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Streamlining the Process of Materials Discovery
The materials platform M3I3 reduces the time for materials discovery by reverse engineering future materials using multiscale/multimodal imaging and machine learning of the processing-structure-properties relationship Developing new materials and novel processes has continued to change the world. The M3I3 Initiative at KAIST has led to new insights into advancing materials development by implementing breakthroughs in materials imaging that have created a paradigm shift in the discovery of materials. The Initiative features the multiscale modeling and imaging of structure and property relationships and materials hierarchies combined with the latest material-processing data. The research team led by Professor Seungbum Hong analyzed the materials research projects reported by leading global institutes and research groups, and derived a quantitative model using machine learning with a scientific interpretation. This process embodies the research goal of the M3I3: Materials and Molecular Modeling, Imaging, Informatics and Integration. The researchers discussed the role of multiscale materials and molecular imaging combined with machine learning and also presented a future outlook for developments and the major challenges of M3I3. By building this model, the research team envisions creating desired sets of properties for materials and obtaining the optimum processing recipes to synthesize them. “The development of various microscopy and diffraction tools with the ability to map the structure, property, and performance of materials at multiscale levels and in real time enabled us to think that materials imaging could radically accelerate materials discovery and development,” says Professor Hong. “We plan to build an M3I3 repository of searchable structural and property maps using FAIR (Findable, Accessible, Interoperable, and Reusable) principles to standardize best practices as well as streamline the training of early career researchers.” One of the examples that shows the power of structure-property imaging at the nanoscale is the development of future materials for emerging nonvolatile memory devices. Specifically, the research team focused on microscopy using photons, electrons, and physical probes on the multiscale structural hierarchy, as well as structure-property relationships to enhance the performance of memory devices. “M3I3 is an algorithm for performing the reverse engineering of future materials. Reverse engineering starts by analyzing the structure and composition of cutting-edge materials or products. Once the research team determines the performance of our targeted future materials, we need to know the candidate structures and compositions for producing the future materials.” The research team has built a data-driven experimental design based on traditional NCM (nickel, cobalt, and manganese) cathode materials. With this, the research team expanded their future direction for achieving even higher discharge capacity, which can be realized via Li-rich cathodes. However, one of the major challenges was the limitation of available data that describes the Li-rich cathode properties. To mitigate this problem, the researchers proposed two solutions: First, they should build a machine-learning-guided data generator for data augmentation. Second, they would use a machine-learning method based on ‘transfer learning.’ Since the NCM cathode database shares a common feature with a Li-rich cathode, one could consider repurposing the NCM trained model for assisting the Li-rich prediction. With the pretrained model and transfer learning, the team expects to achieve outstanding predictions for Li-rich cathodes even with the small data set. With advances in experimental imaging and the availability of well-resolved information and big data, along with significant advances in high-performance computing and a worldwide thrust toward a general, collaborative, integrative, and on-demand research platform, there is a clear confluence in the required capabilities of advancing the M3I3 Initiative. Professor Hong said, “Once we succeed in using the inverse “property−structure−processing” solver to develop cathode, anode, electrolyte, and membrane materials for high energy density Li-ion batteries, we will expand our scope of materials to battery/fuel cells, aerospace, automobiles, food, medicine, and cosmetic materials.” The review was published in ACS Nano in March. This study was conducted through collaborations with Dr. Chi Hao Liow, Professor Jong Min Yuk, Professor Hye Ryung Byon, Professor Yongsoo Yang, Professor EunAe Cho, Professor Pyuck-Pa Choi, and Professor Hyuck Mo Lee at KAIST, Professor Joshua C. Agar at Lehigh University, Dr. Sergei V. Kalinin at Oak Ridge National Laboratory, Professor Peter W. Voorhees at Northwestern University, and Professor Peter Littlewood at the University of Chicago (Article title: Reducing Time to Discovery: Materials and Molecular Modeling, Imaging, Informatics, and Integration).This work was supported by the KAIST Global Singularity Research Program for 2019 and 2020. Publication: “Reducing Time to Discovery: Materials and Molecular Modeling, Imaging, Informatics and Integration,” S. Hong, C. H. Liow, J. M. Yuk, H. R. Byon, Y. Yang, E. Cho, J. Yeom, G. Park, H. Kang, S. Kim, Y. Shim, M. Na, C. Jeong, G. Hwang, H. Kim, H. Kim, S. Eom, S. Cho, H. Jun, Y. Lee, A. Baucour, K. Bang, M. Kim, S. Yun, J. Ryu, Y. Han, A. Jetybayeva, P.