One-factor-at-a-time Method Research Articles

The Effect of Desulfovibrio Desulfuricans To Carbon Steel Grade API 5L X70

Microbiologically Influenced Corrosion (MIC) caused by the presence of Sulfate-reducing bacteria (SRB) is a big concern in heavy industries. Pipeline infrastructure may experience severe metal loss due to corrosion induced by the species and can potentially lead to catastrophic failure. By studying SRB growth condition, important parameter can be controlled to prevent or slow down a corrosion process. This study discussed on the effect of pH value to the corrosion growth rate on API 5L X70 low carbon steel subjected to outer part of underground pipeline. In this research, the type of SRB that's been used is Postgate C of Desulfovibrio Desulfuricans. There are 80 numbers of samples prepared with various pH value and temperature, which each of the samples contains two coupon steel immersed in the medium together with SRB for 7, 14, 21 and 28 days. The process in determining weight loss is analyzed and the corrosion rate for each steel sample is identified by weight loss. The result is plotted and analyzed, the particular pH values and temperature affect the growth of SRB in the medium where the existence of SRB could accelerate the corrosion rate towards the steel surface of API X-70. The samples are exposed to SRB in days’ time. This experiment aims to determine the optimum temperature for SRB growth and demonstrate the corrosion rate simulation using One-Factor-at-A-Time method (OFAT) method. The consequences of SRB activity, it is shown that pitting corrosion produced on the surface of steel. In fact, the sulphur element is identified as one of the corrosion products due to SRB activity.

Optimization of an Activity Assay of Coprinus Cinereus Peroxidase

ABSTRACT To seek a simple, rapid and sensitive Coprinus cinereus Peroxidase (CIP) activity assay, a convenient one-factor-at-a-time (OFAT) method and a response surface methodology (RSM) were used. The recombinant CIP expressed in Pichia pastoris was purified with the Ni-NTA spin column. Based on the results of catalytic efficiency (kcat/Km) analysis, 2,2'-azinobis (ethylbenzthiazoline -6-sulfonate) (ABTS) was selected as the optimal enzyme substrate. Results of the OFAT method showed that enzymatic reaction performed in 0.1 mol/L sodium acetate (pH 5.0) buffer in a 200-µl reaction mixture containing 0.5 mmol/L ABTS, 10 mmol/L hydrogen peroxide (H2O2), 49.7 ng CIP at 25°C gave an average CIP activity of 88 U/mL. The ABTS and H2O2 concentrations were then further optimized to improve the sensitivity of the assay. To do that, RSM was conducted through central composite design, and a reduced quadratic model with good fit regression equation was generated. ANOVA analysis of this model indicated that the concentrations of ABTS and H2O2 and their interaction had significant impact on the assay sensitivity. The optimal reaction mixture was determined to include an initial ABTS concentration of 0.82 mmol/L 49.7 ng CIP and 16.36 mmol/L H2O2, and the activity under this condition was determined to be 138.89 U/mL.

Carboxymethyl cellulase production optimization from Glutamicibacter arilaitensis strain ALA4 and its application in lignocellulosic waste biomass saccharification

In this context, carboxymethyl cellulase (CMCase) production from Glutamicibacter arilaitensis strain ALA4 was initially optimized by one factor at a time (OFAT) method using goat dung as proficient feedstock. Two-level full factorial design (25 factorial matrix) using first-order polynomial model revealed the significant (p < 0.05) influence of pH, moisture, and peptone on CMCase activity. Central composite design at N = 20 was further taken into account using a second-order polynomial equation, and thereby liberated maximum CMCase activity of 4925.56 ± 31.61 U/g in the goat dung medium of pH 8.0 and 100% moisture containing 1% (w/w) peptone, which was approximately two fold increment with respect to OFAT method. Furthermore, the partially purified CMCase exhibited stability not only at high pH and temperature but also in the presence of varied metal ions, organic solvents, surfactants, and inhibitors with pronounced residual activities. The enzymatic hydrolysis using partially purified CMCase depicted the maximum liberation of fermentable sugars from alkali pretreated lignocellulosic wastes biomass in the order of paddy straw (13.8 ± 0.15 mg/g) > pomegranate peel (9.1 ± 0.18 mg/g) > sweet lime peel (8.37 ± 0.16 mg/g), with saccharification efficiency of 62.1 ± 0.8, 40.95 ± 0.4, and 37.66 ± 0.4%, respectively after 72 hr of treatment.

