Cementation is one of the processes employed for recovering Copper from leach liquors especially in small scale mines. The kinetics of cementation is important because of its effect on the capital and operating costs. In this research, the effect of agitation intensity, Cu-concentration, pH, iron surface and reaction time on the cementation kinetics of copper from Cheezeh ore leach liquors has been investigated. The experimental DESIGN method was carried out by using the 2k FACTORIAL approach. Experimental results showed that agitation intensity, Cu-concentration, pH and interaction between Cu-concentration and Ph have the most significant effect on cementation kinetics. Optimum conditions were agitation intensity = 300 rpm, pH=L Cu-concentration= 7 g/l and iron surface= 31.2 cm2. The kinetic constant under these conditions was estimated as 7.66*10-3min-I.

In order to enhancein vitro dissolution and content uniformity of poorly soluble drug glimepiride by preparing solid dispersions using modified solvent fusion method, solid dispersions of drug were prepared by modified fusion solvent method using PEG 6000 and PVP K25 (as carrier). Eight batches (F1-F8) were prepared by FACTORIAL DESIGN (23) by taking three factors i.e. the concentration of: drug (X1), PEG 6000 (X2) and PVP K25 (X3). DSC, FTIR spectroscopy, powder X-ray diffraction (XRD) and SEM studies were used to characterize solid dispersions. In vitro release was carried out using USP II dissolution apparatus. Multilinear regression analysis was applied to develop mathematical model to estimate cumulative drug release.The batch F3 was found to be best batch as it showed maximum in vitro dissolution after 30 min. Improvement in dissolution behavior of solid dispersion batches was observed due to conversion of crystalline form of drug to amorphous form as confirmed by DSC, FTIR studies and X-RD studies. SEM photographs of batch F3 showed porous nature of particle surface. Uniformity of content of different batches was found to be in range as specified by IP. Solid dispersion prepared via modified fusion solvent method was proved to be beneficial in enhancement of dissolution rate of poorly-water soluble drug using hydrophilic carriers. Retrospectively, this model can further be utilized to DESIGN solid dispersions for desired release characteristics.

Solid lipid nanoparticles of atovaquone (ATQ-SLN) were prepared by high shear homogenization method using tripalmitin, trilaurin, and Compritol 888 ATO as the lipid matrices and Phospholipon 90H, Tween 80, and poloxamer 188 as the surfactants. Optimization of the formulations was conducted using 6 sets of 24 full-FACTORIAL DESIGN based on four independent variables that were the number of homogenizing cycles, concentration of the lipid, concentration of the co-surfactant, and concentration of the main surfactant. The dependent variables were particle size and polydispersity index (PdI). The homogenizing cycles showed a negative influence on the dependent variables which reduced both the particle size and the PdI value. Moreover, a combination of certain percentages of the main surfactant and co-surfactant also showed a negative influence that reduced both the particle size and PdI value. Selected formulations from each DESIGN were further characterized for the entrapment efficiency and yield. The optimised formulation of ATQ-SLN consisted of trilaurin, Phospholipon 90H and Tween 80 with a particle size of 89.4 ± 0.2 nm and entrapment efficiency of 83.0 ± 1.7%. The in-vitro release evaluation of the formulation showed a complete and immediate release of ATQ from the SLN that could be a solution to improve the poor aqueous solubility and hence poor bioavailability of the drug.

Bone tissue scaffolds that closely mimic the mechanical and biological properties of natural bone is critical for enhancing the outcomes in treatment of bone tissue damages. This study introduces an optimisation approach to DESIGNing bone tissue engineering scaffolds using Triply Periodic Minimal Surface (TPMS) structures, evaluated through a Full FACTORIAL DESIGN methodology. Finite Element Analysis was applied to simulate the TPMS scaffolds under mechanical loading. The influence of key factors of strut thickness, unit cell configuration, and TPMS type, on the scaffold’s mechanical performance, specifically targeting Young's modulus was evaluated. By employing Full FACTORIAL DESIGN, this study generates empirical models of Young’s modulus as a function of those key factors. Primitive and Gyroid TPMS structures emerged as optimal, achieving Young's modulus values of 4912.3 MPa and 4666.7 MPa, respectively, with configurations of 0.01 mm strut thickness in a 3-unit cell construct. These results demonstrate that optimised TPMS scaffolds can meet the mechanical demands of bone tissue while providing adequate porosity for cell proliferation and nutrient transport, essential for effective bone regeneration.

A chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (Cr+6) mist sampling methods. The results of 48 Cr+6 mist samples collected using the U.S. National Institute for Occupational Safety and Health method 7600 showed that Cr+6 concentration was higher: (1) For sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P<0.001); (2) for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P<0.001); (3) for sampling duration of 30 minutes than for sampling duration of 180 minutes (P<0.001); and, (4) for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling) (P<0.001). It is concluded that the accuracy of Cr+6 mist sampling in electroplating shops will be enhanced when: (1) closed-face filter cassette is used to prevent liquid splash contamination; (2) the recommended sampling height is 35 cm above the solution surface; (3) the sampling duration is short-approximately 30 minutes; and, (4) the extraction of the Cr+6 sample is performed as soon as the sampling is completed.

Purpose: The purpose of this study was to determine the effects of thermal processing and antioxidant formulation variables on the abuse deterrence performance of a high molecular weight poly(ethylene oxide) (PEO) polymer. Methods: A 24 FACTORIAL DESIGN with one categorical factor (antioxidant type) and three continuous factors (curing time, curing temperature, % antioxidant) was used. Abuse deterrence performance was evaluated using solution viscosity, surface melting temperature, and mechanical strength. Thermal degradation of PEO powders before compaction was also studied using DSC, FTIR spectroscopy, and viscosity analysis. Results: Our results showed that curing temperature and type of antioxidant can significantly affect the deterrence performance of PEO. The main effect plot for viscosity shows the most prominent factors affecting viscosity are curing temperature and type of antioxidant. However, curvature in the linear model obtained was not sufficient to completely describe the behavior. For surface melting temperature, butylated hydroxytoluene was associated with higher surface melting temperatures compared to ascorbic acid. Additionally, higher percent of antioxidant resulted in higher melting temperature. Particle size distribution to indicate mechanical strength showed no significant effects of tested factors. This suggests that comminution method has more prominent effect on tablet fragment size than the formulation and processing factors studied. Conclusion: While heat confers the mechanical strength to the polymer, it can diminish its physical stability and solution state viscosity. The experimental studies showed that prolonged exposure to high temperatures, even in the presence of antioxidants, can severely hamper polymer deterrence performance in both solid and solution states.