-P. Choi, J. C. Agar, S. V. Kalinin, P. W. Voorhees, P. Littlewood, and H. M. Lee, ACS Nano 15, 3, 3971–3995 (2021) https://doi.org/10.1021/acsnano.1c00211 Profile: Seungbum Hong, PhD Associate Professor email@example.com http://mii.kaist.ac.kr Department of Materials Science and Engineering KAIST (END)
Researchers Report Longest-lived Aqueous Flow Batteries
New technology to overcome the life limit of next-generation water-cell batteries A research team led by Professor Hee-Tak Kim from the Department of Chemical and Biomolecular Engineering has developed water-based zinc/bromine redox flow batteries (ZBBs) with the best life expectancy among all the redox flow batteries reported by identifying and solving the deterioration issue with zinc electrodes. Professor Kim, head of the Advanced Battery Center at KAIST's Nano-fusion Research Institute, said, "We presented a new technology to overcome the life limit of next-generation water-cell batteries. Not only is it cheaper than conventional lithium-ion batteries, but it can contribute to the expansion of renewable energy and the safe supply of energy storage systems that can run with more than 80 percent energy efficiency." ZBBs were found to have stable life spans of more than 5,000 cycles, even at a high current density of 100 mA/cm2. It was also confirmed that it represented the highest output and life expectancy compared to Redox flow batteries (RFBs) reported worldwide, which use other redox couples such as zinc-bromine, zinc-iodine, zinc-iron, and vanadium. Recently, more attention has been focused on energy storage system (ESS) that can improve energy utilization efficiency by storing new and late-night power in large quantities and supplying it to the grid if necessary to supplement the intermittent nature of renewable energy and meet peak power demand. However, lithium-ion batteries (LIBs), which are currently the core technology of ESSs, have been criticized for not being suitable for ESSs, which store large amounts of electricity due to their inherent risk of ignition and fire. In fact, a total of 33 cases of ESSs using LIBs in Korea had fire accidents, and 35% of all ESS facilities were shut down. This is estimated to have resulted in more than 700 billion won in losses. As a result, water-based RFBs have drawn great attention. In particular, ZBBs that use ultra-low-cost bromide (ZnBr2) as an active material have been developed for ESSs since the 1970s, with their advantages of high cell voltage, high energy density, and low price compared to other RFBs. Until now, however, the commercialization of ZBBs has been delayed due to the short life span caused by the zinc electrodes. In particular, the uneven "dendrite" growth behavior of zinc metals during the charging and discharging process leads to internal short circuits in the battery which shorten its life. The research team noted that self-aggregation occurs through the surface diffusion of zinc nuclei on the carbon electrode surface with low surface energy, and determined that self-aggregation was the main cause of zinc dendrite formation through quantum mechanics-based computer simulations and transmission electron microscopy. Furthermore, it was found that the surface diffusion of the zinc nuclei was inhibited in certain carbon fault structures so that dendrites were not produced. Single vacancy defect, where one carbon atom is removed, exchanges zinc nuclei and electrons, and is strongly coupled, thus inhibiting surface diffusion and enabling uniform nuclear production/growth. The research team applied carbon electrodes with high density fault structure to ZBBs, achieving life characteristics of more than 5,000 cycles at a high charge current density (100 mA/cm2), which is 30 times that of LIBs. This ESS technology, which can supply eco-friendly electric energy such as renewable energy to the private sector through technology that can drive safe and cheap redox flow batteries for long life, is expected to draw attention once again. Publication: Ju-Hyuk Lee, Riyul Kim, Soohyun Kim, Jiyun Heo, Hyeokjin Kwon, Jung Hoon Yang, and Hee-Tak Kim. 2020. Dendrite-free Zn electrodeposition triggered by interatomic orbital hybridization of Zn and single vacancy carbon defects for aqueous Zn-based flow batteries. Energy and Environmental Science, 2020, 13, 2839-2848. Link to download the full-text paper:http://xlink.rsc.org/?DOI=D0EE00723D Profile: Prof. Hee-Tak Kimheetak.firstname.lastname@example.org://eed.kaist.ac.krAssociate ProfessorDepartment of Chemical & Biomolecular EngineeringKAIST
