Article
Chemistry, Physical
Rana Ghannam, Adrien Moll, David Berardan, Loic Coulomb, Antonio Vieira -E-Silva, Benjamin Villeroy, Romain Viennois, Mickael Beaudhuin
Summary: This article reports the effect of nano-structuring and purity on the thermal and thermoelectric properties of alpha-SrSi2. The results show that nanostructured pellets with a grain size of about 200 nm can be obtained using ball milling and spark plasma sintering, which reduces the lattice contribution to the thermal conductivity. The figure of merit ZT is improved to 0.20 around room temperature after nano-structuring. The influence of Sr purity on the thermoelectric properties is also presented.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Ignacio Rodriguez-Barber, Julia Camut, Laura Luhmann, Aidan Cowley, Eckhard Mueller, Johannes de Boor
Summary: alpha-MgAgSb has been identified as a promising thermoelectric material with peak performance around 300 degrees C. Optimal synthesis of the material can reduce impurities and improve thermoelectric performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
C. Suryanarayana, Ahmed A. Al-Joubori, Zhi Wang
Summary: The technique of mechanical alloying has evolved from producing superalloys for aerospace to synthesizing a wide range of advanced materials, such as nanostructured materials and nanocomposites. This process involves repeated cold welding, fracturing, and rewelding of powder particles to enhance alloy formation. The resulting materials can include supersaturated solid solutions, intermetallics, quasicrystalline alloys, high-entropy alloys, amorphous alloys, and composites, with most having nanometer-sized grain structures.
METALS AND MATERIALS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Ruoyu Chen, Adam Bratten, Joshua Rittenhouse, Haiming Wen
Summary: The use of mechanically alloyed Al2O3-Y2O3 mixtures as sintering additives can promote liquid phase sintering of SiC, but prolonged ball milling time results in an excessive volume of complex oxide phases in the sintered specimens, negatively affecting the mechanical properties of SiC specimens.
CERAMICS INTERNATIONAL
(2022)
Article
Chemistry, Physical
Anna Knaislova, Vendula Simunkova, Pavel Novak, Filip Prusa, Marcello Cabibbo, Lucyna Jaworska, Dalibor Vojtech
Summary: Intermetallic alloys based on Ti-Al-Si system are significant for their excellent high-temperature properties, but high brittleness at room temperature is a main concern. Adding alloying elements has been attempted to improve the properties, but porous microstructure remains a challenge.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Inorganic & Nuclear
Arun Raphel, P. Vivekanandhan, Appu Kumar Singh, S. Kumaran
Summary: The facile synthesis of nanocrystalline lead tin tellurium selenium high entropy alloy doped with bismuth through mechanical alloying and spark plasma sintering resulted in enhanced power factor and low thermal conductivity, leading to a significant improvement in figure of merit compared to the pristine alloy.
JOURNAL OF SOLID STATE CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Junaid Ahmed, Ihsan-ul-Haq Toor, Mohamed A. Hussein, Nasser Al-Aqeeli, Mirza M. A. Baig
Summary: Nanostructured ferritic and austenitic stainless steel alloys with different Si contents were developed using mechanical alloying and spark plasma sintering. The addition of Si increased the densification and electrochemical performance of the alloys.
Article
Chemistry, Physical
Linda Abbassi, David Mesguich, Loic Coulomb, Geoffroy Chevallier, Romain Aries, Claude Estournes, Emmanuel Flahaut, Romain Viennois, Mickael Beaudhuin
Summary: In this paper, a simple route to synthesize nano-beta-FeSi2 material is reported. The impact of spark plasma sintering parameters on the material properties is studied. Experimental results show that high-density nano-beta-FeSi2 pellets can be obtained using this method in a short time.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Niraj Chawake, Lavanya Raman, Parthiban Ramasamy, Pradipta Ghosh, Florian Spieckermann, Christoph Gammer, B. S. Murty, Ravi Sankar Kottada, Juergen Eckert
Summary: This study synthesized a composite of two different medium entropy alloys using ball milling and spark plasma sintering, showing excellent microstructural and phase stability as well as multiple desirable mechanical properties. The results can serve as a template for other systems and demonstrate the feasibility of combining different medium entropy alloys.