Unraveling rapid extraction of fucoxanthin from Padina tetrastromatica: Purification, characterization and biomedical application

Abstract Fucoxanthin, a group of carotenoids abundantly present in the marine macro algae which exhibits diverse health benefits. Extraction of such potential biomolecules involves multiple steps in conventional extraction (CE) and also laborious and time-consuming. We attempted to extract high percentage fucoxanthin and phenolic compounds from macro alga, Padina tetrastromatica adopting ultrasound-assisted extraction (UAE). It was further optimized with solvent concentration; temperature and time as 80%, 50 °C and 30 min respectively using one factor at a time method (OFAT) followed by response surface methodology (RSM). It was observed that fucoxanthin yield of about 750 μg g−1 DW was obtained at the maximum by UAE than that of CE (430 μg g-1 DW). It was further purified and characterized using FTIR, HPLC and HRMS technique confirming the presence of purified fucoxanthin at the retention time of 3.14 min and molecular mass of 681.41 m/z. In addition, fucoxanthin exhibits a strong antioxidant activity by inhibiting DPPH and ABTS free radicals upon dose dependent manner. Interestingly, fucoxanthin showed protective effect against H2O2-induced intracellular ROS and cytotoxicity on fibroblast cells at the concentration of 120 μM. Thusly, UAE could be implemented for the extraction at high percentage and eventually be utilized these biomolecules as nutraceuticals.

Culture Optimization Strategy for 1-Deoxynojirimycin-producing Bacillus methylotrophicus K26 Isolated from Korean Fermented Soybean Paste, Doenjang

1-Deoxynojirimycin (1-DNJ) is an α-glucosidase inhibitor that is used for the treatment of type 2 diabetes. In this study, we isolated Bacillus methylotrophicus K26 with α-glucosidase inhibition (AGI) activity from Korean fermented soybean paste (Doenjang) and confirmed that the genome harbored the DNJ biosynthesis genes including gabT1, yktc1, and gutB1 by PCR screening, while 1-DNJ production was confirmed by ultra-performance liquid chromatography–quadrupole time-of-flight–mass spectrometry. To increase 1-DNJ production by B. methylotrophicus K26, culture conditions were optimized with one-factor-ata- time (OFAT) and response surface methodology (RSM) approaches. Screen of 11 carbon and 9 nitrogen sources by the OFAT method identified sucrose and yeast extract as optimal culture components. Sucrose concentration (X1), yeast extract concentration (X2), and culture temperature (X3) were selected as independent variables for central composite design. The coefficient of determination (R2) for the model was 0.927, and the probability value of the regression model was highly significant. RSM predicted the optimal conditions for 1-DNJ production by B. methylotrophicus K26 as sucrose and yeast extract concentrations of 4.61% and 7.03%, respectively, at a temperature of 34°C. Under these conditions, AGI activity was experimentally measured as 89.3%, which was close to the predicted value of 91.9%.

Optimization of in vitro refolding conditions of recombinant Lepidium draba peroxidase using design of experiments

The main objective of this study was to optimize the in vitro refolding conditions of the recombinant Lepidium draba peroxidase (LDP). Initially, the effects of various factors were investigated on LDP refolding yield using one-factor-at-a-time (OFAT) method. Based on the OFAT results, optimum concentrations for LDP refolding were 2 M urea, 2 mM CaCl2, 0.42 mM l-glutathione oxidized (GSSG), 0.20 mg/ml protein, and 12 μM hemin as well as pH 7. Secondly, according to the OFAT results, design of experiments (DOE) was applied for investigation of the interactions between factors including protein (P), urea (U), CaCl2 (C), and GSSG (G). The results showed the possible interaction between PC, PG, PU, and GU. Lastly, response surface methodology (RSM) was used for final refolding conditions optimization. The final optimized refolding conditions for LDP were conducted as 2 M urea, 1 mM CaCl2, 0.70 mM GSSG, 0.07 mM DTT, 0.15 mg/ml protein which they obtained from RSM results and 12 μM hemin, and pH 7 according to the results of OFAT method. Overall, under optimal conditions, 23.4 mg active refolded LDP per liter of expression medium was obtained. So, the refolding yield was calculated to be approximately 48%.