Energy Storage Using Oxygen to Boost Battery Performance
Researchers have presented a novel electrode material for advanced energy storage device that is directly charged with oxygen from the air. Professor Jeung Ku Kang’s team synthesized and preserved the sub-nanometric particles of atomic cluster sizes at high mass loadings within metal-organic frameworks (MOF) by controlling the behavior of reactants at the molecular level. This new strategy ensures high performance for lithium-oxygen batteries, acclaimed as a next-generation energy storage technology and widely used in electric vehicles. Lithium-oxygen batteries in principle can generate ten times higher energy densities than conventional lithium-ion batteries, but they suffer from very poor cyclability. One of the methods to improve cycle stability is to reduce the overpotential of electrocatalysts in cathode electrodes. When the size of an electrocatalyst material is reduced to the atomic level, the increased surface energy leads to increased activity while significantly accelerating the material’s agglomeration. As a solution to this challenge, Professor Kang from the Department of Materials Science and Engineering aimed to maintain the improved activity by stabilizing atomic-scale sized electrocatalysts into the sub-nanometric spaces. This is a novel strategy for simultaneously producing and stabilizing atomic-level electrocatalysts within metal-organic frameworks (MOFs). Metal-organic frameworks continuously assemble metal ions and organic linkers. The team controlled hydrogen affinities between water molecules to separate them and transfer the isolated water molecules one by one through the sub-nanometric pores of MOFs. The transferred water molecules reacted with cobalt ions to form di-nuclear cobalt hydroxide under precisely controlled synthetic conditions, then the atomic-level cobalt hydroxide is stabilized inside the sub-nanometric pores. The di-nuclear cobalt hydroxide that is stabilized in the sub-nanometric pores of metal-organic frameworks (MOFs) reduced the overpotential by 63.9% and showed ten-fold improvements in the life cycle. Professor Kang said, “Simultaneously generating and stabilizing atomic-level electrocatalysts within MOFs can diversify materials according to numerous combinations of metal and organic linkers. It can expand not only the development of electrocatalysts, but also various research fields such as photocatalysts, medicine, the environment, and petrochemicals.” This study was reported in Advanced Science (Title: Autogenous Production and Stabilization of Highly Loaded Sub-Nanometric Particles within Multishell Hollow Metal-Organic Frameworks and Their Utilization for High Performance in Li-O2 Batteries). This research was mainly supported by the Global Frontier R&D Program of the Ministry of Science, ICT & Planning (Grant No. 2013M3A6B1078884) funded by the Ministry of Science, ICT & Future Planning, and the National Research Foundation of Korea (Grant No. 2019M3E6A1104196). Profile:Professor Jeung Ku Kang email@example.com http://nanosf.kaist.ac.kr/ Nano Materials Simulation and Fabrication Laboratory Department of Materials Science and Engineering KAIST
Professor Emeritus Jung Ki Park Won the IBA Technology Award 2018
(Professor Emeritus Jung Ki Park) Professor Emeritus Jung Ki Park from the Department of Chemical and Biomolecular Engineering received the IBA Technology Award from the International Battery Association (IBA). IBA 2018 was held from March 11 to 16 on Jeju Island, which was the first time it was hosted in Korea. The conference was an excellent opportunity to let the world know the level of the Korean rechargeable battery industry and its technology. Professor Park delivered his keynote speech titled Advances in Lithium Batteries in Korea at the conference and received the IBA Technology Award as the first Korean recipient. Professor Park is a world-renowned scholar who was a groundbreaker in the rechargeable battery industry. He was recognized by the IBA Award Committee for his contributions carrying out research and development, fostering competent people, and enhancing the lithium rechargeable battery industry in Korea over the last 30 years. Professor Park said, “It is my great honor to receive this award, which is the best international award in the field of rechargeable batteries. I would like to share this with my colleagues and students. As competition in the rechargeable industry intensifies, systemic cooperation among industries, academia, and government is needed for the continued development of the battery industry in Korea.
