statistical experimental design
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Christian Steinfelder ◽  
Johann Acksteiner ◽  
Christina Guilleaume ◽  
Alexander Brosius

AbstractClinching is a joining process that is becoming more and more important in industry due to the increasing use of multi-material designs. Despite the already widespread use of the process, there is still a need for research to understand the mechanisms and design of clinched joints. In contrast to the tool parameters, process and material disturbances have not yet been investigated to a relatively large extent. However, these also have a great influence on the properties and applicability of clinching. The effect of process disturbances on the clinched joint are investigated with numerical and experimental methods. The investigated process variations are the history of the sheets using the pre-hardening of the material, different sheet thicknesses, sheet arrangements and punch strokes. For the consideration of the material history, a specimen geometry for pre-stretching specimens in uniaxial tension is used, from which the pre-stretched secondary specimens are taken. A finite element model is set up for the numerical investigations. Suitable clinching tools are selected. With the simulation, selected process influences can be examined. The effort of the numerical investigations is considerably reduced with the help of a statistical experimental design according to Taguchi. To confirm the simulation results, experimental investigations of the clinch point geometry by using micrographs and the shear strength of the clinched joint are performed. The analysis of the influence of difference disturbance factors on the clinching process demonstrate the importance of the holistic view of the clinching process.

2021 ◽  
Eugene Marfo Obeng ◽  
Clarence M. Ongkudon

Abstract The derivation of reduced sugars from lignocellulosic biomass requires an optimum blend of cellulolytic enzymes and reaction conditions that favour high sugar yield. In this respect, statistical design of experiment strategies become useful, but the technique is often misguided such that enzyme redundancy becomes overlooked. Herein, we demonstrate a systematic approach that involves simplex lattice mixture design and central composite design for optimizing enzyme cocktails for the saccharification of lignocellulosic biomass. The simplex lattice mixture design yielded 0.3333: 0.3333: 0.3333 of Celluclast (5%), Hemicellulase (5%) and Laccase (2%), respectively, as the optimum enzyme blend (volume) ratio for the saccharification of hydrothermally pretreated empty palm fruit bunch (EPFB, 10% solid loading). A subsequent application of central composite design resulted in 40 oC, pH 6 and 24 hrs as the optimum saccharification conditions. The individual Celluclast (5%) and Hemicellulase (5%) yielded a reduced sugar equivalence (RSE) of 1.77 mg/mL and 1.67 mg/mL, respectively. However, the blended enzyme cocktail upon subjection to simplex lattice mixture design and subsequent central composite design yielded an RSE of 2.215 mg/mL and 2.431 mg/mL, respectively. The overall results exemplify the significance of enzyme synergism in lignocellulosic biomass saccharification. The approach herein is intended as an easy-to-copy plan for optimizing enzyme cocktails.

Saikumar D ◽  
Leela Prasanna J

The Lipid-based drug delivery system is extensively reported within the literature for the enhancing drug solubility, permeability, and bioavailability. A considerable majority of novel pharmacologically active constituents produced in recent drug discovery programs are lipophilic and poorly soluble, posing a significant problem for pharmaceutical researchers enhancing the oral bioavailability of such drug molecules. Self-nano emulsifying drug delivery systems (SNEDDS), are the viable oil-based approaches for drugs that exhibit low dissolution rate and inadequate absorption. Ever since the progress of SNEDDS, researchers have been focusing on the challenges of BCS Class II and Class IV Drugs for enhancing water Solubility of poorly water-soluble drugs. SNEDDS is a Validate method for enhancing the solubility and bioavailability of lipophilic compounds. It’s the isotropic mixture of oil, surfactant, co-surfactant molecules and it also containing co-solvent molecule. which spontaneously form oil-in-water nano emulsion of approximately 200 nm or less in size upon dilution with water under gentle stirring. It’s Drug delivery system Which possess thermodynamically and kinetically stability. The physicochemical properties, drug solubilization capacity considerably regulates the selection of the SNEDDS components. The compositions of the SNEDDS are often optimized with the assistance of phase diagrams. Further to optimize SNEDDS can be done with the help of statistical experimental design. It’s a Novel drug delivery system which is applicable for the parenteral, Ophthalmic, intranasal and cosmetic drug delivery system. And therefore, the present review describes Preparation, components, mechanism of self-Nano emulsification, biopharmaceutical aspects, characterization methods and applications of Selfnanoemulsifying drug delivery system (SNEDDS).