Degradation of toluidine red, an oil soluble azo dye by Halomonas strain IP8 at alkaline condition

A salt tolerant bacteria, Halomonas strain IP8, was used for the degradation of an oil soluble azo dye, Toluidine Red (C.I. no. 12120). The effect of different culture conditions such as initial dye concentration, pH, NaCl percent (w/v) and temperature were studied at static condition using the one-factor-at-a-time method (OFAT) method as optimization technique. According to the results, the optimized conditions were 25 mg/l dye concentration, pH 9.5, 5% (w/v) NaCl, and temperature 35 °C. The decolorization mechanism was analyzed through UV–vis spectrophotometric method, high-performance liquid chromatography (HPLC), and gas chromatography-mass spectrometer (GC-MS) analyses. UV–vis scan of supernatants before and after treatment suggested that decolorization was accrued under degradation mechanism rather than inactive surface adsorption. HPLC analysis confirmed this conclusion. The identified metabolite from GC-MS results was 1-diazo 2-naphtol at m/z 170 ± 1. A pathway was proposed for dye degradation based on the identified fragment by GC-MS analysis.

Recovery of energy and simultaneous treatment of dewatered sludge using membrane‐less microbial fuel cell

Microbial fuel cells (MFC) haves drawn much attention as a potential approach for sludge treatment and renewable energy production. In this study, a single chamber air‐cathode in a membrane‐less MFC (ML‐MFC) was operated in batch mode with dewatered sludge from a municipal wastewater treatment plant as the substrate. Electrogenic bacterial species in the sludge acted as a catalyst for the generation of electricity. The performance of the ML‐MFC was evaluated using one‐factor‐at‐a‐time (OFAT) method followed by response surface methodology (RSM) via Central Composite Design using a quadratic model. In the preliminary OFAT study, the highest voltage generation (852.7 mV) and COD removal (149.2 mg/L) were obtained when the pH, electrode distance, moisture content, and temperature were at 6.0, 3 cm, 30% (vol/wt), and 35°C, respectively. After incubation of the ML‐MFC using optimum conditions suggested by the RSM, the voltage was successfully increased to 927.7 mV (improved 9%), while COD removal increased to 170.8 mg/L (improved 15%). This showed that optimization using RSM gave better results than the OFAT method. The maximum power density recorded from the optimum conditions was 41.3 mW/m2. © 2018 American Institute of Chemical Engineers Environ Prog, 38: 208–219, 2019

Enhancement of anti-tubercular activity and biomass of fermented food associated Staphylococcus hominis strain MANF2 using Taguchi orthogonal array and Box-Behnken design

The prime focus of the present investigation was to optimize statistically the anti-tubercular activity and biomass of fermented food associated Staphylococcus hominis strain MANF2 using Taguchi orthogonal array (OA) and Box-Behnken design (BBD). The anti-tubercular activity of strain MANF2 was determined against Mycobacterium tuberculosis H37Rv using luciferase reporter phase assay. Among varied media examined, the isolate exhibited impressive anti-tubercular activity with paramount relative light unit reduction of >90% in de Man Rogose Sharpe (MRS) broth. Primarily, the anti-tubercular activity and biomass of strain MANF2 were estimated in MRS broth by optimizing eight diversified parameters using one factor at a time (OFAT) method after working out a series of experiments. The most significant contributing factors selected through OFAT tool were optimized using Taguchi approach with a standard OA layout of L18 (22 × 36). Results demonstrated the significant (P ≤ 0.05) influence of pH, temperature, yeast extract, magnesium sulphate, and glycerol on response variables. These controlled variables were further optimized using BBD matrix at N = 46 by second-order polynomial equation. The fermentation medium of pH 6.5 constituting yeast extract (0.5% w/v), magnesium sulphate (0.1% w/v), and glycerol (1.5% v/v), being further incubated at 30 °C showed enhanced anti-tubercular activity (98.7%) and approximately 4 fold increment in the bacterial biomass yield (8.3 mg/mL) with respect to traditional OFAT method. Three-dimensional response plots of the quadratic model showed interdependent interaction between the significant variables. In conclusion, the present study revealed the first report on the optimization of anti-tubercular activity and biomass of S. hominis via Taguchi OA as well as BBD design, and thus, paved a path for its proficient applications in pharmaceutical industries as dynamic mycobactericidal agent in future.

Radiographic knee osteoarthritis impacts multiple dimensions of health-related quality of life: data from the Osteoarthritis Initiative.

