influencing, whereas pH was the most significant negative contributors. The optimal levels of significant factors were further predicted from five level factorial designs, Central Composite Design (CCD). The optimum parameter values were CuSO4.5H2O (60.375) mg/l, FeCl3·6H2O (240 mg /L), pH (6.135) and Na2MoO4·2H2O (150 mg /L). The biogenic Iron oxide nanoparticles "IONPs" were characterized; the dark brown IONPs exhibit maximum absorption from 400 to 464 nm, XRD reveals crystallite rhombohedral hematite, EDX confirms presence of 62% of iron, TEM illustrates formation of tiny IONPs, 1.4 and 2.8 nm in size, ξ potential and PDI recorded -42.9 mV and 0.268 respectively exhibiting high stability and monodispersed with no agglomeration by the help of biomolecules. This study conclude that Achromobacter sp. KT735046 consider being biofactory for synthesis nanoparticles by the help of NR enzyme and it may be the first time to optimize Achromobacter sp. KT735046 for IONPs biosynthesis using statistical designs.Â

Optimization of extraction of stinging nettle leaf phenolic compounds using response surface methodology

A full three level factorial design was implemented for optimization of extraction parameters in order to maximize total phenolic (TP) yield from stinging nettle leaf. Factors considered were percentage of methanol in solvent (X1: 50–100% methanol) and extraction time (X2: 30–90min), and maceration was used as extraction method. A second-order polynomial model was applied for fitting experimental data and predicting the response, and this mathematical model produced a satisfactory fit (R2=0.993, p˂0.01). The optimal extraction conditions were 54% aqueous methanol and 38min extraction time, while maximal theoretical TP yield was 8.9mgGAE/g DW. Solvent composition significantly affected extraction efficiency causing decrease of TP yield with increase of methanol percentage. On the other hand, extraction time did not influence significantly efficiency of extraction. Using LC/MS and HPLC analysis we detected and quantified three most abundant phenolic compounds: 2-O-caffeoyl malic acid, chlorogenic acid, and rutin. Comparison between maceration and ultrasound-assisted extraction (UAE) obtained extracts based on TP content as well as antiradical activity and HPLC results, showed that UAE have a better extraction capability affecting yield and time of extraction. Of all tested extracts, 54% aqueous methanolic extracts obtained with UAE and 38min extraction time had the highest TP content.

Simple RP-UFLC Method for Analysis of Asenapine Maleate

A stability-indicating reversed phase ultra-fast liquid chromatographic method was developed to determine asenapine maleate (ASN) in pharmaceutical dosage form. A two level factorial design was adopted to improve intermediate precision considering analysts, instruments and number of days as the variables. Chromatographic separation was achieved on Enable-C18G (250× 4.6 mm i.d., 5 μm) column using acetonitrile: 0.01M TBAHS (40:60 v/v) as mobile phase at flow rate of 1.0 ml/min and with PDA detection at 229 nm. Calibration curve was linear in the range of 1.0-200 μg/ml. Values of accuracy were within the acceptance limit with mean percent recoveries between 101.2-101.5%. The percent RSD values were within the acceptance limit for repeatability and intermediate precision. Limit of detection and limit of quantitation were found to be 0.25 and 0.5 μg/ml, respectively. Besides, applicability of analytical method showed high specificity for ASN and its degradation products formed during forced degradation studies. The developed UFLC method was found to be specific, selective, accurate, precise and robust for determination of ASN in bulk and pharmaceutical dosage form.

Sidetrack/Recompletion Time Evaluation by Proxy Model

Sidetrack during field development and ongoing production arises to exploit bypassed reserves, unexploited zones and to tackle unforeseen conditions that are likely to occur due to uncertainties and heterogeneity in initially characterizing a reservoir. Whereas recompletion is due to sequential production of stacked reservoirs or multiple pay zones that is caused by regulation on commingling. The purpose of this paper is to investigate the application of experimental design (ED) in optimizing sidetrack/recompletion time of multiple pay zones in view of maximizing returns on investment by net present value (NPV) and expected monetary value (EMV). A hypothetical reservoir of two pay zones with uncertainties associated with pay thickness, porosity, permeability and time to perform the sidetrack was considered. The ED method of Box-Behnken response surface design was used to reduce the number of runs made by generating the most effective combination of variables for the experiment. Experimental runs were conducted with a Black Oil reservoir simulator to give production profile and the computed NPV was used afterwards to produce the Proxy model in ED. NPV computed from the Proxy Model was reasonable compared to that of the production profile from the simulator. However, a higher level D-Optimal or factorial design may be required for a reasonable match of EMV with respect to obtaining a realistic sidetrack/recompletion time.

