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2017-04 03 Important News

[Academics][Researcher of the Month] Detecting Ultra-Sensitive Benzene

Professor Kim Hyoun-woo of the Division of Materials Science and Engineering is April’s Researcher of the Month, for his active role in exploring the field of materials science and engineering. In his paper “Ultra-sensitive benzene detection by a novel approach: Core-shell nanowires combined with the Pd-functionalization”, Kim explains how the detection of benzene gas has become much more efficient than ever. The palladium being extra sensitive to benzene gas has been the key to the detection technique which has drawn attention in this field. Kim has discovered the link between palladium and benzene gas. The Pd-functionalized SnO2-ZnO C-S NW is the substance developed by Kim in order to detect benzene, a toxic gas. Since nano-sized palladium particles are added on a cell with SnO2 and ZnO covered on top, the sensor produces a spillover effect, distributing the benzene gas particles along the conduction band. The effectiveness of Kim's model is proven through the gas response. (Photo courtesy of Kim) This is important since benzene gas can be found in everyday life. It is inside cigarette smoke, smog, exhaust fumes and may be found in new houses, creating sick house syndrome. Through Kim’s finding, this benzene gas, which could be lethal to human lives, can be spotted in a much more sensitive manner. Since the sensors and cells created in a smaller size would lead to higher sensitivity, the particles have been selected in nano-sizes. The only problem that could arise with this sensor is that it depends heavily upon the selectivity of which gas it wants to detect. The compatibility between different particles could create great results as Kim has found out in the case of palladium and benzene, while in other cases, disastrous results may be spawned. Kim explains how his model works. Kim wishes to develop better usage of sensors than those that are being distributed in every day life as of now. “I want to find the best usage of a new sensing principle totally different from the current ones,” said Kim. Kim Seung-jun nzdave94@hanyang.ac.kr Photos by Choi Min-ju

2017-03 28

[Academics]Impact of Nickel on Frog Embryos

Environmental pollution permeates many lives of animals and humans and lowers the quality of life due to causes that consist of not only diseases but surprisingly of malformations as well. Professor Gye Myung-chan of the Department of Life Science specializes in the embryology of mammals and amphibians, and the harmful effects of environmental pollutants, such as heavy metals and endocrine-disrupting chemicals (EDC). Graduated from both HYU and its graduate school, he was given many awards and president of various academic societies, such as Korean Society of Environmental Biology. His recently published paper called “Nickel affects gill and muscle development in oriental fire-bellied toad (Bombina orientalis) embryo” observes nickel’s adverse influence to frog’s embryos. Gye is interested in embryology, which is a field of study that observes the early stages of life including the formation of sperm, ovum, and embryo. Even though amphibians include most endangered animals compared to other species, there is not enough research about frogs. This situation applies to studies about how organisms are affected by environmental pollutants occurred by artificial causes, such as nickel and other heavy metals, which is being researched by a lot of scholars. Searching for his own domain of studies, Gye decided to conduct an experiment regarding how nickel can negatively affect Bombina orientalis, a common widespread frog that lives in Korea. Due to its mild disposition, big and thus easily observable eggs, and the small body size being the advantage of handling with ease, the frog was chosen for the subject of Gye’s studies. “I also wanted to show that Korean frogs can be used as an important biological resource.” Gye included. To begin with, Gye let the frog’s embryos grow in multiple amount of nickel for 168 hours and found out the sublethal and lethal concentrations of the substance. “Sublethal concentration, which is about 1~10 uM (the 1,000,000/1 of 1 mole) is where embryos survive to display various abnormalities, such as underdevelopment of gills, tail dysplasia, bent trunk, and abdominal blister. On the other hand, lethal concentration, approximately 100 uM, is where death of embryos disenable the observation of their malformation,” said Gye. Various deformations of tadpoles under sublethal nickel concentration. (Photo courtesy of Gye) The period where the embryos were most sensitive to nickel was the ‘pre-muscular response to muscular response stages’. These stages are when the embryos develop to use their muscles to make their tail move. “Like the thalidomide incident where the babies of women who take doses of the medicine to reduce nausea in the early stage of their pregnancy became deformed, there is a much more sensitive period of certain substance’s adverse effects, ” explained Gye. The deformation of the embryo's tail during ‘pre-muscular response to muscular response stages’. The stage is where the tadpole starts to move its tail using its muscles. (Photo courtesy of Gye) Seeing that the tadpoles displayed signs of deformations, especially the abnormality of tail muscles, he cloned their DNA that controls the development of the muscles to find out the exact causes for the malformations. “DNA transcripts RNA, and it makes proteins. Proteins that are needed for composing muscles is then selectively turned on by hormones. Next, the signals of the hormones are caught by the transcription factors that help produce RNA,” Gye described. Then, he discovered that nickel prevented the activation of the transcription factors such as myogenic regulatory factor 4 mRNA, thus inhibiting the development of muscle proteins. Gye also found out that exogenous calcium reacts oppositely to nickel’s adverse effects. “The composition of calcium is similar to that of nickel. They compete against each other and then calcium replaces nickel, “ Gye mentioned. Gye found out that calcium’s substitution of nickel restores some of its negative effects to the embryos by re-increasing protein levels and calcium-dependent kinase activities, which has the role of changing the structures of proteins. “The dangers of nickel and other heavy metals apply not only to frog embryos, but also to other species and humans. The only solution to the problem is to reduce and prevent the spills of nickel caused by mining and industrial production, and law enforcement that regulates the spills is necessary,” Gye explained. Greatly interested in environment and the humans that live in it, Gye is currently leading the Enterprise Organization for Development of Alternative Chemicals of EDC of the Ministry of Science, ITC, and Future Planning. “I hope, through my research that I could realize Hanyang’s founding philosophy, Love in Deed, by enabling people to live healthier. I wish I could benefit the society by conducting useful and practical research,” Gye said. "I want to realize the founding philosophy of Hanyang by heightening the quality of life through my research." Jang Soo-hyun luxkari@hanyang.ac.kr Photos by Choi Min-ju

