• Environmental Engineering Research
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• 제22권1호
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• pp.61-74
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• 2017

This study investigated the effect of various cations ($Ca^{2+}$, $Mg^{2+}$, $Al^{3+}$, $Mn^{2+}$, $Zn^{2+}$) on the autoaggregation (AAg) and surface hydrophobicity (SHb) of three different bacteria (Brevibacillus panacihumi strain (ZB1), Lysinibacillus fusiformis strain (ZB2) and Enterococcus faecalis strain (ZL)) using a 2-level factorial design. The AAg ratio was measured from the changes in the absorbance of the media. Results show that ZB2 had maximum AAg for the three bacteria investigated. A microscopic clustering of cells was observed when $Ca^{2+}$ was added to ZB2. The AAg was in the range of 62%, 58% and 34% for ZB2, ZB1 and ZL, respectively and correlated to the SHb. The aggregation and SHb of the microbial cells increased with increasing ionic strength due to the repulsive steric or overlap forces between the polymer covered surfaces. $Ca^{2+}$ demonstrated a more significant effect on aggregation and SHb of microbial cells due to an attractive binding force.

• 복식문화연구
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• 제17권3호
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• pp.459-471
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• 2009

The purpose of the study is to examine the effect of VMD image appropriateness in apparel shopping contexts. Two competing models are utilized. The first model is developed from the emotion-cognition theory which explains that environmental cues(i.e., VMD image appropriateness) generate consumers' emotion, and in turn, consumers' behaviors. The second model is developed based on the cognitive theory of emotions and posits that environmental cues stimulates consumers' cognitive perceptions of retail environments, subsequently influencing consumers' emotional and behavioral response. A 2(VMD image appropriateness: high vs. low) between-subjects factorial design experiment was conducted. Female college students(n=592) participated in the experiment. Using structural equation modeling the study found that the emotion-cognition model better explains the effect of VMD image appropriateness on consumers' emotional, cognitive, and behavioral responses.

• Journal of Pharmaceutical Investigation
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• 제40권5호
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• pp.297-304
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• 2010

The present work focuses on preparation of olanzapine, orally dispersing tablets by direct compression method. Effect of super disintegrant crospovidone, disintegration time, drug content on in vitro release has been studied. A factorial design was employed in formulating a prompt dispersible tablet. The selected independent variables crospovidone and fmelt showed significant effect on dependent variables i.e. disintegration time and percent drug dissolved. Disintegration time and percent drug dissolved decreased with increase in the level of crospovidone. The similarity factor $f_2$ was found to be 97.48 for the developed formulation indicating the release was similar to that of the marketed formulation. Pharmacokinetics of olanzapine after single-dose oral administration of orally disintegrating tablet in normal volunteers were evaluated and the results showed that PK parameters (Cmax, Tmax, AUC) of the designed ODT matrix were similar to those of commercial product, Zyprexa Zydis$^{(R)}$ as a reference.

• Advances in environmental research
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• 제5권3호
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• pp.189-200
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• 2016

This study aimed at advanced oxidation of hetero tri-functional reactive dye Acid orange 7 using photo-Fenton conditions in a lab-scale experiment. Decolourisation of Acid Orange 7 dye by Fenton's process was dependent on concentration of Hydrogen peroxide, Ferrous sulphate, pH, and contact time. A $2^3$ factorial design was used to evaluate the effects of these key factors: pH, Fe(II), and $H_2O_2$ concentration, for a dye concentration of 50 mg/L with COD of 340 mg/L at pH 3.0. The response function was removal of colour under optimised conditions; pH 3.0, [Fe(II)] 40.83 mg/L, [$H_2O_2$] 4.97 mmol/L; 13.6 min. of treatment resulting in 100% colour removal. The final COD of treated wastewater was nil suggesting that AOP is a potentially useful process of color removal and dye degradation/mineralisation of effluent having AO7. Minimum contact time for complete decolourisation was at 5 mmol/l $H_2O_2$ concentration. Increase in $FeSO_4$ (mg/l) concentration resulted in decrease of time for complete decolourisation. Box-Behnken Design was used to optimize the process variables. Maximum and minimum levels of pH (3-5), $H_2O_2$ (4-6 mmol/l), $FeSO_4$ (30-46 mg/l) and contact time (5-15 minutes) were used. The statistical analysis revealed a value of 0.88 for coefficient of regression ($R^2$) indicating a good fit of model. Calculated F-value was found higher than the tabulated value confirming to significance of the model. Based on student's t-test, Ferrous sulphate, pH, and contact time have a positive effect on the percent decolourisation of Acid Orange 7.