The use of equivalent estimation designs in tribological studies

Tribological experiments in which friction is examined as a function of multiple factors often involve some factors whose levels are harder to change than others. For example, changing the temperature in a test setup usually is more time consuming than changing the sliding speed or the contact pressure. In such cases, it is preferable to rearrange the runs in the experiment in a way that minimizes the number of changes of the factor levels that are hard to change. This restricts the randomisation of the experiment and leads to a split-plot structure. A new class of split-plot designs called equivalent estimation designs has properties which seem to be well suited for use in tribological studies. This paper compares the performance of these designs to two commonly used designs (a completely randomised three level factorial design and a one-factor-at-a-time experiment) in a tribological example study. The results show that using equivalent estimation designs in tribology can deliver results that are similar to those of conventional designs while requiring just a fraction of their effort.

Screening and Optimization of the Reaction of Polymyxin B Sulphate with NBD-Cl for the Synchronous Spectrofluorimetric Determination of Polymyxin B Sulphate in Human Plasma.

An accurate and sensitive synchronous spectrofluorimetric method has been developed for the determination of Polymyxin B sulphate (Poly B) in human plasma. The method is based on the reaction of non-fluorescent Poly B with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) in borate buffer of pH7 producing a yellow color with maximum relative fluorescence at 440nm using a constant wavelength difference Δλ = 80nm. Reaction conditions and other analytical parameters were studied and optimized using factorial design. Three level factorial designs have been employed for the screening, optimization of all experimental variables and determination of their interactions on the final product formation. The variables under investigation were: pH of borate buffer, volume of buffer, volume of NBD-Cl, temperature, time of heating and volume of sulfuric acid. A linear plot between relative fluorescence and concentration was obtained over the concentration range 100.00-1200.00ngmL(-1). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 10.31 and 31.24ngmL(-1), respectively. The proposed method was validated according to ICH guidelines and successfully applied for the determination of Poly B in human plasma, where satisfactory results were obtained. The results obtained were statistically compared with those of a published method, where no significant difference was observed.

Gentiana dinarica Beck. hairy root cultures and evaluation of factors affecting growth and xanthone production

The induction and establishment of hairy root cultures of Gentiana dinarica using two strains of Agrobacterium rhizogenes (A4M70GUS and 15834/PI) is reported for the first time. Strain 15834/PI had higher induction rate of hairy roots (32.15 %) than strain A4M70GUS (6.12 %). Transgenic nature of the roots was confirmed by GUS assay and PCR analysis. Two clones per strain (A4M70GUS-D and -I, and 15834/PI-2 and -3) with marked differences in general morphology and growth rate were further studied. The methanol extracts of hairy root clones were analyzed for xanthones content using HPLC method. The effects of the type of carbohydrate source (sucrose, fructose or glucose) at different concentrations on the growth parameters (growth index, dry weight, fresh/dry weight ratio), phenolic and xanthone production, and free radical scavenging activity of the transgenic clones were evaluated. Statistical two level factorial design was used to define optimal conditions for growth and successful secondary metabolite production in G. dinarica hairy root clones. The results showed that clones A4M70GUS-D and 15834/PI-3 were the superior ones. These two clones had the highest dry weight on 116.8 mM sucrose, producing up to threefold higher amounts of total phenolics and norswertianin-1-O-primeveroside than other clones, untransformed roots and roots of wild-grown plants.

Fabric phase sorptive extraction: A new sorptive microextraction technique for the determination of non-steroidal anti-inflammatory drugs from environmental water samples