To estimate the multi-dimensional health impact of radiographic knee OA and quantify the overall health-related quality of life (HRQoL) burden, using a preference-based health utilities measure. Data on self-reported HRQoL, measured using the SF-12 multi-dimensional health state instrument, were obtained for 2895 patients with radiographic knee OA (Kellgren-Lawrence grade of at least 2) from the Osteoarthritis Initiative and for a general population sample of 3202 from the National Health Measurement Study. The SF-12 was converted to the six-dimensional SF-6D classification to compute preference-based health utilities. Generalized ordinal regression and multinomial regression were used to estimate the health loss on each SF-6D dimension for Osteoarthritis Initiative participants with radiographic knee OA relative to the general population, adjusted for differences in age, BMI, sex, ethnicity and educational level. Predicted SF-6D profiles were then used to compute the average HRQoL loss attributable to radiographic knee OA. Radiographic knee OA was associated with substantial health losses on all dimensions of the SF-6D except for social functioning. Health losses increased with the radiographic severity of OA in dimensions related to physical health, while there was no relationship between worse radiographic disease and worse self-assessed health in mental and emotional dimensions of health. Overall, radiographic knee OA was associated with a HRQoL detriment of 0.040-0.044 at Kellgren-Lawrence grade 2, increasing to 0.045-0.050 at grade 3 and 0.073-0.081 at grade 4. Radiographic knee OA is significantly associated with worse HRQoL across most dimensions of health.

A Statistical Approach for Production Improvement of a Neutral Protease From a Newly Isolated Strain of Aeromonas Hydrophila

Neutral proteases have a large variety of industrial applications. Therefore, the optimization of their production for the large-scale commercial purpose is critical. The present study was aimed to the optimization of nutritional and physical conditions affecting neutral protease production of Aeromonas hydrophila MSB16, not previously reported for this genus. Four key determinants (pH, temperature, glucose and peptone concentration), were selected based on the results of the one-factor-at-a-time (OFAT) method and then optimized by the response surface methodology (RSM). Maximum enzyme production (229.72 U/ml) which was 2.3 folds higher than that of the OFAT method (99.25 U/ml) and 3.15 times higher than unoptimized conditions (72.86 U/ml) was observed at 30 °C, pH 7, 4.5% w/v glucose and 4.5%w/v peptone by using a rotatable central composite design (RCCD). The results showed that the OFAT and RSM strategies were a useful screening and optimization methods for enhancing the protease production of the strain MSB16, respectively.

Dielectric Strength Improvement of Natural Ester Insulation Oil via Mixed Antioxidants: Taguchi Approach

&lt;span lang="EN-US"&gt;Recently, natural ester insulation (NEI) oils are found to be the best candidates to replace mineral-based insulation oils for oil-immersed transformer applications. However, NEI oils are prone to oxidation due to their poor oxidative stability which can be improved by adding antioxidants into the oils. Latest studies have also shown that the use of selected antioxidants improves the AC breakdown voltage (BdV) of NEI oils. However, the experiments in previous studies were designed using the conventional one-factor-at-a-time (OFAT) method, which requires a large number of samples to be tested in order to determine the optimum response. Thus, a Taguchi-based designed experiment is introduced in this study in replacement of the OFAT method. It is found that this method is capable of determining the optimum concentrations of propyl gallate (PG) and citric acid (CA) which will maximize the AC BdV and improve the oxidative stability of the NEI oil. An AC breakdown voltage test is conducted in accordance with the ASTM D1816 standard using Megger OTS60PB portable oil tester, in which the electrode gap distance is kept fixed at 1 mm. The results indicate that the addition of PG and CA antioxidants increases the AC BdV of the rapeseed-based NEI oil. It is found that the optimum concentrations of PG and CA antioxidant is 0.05 and 0.25 wt.%, respectively. Lastly, the model developed in this study is analysed using analysis of variance (ANOVA). Validation test is also conducted on the optimized NEI oil to determine its dielectric strength and oxidative stability.&lt;/span&gt;

Optimization of Thermo-Alkali Stable Amylase Production and Biomass Yield from Bacillus sp. Under Submerged Cultivation

The present context was investigated to optimize amylase production and cell biomass of poultry-associated Bacillus sp. using a conventional as well as statistical approach. Box-Behnken design (BBD) matrix at N = 29 was employed to optimize four independent variables, selected from one factor at a time (OFAT) technique, for maximum amylase production and biomass yield. The relative activity of crude amylase obtained from the isolate showed stability at high temperature (60 °C) and alkaline condition (pH 9) up to 4 h of incubation, thereby indicating its alkali-tolerant and thermo-stable property. The BBD resulted in enhanced amylase activity of 145.32 U/mL when the basal medium was slightly acidic (pH 6) and kept at a temperature of 35 °C with the shaking speed of 130 rpm, in addition to being incubated for 24 h. The selected factors, when employed with this statistical optimization approach, showed 1.5-fold and 2-fold enhancements in the amylase production and biomass yield respectively compared to the OFAT method. Analysis of variance (ANOVA) revealed high coefficient of determination (R2) of 0.96 to 0.99 for both the responses at significant level (p &lt; 0.05). Three-dimensional response and 2D contour plot of the quadratic model showed interdependent interaction between the effective variables. Long-term thermo-alkali stability of amylase obtained from Bacillus sp. suggested not only its wide applications in pharmaceutical, food and biotechnological industries, but also suggested a potent replacement of existing amylases on the market.