KAIST Ph.D. Candidate Wins the Next Generation of Engineers Award
Joo-Sung Kim, a doctoral student at the EEWS (Environment, Energy, Water and Sustainability) Graduate School won the inaugural Next Generation of Engineers Award in Leadership on December 14, 2016. The National Academy of Engineering of Korea hosts this award to support creative and ambitious students who have the potential to become leaders in engineering and who will serve as role models for future Korean engineers. Based on the recommendations of university professors in engineering and members of the academy, seven students are selected for the award in the categories of leadership and entrepreneurship. With his research focus on the development of high-performance, next-generation secondary cells for wearable devices such as smart watches, health bands, and smart eyewear, Joo-Sung created a startup, Lithium-ion Battery Energy Science and Technology (LiBEST), Inc. He plans to base his company at the Office of University and Industry Cooperation, KAIST, where he can receive assistance for launching the mass-production system for his technology. His adviser, Professor Jang-Wook Choi of the EEWS Graduate School, noted, “Joo-Sung has been a great student who has a strong sense of curiosity and perseverance. The award is the by-product of his hard work.” “I have always enjoyed my work and study as a researcher, but eventually would like to expand my career into business based on the results of my research. It would be wonderful if I could become a businessman like Elon Musk, Masayoshi Son, or Ma Yun and create a role model for aspiring engineers in Korea by combining science and technology with business demand to create social values that benefit many people,” Joo-Young said.
The First Demonstration of a Self-powered Cardiac Pacemaker
As the number of pacemakers implanted each year reaches into the millions worldwide, improving the lifespan of pacemaker batteries has been of great concern for developers and manufacturers. Currently, pacemaker batteries last seven years on average, requiring frequent replacements, which may pose patients to a potential risk involved in medical procedures. A research team from the Korea Advanced Institute of Science and Technology (KAIST), headed by Professor Keon Jae Lee of the Department of Materials Science and Engineering at KAIST and Professor Boyoung Joung, M.D. of the Division of Cardiology at Severance Hospital of Yonsei University, has developed a self-powered artificial cardiac pacemaker that is operated semi-permanently by a flexible piezoelectric nanogenerator. The artificial cardiac pacemaker is widely acknowledged as medical equipment that is integrated into the human body to regulate the heartbeats through electrical stimulation to contract the cardiac muscles of people who suffer from arrhythmia. However, repeated surgeries to replace pacemaker batteries have exposed elderly patients to health risks such as infections or severe bleeding during operations. The team’s newly designed flexible piezoelectric nanogenerator directly stimulated a living rat’s heart using electrical energy converted from the small body movements of the rat. This technology could facilitate the use of self-powered flexible energy harvesters, not only prolonging the lifetime of cardiac pacemakers but also realizing real-time heart monitoring. The research team fabricated high-performance flexible nanogenerators utilizing a bulk single-crystal PMN-PT thin film (iBULe Photonics). The harvested energy reached up to 8.2 V and 0.22 mA by bending and pushing motions, which were high enough values to directly stimulate the rat’s heart. Professor Keon Jae Lee said: “For clinical purposes, the current achievement will benefit the development of self-powered cardiac pacemakers as well as prevent heart attacks via the real-time diagnosis of heart arrhythmia. In addition, the flexible piezoelectric nanogenerator could also be utilized as an electrical source for various implantable medical devices.” This research result was described in the April online issue of Advanced Materials (“Self-Powered Cardiac Pacemaker Enabled by Flexible Single Crystalline PMN-PT Piezoelectric Energy Harvester”: http://onlinelibrary.wiley.com/doi/10.1002/adma.201400562/abstract). Youtube link: http://www.youtube.com/watch?v=ZWYT2cU_Mog&feature=youtu.be Picture Caption: A self-powered cardiac pacemaker is enabled by a flexible piezoelectric energy harvester.