Fabric phase sorptive extraction (FPSE) is a new, yet very promising member of the sorbent-based sorptive microextraction family. It has simultaneously improved both the extraction sensitivity and the speed of the extraction by incorporating high volume of sol–gel hybrid inorganic–organic sorbents into permeable fabric substrates. The advantages of FPSE have been investigated for the determination of four non-steroidal anti-inflammatory drugs, ibuprofen, naproxen, ketoprofen and diclofenac, in environmental water samples in combination with gas chromatography–mass spectrometry. Initially, the significance of several parameters affecting FPSE: sorbent chemistry, matrix pH and ionic strength were investigated using a mixed level factorial design (31×22). Then, other important parameters e.g., sample volume, extraction kinetics, desorption time and volume were also carefully studied and optimized. Due to the high sorbent loading on the FPSE substrate in the form of ultra-thin coating and the open geometry of the microextraction device, higher mass transfer of the target analytes occurs at a faster rate, leading to high enrichment factors in a relatively short period of time (equilibrium times: 45–100min). Under optimal operational conditions, the limits of detection (S/N=3) were found to be in the range of 0.8ngL−1 to 5ngL−1. The enrichment factors ranged from 162 to 418 with absolute extraction efficiencies varied from 27 to 70%, and a good trueness (82–116% relative recoveries) indicating that the proposed method can be readily deployed to routine environmental pollution monitoring. The proposed method was successfully applied to the analysis of target analytes in two influent and effluent samples from a wastewater treatment plant and two river water samples in Spain.

Effect of Machining Parameters and Machining Time on Surface Roughness in Dry Turning Process

The most important measures of surface quality during the machining process is the average surface roughness (Ra), and it is mostly caused by many machining parameters, such as true rake angle and side cutting edge angle, cutting speed, feed rate, depth of cut, nose radius, machining time etc. This paper a model of surface roughness was developed based on the response surface method to investigates the machining parameters such as feed rate, tool geometry, nose radius, and machining time, affecting the roughness of surface produced in dry turning process. The experiment has been designed and carried out on the basis of a three level factorial design. Obtained results are in good accordance with the published results in the field, validating the effectiveness of regression analysis in modeling of surface roughness in dry turning process.

An Investigation of the Effect of Task Type on the Discourse Produced by Students at Various Score Levels in theTOEFL iBT®Writing Test

This study, which forms part of theTOEFL iBT® test validity argument for the writing section, has two main aims: to verify whether the discourse produced in response to the independent and integrated writing tasks differs and to identify features of written discourse that are typical of different scoring levels. The integrated writing task was added to theTOEFL iBTtest to “improve the measurement of test‐takers' writing abilities, create positive washback on teaching and learning as well as require test‐takers to write in ways that are more authentic to academic study” (Cumming et al., 2006, p. 1). However, no research since the study by Cumming et al. (2006) on the prototype tasks has investigated if the discourse produced in response to this new integrated reading/listening‐to‐write task is in fact different from that produced in response to the independent task. Finding such evidence in the discourse is important, as it adds to the validity argument of theTOEFL iBTwriting test and is useful for a verification of the rating scale descriptors used in operational rating. This study applied discourse‐analytic measures to the writing of 480 test takers who each responded to the two writing tasks. The discourse analysis focused on measures of accuracy, fluency, complexity, coherence, cohesion, content, orientation to source evidence, and metadiscourse. An analysis with a multivariate analysis of variance (MANOVA) using a two‐by‐five (task type by proficiency level) factorial design with random permutations showed that the discourse produced by the test takers varies significantly on most variables under investigation. The discourse produced at different score levels also generally differed significantly. The findings are discussed in terms of theTOEFL iBTtest validity argument. Implications for rating scale validation and automated scoring are discussed.

Energy utilization of by-products from the soybean oil industry by broiler chickens: acidulated soapstock, lecithin, glycerol and their mixture

Acidulated soy soapstock (ASS) and lecithin (LEC) are by-products from processing soy oil (SO) for human consumption, whereas glycerol (GLY) can be obtained through the transesterification of vegetable oils during the production of biodiesel. These are valuable by-products for poultry feeds that have been underutilized in many parts of the world. One study was conducted to estimate the AMEn of ASS, LEC, GLY as well as of their mixture (MIX: 85% ASS, 5% LEC and 10% GLY). Two hundred and sixty Cobb 500 female broilers of 20 days of age were housed in steel wire battery cages in a controlled temperature room for broilers. A completely randomized (energy sources x fat inclusion level) factorial design was applied, with 4 replicates of three birds per treatment. Birds were fed a corn-soybean meal control diet without supplemental fat or with the addition of 2, 4, or 6 % of the four energy sources. Total excreta collection was performed from 26 to 28 days. The AMEn values of by-products were calculated using regression analysis as well as by the difference method. The average AMEn values calculated by regression analysis were: 9,232, 7,502, 5,447 and 8,404, whereas results with the difference method were: 7,951, 6,579, 3,979 and 8,101 kcal/kg for, in both cases for ASS, LEC, GLY and MIX, respectively. It is concluded that these energy sources can be for broilers and that there are significant differences between the methods used to estimate AMEn of fats.