Experimental investigation and optimization of supercritical carbon dioxide extraction of toxic heavy metals from solid waste using different modifiers and chelating agents

Supercritical carbon dioxide extraction of toxic heavy metals including Uranium (U), Hafnium (Hf), Zirconium (Zr) and Cadmium (Cd) from a synthetic solid waste matrix was carried out using Cyanex 302, Cyanex 301, Cyanex 272, EDTA and TOPO as chelating agents in conjugation with methanol, acetylacetone, MIBK, acetone and acetonitrile as modifier. The dynamic extraction time (10–90min), pressure (8–35MPa), temperature (40–100°C), type of modifier and chelating agent were investigated as the main effective variables on the extraction yield of toxic heavy metal ions. The quantities of toxic heavy metals in the original and extracted samples were determined by ICP analysis. The optimal conditions for the extraction of heavy metal ions were determined by one factor at a time method (OFAT) to be 80°C, 26MPa and 70min (dynamic) using Cyanex 272 as chelating agent and methanol as modifier. The extraction yield of Zr, Hf, U and Cd at optimal conditions was predicted to be 100, 100, 99.1 and 100%, respectively.

Enhanced production of thermostable amidase from Geobacillus subterraneus RL-2a MTCC 11502 via optimization of physicochemical parameters using Taguchi DOE methodology.

The specific effect of chemical and physical factors on amidase production from Geobacillus subterraneus RL-2a was investigated using design of experiments (DOE) methodology. The one-factor-at-a-time (OFAT) method was used to study the effects of carbon and nitrogen sources on amidase production. Subsequently, optimal levels of physical parameters and key media components, namely temperature, pH, sucrose, K2HPO4, NaCl, yeast, CaCl2·2H2O and MgSO4·7H2O, were determined using the Taguchi orthogonal array (OA) experimental design (DOE) methodology. Taguchi method based on three levels with a OA layout of L18 (21 × 37) with eight most influential factors on amidase synthesis for the proposed experimental design. Analysis of variance was performed on the obtained results and optimum condition suggested by statistical calculations was tested in a verification test. An increase of 169.56 % in amidase production compared to the unoptimized conditions was observed and the conversion of isonicotinamide was significantly improved after performing optimization techniques, including OFAT and Taguchi method. The result indicated that Taguchi method was effective in optimizing the culture conditions of amidase production.Electronic supplementary materialThe online version of this article (doi:10.1007/s13205-016-0390-1) contains supplementary material, which is available to authorized users.

Optimization Studies for Selective Recovery of Phenolics from Wine Wastes

The objective of the present study was the recovery and selective separation of phenolics from grape marc and lees, two primary wastes from wine-making industry, with solvent extraction method, optimized using One-Factor-at-a-Time method (OFAT) and Response Surface Methodology (RSM). Phenolics from the whole fresh grapes have been studied in previous work, but not the valorization of wine wastes and their phenolic content. Extraction resulted in 19, 15 and 10 mg/g (dry weight) total phenolics with 96%, 87% and 64% antioxidant activity from red, white marc and white lees, respectively. Extracts thus obtained were subsequently treated with several sorbents followed by HCl-desorption. NaOH and CH3OH treated zeolite and aluminum oxide, respectively, performed better, separating phenolics up to 93% from total sugars. The latter resulted in a fraction containing up to 50% of the initial phenolics holding the antioxidant activity (up to 85%) of the initial extract. The results indicate the significance of the applied methodology being fast and low cost for the selective recovery of phenolics from wine wastes.

