Project description:The manufacturing process for ointments typically involves a series of heating, cooling, and mixing steps. Precise control of the level of mixing through homogenization and the cooling rate, as well as temperature at different stages, is important in delivering ointments with the desired quality attributes, stability, and performance. In this work, we investigated the influence of typical plant processing conditions on the microstructure, stability, and sensorial properties of a model ointment system through a Design of Experiments (DoE) approach. Homogenization speed at the cooling stage after the addition of the solvent (propylene glycol, PG) was found to be the critical processing parameter that affects stability and the rheological and sensorial properties of the ointment. A lower PG addition temperature was also found to be beneficial. The stabilization of the ointment at a lower PG addition temperature was hypothesized to be due to more effective encapsulation by crystallizing mono- and diglycerides at the lower temperature. The in vitro release profiles were found to be not influenced by the processing parameters, suggesting that for the ointment platform studied, processing affects the microstructure, but the effects do not translate into the release profile, a key performance indicator. Our systematic study represents a Quality-by-Design (QbD) approach to the design of a robust manufacturing process for delivering stable ointments with the desired performance attributes and properties.
Project description:This study aimed to understand the influence of extruded microparticulated whey proteins (eMWPs) and process design in light ice cream processing by evaluating the microstructure and physicochemical properties. The inulin (T1), a commercial microparticulated whey protein (MWP) called simplesse (T2), a combination (T3), as well as eMWPs (as 50% volume of total particles): d50 < 3 µm (T4), and d50 > 5 µm (T5) were used as fat replacers. The first process design was pasteurization with subsequent homogenization (PH). The second process was homogenization with subsequent pasteurization (HP) for the production of ice cream (control, 12% fat, w/w; T1 to T5, 6% fat, w/w). The overrun of light ice cream treatments of PH was around 50%, except for T4 (61.82%), which was significantly higher (p < 0.01). On the other hand, the overrun of HP was around 40% for all treatments except T1. In both the PH and HP groups, the color intensities of treatments were statistically significant (p < 0.001). The melting behavior of light ice cream was also significantly different. The viscosity of all treatments was significant (p < 0.05) at a shear rate of 64.54 (1/s) for both cases of process design. A similar firmness in both the PH and HP groups was observed; however, the products with eMWPs were firmer compared to other light ice creams.
Project description:Emulsification-diffusion method is often used to produce polymeric nanoparticles. However, their numerous and/or lengthy steps make it difficult to use widely. Thus, a modified method using solvent blends (miscible/partially miscible in water, 25-100%) as the organic phases to overcome these disadvantages and its design space were investigated. To further simplify the process, no organic/aqueous phase saturation and no water addition after the emulsification step were performed. Biodegradable (PLGA) or pH-sensitive (Eudragit® E100) nanoparticles were robustly produced using low/medium shear stirring adding dropwise the organic phase into the aqueous phase or vice versa. Several behaviors were also obtained: lowering the partially water-miscible solvent ratio relative to the organic phase or the poloxamer-407 concentration; or increasing the organic phase polarity or the polyvinyl alcohol concentration produced smaller particle sizes/polydispersity. Nanoparticle zeta potential increased as the water-miscible solvent ratio increased. Poloxamer-407 showed better performance to decrease the particle size (~50 nm) at low concentrations (≤1%, w/v) compared with polyvinyl alcohol at 1-5% (w/v), but higher concentrations produced bigger particles/polydispersity (≥600 nm). Most important, an inverse linear correlation to predict the particle size by determining the solubility parameter was found. A rapid method to broadly prepare nanoparticles using straightforward equipment is provided.
Project description:Due to the rapid melting and solidification mechanisms involved in selective laser melting (SLM), CoCrMo alloys fabricated by SLM differ from the cast form of the same alloy. In this study, the relationship between process parameters and the morphology and macromechanical properties of cobalt-chromium alloy micro-melting pools is discussed. By measuring the width and depth of the molten pool, a theoretical model of the molten pool is established, and the relationship between the laser power, the scanning speed, the scanning line spacing, and the morphology of the molten pool is determined. At the same time, this study discusses the relationship between laser energy and molding rate. Based on the above research, the optimal process for the laser melting of cobalt-chromium alloy in the selected area is obtained. These results will contribute to the development of biomedical CoCr alloys manufactured by SLM.
Project description:The Ni-GQDs composite plating was created using direct current (DC), single-pulse, and double-pulse power supplies, with GQDs serving as additives under supercritical CO2 conditions. A comparative analysis was conducted to evaluate the effects of different electrodeposition power sources on the microstructure and properties of the Ni-GQDs composite plating. High-Resolution Transmission Electron Microscopy (HRTEM) was employed to investigate the distribution of GQDs within the composite plating as well as to analyze d-spacing and diffraction patterns. Scanning Electron Microscopy (SEM) was utilized to illustrate the surface morphology of the plating and assess its surface quality. The grain size and preferred orientation of the plated layer were examined using X-ray Diffraction (XRD), while Atomic Force Microscopy (AFM) was used to evaluate the roughness of the surface. To compare the abrasion resistance of the various plating types, wear amounts and friction coefficients were measured through friction and wear tests. Additionally, corrosion resistance tests were performed to assess the corrosion resistance of each plating variant. The results indicate that the Ni-GQDs-III composite layers produced via double-pulse electrodeposition exhibit superior surface quality, characterized by smaller grain sizes, enhanced surface flatness, reduced surface roughness, and improved resistance to wear and corrosion.