• Environmental Engineering Research
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• 제15권2호
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• pp.63-70
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• 2010

In this study, the response surface method and experimental design were applied as an alternative to conventional methods for the optimization of coagulation tests. A central composite design, with 4 axial points, 4 factorial points and 5 replicates at the center point were used to build a model for predicting and optimizing the coagulation process. Mathematical model equations were derived by computer simulation programming with a least squares method using the Minitab 15 software. In these equations, the removal efficiencies of turbidity and total organic carbon (TOC) were expressed as second-order functions of two factors, such as alum dose and coagulation pH. Statistical checks (ANOVA table, $R^2$ and $R^2_{adj}$ value, model lack of fit test, and p value) indicated that the model was adequate for representing the experimental data. The p values showed that the quadratic effects of alum dose and coagulation pH were highly significant. In other words, these two factors had an important impact on the turbidity and TOC of treated water. To gain a better understanding of the two variables for optimal coagulation performance, the model was presented as both 3-D response surface and 2-D contour graphs. As a compromise for the simultaneously removal of maximum amounts of 92.5% turbidity and 39.5% TOC, the optimum conditions were found with 44 mg/L alum at pH 7.6. The predicted response from the model showed close agreement with the experimental data ($R^2$ values of 90.63% and 91.43% for turbidity removal and TOC removal, respectively), which demonstrates the effectiveness of this approach in achieving good predictions, while minimizing the number of experiments required.

• 대한인간공학회지
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• 제30권4호
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• pp.551-562
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• 2011

Objective: We proposed an effective 3D menu manipulation alternative with a usability test. This was performed in a 3D environment with 3D menu and control manipulation methods. Background: As 3D stereoscopic displays became generalized, various 3D applications were being used not just movies, games, but also mobile contents and advertisements. However, when a user interface was designed in a 3D environment, it was lacked that a clear standard and result of an efficiency and usability as like a 2D environment. Method: We implemented 9 kinds of 3D menu types based on 3D menu hierarchies, menu layouts and dimensions. And we extracted 3 representative control types in a 3D environment. We performed usability evaluation with full factorial design for 27 menu alternatives with 2 types of menu manipulation tasks. In this condition, we measured the performance time, subjective discomfort and eye-fatigue. Results: A control type had the significant effect, and the effect of menu types had the different result depending on given tasks. Conclusion: This experiment showed the interaction of menu and control types depended on 3D menu manipulation tasks were significant in a 3D user interface design. Therefore, as a purpose of a 3D menu manipulation task, 3D menu types and control types were should be considered. Application: We supposed this result was should be applied in a 3D menu contents design.

• 한국염색가공학회지
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• 제20권2호
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• pp.19-28
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• 2008

The objective of this study was to apply the statistical technique known as design of experiments to optimize the % exhaustion variables for phthalocyanine dyeing of nylon fiber. In this study, a three-factor Central Composite Rotatable Design (CCRD) was used to establish the optimum conditions for the phthalocyanine reactive dyeing of nylon fiber. Temperature, pH and liquor ratio were considered as the variable of interest. Acidic solution with higher temperature and lower liquor ratio were found to be suitable conditions for higher % exhaustion. These three variables were used as independent variables, whose effects on % exhaustion were evaluated. Significant polynomial regression models describing the changes on % exhaustion and % fixation with respect to independent variables were established with coefficient of determination, R2, greater than 0.90. Close agreement between experimental and predicted yields was obtained. Optimum conditions were obtained using surface plots and Monte Carlo simulation techniques where maximum dyeing efficiency is achieved. The significant level of both the main effects and interaction was observed by analysis of variance (ANOVA) approach. Based on the statistical analysis, the results have provided much valuable information on the relationship between response variables and independent variables. This study demonstrates that the CCRD could be efficiently applied for the empirical modeling of % exhaustion and % fixation in dyeing. It also shows that it is an economical way of obtaining the maximum amount of information in a short period of time with least number of experiments.