SCRIPTA MATERIALIA
(2021)
Article
Biochemistry & Molecular Biology
Alvaro Javier Gomez Rodriguez, Dagoberto Oyola Lozano, Humberto Bustos Rodriguez, Yebrail Rojas Martinez, German Antonio Perez Alcazar, Ligia Edith Zamora Alfonso, Juan Sebastian Trujillo Hernandez
Summary: The objective of this study is to evaluate the applicability of exchange coupling between nanoparticles of Nd2Fe14B and Fe90Al10 as permanent magnets produced by surfactant-assisted mechanical alloying. The results show a significant decrease in coercive force with temperature and percentage of soft phase during the sintering process.
Article
Materials Science, Multidisciplinary
D. Garzon, J. E. Diosa, C. Ostos, F. H. Sanchez, G. A. Munoz Medina, F. Sieves, O. Arnache
Summary: (Fe30Cu70)(96)B-4 (FCB) alloys were prepared by mechanical milling and characterized for structural, morphological, and magnetic properties with increasing milling time. The nanoparticles formed after 12 hours of milling exhibit superparamagnetic-like behavior at temperatures below 60 K despite being ferromagnetic at room temperature. The saturation magnetization and coercive field values change with milling time.
MATERIALS CHARACTERIZATION
(2021)
Article
Chemistry, Physical
Jiang Wu, Xuguang An, Jing Zhang, Shaofeng Lei, Yi Guo, Xiwei Xu, Weitang Yao, Qingyuan Wang, Qingquan Kong
Summary: Ti-24Nb-4Zr-3Mn alloys were prepared using mechanical alloying and spark plasma sintering. The study found that increasing the milling time reduces the particle size of the alloy powder, but increases the oxygen content. Among all the investigated alloys, Ti-24Nb-4Zr-3Mn alloy prepared by 20-hour milling showed excellent comprehensive mechanical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Physics, Condensed Matter
Arun Raphel, Appu Kumar Singh, P. Vivekanandhan, S. Kumaran
Summary: The study successfully synthesized a high-density nanocrystalline lead-tin-selenium-tellurium high-entropy alloy, achieving excellent thermoelectric performance by reducing lattice thermal conductivity.
PHYSICA B-CONDENSED MATTER
(2021)
Article
Materials Science, Multidisciplinary
Chongfeng Sun, Yongchun Guo, Zhong Yang, Jianping Li, Shengqi Xi, Ziqi Jie, Tao Xu
Summary: Refractory high entropy alloy WTaMoNb was incorporated into a Cu matrix to synthesize WTaMoNb/Cu nanocomposite, with BCC/FCC structure, via two-step mechanical alloying and hot pressing sintering. The resulting Cu-10wt.%WTaMoNb alloy exhibited excellent thermal stability, high tensile strength, and electrical conductivity.
Article
Nanoscience & Nanotechnology
Brian T. Heligman, Kevin P. Scanlan, Arumugam Manthiram
Summary: In this work, a new nanostructured composite foil (NCF) alloying anode framework for high-capacity anode materials for lithium-ion batteries is introduced. The NCF materials are manufactured with a simple process, providing hierarchical nanostructures. The NCF system shows promising results in terms of volumetric capacities and energy density, and further development may lead to the production of high-energy battery materials.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Applied
Tae Wan Kim, Hwiram Jeong, Yeongin Jo, Dongun Kim, Ji Hoon Park, Seok Ki Kim, Young-Woong Suh
Summary: A highly active K-added Ru/MgO catalyst was reported for hydrogen storage into aromatic benzyltoluenes at low temperatures to advance liquid organic hydrogen carrier technology.
