Progress in Applied Science and Technology

Effects of Impeller Shape and Rotational Speed in a Stirred Tank on the Microplastic Capture Efficiency using Oil-Based Ferrofluid

Wed, 17 Dec 2025 00:00:00 +0700

Microplastics in aquatic environments pose serious threats to ecosystems and human health due to their persistence and ability to adsorb toxic substances. This research focuses on developing an application method for oil-based ferrofluid to capture microplastics. Experiments were conducted in a stirred tank designed to enhance contact between microplastics and ferrofluid. Three impeller types were tested: a 4-blade EMI Rotofoil, a 4-blade propeller, and a 4-blade 45° pitched blade turbine, each operated at rotational speeds of 100, 150, 200, 250, 300, and 350 rpm. The efficiency of microplastic capture was evaluated by comparing the Number of microplastic particles in water samples before and after mixing, using microscopic analysis. Results showed that the 4-blade EMI Rotofoil at 350 rpm achieved the highest capture performance, while the 4-blade propeller at 100 rpm yielded the lowest. These findings highlight the potential of integrating ferrofluid with mechanical mixing in a stirred tank as an effective approach for microplastic removal from water systems.

A Novel Mixed Attribute-Variable Sampling Plan Based on a Multiple Dependent State Repetitive Framework

Sirorath Channgam, Kanittha Yimnak — Wed, 17 Dec 2025 00:00:00 +0700

This paper presents a novel mixed acceptance sampling plan, termed the attribute-variable sampling plan based on a multiple dependent state repetitive framework (AVS-MDSR), designed to enhance efficiency and accuracy in modern quality inspection. AVS-MDSR integrates attribute, variable, and multiple dependent state repetitive sampling, using the process capability index as the primary decision statistic for normally distributed quality characteristics. A key innovation is the inclusion of a repetitive sampling stage, allowing re-inspection when initial results are inconclusive, thereby reducing the risks of accepting nonconforming lots and rejecting conforming ones. To ensure optimal performance, a genetic algorithm determines the plan’s design parameters, minimizing the average sample number while controlling producer’s and consumer’s risks. Numerical studies, considering both symmetric and asymmetric nonconforming proportions, demonstrate the superiority of AVS-MDSR over existing mixed acceptance sampling plans, consistently reducing the required sample size. Its practical applicability is further validated with real industrial data. The findings confirm that AVS-MDSR provides an accurate and flexible solution for stringent quality control environments.

On the bi-periodic k-Jacobsthal and k-Jacobsthal-Lucas numbers

Mongkol Tatong, Oam Sthityanak — Mon, 29 Dec 2025 00:00:00 +0700

This paper introduces and investigates the bi-periodic Jacobsthal and Jacobsthal–Lucas sequences, extending the classical Jacobsthal framework by incorporating periodicity and a tunable parameter . We establish recurrence relations, derive generating functions, and present Binet-type formulas for these generalized sequences. Furthermore, we obtain extensions of well-known identities, including Catalan’s, Cassini’s, and d’Ocagne’s identities. The proposed generalization reveals deeper algebraic structures and periodic patterns, offering potential applications in cryptography, coding theory, and recurrence-based modeling. These findings provide a foundation for future research on combinatorial interpretations and connections with other special sequences.