Project description:In this study, the visible-light-driven photocatalytic regeneration performance of TiO2-loaded activated carbon (TiO2/AC) was effectively improved. By carefully controlling the activation condition at 700 °C for 2 h with a 60% H3PO4 concentration and 3:1 TBT (tetrabutyl titanate) impregnation ratio, 90.5% of methylene blue (50 mg/L) was removed within 2 h by a low-dose TiO2/AC (0.5 g/L), which was much higher than those obtained in previous studies on TiO2/AC. Moreover, the effects of process variables on the microstructure and performance of TiO2/AC were systematically investigated. The results showed that (1) the long period of activation time effectively inhibited the photogenerated charge carrier recombination and enhanced the regeneration performance of samples; (2) the photogenerated charge carrier recombination rate was lowered initially and then increased as the temperature ascended, whereas the pore volume showed an opposite variation tendency, and thus the adsorption and regeneration performances of samples were improved at 500-700 °C and then weakened at 800 °C; (3) the increase of H3PO4 concentration effectively inhibited the charge carrier recombination and had an improvement in the adsorption and regeneration performances of samples; and (4) the photogenerated charge carrier recombination rate and bandgap value of samples decreased initially and then increased with increasing TBT mass ratio, so the regeneration performances of samples were improved initially and then lowered.
Project description:Organic aerogels in the form of powder, microgranules and microsized particles receive considerable attention due to their easy fabrication, low process time and costs compared to their monolithic form. Here, we developed resorcinol-formaldehyde (RF) aerogel microparticles by using an emulsion-gelation method. The main objective of this study is to investigate the influence of curing time, stirring rate, RF sol:oil ratio and initial pH of the sol in order to control the size and properties of the microparticles produced. The emulsion-gelation of RF sol prepared with sodium carbonate catalyst in an oil phase at 60 °C was explored. RF microparticles were washed with ethanol to remove the oil phase followed by supercritical and ambient pressure drying. The properties of the dried RF microparticles were analyzed using FT-IR, N2 adsorption isotherm, gas pycnometry, wide angle X-ray scattering and scanning electron microscope. RF microparticles with high surface area up to 543 m2/g and large pore volume of 1.75 cm3/g with particle sizes ranging from 50-425 µm were obtained.
Project description:Carboxymethyl chitosan (CMCH) from native chitosan of high molecular weight (H, 310-375 kDa) was synthesized for improving water solubility. The water solubility of high-molecular-weight carboxymethyl chitosan (H-CMCH) was higher than that of native chitosan by 89%. The application of H-CMCH as enhancing the moisturizer in mangosteen extract deodorant cream was evaluated. Different concentrations of H-CMCH (0.5-2.5%) were investigated in physicochemical characteristics of creams, including appearance, phase separation, pH, and viscosity, by an accelerated stability test. The different degrees of skin moisturizing (DM) on pig skin after applying H-CMCH solution, compared with untreated skin, water, and propylene glycol for 15 and 30 min using a Corneometer®, were investigated. The results showed that the 0.5% H-CMCH provided the best DM after applying the solution on pig skin for 30 min. Trans-2-nonenal, as an unsatisfied odor component, was also evaluated against components of the mangosteen extract deodorant cream, which were compared to the standard, epigallocatechin gallate (EGCG). In addition, DPPH and ABTS radical scavenging activity, ferric reducing antioxidant power (FRAP), and antibacterial activities were examined for the mangosteen extract deodorant cream using 0.5% H-CMCH. Results indicated that the mangosteen extract synergized with H-CMCH, which had a good potential as an effective skin moisturizing agent enhancer, deodorizing activity on trans-2-nonenal odor, antioxidant properties, and antibacterial properties.
Project description:The mould foot roller is a key component of a continuous casting machine. In order to investigate the possibility of using laser cladding to repair mould foot roller, Fe-based powders and 42CrMo steel are used in this work. The laser cladding process parameters were optimized by orthogonal experiments. The chemical compositions, microstructure, properties of the cladding layer under the optimum process parameters, and substrate were systematically investigated by using optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), microhardness test, wear test, and salt spray corrosion test. The results indicate that the primary factor affecting the width and depth of the cladding layer is laser power. The scanning speed also has a significant effect on the height of the cladding layer. The optimum process parameters for repairing the mould foot roller are 2 kW laser power, 4 mm/s scanning speed, and 15 g/min feeding rate of powder. Along the depth direction of the cladding layer, the microstructure of the coating gradually transforms from plane crystal, cell grains, or dendrites to equiaxed grains. The matrix is mainly martensite with retained austenite; the eutectic phase is composed of netlike M?B, particulate M23(C,B)?, and M?(C,B)? phase. The hardness of the cladding layer is significantly improved, about three times that of the substrate. The weight loss of the cladding layer is just half that of the substrate. Its wear resistance and corrosion resistance have been significantly improved. The work period of the laser cladding-repaired foot roller is much longer than for the surfacing welding-repaired one. In summary, laser cladding technology can increase the life of mould foot rollers.
Project description:Microencapsulated flaxseed oil powder (MFOP) was supplemented for the fortification of α-linolenic acid (ALA, ω-3 fatty acid) in ice cream. Processing parameters were optimized in terms of the stage of homogenization of ice-cream mix, level of fortification (3, 4 and 5%) and flavors (vanilla, butter scotch and strawberry). Data revealed that free fatty acids increased significantly during first 15 days in all the samples and then remained constant. Peroxide value and thiobarbituric acid value first increased up to 30 and 45 days, respectively; and then decreased followed by a gradual increase up to 120 days. Fatty acids profile showed 18.74-21.38% decrease in ALA content in fortified ice creams after 120 days. A serving of 100 g of freshly prepared functional ice cream was able to meet ~ 45% of the RDA (1.4 g ALA/day), which reduced to 35.37-36.56% on the end of storage i.e. 120 days. Overall, it can be concluded that MFOP was oxidative stable in ice-cream throughout the storage, which could be fortified successfully at 4% (w/w) level.