Ligandless ultrasonic-assisted and ionic liquid-based dispersive liquid–liquid microextraction of copper, nickel and lead in different food samples

A simple and rapid ultrasonic assisted-ionic liquid based-liquid–liquid microextraction (UA-IL-DLLME) method has been developed for the enrichment and separation of Cu(II), Ni(II) and Pb(II). A two level factorial design was used to determine the effect of key factors such as pH, volume of ionic liquid (IL), carbon tetra chloride (CCl4) and sonication time (St). 1-Butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) and CCl4 were used as an extractant and dispersant solvent, respectively. The accuracy of the proposed method was evaluated by analysing of SRM Apple Leaves 1515 certified reference material. The limits of detections (LODs) were 0.17μg/L, 0.49μg/L and 0.95μg/L for Cu, Ni and Pb, respectively. The enrichment factor (EF) was 100. The method has been successfully applied for the analysis of the content of Cu, Ni and Pb in spice, vegetable and fruit samples by flame atomic absorption spectrometry (FAAS).

Resolution of heterogeneous charged antibody aggregates via multimodal chromatography: A comparison to conventional approaches

Clearance of aggregates during protein purification is increasingly paramount as protein aggregates represent one of the major impurities in biopharmaceutical products. Aggregates, especially dimer species, represent a significant challenge for purification processing since aggregate separation coupled with high purity protein recovery can be difficult to accomplish. Biochemical characterization of the aggregate species from the hydrophobic interaction and cation exchange chromatography elution peaks revealed two different charged populations, i.e. heterogeneous charged aggregates, which led to further challenges for chromatographic removal. This paper compares multimodal versus conventional cation exchange or hydrophobic chromatography methodologies to remove heterogeneous aggregates. A full, mixed level factorial design of experiment strategy together with high throughput experimentation was employed to rapidly evaluate chromatographic parameters such as pH, conductivity, and loading. A variety of operating conditions were identified for the multimodal chromatography step, which lead to effective removal of two different charged populations of aggregate species. This multimodal chromatography step was incorporated into a monoclonal antibody purification process and successfully implemented at commercial manufacturing scale.

Application of the Taguchi method in poultry science: estimation of the in vitro optimum intrinsic phytase activity of rye, wheat and barley

1. In poultry investigations, the main interest is often to study the effects of many factors simultaneously. Two or three level factorial designs are the most commonly used for this type of investigation. However, it is often too costly to perform when number of factors increase. So a fractional factorial design, which is a subset or a fraction of a full factorial design, is an alternative. The Taguchi method has been proposed for simplifying and standardising fractional factorial designs.2. An experiment was conducted to evaluate the applicability of the Taguchi method to optimise in vitro intrinsic phytase activity (IPA) of rye, wheat and barley under different culture conditions.3. In order to have a solid base for judging the suitability of the Taguchi method, the results of the Taguchi method were compared with those of an experiment that was conducted as a 34 full factorial arrangement with three feed ingredients (rye, wheat and barley), three temperatures (20°C, 38°C and 55°C), three pH values (3.0, 5.5 and 8.0) and three incubation times (30, 60 and 120 min), with two replicates per treatment.4. After data collection, a Taguchi L 9 (34) orthogonal array was used to estimate the effects of different factors on the IPA, based on a subset of only 9 instead of 81 treatments. The data were analysed with both Taguchi and full factorial methods and the main effects and the optimal combinations of these 4 factors were obtained for each method.5. The results indicated that according to both the full factorial experimental design and the Taguchi method, the optimal culture conditions were obtained with the following combination: rye, pH = 3, temperature = 20 °C and time of incubation = 30 min. The comparison between the Taguchi and full factorial results showed that the Taguchi method is a sufficient and resource saving alternative to the full factorial design in poultry science.

