Papers by Keyword: Simulation

Abstract: Water pollution by heavy metals constitutes a significant environmental and health risk, necessitating efficient and reusable adsorbents. The current study investigates the application of inexpensive biopolymer chitosan to extract Ni²⁺ and Cd²⁺ ions from aqueous solutions. Material characterization using X-ray diffraction (XRD) showed the amorphous nature (absence of peak at 10°), and Brunauer-Emmett-Teller (BET) analysis exhibited the mesoporous surface area of 302.12 m²/g, suitable for the adsorption of metal ions. The Swan model was parameterized with batch-derived adsorption parameters (i.e., Qₘₐₓ = 220 mg/g for Ni²⁺, 226 mg/g for Cd²⁺) and successfully predicted packed-bed breakthrough curves at optimum pH (7 for Ni²⁺, 6 for Cd²⁺), with transport rates of 3.65 × 10^-11 m²/s (Ni²⁺) and 3.14 × 10^-11 m²⁺/s (Cd²⁺) for a 1.2 m column. The material retained over 95% removal efficiency after five regeneration cycles. These findings show the potential of chitosan for large-scale water treatment with high efficiency, model-driven design, and strong reusability.

Abstract: This paper presents the development and optimization of a 1.2 kV Silicon Carbide (SiC) Trench MOSFET with a Bottom P-well (BPW), designed to achieve a compact structure and a simplified fabrication process. By performing the BPW implant before the trench etching process and utilizing it in conjunction with a shallow trench, the process complexity was reduced while maintaining effective corner coverage of the trench gate. Comprehensive simulations and unit process analyses were conducted to evaluate the effects of the hard mask sidewall angle, P-well, and JFET implant doses on device characteristics. Optimal performance was achieved by introducing an additional P+ implant in the P-well region, which significantly enhanced breakdown voltage without affecting channel properties. The optimized device demonstrated a specific on-resistance (R_on,sp) of 2.2 mΩ·cm², a breakdown voltage (BV) of 1600 V, and a threshold voltage (V_th) of 3 V, with potential further reductions in R_on,sp through substrate thinning.

Abstract: This study theoretically proposes a refractive index (RI) sensor based on a polymer composite with a no-core fiber (NCF) design structure. Sensor designs with diameter variations of 125 µm, 105 µm, and 85 µm are simulated using the Wave Optics Module of COMSOL Multiphysics® software. The sensors are characterized within an analyte range of 1.470 RIU to 1.500 RIU, at intervals of 0.005 RIU. The results demonstrate effective interaction between the structure and the sensing medium. The highest recorded sensitivity is 4×10⁻⁶ (dimensionless) for the 85 µm sensor, followed by 2×10⁻⁶ for the 105 µm sensor, and 1×10⁻⁶ for the 125 µm sensor. This study offers valuable insights, guiding the optimal design of polymer-based RI sensors for future environmental monitoring, chemistry, and biomedicine applications.

Abstract: This study focuses on the simulation and experimental validation of orbital laser welding for aluminum alloy tubes. The trials were conducted on the TRU LASER ROBOT 5020 system by TRUMPF, which features a 30 kg robotic arm, a diode-pumped disk laser with a beam quality of 8 mm*mrad, and a minimum output power of 4000W on the workpiece. Aluminium 6082 Tubes were mounted on a fixture attached to an integrated rotary table, and a series of tests were performed with varying levels of edge preparation accuracy and different laser beam parameters such as power and head linear speed. The simulation was carried out using Ansys Mechanical witch ACT toolkit heat source model. The thermocouple mesurments and metallographic tests was a key parameter used to validate the simulation results. The temperature distribution during welding was compared with simulation results to adjust the thermal properties of the material within the simulation model. The combined simulation and experimental analysis provide a framework for optimizing the laser welding process, enabling the reduction of costly experimental trials by simulating different parameter ranges.

Abstract: To meet the energy needs of devices such as wireless sensor networks and MEMS systems，improve the adaptability of piezoelectric energy harvester, this paper studies a two-degree-of-freedom(2-DOF) monostable piezoelectric energy harvester based on magnetic. The electromechanical coupling dynamics equation of the 2-DOF monostable system is established. The dynamic equation is solved by harmonic balance method. The output of dimensionless amplitude-frequency curves of a 2-DOF monostable piezoelectric system in the first and second order resonances is simulation analyzed. The results show that the output amplitude-frequency curve of the 2-DOF monostable system shows linearity of single peak value in the first-order resonance interval and hard spring characteristics in the second-order resonance interval. The research results provide reference for improving the energy harvesting efficiency and expanding the application in the radio field of piezoelectric energy harvester device.