JOURNAL OF ENERGY CHEMISTRY
(2022)
Article
Engineering, Environmental
Sungjune Lee, Chul-Ung Kim, Jeong-Chul Kim, Su-Un Lee, Ja Hun Kwak, Ryong Ryoo, Tae-Wan Kim
Summary: To improve the catalytic activity of the ethylene-to-propylene (ETP) reaction for propylene production, a phosphorus-modified SSZ-13 zeolite catalyst was prepared. The phosphorus species weakened the acidity of the zeolite and partially blocked the pores, leading to increased propylene selectivity and yield.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Physical
Yeongin Jo, Tae Wan Kim, Jinho Oh, Donghyeon Kim, Young-Woong Suh
Summary: The addition of sulfur to supported Pt catalysts has an impact on Pt defect sites and side reactions, which is influenced by the catalyst preparation methods. In this study, mesoporous sulfur-decorated Pt-Al2O3 catalysts with different sulfur contents were prepared using the solvent-deficient precipitation (SDP) method. The dehydrogenation of perhydro benzyltoluenes showed a volcano-shaped dependence on the sulfur content, with the maximum dehydrogenation achieved at 0.21 wt% sulfur. The best performing catalyst exhibited excellent recyclability due to negligible Pt growth and sulfur loss. The SDP method facilitated favorable contact between Pt and sulfur species, resulting in a reduction in electron density of Pt atoms. This electron-deficient Pt atoms weakened the adsorption of aromatic products and facilitated appropriate H-2 adsorption. As a result, the titled catalyst exhibited tolerance towards dehydrogenation products and lower selectivity towards the side product methylfluorene.
JOURNAL OF CATALYSIS
(2022)
Article
Engineering, Industrial
Jun Young Jang, Jung In Kim, Choongwan Koo, Tae Wan Kim
Summary: This study develops an automated method for establishing a PC components-vehicle allocation (CVA) plan in precast concrete (PC) projects. The method incorporates considerations derived from interviews and literature review, and formalizes a CVA process that satisfies these considerations. The results show that the automated method can generate CVA plans faster and reduce the number of vehicles, contributing to the off-site construction management theory and helping to alleviate social and environmental problems.
JOURNAL OF MANAGEMENT IN ENGINEERING
(2022)
Article
Chemistry, Physical
Tae Wan Kim, Hwiram Jeong, Dongun Kim, Yeongin Jo, Hwi Ju Jung, Ji Hoon Park, Young-Woong Suh
Summary: This study investigates the impacts of CH4 fraction on the essential steps for liquid organic hydrogen carrier systems. The results show that a CH4 fraction higher than 30% negatively affects the carbon content and catalytic activity, but has less impact under mild conditions.
JOURNAL OF POWER SOURCES
(2022)
Article
Behavioral Sciences
Ji Sun Kim, Oc-Hee Kim, In Soo Ryu, Yong-Hyun Kim, Kyung Oh Jeon, Li-Na Lim, Tae Wan Kim, Sumin Sohn, Sunghyun Kim, Jeong-Wook Seo, Eun Sang Choe, Eun Young Jang
Summary: Nicotine stimulates nicotinic acetylcholine receptors (nAChRs) in the brain, leading to the psychomotor, rewarding, and reinforcing effects of tobacco dependence. This study found that alpha 4132 nAChRs regulate locomotor sensitization by altering dopamine concentration in the nucleus accumbens (NAc) after exposure to whole cigarette smoke condensate (WCSC). The findings suggest that challenge WCSC increases locomotor sensitization by elevating dopamine concentration through stimulation of alpha 4132 nAChRs expressed in NAc neurons in rats.
PHARMACOLOGY BIOCHEMISTRY AND BEHAVIOR
(2022)
Article
Green & Sustainable Science & Technology
Junsoo Lee, Tae Wan Kim, Choongwan Koo
Summary: This study proposed a novel process model for developing a scalable room-level energy benchmark using real-time big data, which focused on identifying representative energy usage patterns and encouraging occupant behavior change for energy savings. Three views were taken into account when creating the scalable room-level energy benchmark: space unit, time unit, and equipment unit.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2022)
Article
Chemistry, Multidisciplinary
Hwiram Jeong, Tae Wan Kim, Minseok Kim, Gi Bo Han, Byunghun Jeong, Young-Woong Suh
Summary: Transition-metal catalysts are crucial for liquid organic hydrogen carrier (LOHC) systems, and blending catalyst constituents to improve adsorption and kinetics is necessary for achieving comparable hydrogenation activity. In this study, mesoporous supports were prepared with different alkyl substituents, and a volcano-shaped relationship between the hydrogenation activity of the catalyst and alkyl substituent length was observed.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2022)
Article
Robotics
Seungwon Choi, Hee-Won Chae, Yunsuk Jeung, Seokjoon Kim, Kyusung Cho, Tae-wan Kim
Summary: We propose a fast and versatile feature-based LiDAR odometry method that uses local quadratic surface approximation and point-to-surface alignment. Our method tackles the inconsistency between feature class and map's local geometry by approximating the local LiDAR scan's geometry as a quadratic surface. By leveraging a symmetric objective function, we achieve computational efficiency without time-consuming surface parameter evaluation. Evaluation on KITTI and Newer College datasets shows that our method outperforms other feature-based methods, especially in environments with considerable feature classification ambiguity. Moreover, we demonstrate the robustness of our method in sparse LiDAR scans with a relatively small number of scan channels.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2023)
Article
Construction & Building Technology
Minguk Kim, Youngjib Ham, Choongwan Koo, Tae Wan Kim
Summary: This study proposes a novel approach for generating realistic paths by simulating workers' way-finding decision-making process using deep reinforcement learning. The results show that the proposed approach simulates workers' trajectories better than the traditional A* algorithm.
