明志科技大學

Background Dynamic binding capacity at 5% breakthrough (DBC5%) is a key performance parameter in packed-bed chromatography because it determines the effective working capacity of the adsorbent and directly influences process productivity under dynamic-flow conditions. Methods This study presents a systematic methodology for the predictive optimization and scale-up of DBC5% for C-phycocyanin (CPC) purification from Spirulina platensis using a sequential design of experiments (DoE) approach. A 2⁴ full factorial design with two center points (2⁴ + 2) was first employed to identify the significant operating variables, followed by a central composite design (CCD) to evaluate potential nonlinear responses. Significant findings The 2⁴ + 2 factorial model exhibited superior predictive performance, achieving an R² of 98.97% and a predicted R² of 94.82%, compared with corresponding values of 91.04% and 48.50%, respectively, for the CCD model. The optimized operating conditions (pH 6.0, 10% (w/v) feed concentration, 1.6 cm bed height, and a flow rate of 10.0 mL/min) yielded a predicted DBC5% of 10.51 mg/mL, which was experimentally validated by an observed value of 10.45 mg/mL, corresponding to a relative error of 2.9%. Furthermore, scale-up from 1.6 cm to 5.0 cm internal-diameter columns while maintaining hydrodynamic similarity successfully preserved DBC5%, demonstrating consistent adsorption performance across the investigated scales. Although the developed regression model is specific to the chromatographic system investigated, the proposed DoE-based optimization framework and hydrodynamic scale-up strategy provide a practical methodology that can be applied to other packed-bed chromatography systems following appropriate experimental calibration and validation.

The crystallographic orientation of β-Sn plays a critical role in determining the reliability of solder joints owing to its highly anisotropic properties. In this study, a scalable orientation-control strategy was developed by depositing CoSn3 thin films onto Cu wires using DC magnetron sputtering. Following solder-joint fabrication, the influence of the deposited CoSn3 layer on β-Sn orientation selection and electromigration behavior was systematically investigated. EBSD analysis revealed that majority of the solder joints fabricated using CoSn3-deposited Cu wires exhibited β-Sn grains with their [001] direction (c-axis) oriented nearly perpendicular to the sample Z-axis, whereas conventional Cu/solder/Cu joints showed nearly random orientations. Electromigration tests were conducted at current densities ranging from 1 × 104 to 3 × 104 A cm−2 and ambient temperatures of 25–60 °C. Pronounced orientation-dependent growth of intermetallic compounds (IMC) was observed in joints with small angles between the β-Sn c-axis and the current direction, while IMC growth was strongly suppressed when the c-axis was nearly perpendicular to the electron flow direction. The CoSn3 seed layer effectively controlled the orientation of β-Sn grains, thereby suppressing Cu diffusion and the subsequent excessive growth of IMCs. These findings demonstrate that sputter deposited CoSn3 thin films provide an effective and scalable route for controlling β-Sn orientation and offer valuable insights into the microstructural evolution of orientation-controlled solder joints under electromigration.

In the pursuit of sustainable materials for next-generation energy storage, the coconut palm represents a uniquely circular biomass system capable of delivering both hard and soft carbons from a single plant source. The components exhibit distinct lignin-to-cellulose ratios, which critically determine carbon purity, graphitizability, and electrochemical behavior. This review consolidates the current understanding of coconut-derived carbons with a focus on their structural evolution during carbonization and activation, the resulting pore architectures, and their performance in batteries and supercapacitors. Hard carbons derived from cellulose-rich precursors exhibit disordered microstructures with high durability and ion-storage capability, while lignin-rich components yield soft, partially graphitized carbons offering superior conductivity and rate performance in supercapacitors. The effects of carbonization temperature, activating agents, and electrolyte composition on pore distribution, surface functionality, and charge-storage mechanism are systematically analyzed. These carbons can have surface areas up to 3000 m2·g− 1, specific capacitances up to 600 F·g− 1 in supercapacitors, and battery capacities up tp 292 mAh·g− 1. Beyond performance, the study highlights the global potential of coconut palm waste, which is estimated at 15 Mt y− 1 carbon yield, as a low-carbon feedstock for high-value electrochemical materials. By linking compositional chemistry with electrochemical function, this review underscores coconut palm as a scalable, sustainable and renewable carbon resource for developing circular energy-storage technologies.

The Eugenol (4 allyl- 2 methoxyphenol), which is a critical phenolic compound found in several Asian spices and widely recognized for their medicinal purposes. However, its the concentration must be monitored strictly in food products to mitigate any potential toxicity. This work discusses the need for trace level sensing of Eugenol through electrochemical sensor platform. The electrode used was ZnFe2O4@GCN-modified GCE. ZnFe2O4 nanoparticles were synthesized by the reflux condensation method. Graphitic carbon nitride (GCN) was prepared by thermal polymerization of urea. The present study explores the optimum circumstances to detect Eugenol, focusing on factors like electrode modification and the effect of pH on the electrochemical response. The prepared ZnFe2O4@GCN nanocomposites were analyzed structurally, morphologically, and compositionally to understand their crystallinity, surface topology, elemental composition, and chemical bonds. The electrochemical studies to analyze the conductivity and charge transfer of the electrode the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed in the redox probe environment. The surface of the GCE (glassy carbon electrode) modified with ZnFe2O4@GCN exhibited a good electrochemical response for detection of Eugenol. The voltammetric studies were carried out for an optimized ratio in phosphate buffer (pH = 2). The initial parameters were optimized so that the modified electrode exhibited good electro catalytic activity. The sensitivity, limit of detection (LOD), and linear detection of eugenol were studied by Differential pulse voltammetry (DPV) analysis. The studies revealed that ZnFe2O4@GCN-modified GCE has the LOD = 0.013 µM and a sensitivity of 27.67 µA µM−1 cm−2. The real-world application of these sensors has been studied with real-life samples with the recovery percentage calculated.

Polymer gears are increasingly applied in precision transmission systems due to their low weight, corrosion resistance, and acoustic advantages, although their limited wear resistance continues to restrict long-term durability. To address this limitation, this study investigates epoxy-based composite gears reinforced with metal powders and modified with solid lubricants, aiming to enhance load-bearing and sliding wear performance. Epoxy composites are prepared by incorporating copper, iron, or aluminum powders as mechanical reinforcements and introducing polytetrafluoroethylene (PTFE), molybdenum disulfide, tungsten disulfide, or graphite as solid lubricants to improve lubricity. Ball-on-disc tribological tests under a 2 N normal load and a sliding speed of 0.1 m/s indicate that PTFE-modified composites exhibit the lowest steady-state friction coefficients, reaching 0.203, 0.276, and 0.352 for copper-, iron-, and aluminum-filled systems. Wear track measurements further show substantial reductions in wear depth and width, with PTFE-modified composites demonstrating improvements of 73.93