Two-level Factorial Design Method Research Articles

THE EFFECT OF THE MEMBRANE THICKNESS ON THE PERFORMANCE OF DIRECT METHANOL FUEL CELL: FACTORIAL DESIGN

The direct methanol fuel cell (DMFC) is one of the most promising technologies to achieve high power density at room temperature. Many studies have been conducted to improve its performance by optimizing the operating conditions. The purpose of this work is to investigate the effects of membrane thickness under various pertinent operating conditions on the performance of the DMFC using the two-level factorial design method. The operating conditions include methanol concentration, temperature, cathode flow rate, and backpressure. Two models have been developed for the maximum power density of the DMFC using factorial design. The first model is a function of membrane thickness, temperature, cathode flow rate, and backpressure, while the second model is a function of membrane thickness and methanol concentration. The effects of membrane thickness with the other operating conditions are analyzed from the parameters of the developed models. It has been shown that increasing the membrane thickness decreases the maximum obtained power density. Increasing the membrane thickness along with methanol concentration or backpressure increases the obtained power density. The negative effect of membrane thickness increases with the rise of temperature or the lowering of the cathode flow rate. Using the factorial design, two other models are developed for the open circuit voltage (OCV) of the DMFC. The effect of the membrane thickness is always positive on the OCV.

Screening The Effect of Cu, Mn, and Mg on Ethanol Formation in Degradation Process of Palm Oil Mill Effluent (POME) under Anaerobic Condition Using Two-Level Factorial Design Method

Anaerobic digestion can be used for the treatment of POME to reduce organic content and generate some substances, such as volatile acids, ethanol, and various gasses. During anaerobic fermentation process, microorganism requires the presence of trace elements for growth to improve their performance. This research will be carried out as a study of the presence of trace elements, such as metals (Cu2+, Mn2+, and Mg2+) that has significant effects on ethanol formation. Circulating Bed Reactor was used and operated in a batch system for 48 hours. Metal ions were screened and analyzed by using two-level factorial design method whether there is any correlation effect between the addition of Cu2+, Mn2+, and Mg2+ and ethanol formation. Several parameters which consists of Total Volatile Acids (TVA), dissolved Chemical Oxygen Demand (CODs), Volatile Suspended Solid (VSS), pH, Dissolved Oxygen (DO), and ethanol were measured every sampling. Mn metal is proven statistically affect both TVA and ethanol formation while Mg metal only affect TVA formation. Cu2+ and Mg2+ metals combination affect ethanol formation with largest detected ethanol concentration is 7,483.07 mg/L. The result from this study had identified the metal ions which has significant effect as a foundation for optimization ethanol formation.

Development of a chitosan based double layer-coated tablet as a platform for colon-specific drug delivery.

A double layer-coated colon-specific drug delivery system (DL-CDDS) was developed, which consisted of chitosan (CTN) based polymeric subcoating of the core tablet containing citric acid for microclimate acidification, followed by an enteric coating. The polymeric composition ratio of Eudragit E100 and ethyl cellulose and amount of subcoating were optimized using a two-level factorial design method. Drug-release characteristics in terms of dissolution efficiency and controlled-release duration were evaluated in various dissolution media, such as simulated colonic fluid in the presence or absence of CTNase. Microflora activation and a stepwise mechanism for drug release were postulated. Consequently, the optimized DL-CDDS showed drug release in a controlled manner by inhibiting drug release in the stomach and intestine, but releasing the drug gradually in the colon (approximately 40% at 10 hours and 92% at 24 hours in CTNase-supplemented simulated colonic fluid), indicating its feasibility as a novel platform for CDD.

Optimization of steel bar manufacturing process using six sigma

Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and controlmethodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar(Khyber Pakhtunkhwa, Pakistan). The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

The Effect of Process Parameters on the Microstructure and Mechanical Properties of Semisolid Cast Al6061

An examination of the microstructure and mechanical properties of aluminum 6061 alloy samples produced by a miniature cooling slope is presented. The effects of several process parameters including pouring rate, cooling slope angle, superheat and cooling slope length on the microstructure and mechanical characteristics of the samples were investigated. An attempt was made to use the two-level factorial design method to determine the relationships between the process parameters and the properties of the semisolid aluminum 6061 alloy manufactured by the miniature cooling slope. Finally, an optimum processing region was identified. The interaction between the cooling slope length and the pouring rate (BC); the interaction among the superheat, the pouring rate, and the cooling slope length (ABC); and the cooling slope length (C), in the order mentioned, were identified as the most important effects.

Process optimization for the preparation of oligomycin-loaded folate-conjugated chitosan nanoparticles as a tumor-targeted drug delivery system using a two-level factorial design method

Oligomycin-A (Oli-A), an anticancer drug, was loaded to the folate (FA)-conjugated chitosan as a tumor-targeted drug delivery system for the purpose of overcoming the nonspecific targeting characteristics and the hydrophobicity of the compound. The two-level factorial design (2-LFD) was applied to modeling the preparation process, which was composed of five independent variables, namely FA-conjugated chitosan (FA-CS) concentration, Oli-A concentration, sodium tripolyphosphate (TPP) concentration, the mass ratio of FA-CS to TPP, and crosslinking time. The mean particle size (MPS) and the drug loading rate (DLR) of the resulting Oli-loaded FA-CS nanoparticles (FA-Oli-CSNPs) were used as response variables. The interactive effects of the five independent variables on the response variables were studied. The characteristics of the nanoparticles, such as amount of FA conjugation, drug entrapment rate (DER), DLR, surface morphology, and release kinetics properties in vitro were investigated. The FA-Oli-CSNPs with MPS of 182.6 nm, DER of 17.3%, DLR of 58.5%, and zeta potential (ZP) of 24.6 mV were obtained under optimum conditions. The amount of FA conjugation was 45.9 mg/g chitosan. The FA-Oli-CSNPs showed sustained-release characteristics for 576 hours in vitro. The results indicated that FA-Oli-CSNPs obtained as a targeted drug delivery system could be effective in the therapy of leukemia in the future.