A Compendium of Deformation-Mechanism Maps for Metals

Deformation-mechanism maps represent an invaluable guide to predicting the optimum processing conditions for a material. They are also useful in matching a material to a given engineering application. The present book summarizes recent research results in the field. The book references 106 original resources and includes their direct web link for in-depth reading.

Process Model Approach to Predict Tablet Weight Variability for Direct Compression Formulations at Pilot and Production Scale

Optimizing processing conditions to achieve a critical quality attribute (CQA) is an integral part of pharmaceutical quality by design (QbD). It identifies combinations of material and processing parameters ensuring that processing conditions achieve a targeted CQA. Optimum processing conditions are formulation and equipment-dependent. Therefore, it is challenging to translate a process design between formulations, pilot-scale and production-scale equipment. In this study, an empirical model was developed to determine optimum processing conditions for direct compression formulations with varying flow properties, across pilot- and production-scale tablet presses. The CQA of interest was tablet weight variability, expressed as percentage relative standard deviation. An experimental design was executed for three model placebo blends with varying flow properties. These blends were compacted on one pilot-scale and two production-scale presses. The process model developed enabled the optimization of processing parameters for each formulation, on each press, with respect to a target tablet weight variability of <1%RSD. The model developed was successfully validated using data for additional placebo and active formulations. Validation formulations were benchmarked to formulations used for model development, employing permeability index values to indicate blend flow.

Experimentally Predicted Optimum Processing Parameters Assisted by Numerical Analysis on the Multi-physicomechanical Characteristics of Coir Fiber Reinforced Recycled High Density Polyethylene Composites

This paper presents the analysis of processing parameters in the fabrication of coir fiber recycled high density polyethylene composite through experimental data and Taguchi grey relational analysis. Three processing parameters; fiber conditions, fiber length, and fiber loading with mixed level design, having orthogonal array L32 (2**1 4**2) were employed in the preparation of polymer composite. Numerical analysis assisted by Taguchi design was conducted on the experimental multi-physicomechanical characteristics of the polymer composite for optimum processing parameters. The optimum grey relational grade was gotten to be 0.8286 and was experimentally validated with 95% confidence interval. The optimum processing parameters were discovered to be a treated fiber having 8 mm length at 30% loading. Although, other processing parameters are significant, but fiber loading is the most significant parameter. Correspondingly, the contribution of residual error on the overall multi-physicomechanical characteristics is insignificant having 2.43% of contribution.

A study of optimum processing parameters and abnormal parameter identification of the twin-screw co-rotating extruder mixing process based on the distribution and dispersion properties for SiO2/low-density polyethylene nano-composites

This study took nano-silica particles mixed in low-density polyethylene to implement the optimum processing parameters and make abnormal parameter identification for the twin-screw co-rotating extruder used in the manufacturing process. The mixing quality was divided into distribution and dispersion, where distribution was tested by an energy dispersive spectrometer and evaluated using the coefficient of variation. Dispersion was assessed by the surface effect and specific surface equations, as based on the spectrum of scanning electron microscopy. By using the Taguchi method in planning the experiment coupled with an analysis of variance, we conducted the single-quality characteristic analysis of the experimental results of the two quality characteristics, namely the distribution and dispersion. Then, by using the hierarchical architecture of analytic level process, we can obtain the optimized parameter factors and levels and the calculation of the total weighting of various parameter levels, as well as the ranking of the parameter levels. According to the confirmation experimental results, the signal-to-noise ratios of distribution and dispersion fell within 95% confidence intervals, indicating that the experiment can be represented and reliable. The optimum parameters combination is SiO2 addition level 1%, screw speed 60 rpm, mixing time 5 min, temperature (upper) 150℃, temperature (middle), 175℃ and temperature (lower) 190℃. After that, by using the optimal parameters and operation processing parameters for support vector machine classification, the abnormality of the processing parameters can be identified for 100%. The good quality of the production can be guaranteed during the extrusion.

Effect

This study was conducted to determine the effect of Ipomoea batatas L. leaf extract as flocculants on the reduction of Ca2 + and Mg2 + (hardness) levels in water treatment for chemical practicum on environmental analysis at the FPMIPA UPI Chemical Department. This study continued from previous research on the optimization of Ipomoea batatas L. leaf extract as a flocculant in water treatment, the results of the study showed that Ipomoea batatas L. leaf extract can make water clearer and provide greater reduction in turbidity value. In this follow-up study it will be carried out through two stages, the first step is optimizing the optimum processing parameters. The second stage is water treatment using optimum processing parameters, followed by hardness testing in water samples before and after processing. In hardness testing the EDTA titration method is used with the EBT indicator. The results showed the optimum parameters of water treatment with Ipomoea batatas L leaf extract as flocculant was pH 6.5, coagulant dose 50 mg / L, flocculant dose 2 mg / L, stirring coagulant speed 200 rpm for 5 minutes, and flocculant stirring speed 40 rpm for 5 minutes. In testing the total hardness as CaCO3, the initial sample (without treatment) obtained hardness of 285 mg / L, whereas in the sample treated with Ipomoea batatas L. leaf extract as flocculant hardness was obtained at 190 mg / L. From the results of the study it can be concluded that Ipomoea batatas L. leaf extract as flocculant in water treatment can reduce the hardness level in water.

Optimization of microwave assisted enzymatic extraction of steviol glycosides and phenolic compounds from Stevia leaf

Stevia (Stevia rebaudiana Bertoni) has gained great interests due to its non-caloric and health related properties with its steviol glycosides and phytochemical constituents. Currently, it is being utilized as a natural sweetener in many food formulations such as soft drinks, jams, dairy products, chocolates, etc. Green extraction techniques using non-hazardous solvents and yield-enhancing strategies have been subject matters of various disciplines such as food technology, chemistry and pharmacology. Stevia powders are industrially produced by aqueous-extraction with further purification and drying steps. There has been no any report handling combined microwave and enzyme assisted technique on the extraction of steviol glycosides and antioxidant compounds to date. The objective of this study was to determine optimum processing parameters of microwave assisted enzymatic extraction of steviol glycosides and phenolic compounds by investigating the effects of independent variables. The plant was collected from a stevia garden and its leaves were detached from flower part, dried and milled into powder form before commencement of the treatments. Operations were performed using a microwave extraction system equipped with a digital control system for irradiation time, temperature and microwave power. Viscozyme L which is a widely used cellulolytic enzyme cocktail was used in this study. The effects of enzyme concentration (1.2 - 60 FBG unit g-1), temperature (25-60?C) and time (1 - 20 min) were evaluated using a five-level rotatable central composite design by response surface methodology (RSM). The validities of models were assessed by ANOVA outputs which were determination coefficient (R2), lack of fit and Fisher's test value (F-value). The maximized yields of stevioside, rebaudioside A and total phenolic compounds were determined as 62.5, 25.6 and 20.7 mg g-1, respectively at optimum processing conditions which were estimated as 10.9 FBG unit g-1, 53?C and 16 min.