Rechargeable Lithium Sulfur Battery for Greater Battery Capacity
Professor Do Kyung Kim from the Department of Material Science and Engineering and Professor Jang Wook Choi from the Graduate School of EEWS have been featured in the lead story of the renowned nanoscience journal Advanced Materials for their research on the lithium sulfur battery. This new type of battery developed by Professor Kim is expected to have a longer life battery life and [higher] energy density than currently commercial batteries. With ample energy density up to 2100Wh/kg—almost 5.4 times that of lithium ion batteries—lithium sulfur batteries can withstand the sharp decrease in energy capacity resulting from charging and discharging—which has been considered the inherent limitation of the conventional batteries. Professor Kim and his research team used one-dimensional, vertical alignment of 75nm tick, 15μm long sulfur nanowires to maximize electric conductivity. Then, to prevent loss of battery life, they carbon-coated each nanowire and prohibited direct contact between the sulfur and electrolyte. The result was one of the most powerful batteries in terms of both energy performance and density. Compared to conventional batteries which suffer from continuous decrease in energy capacity after being discharged, the lithium sulfur battery maintained 99.2% of its initial capacity after being charged and discharged 300 times and up to 70% even after 1000 times. Professor Kim claims that his new battery is an important step forward towards a high-performance rechargeable battery which is a vital technology for unmanned vehicles, electric automobiles and energy storage. He hopes that his research can solve the problems of battery-capacity loss and contribute to South Korea’s leading position in battery technology. Professor Kim’s research team has filed applications for one domestic and international patent for their research.
Technology Developed for Flexible, Foldable & Rechargeable Battery
Flexible, Foldable & Rechargeable Battery The research group of professors Jang-Wook Choi & Jung-Yong Lee from the Graduate School of EEWS and Taek-Soo Kim from the Department of Mechanical Engineering at KAIST has developed technology for flexible and foldable batteries which are rechargeable using solar energy. The research result was published in the online issue of Nano Letters on November 5. Trial versions of flexible and wearable electronics are being developed and introduced in the market such as Galaxy Gear, Apple’s i-Watch, and Google Glass. Research is being conducted to make the batteries softer and more wearable and to compete in the fast-growing market for flexible electronics. This new technology is expected to be applied to the development of wearable computers as well as winter outdoor clothing since it is flexible and light. The research group expects that the new technology can be applied to current battery production lines without additional investment. Professor Choi said, “It can be used as a core-source technology in the rechargeable battery industry in the future. Various wearable mobile electronic products can be developed through cooperation and collaboration within the industry.”
Core Technology for Lithium Air Secondary Battery Developed
KAIST-Kyonggi University joint research team developed composite catalyst out of nano fiber and graphene Five times improvement in capacity compared to lithium-ion secondary battery, driving 800 km at maximum The core technology for lithium air secondary battery, the next generation high capacity battery, has been developed. A research team formed by KAIST Department of Materials Science’s Professors Il-Doo Kim and Seokwoo Jeon, and Kyonggi University Department of Materials Science’s Professor Yong-Joon Park has created a lithium air secondary battery, with five times greater storage than the lithium-ion secondary battery, by developing a nano fiber-graphene composite catalyst. The research results are published in the August 8th online edition of Nano Letters. A cathode of a lithium-ion battery consists of graphite and an anode of the battery consists of a lithium transition metal oxide. Lithium-ion batteries are widely used in mobile phones and laptops. However, lithium-ion batteries cannot support electric vehicles, providing energy for only 160 kilometers on one full charge. The lithium air secondary battery just developed by the research team uses lithium on the cathode and oxygen on the anode. It is earning a popular acknowledgement among the next generation secondary battery research community for having lightweight mass and high energy density. However, lithium-ion batteries remain difficult to commercialize because of their short lifespan. Lithium and oxygen meet up to form lithium oxide (Li2O2) at discharge, and decompose again at charge. In a traditional lithium air battery, this cycle does not occur smoothly and results in high resistance, thereby reducing the lifespan of the battery. It is thus essential to develop high efficiency catalyst that facilitates the formation and decomposition of lithium oxides. The research team used electric radiation to develop a nano composite catalyst by mixing cobalt oxide nano fiber and graphene. The performance of the battery has been maximized by settling nonoxidative graphene, which has high specific surface area and electrical conductivity, on catalyst active cobalt oxide nano fiber. Applying the nano composite catalyst on both poles of the lithium air battery resulted in an improved lifespan of over 80 recharge cycles with capacity greater than 100mAh/g, five times greater than a lithium ion battery. The newly discovered charge-discharge property is the highest among the reported performances of the lithium air battery so far. The lithium air battery is cheap to make, as the main materials are metal oxide and graphene. “There are yet more issues to resolve such as stability, but we will collaborate with other organizations to open up the era of electronic vehicles,” said Professor Il-Doo Kim. “We hope to contribute to vitalizing the fields of next generation lithium air battery by leading nanocatalyst synthesis technology, one of the core materials in the fields of secondary battery,” Professor Kim spoke of his aspiration. The graduate students participated in the research are Won-Hee Ryu, a postdoctorate at KAIST Department of Materials Science, Sungho Song, a PhD candidate at KAIST Department of Materials Science, and Taek-Han Yoon, a graduate student at Kyonggi University. Picture I: Schematic Diagram of Lithium Air Battery Made of Nano Composite Catalysts Picture II: Images of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts Picture III: Images of Manufacturing Process of Cobalt Oxide Nano Fibers and Graphene Nano Composite Catalysts for Lithium Air Battery
International Workshop on EEWS 2010 was held.
