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22 pages, 14112 KB

Open AccessArticle

A Topology-Independent and Scalable Methodology for Automated LDO Design Using Open PDKs

by Daniel Arévalos, Jorge Marin, Krzysztof Herman, Jorge Gomez, Stefan Wallentowitz and Christian A. Rojas

Electronics 2025, 14(17), 3448; https://doi.org/10.3390/electronics14173448 - 29 Aug 2025

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Abstract

This work proposes a methodology for the automated sizing of transistors in analog integrated circuits, based on a modular and hierarchical representation of the circuit. The methodology combines structured design techniques and systematic design flow to generate a hierarchy of simplified macromodels that define their specifications locally and are interconnected with other macromodels or transistor-level primitive blocks. These primitive blocks can be described using symbolic models or pre-characterized data from look-up tables (LUTs). The symbolic representation of the system is obtained using Modified Nodal Analysis (MNA), and the exploration of each block is performed using local design spaces constrained by top-level specifications. The methodology is validated through the design of low dropout voltage regulators (LDOs) for DC-DC integrated power systems using open-source tools and three process design kits: Sky130A, GF180MCU, and IHP-SG13G2. Results show that the methodology allows the exploration of several topologies and technologies, demonstrating its versatility and modularity, which are key aspects in analog design. Full article

(This article belongs to the Special Issue Mixed Design of Integrated Circuits and Systems)

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23 pages, 9173 KB

Open AccessReview

Layered Double Hydroxide-Based Photocatalysts for the Removal of Emerging Contaminants: Progress in Past Ten Years

by Lingfeng Luo, Chen Hou, Lan Wang, Wei Zhang, Cong Wang, Junjie Liu, Yiqian Wu and Chuanyi Wang

Catalysts 2024, 14(4), 252; https://doi.org/10.3390/catal14040252 - 11 Apr 2024

Cited by 14 | Viewed by 5452

Abstract

Currently, public health is seriously threatened by the massive concentrations of emerging contaminants. Treating emerging contaminants in water using effective methods has become a major challenge worldwide. Photocatalytic technology, as an eco-friendly technology, has been recognized as an effective means of removing contaminants from water. Among the various photocatalysts, layered double hydroxides (LDHs), known as hydrotalcite-like materials, have been explored extensively in photocatalytic reactions due to their switchable properties and the large surface areas of their unique two-dimensional structures. In this article, recent advances in the photocatalytic degradation of emerging contaminants by LDH-based photocatalysts are reviewed. Firstly, the fundamental principles of the photocatalytic degradation of emerging contaminants using LDH-based materials are briefly introduced. Various LDHs applied in the photocatalytic degradation of emerging contaminants are broadly summarized into four types: pure-phase LDHs, interlayer-modified LDHs, LDH-based composites, and layered double oxides (LDOs). Moreover, the synthesis process and catalytic mechanism of LDH-based photocatalysts are also reviewed. An outlook on the problems and future development of LDH-based photocatalysts in water remediation is provided at the end. Full article

(This article belongs to the Special Issue Photocatalysis and Renewable Materials, 2nd Edition)

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16 pages, 4456 KB

Open AccessArticle

Interaction Mechanism Characterized by Bond Performance and Diffusion Performance between TiO₂@LDO and Asphalt Based on Molecular Dynamics Simulation

by Jinting Wu, Peirou Zhao, Ping Wang, Yang Guo, Fei Sun and Cheng Li

Materials 2023, 16(22), 7235; https://doi.org/10.3390/ma16227235 - 20 Nov 2023

Cited by 3 | Viewed by 1673

Abstract

In order to study the interaction between composite photocatalytic material TiO₂@LDO and matrix asphalt, the four-component 12 molecular structure model of 70# matrix asphalt was optimized by using software Materials Studio 2020, and its heterostructure with TiO₂@LDO composite was modeled. The bonding performance between asphalt and composite photocatalytic material was analyzed by interface energization, and the diffusion performance between asphalt and composite photocatalytic material was analyzed from the perspectives of particle movement and Z-direction density. By changing the temperature and other parameters in the simulation process, the change in bonding strength between TiO₂@LDO and asphalt was investigated. Through the calculation and analysis of interaction energy, it was found that the adsorption and bonding strength between asphalt and TiO₂@LDO were the strongest at 40 °C. At the same time, the diffusion performance was studied, and it was found that the molecular diffusion distribution of TiO₂@LDO was more extensive at 60 °C, which laid the foundation for further blending of asphalt and TiO₂@LDO. The simulation results show that TiO₂@LDO molecules have a certain attraction to asphalt molecules and can modify the matrix asphalt to some extent. Full article

(This article belongs to the Section Construction and Building Materials)

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25 pages, 9505 KB

Open AccessArticle

Optimization of LDO-Pectin Synthesis Conditions for the Removal of Metals from Wastewater: A Comparison of Response Surface Methods and Taguchi Approaches

by Ava Mohrazi, Reza Ghasemi-Fasaei, Amin Mojiri and Sedigheh Safarzadeh Shirazi

Polymers 2023, 15(18), 3778; https://doi.org/10.3390/polym15183778 - 15 Sep 2023

Cited by 7 | Viewed by 1668

Abstract

With the continuous growth of industrialization, the presence of heavy metals (HMs) in the environment has become a critical issue, necessitating cost-effective and efficient techniques for their removal. The present study aimed to determine the optimal preparation conditions for synthesizing pectin (PC) as a polymer sorbent, combined with Magnesium (Mg) Aluminum (Al) layered double oxides (LDOs), using a fast and facile co-precipitation method. Both the response surface method (RSM) and the Taguchi method were employed to optimize the influence of key independent variables, including the molar ratio of cations Mg:Al, the ratio of pectin to LDO, and the temperature for removing multiple elements from wastewater. The results indicated that RSM is more accurate and examines more interactions, while Taguchi reduces the number of tests and is more economical than RSM. However, both statistical methods showed good potential for predicting the adsorption capacity (Qe) of HMs. The optimal preparation conditions were identified as a molar ratio of 3:1, a ratio of pectin to LDO of 7% w/w, and a temperature of approximately 600 °C. In conclusion, the application of RSM and Taguchi approaches was found to be feasible and effective in optimizing the preparation conditions of modified LDO, which can be utilized as a potential adsorbent for removing multiple elements from wastewater. Full article

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