AUTOMATION IN CONSTRUCTION
(2023)
Article
Chemistry, Physical
Tae Wan Kim, Dongun Kim, Yeongin Jo, Hwi Ju Jung, Ji Hoon Park, Young-Woong Suh
Summary: Alkali metals (AM) are commonly used as promoters in various reactions, and in the hydrogenation of aromatic compounds over Ru/MgO catalysts, their basicity can promote heterolytic H2 adsorption, enhancing reaction kinetics. Ru/AM/MgO catalysts (AM: Na, K, and Cs) with different AM/Ru molar ratios were prepared and evaluated, showing a volcano-type relationship between activity and AM/Ru molar ratio. The best promoter among the AMs was found to be K+, followed by Na+ and Cs+, attributed to heterolytic H2 adsorption induced by charge transfer from AM to proximate Ru atoms at the Ru-MgO interface.
JOURNAL OF CATALYSIS
(2023)
Article
Chemistry, Analytical
Sonali Pandithawatta, Seungjun Ahn, Raufdeen Rameezdeen, Christopher W. K. Chow, Nima Gorjian, Tae Wan Kim
Summary: This research created a new ontology, the Job Hazard Analysis Knowledge Graph (JHAKG), by analyzing actual JHA documents and interviewing JHA domain experts. The JHAKG can answer queries regarding hazards, external factors, level of risks, and appropriate control measures. It provides more complete and comprehensive JHA documents compared to those produced by an individual safety manager.
Article
Chemistry, Physical
Seok-Mo Kang, Tae Wan Kim, Nam-Hoon Kim, Sung-Jin Kim, Jung-Hyuk Koh
Summary: The composition of lead-free piezoelectric ceramics (1 - x)(Bi0.5Na0.5)TiO3-x(Ba0.5Sr0.5)TiO3 with excellent piezoelectric properties was investigated in this study. Crystal analysis, electrical and piezoelectric properties were analyzed based on the content of BST composition. It was found that the optimal composition was 0.12 BST, which exhibited a phase change from rhombohedral to tetragonal structure, the highest permittivity, and the highest values of P-r, d(33), k(p), and Curie temperature (T-m). These results confirm that 0.12 BST is the optimal composition for (1 - x)BNT-xBST piezoelectric ceramics.
Article
Energy & Fuels
Tae Wan Kim, Yeongin Jo, Kwanyong Jeong, Hyunwoo Yook, Jeong Woo, Jung Hee Jang, Gi Bo Han, Ji Hoon, Young-Woong Suh
Summary: This work is the outcome of a three-year journey to develop a technically feasible way to overcome the limits of the benzyltoluene (H0-BT) and perhydro benzyltoluene (H12-BT) pair, recognized as an attractive liquid organic hydrogen carrier (LOHC) system. The study found that the para isomer of H0-BT showed faster H2 storage and release rates than the ortho and meta counterparts due to its favorable adsorption capacity and strength on the catalyst surface. The research highlights the importance of tuning the isomeric composition of H0-BT to increase the para isomer content for optimal LOHC performance.
JOURNAL OF ENERGY STORAGE
(2023)
Proceedings Paper
Engineering, Marine
Vamshikrishna Domala, Tae-Wan Kim
Summary: In this study, machine learning and deep learning approaches are used to predict significant wave height. Based on exploratory data analysis and model training, reliable predictions were obtained.
2022 OCEANS HAMPTON ROADS
(2022)