On October 7 and 8th at Fusion Hall of KI Building, KAIST, the 2010 International Workshop on EEWS (Energy, Environment, Water, and Sustainability) was held. The third to be held, forty national and international academic professionals including Mark Shannon, professor at University of Illinois at Urbana-Champaign, Domen Kazunari, Tokyo University professor, Dong Sub Kim, CTO of SK Energy and Doyoung Seung, Senior Vice President of GS Caltex, participated at this year’s workshop. In twelve sessions, themes including Artificial Photosynthesis, Wireless Power Transfer, Green Aviation, Safe Nuclear Fuel Reuse, Fuel Cells in Action, LED 2.0, Foundation of Energy-Water Nexus, and Flexible Battery & Solar Cell were presented and discussed. “Through this workshop, current EEWS policy and research progress from different countries and the future of related technologies will be foreseen,” said Jae Kyu Lee, Dean of KAIST EEWS Initiative. “I hope it became an opportunity to create cooperative relationships with leading researchers.” EEWS is a research project conducted by KAIST to solve global issues that mankind faces today such as depletion of energy, environmental pollution, water shortage, and sustainability.
Prof. Song Develops Nano-Structure to Enhance Power of Rechargeable Lithium-ion Battery
A team of scientists led by Prof. Hyun-Joon Song of the Department of Chemistry, KAIST, developed a nano-structure that could increase the power of rechargeable lithium-ion batteries, university sources said on Monday (Feb. 16). The research team found that a nano-structured material using copper oxide (CuO) could produce lithium-ion batteries with some 50 percent more capacity than conventional products. The study was published in the online edition of peer-review journal Advanced Materials. In rechargeable lithium-ion batteries, lithium ions move between the battery"s anode and cathode. The high-energy density of the batteries led to their common use in consumer electronics products, expecially portable devices. Their demand in automotive and aerospace applications is growing, and nano-structured, or nano-enabled batteries are emerging as the new generation of lithium-ion batteries for their edge in recharging time, capacity and battery life. Graphite has been a popular material for cathodes in lithium-ion batteries. However, graphite cathodes are also blamed for lost capacity due to their consumption of lithium ions, which are linked to shorter battery life. As such, scientists have been looking for materials that could replace graphite in cathodes, and silicon and metal oxide have been studied as possible alternatives.
Method to Synthesize New Lithium Ion Battery Cathode Material Identified
A KAIST research team headed by Prof. Do-Kyung Kim at the Department of Materials Science and Engineering developed a technology to synthesize a new lithium ion battery spinel cathode which is regarded as a core part of hybrid and lithium battery cars. The research was conducted in collaboration with a research team of Prof. Yi Cui at Stanford University"s Department of Chemistry. Their findings were introduced in the November issue of Nano Letters, one of the leading academic journals in nano-science. The newly synthesized lithium ion battery spinel cathode known as spinel LiMn2O4 nanorods is attracting interests as an alternative cathode material since it is a low-cost, environmentally friendly substance for Li-ion battery cathodes. Its raw material is also highly available. Lithium ion batteries with high energy and power density are important for consumer electronic devices, portable power tools, and vehicle electrification. LixCoO2 is a commonly used cathode material in commercial lithium iron batteries. However, the high cost, toxicity, and limited abundance of cobalt have been recognized to be disadvantageous.
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