The impact of exogenous ω-6 and ω-3 polyunsaturated fatty acids on the induced production of pro- and anti-inflammatory prostaglandins and leukotrienes in Atlantic salmon head kidney cells using a full factorial design and LC–MS/MS

The production of prostaglandins (PGE2, PGE3) and leukotrienes (LTB4, LTB5) in salmon head kidney cell cultures, exposed to different combinations of 20:4ω-6, 20:5ω-3 and 22:6ω-3 polyunsaturated fatty acids (PUFAs), was evaluated by means of a two level factorial design and LC-MS/MS. The method was selective for the pro- and anti-inflammatory analytes and their corresponding stable-isotope labelled internal standards. The regression models were linear over the concentration range 0.5-150 ng/ml with limits of detection of 0.25 ng/ml and quantification of 0.40 ng/ml for the analysed metabolites. The recovery ranged from 78 to 107% for prostaglandins and 73 to 115% for leukotrienes. The analysis of the samples exposed to different combinations of PUFAs revealed that the presence of single ω-3 PUFAs brought an enhancement of the metabolites from the lipooxygenase pathway, specially LTB4, and a reduction of the metabolites from the cyclooxygenase pathway (PGE2 and PGE3), while the two-term interactions generated the opposite effect (high concentration of prostaglandins and low concentrations of leukotrienes). To our knowledge, this is the first implementation of a fully crossed design for investigating the impact of ω-6 and ω-3 PUFAs on the production of eicosanoids not only through their individual but also through their combined effects on Atlantic salmon head kidney cells.

Combind Effect of Machining Parameters With Nose Radius of the Custting Tool on Surface Roughness of 304- Austenitic Stainless Steel Alloy Produced by Cnc-Turning Machin

It is well known that machining parameters have strong effect on the properties of surface roughness. Many investigations have done on this area. This work studies of combining effect of turning process parameters (cutting speed, feed rate, and depth of cut) with on surface roughness. Where, nose radius of the tool and machining parameters have taken as input variables and the surface roughness (Ra) as response or output. Three experiments were conducted; they were used to investigate the surface roughness resulted by tool corner radiuses of the values: 0.4mm, 0.8mm, and 1.2mm Response surface methodology (R.S.M) is applied as a tool to show the cause and effect of output (response) and input control and relationship between them as a two or three dimensional hyper surface. A three factor with five level central composite rotatable factors design was used. The results showed that R.S.M is a strong tool and capability tool to predict the effect of machining parameters on surface roughness. Results improved that the five level factorial designs can be employed for developing statistical models to predict surface roughness by controllable machining parameters. Results showed that the combined effect of cutting speed at its higher level, feed rate and depth of cut at their lower values, and large nose radius can result in better surface roughness.

Bioinspired silica as drug delivery systems and their biocompatibility.

Silica nanoparticles have been shown to have great potential as drug delivery systems (DDS), however, their fabrication often involves harsh chemicals and energy intensive laborious methods. This work details the employment of a bioinspired "green" method for the controlled synthesis of silica, use of the products to entrap and release drug molecules and their cytotoxicity in order to develop novel DDS. Bioinspired silica synthesis occurs at pH 7, room temperature and in less than 5 minutes, resulting in a rapid, cheaper and greener route. Drugs were loaded into silica during the silica formation, thus allowing a one step and one pot method for simultaneous silica synthesis and drug loading. We established that the drug release profile can be modulated by synthetic parameters, which can allow design of tailored DDS. A systematic investigation using a two level factorial design was adopted in order to identify the key synthetic parameters and quantify their effects on silica formation, drug loading and drug release. The observation that these new DDS are considerably less cytotoxic than their current counterparts, and exhibit additional benefits such as green synthesis and ease of functionalization, strengthens the argument for their future use in DDS and other biomedical applications.

Formulation optimization of erythromycin solid lipid nanocarrier using response surface methodology.

In present work response surface methodology (RSM) using the miscellaneous design model was used to optimize formulations of erythromycin solid lipid nanocarriers (ERY-SLN). Two-factor three level factorial design was considered for optimization. There were three parameters, drug entrapment efficiency (EE), drug loading (DL) percentage, and mean particle size of ERY-SLN, considered for investigating the optimal formulation with respect to two independent variables, including lipid concentration (X 1) and surfactant : cosurfactant ratio (X 2). The result showed that the optimal ERY-SLN was composed of lipid concentration (X 1) 15 mg/mL and surfactant : cosurfactant ratio (X 2) 1 : 1 with %EE of 88.40 ± 2.09%, DL of 29.46 ± 0.69%, mean particle size of 153.21 ± 2.31 nm, polydispersity index (PDI) of 0.026 ± 0.008, and zeta potential value of −15.18 ± (−5.53) mV. DSC and TEM study showed that there was no chemical interaction between ERY and lipid (GMS) and the ERY-SLN particles are nonspherical, respectively. The drug release experiments exhibited a sustained release over during 24 h, up to 66.26 ± 2.83%. Accelerated stability studies showed that there was no significant change occurring in the responses after storage condition for a total period of 3 months.