• Journal of Welding and Joining
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• 제24권4호
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• pp.27-31
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• 2006

Optimization of process parameters for laser-arc hybrid welding process is intrinsically sophisticated because the process has three kinds of parameters-arc, laser and hybrid welding parameters. In this paper, the relationship between weldability and several process parameters such as laser beam-arc distance, electrode height, welding current and welding speed, were investigated by the full factorial experimental design. Weld quality was evaluated by using weight of spatters which is related with the pore area. It was found that the weld quality was increased with the increases in laser beam-arc distance and welding current, and decreased with the increases in electrode height and welding speed.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권1호
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• pp.9-18
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• 2010

In this study, Solid-phase micro-extraction (SPME) with Gas Chromatograph using Flame Ionization Detector (GC/FID) was studied as a possible alternative to liquid-liquid extraction for the analysis of Methyl tert-butyl ether (MTBE) and Tertiary-butyl ether (TBA) in water and an optimization condition of trace analysis of MTBE and TBA using the design of experiment (DOE) was described. The aim of our research was to apply experimental design methodology in the optimization condition of trace analysis of fuel oxygenated compounds in soil-phase microextraction with GC/FID. The reactions of SPME were mathematically described as a function of parameters of Temp ($X_1$), Volume ($X_2$), Time ($X_3$) and Salt ($X_4$) being modeled by the use of the partial factorial designs, which was used for fitting 2nd order response surface models and was alternative to central composite designs. The model predicted agreed with the experimentally observed result ($Y_1$(MTBE, $R^2$ = 0.96, $Y_2$ (TBA, $R^2$ = 0.98)). The estimated ridge of the expected maximum responses and optimal conditions for MTBE and TBA were 278.13 and (Temp ($X_1$) = $48.40^{\circ}C$, Volume ($X_2$) = 73.04 mL, Time ($X_3$) = 11.51 min and Salt ($X_4$) = 12,50 mg/L), and 127.89 and (Temp ($X_1$) = $52.12^{\circ}C$, Volume ($X_2$) = 88.88mL, Time ($X_3$) = 65.40 min and Salt ($X_4$) = 12,50 mg/L), respectively.

• Journal of Animal Science and Technology
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• 제58권6호
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• pp.19.1-19.7
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• 2016

Background: Cowpea (Vigna unguiculata [L.]) is a legume cultivated throughout most tropical countries and is valued as food and feed for human and livestock respectively. The search for an improved cowpea variety has been on-going with the aim of improving traits such as grain yield, drought and pest resistance. But no information exist on the feeding value of these improved varieties. Phosphate (P) fertilizer application is recommended to augment grain yield in grain legumes but data on the effect of P fertilizer on haulm quality is limited. Results: Two separate experiments were conducted to determine the effect of P fertilizer dose on the nutritive value of haulms from different cowpea varieties (V). In experiment 1, effect of three P doses (30, 60 and 90 kg $P_2O_5/ha$) on in vitro gas production (IVGP) characteristics, concentrations of digestible organic matter (DOM), crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) of haulms from five cowpea varieties (Zaayura-SARC 4-75, Songotra-IT97K-499-35, Hewale-IT93K-192-4, IT99K 573-1-1 and Asomdwe-IT94K-410-2) were investigated using the $3(P){\times}5(V)$ factorial treatment arrangements in a completely randomized design. In experiment 2, the effects of two P doses (30 and 90 kg $P_2O_5/ha$) and two varieties (Zaayura-SARC 4-75 and Hewale-IT93K-192-4) on the voluntary feed intake, live weight, haematology and carcass characteristics of Djallonke lambs were also assessed using a $2(P){\times}2(V)$ factorial treatment arrangement. The $V{\times}P$ interaction significantly affected CP, NDF and ADF with CP concentration increasing with increase in P doses in Zaayura-SARC 4-75 and Asomdwe-IT94K-410-2. Whilst an increase (P < 0.05) in NDF was observed in Songotra-IT97K-499-35and Asomdwe-IT94K-410-2 as P doses increased, the other V only increased from P dose 30 to 60 kg/ha and declined at P dose 90 kg/ha. The ADF decreased (P < 0.05) with increase in P dose for all V with the exception of Songotra-IT97K-499-35. There was a significant V effect on DOM with the highest reported in Zaayura-SARC 4-75 (43.44 %). Daily DM intake, carcass length and blood urea nitrogen of the lambs were significantly affected by the V x P interaction. There was a significant V effect on globulin and P effect on live weight at slaughter, dressed weight, chuck, leg, loin, rib and flank and liver and lungs. Conclusion: It can be concluded that nutrient concentrations of cowpea haulms were positively influenced by different P dose and varieties with favorable effects on growth, haematology and carcass composition of lambs. Varieties Zaayura-SARC 4-75 and Hewale-IT93K-192-4 at P dose at 90 kg/ha are recommended to enhance growth performance and carcass yield of Djallonke lambs.