S. Jayaseelan ◽  
N. Kannappan ◽  
V. Ganesan

Aims: A RP-HPLC method was developed and validated for simultaneous estimation of Tadalafil and Dapoxetine applying statistical experimental design. Methodology: Multivariate optimization of the experimental conditions of RP-HPLC method was using Design of experiments. Independent three factors like phosphate buffer pH, mobile phase composition and flow rate were applied to design mathematical models. To study the response surface methodology by using Central composite design (CCD). In depth the effects of these independent factors was studied using CCD. Simultaneously optimize the retention time and resolution of the analytes was applying Desirability function. Results: The predicted and optimized data from contour picture containing phosphate buffer (pH 3.4) and acetonitrile in the ratio of 40:60%v/v respectively. Flow rate was found to be 0.8 ml/min. Baseline separation of both analytes with run time of less than 10.0 min and good resolution were achieved using these optimum conditions. Conclusion: Method was validated according to ICH guidelines by using optimized assay conditions. Therefore, the reports distinctly indicated that Quality by design access could be satisfactorily used to optimize RP-HPLC method for simultaneous estimation of Tadalafil and Dapoxetine.

2021 ◽  
Genilton S Faheina ◽  
Kally A Sousa ◽  
Jerri E Zilli ◽  
Carlos Vergara ◽  
Gustavo A. Saavedra Pinto ◽  

Abstract Cellulases are a complex of enzymes necessary for the complete solubilization of cellulose in sugars, thus playing a key role in the natural carbon cycle through the hydrolysis of lignocellulosic structures. The aim of this study was to evaluate the increase in the capacity of Talaromyces amestolkiae CMIAT 055 to produce cellulases by optimizing the components of the culture medium containing banana pseudostem as an inducer, as well as in different agitation configurations in a bioreactor. Optimization was performed through statistical experimental design (Plackett-Burman and DCCR), a study of pH control in bioreactors, and a study of the agitation system by comparing impellers with different flow profiles in the liquid medium. For this purpose, a wild strain of Talaromyces amestolkiae CMIAT 055 was used. In the Plackett-Burman and DCCR statistical design, four components of the culture medium were significant and optimized for greater synthesis of FPase: banana pseudostem, CaCl2, KH2PO4, and urea. In bioreactors tests, these parameters were beneficial for greater enzyme activities: maintenance of pH at 5.0, use of Pitched blade impeller, and rotation speed at 300 rpm. Comparing the first test using banana pseudostem in an Erlenmeyer flask to the last fermentation process in bioreactors, it was observed that the total cellulase activity increased from 424.7 FPU/L to 2172.8 FPU/L. This fact showed that the strategies adopted in this study are a pertinent way to reduce the cost of enzyme production through the use of lignocellulosic materials.

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3962
Derek G. Spear ◽  
Anthony N. Palazotto

This paper describes the background, test methodology, and experimental results associated with the testing and analysis of quasi-static compression testing of additively manufactured open-cell lattice structures. The study aims to examine the effect of lattice topology, cell size, cell density, and surface thickness on the mechanical properties of lattice structures. Three lattice designs were chosen, the Diamond, I-WP, and Primitive Triply Periodic Minimal Surfaces (TPMSs). Uniaxial compression tests were conducted for every combination of the three lattice designs, three cell sizes, three cell densities, and three surface thicknesses. In order to perform an efficient experiment and gain the most information possible, a four-factor statistical experimental design was planned and followed throughout testing. A full four-factor statistical model was produced, along with a reduced interactions model, separating the model by the significance of each factor and interaction terms. The impact of each factor was analyzed and interpreted from the resulting data, and then conclusions were made about the effects of the design parameters on the resultant mechanical performance.

2021 ◽  
Vol 11 (1) ◽  
Qammer Zaib ◽  
Hung Suck Park ◽  
Daeseung Kyung

AbstractIn this study, we investigated the reduction of toxic Cr(VI) to less toxic Cr(III) using ascorbic acid in various aqueous solutions: deionized water, synthetic soft water, synthetic hard water, and real tap water. The experiments were performed using a statistical experimental design. Response surface methodology (RSM) was used to correlate Cr(VI) reduction (response variable) with experimental parameters such as initial Cr(VI) concentration, humic acid concentration, and ascorbic acid dosage. The empirical model obtained from the experiments was used to estimate and optimize the quantity of ascorbic acid required for the reduction of ≥ 99% Cr(VI) in water. The optimized dosages of ascorbic acid were predicted and experimentally validated for > 99.5% reduction of Cr(VI) (1, 10, 20, and 100 mg/L) in the solutions. Even a solution containing an initial Cr(VI) concentration of 100 mg/L was reduced in concentration ≥ 99.9% with optimal dosage of ascorbic acid (500 mg/L) in the presence of 20 mg/L humic acid. Moreover, the reaction kinetics (kobs-Cr(VI) = 0.71 mM−1 s−1) were sufficient to reduce the ≥ 99.9% Cr(VI) in 20 min. This study sheds new light on the effect of ascorbic acid on Cr(VI) reduction, and provides knowledge fundamental to optimize treatment of Cr(VI) contaminated water to environmentally acceptable endpoints.

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