Abstract: The study focuses on simulating the current and future value stream of external cable production, identifying bottlenecks, and proposing improvements. It provides a comprehensive overview of production processes, analyzing their current state and modeling future developments. Utilizing Visual Components simulation software, the study evaluates modernization efforts and quantifies their impact. Special attention is given to lean management, Industry 4.0, and robotics. The results guide recommendations for optimizing workstations, workforce, and efficiency, ensuring a more balanced and streamlined production process.

Abstract: This paper presents a qualitative, descriptive study addressing the imperative of developing multidisciplinary skills in STEM education to prepare students for the challenges of Industry 4.0. Acknowledging the limitations of traditional analytical and technical training, the study focuses on the significance of teamwork and the combination of multiple STEM skills. Multidisciplinary programming projects can be used effectively in higher education to facilitatie cross-disciplinary collaboration among students. Our pilot project, presented in this paper, uniquely contributes to this discourse by integrating logistics, robotics, and programming into a graphical simulation software that represents the 3D model of a warehouse with a programmable forklift truck tasked with navigating and transporting parcels. This paper discusses the methodology, outcomes, and implications of the pilot project, highlighting its role in preparing STEM students for the complex challenges of an interconnected world and Industry 4.0.

Abstract: The paper focuses on the simulation process of Incremental Sheet forming (ISF) technology of the stainless steel SUS304 by the Multi-Stage Single Point Incremental Forming (MSPIF) with Abaqus software. Although being a popular stainless material with high mechanical and corrosion-resistant properties, widely used in various industries, forming of SUS304 steel by MSPIF technology still faces several challenges so in this study, with the simulation process, we have to determine the suitable values of influential factors to enhance the formability of SUS3043 sheet material. In the paper, with Abaqus software, we construct a model of simulation of SUS304 steel sheet by MSPIF technology to collect data for design of experiment (DOE). The results of the research provide valuable information on the forming process of SUS304 steel by MSPIF technology in order to improve the formability of the products.

Abstract: This study investigates the modeling and optimization of a single solar cell structure, utilizing the inorganic double perovskite Cs₂AuBiCl₆. This material features an A₂BB'X₆ composition and possesses a bandgap energy of 1.12 eV. The fundamental structure of the solar cell has been described, and the physical parameters of its primary layers have been outlined. A simulation model was developed to calculate the current-voltage characteristics and photovoltaic parameters, taking into account recombination rates due to defects within the absorber and at the interfaces with the electron transport layer (ETL) and hole transport layer (HTL). The influence of various parameters was analyzed, including bulk and interface density of defects, layer thicknesses, back contact work function and operating temperature. Additionally, the performance of structures with alternative transport materials for the ETL and HTL layers was evaluated. The impact of energy bandgap offsets with the absorbing perovskite layer was considered to identify materials that enhance the collection of photogenerated carriers and ultimately improve efficiency. The simulations revealed an optimized structure that demonstrated enhanced performance compared to the initial design. The optimized solar cell achieved a yield of 18.4 %, representing an increase of 5.4 % over the basic structure, with key performance metrics including, short-circuit current density Jsc = 36.75 mA/cm², fill factor FF = 76.76 %, open-circuit voltage V_oc = 0.5879 V. Given its narrow bandgap value, the optimized structure was further examined in a tandem cell configuration, showcasing its potential for high-efficiency devices with a yield reaching 33 %. This work significantly contributes to the development of efficient, stable, and non-toxic perovskite solar cells for photovoltaic applications, paving the way for advancements in sustainable energy technologies.

Abstract: In this paper, invoking the mechanism of laser phase change hardening, the presence of latent heat of phase change, the temperature-dependent fluctuation of the thermal coefficient, and the disparity of microstructure austenitizing during rapid heating and static heating are duly reckoned. The repercussion of laser energy density distribution on the geometric configuration of the laser quenching phase change zone is probed via a numerical simulation model. Concurrently, the self-developed laser shaper is employed to modify the energy allocation of the conventional laser, and laser quenching is executed on the surface of AISI1045 steel with the spotlight subsequent to the shaper. Through the comparison of the cross-sectional area of the experimental sample phase change zone and the simulated phase change zone, the projected error ratio of the model established in this research is less than 10%.