Response Surface Methodology as a StatisticalTool for Fermentation Media Optimization inLipase Production by Palm Oil Mill Effluent(POME) Isolate Emericella Nidulans NFCCI 3643

Among enzymes, lipases have been attracting biotechnologists owing to their numerous applications in various industries like – food, pharmaceutical, detergent, dairy, cosmetic, textiles etc. In the present study, optimization of lipase production by Emericella nidulans NFCCI 3643 was carried out using statistical experimental designs. Initially, a Plackett-Burmen design (PBD) was employed to find out the significant process variables. The results indicated that olive oil, ammonium sulphate, incubation period, temperature and pH had significant influences on lipase production. The optimal conditions were further obtained by subsequently using Box-Behnken design under response surface methodology (RSM). The interactive effects of 5 variables on lipase production were studied in 46 experimental runs and the optimum concentrations of these parameters were found to be olive oil, 18.98 mL/L; ammonium sulphate, 14.38 g/L; incubation time, 3.66 days; temperature, 25.71 °C and pH, 5.17. Under these optimal conditions the lipase activity was found to be 409.723 U/ml, which is a 2.76-fold increase in comparison with that obtained by optimization using traditional OFAT (one factor at a time) method.

Response Surface Methodology for the Optimization of Kojic Acid Production by Aspergillus Flavus Using Muntingia Calabura Fruits as a Carbon Source

The current study focused on the optimization of kojic acid production by a soil isolated fungal organism Aspergillus flavus through Surface Fermentation (SF) by utilizing a novel carbon source i.e. ripened fruits of Muntingia calabura L. Initially the most significant 7 physico-chemical factors were studied for the optimization process through One-Factor-At-A-Time Method (OFAT). Among these 5 influential factors were screened and five-factor-three-level Central Composite Design (CCD) matrix and Response Surface Methodology (RSM) was performed to enhance the production rate of kojic acid. Through one-factor-at-a-time method the optimal values were Substrate concentration 100g/L, Peptone concentration 4g/L, KH 2 PO 4 concentration 2g/L, MgSO 4 concentration 0.7g/L, pH 6.0, Time 28d and Temperature 30°C and the maximum kojic acid production was 85.1g/L. The maximum production obtained at the predicted optimal conditions through response surface methodology was Substrate concentration 100g/L, Peptone concentration 4g/L, pH 6.0, Time 28d and Temperature 29°C and the maximum kojic acid production was 88.8 g/L. These results directs to the success of the model in improving a process for the production of kojic acid, a significant organic acid with vast industrial importance.

Optimization and preparation of nanocapsules for food applications using two methodologies

This study investigated preparation of nanocapsules (NCs) containing food-grade ingredients using two experimental designs: a one-factor-at-a-time method (OFATM) and an optimization method (OM). Response surface methodology (RSM) was used to optimize the process. The variables explored were concentration and type of polymer wall, using polycaprolactone (PCL) and polyethylene glycol–polybutylene adipate–polyethylene glycol (PEG–PBA–PEG) (1.0–4.0mg) polyester triblock copolymer; food oil, using olive and avocado oil (0.5–2.0mg); solvent, using acetone and ethyl acetate (6–12ml); and surfactant concentration, using Tween 80 and Tween 60 (1–5mg). The optimum conditions to obtain NCs were found to be 2.0mg of PCL and 1.65mg of PEG–PBA–PEG, olive oil (0.5 and 0.88mg), acetone (6 and 10.25ml), and Tween 60 (3.0 and 4.25mg), with 90.9 and 71.9nm for OFATM and OM, respectively. This research was conducted to investigate the use of NCs in the manufacture of fruits.

Improving Quality of Wind Tunnel Test Data Through the MDOE

Researching on the improvement of the wind tunnel data quality through Modern Design Of Experiments (MDOE) was carried out. A body with fin model was tested in wind tunnel through the MDOE and traditional OFAT (One Factor at A Time) methods. The uncertainties of data from these two different methods were analyzed, and mechanism of defense against systematic error of Randomization and Repetition in the MDOE method was studied. The defense abilities against the time various systematic errors in wind tunnel tests of the MDOE and the OFAT method were compared, and the mean to improve test data quality using repetition principle in the MDOE was studied with the increasing of cost. Main conclusions: The MDOE method can test and eliminate the time various systematic errors during the wind tunnel tests, while the OFAT test data were polluted by the time various systematic errors; The independent variable changes sequently in the OFAT tests, so the test data are not statistically independent. It is the reason of the disability of the defense against the time various systematic errors in OFAT tests. Randomization can transform the systematic errors into random errors in MDOE tests, which can be eliminated. Repetition in MDOE tests can improve the quality of test data since the average variance in the predicted response can be reduced by adding sample points, and amount of the measured data are still less than the amount in OFAT tests.