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Recent Submissions

Dual resource constrained flexible job shop scheduling with sequence-dependent setup time
(Wiley, 2024) Barak, Sasan; Javanmard, Shima; Moghdani, Reza
This study addresses the imperative need for efficient solutions in the context of the dual resource constrained flexible job shop scheduling problem with sequence-dependent setup times (DRCFJS-SDSTs). We introduce a pioneering tri-objective mixed-integer linear mathematical model tailored to this complex challenge. Our model is designed to optimize the assignment of operations to candidate multi-skilled machines and operators, with the primary goals of minimizing operators' idleness cost and sequence-dependent setup time-related expenses. Additionally, it aims to mitigate total tardiness and earliness penalties while regulating maximum machine workload. Given the NP-hard nature of the proposed DRCFJS-SDST, we employ the epsilon constraint method to derive exact optimal solutions for small-scale problems. For larger instances, we develop a modified variant of the multi-objective invasive weed optimization (MOIWO) algorithm, enhanced by a fuzzy sorting algorithm for competitive exclusion. In the absence of established benchmarks in the literature, we validate our solutions against those generated by multi-objective particle swarm optimization (MOPSO) and non-dominated sorted genetic algorithm (NSGA-II). Through comparative analysis, we demonstrate the superior performance of MOIWO. Specifically, when compared with NSGA-II, MOIWO achieves success rates of 90.83% and shows similar performance in 4.17% of cases. Moreover, compared with MOPSO, MOIWO achieves success rates of 84.17% and exhibits similar performance in 9.17% of cases. These findings contribute significantly to the advancement of scheduling optimization methodologies.
Computational study of elastic waves generated by ultrafast demagnetization in fcc Ni
(American Physical Society, 2024) Korniienko, I.; Nieves, P.; Fraile, A.; Iglesias, R.; Legut, Dominik
Picosecond ultrasonics is a fast growing and advanced research field with broad application to the imaging and characterization of nanostructured materials as well as at a fundamental level. The aim of this paper is to provide an advanced 3D model based on atomistic spin -lattice simulations of the laser -induced elastic response in ferromagnetically ordered fcc Ni. The advantage of such an approach is the possibility to take into account the laser radiation interaction with the spins and thus characterize the magnetic contribution to the total stress. We analyze the atomic displacements caused both by the ultrafast thermal expansion of the crystal lattice and by the demagnetization process due to the heating of a certain area of the sample by an ultrashort laser pulse. Subsequently, an attempt is made to propose mathematical expressions for describing the corresponding total stress. The lattice and magnetic contributions have been evaluated, whereupon the former is found to be much greater than the latter.
Mitigation of humidity interference by graphene derivatives for efficient temperature sensors without encapsulation
(Wiley, 2024) Šedajová, Veronika; Štulík, Jiří; Jakubec, Petr; Otyepka, Michal
Temperature monitoring and regulation are essential in various environments, including modern industry and living and storage spaces. The growing demand for temperature sensors calls for affordable, efficient, interference-resistant, and eco-friendly solutions. The challenge of humidity interference in constructing temperature sensors often leads to compromising on the dynamic sensor properties in particular due to the need for encapsulation. To this end, this study introduces a temperature sensor leveraging a carefully designed graphene derivative to mitigate the humidity interference. The material, synthesize through scalable fluorographene chemistry with benzylamine, is optimized in order to enhance its properties, which led to achieving peak efficiency with a minimal humidity impact. The sensor demonstrated full functionality across a temperature range from 10 to 90 degrees C, with a temperature coefficient of resistivity 8.63 x 10-3 K-1, which is more than twice as high as that of conventional platinum thermometers. Remarkably, the sensor exhibited only a 2% change in resistance when exposed to relative humidity in the range of 20 to 70%. Notably, the sensor continues to give a consistent performance even after six months, which proved its stability. The presented device holds promise for evolving into a fully printed, cost-effective and reliable next-generation temperature sensors.
Exploration of bismuth-based materials for photocatalytic decomposition of N2O
(Royal Society of Chemistry, 2024) Atri, Shalu; Uma, Sitharaman; Nagarajan, Rajamani; Gregor, Maroš; Roch, Tomáš; Filip Edelmannová, Miroslava; Reli, Martin; Kočí, Kamila; Motola, Martin; Monfort, Olivier
This work is focused on the investigation of three different Bi-based materials, i.e., CaBi2O2(CO3)(2) (CBOC), Ca4Bi6O13 (CBO), and Bi2Ce2O7 (BCO), as photocatalysts in N2O reduction. This study has emphasized the effectiveness of the bismuth ion, irrespective of its presence in different structures with self-regulating electronic and morphological properties, when employed as a photocatalyst. Monophasic CBOC, CBO, and BCO samples have been synthesized by wet-chemical methods, and they exhibit distinct morphological features such as plate-like, dumbbell-shaped, and irregularly shaped crystallites. From the UV-visible diffuse reflectance spectroscopy (DRS) data, CBO exhibits a lower optical band gap of 2.52 eV compared to CBOC (3.95 eV), which CBO is synthesized from. BCO shows the lowest optical band gap of 2.16 eV. CBO exhibits the highest photocurrent generation and the lowest value in work function measurements, following the trend as CBO > CBOC > BCO. The efficiency of the Bi-based materials in photocatalytic decomposition of N2O also follows a similar trend as observed in the photocurrent measurements, wherein the CBO sample exhibits a maximum of 10.4% decomposition of N2O under UV-A in 24 h. Oxygen vacancies in CBO and BCO have been reasoned to play a crucial role in the photocatalytic decomposition of N2O.
Analytical study of fractional DNA dynamics in the Peyrard-Bishop oscillator-chain model
(Elsevier, 2024) Riaz, Muhammad Bilal; Fayyaz, Marriam; Rahman, Riaz Ur; Martinovič, Jan; Tunç, Osman
In this research, we present a new auxiliary equation approach, which uses two distinct fractional derivatives: /3- and M-truncated fractional derivatives to explore the space-time fractional Peyrard-Bishop DNA dynamic model equation. This examines the nonlinear interplay between neighboring displacements and hydrogen bonds through mathematical modeling of DNA vibration dynamics. The solutions are tasked with examining the nonlinear interaction among neighboring displacements of the DNA strand. The generated solutions exhibit various wave patterns under varying fractional values and parametric conditions: w-shape, bright, combined periodic wave solutions, dark-bright, bell shaped, m-shaped, w-shaped with two bright solutions, and m-shape with two dark solutions. Graphical representations provide a complete analysis of these physical features. The results demonstrate the successful implementation of the proposed approach, which will be advantageous for locating analytical remedies to more nonlinear challenges.