2017-03 21 Important News

[Academics]Genetic Architecture of Rheumatoid Arthritis

Rheumatology is a rather unexplored branch in the medical field, and its causes and cures have not yet been fully prepared. However, Professor Bae Sang-cheol of the College of Medicine at Hanyang University stands as one of the pioneers to define and research the causal factors of rheumatology and discover better remedies. In his research “Update on the genetic architecture of rheumatoid arthritis”, Bae clearly defines the factors of rheumatoid arthritis with regards to human genetics, and predicts the possibility for precision medicine. Bae is one of the pioneers in Korea to research and advance cures rheumatoid arthritis. In his paper, Bae has organized the causes and possible remedies for rheumatology researched in the last five years- collecting all data with advanced medical technology. Rheumatism hasn't been explored completely yet, so its causes are only speculated to be genetic and environmental factors. “Rheumatism is an autoimmune disorder, which means that the causes tend not to be external factors. It's assumed that 60% of the causes is the immune system attacking upon itself, acting out of misconception,” said Bae. Human genetic studies into rheumatoid arthritis have uncovered more than 100 genetic loci associated with susceptibility to the disease. This means that the majority of factors are highly shared across multiple ancestral populations. Bae and his fellow researchers organized the data on impaired immune processes and disease phenotypes for rheumatism. “The ultimate goal of this research paper was to enhance the possibility of finding the repurposed drug for each rheumatoid arthritis patient,” mentioned Bae. Since 2005, medical technology developed rapidly, especially in the genome field. For about a decade, a significant amount of the data was collected on genome structures that are likely to influence the rheumatoid diseases. “The grand development in this area is that now, technology can examine the whole genetic variants, instead of individual ones, using the whole genome analysis technique,” said Bae. Rheumatology-related genetics directly affect gene expression and protein function, and also influence cell signaling pathways. According to the cumulated data, this process causes the immune function to be disordered, and spawns diseases in patients. “Proteins that are encoded by rheumatoid risk variants have the potential to help the development of targeting drugs,” Bae explained. Two years were spent in total on the production of this paper, and each process was intricate. First, Bae was invited to co-write with rheumatology experts to analyze the causes and possibilities of advancing repositioning drugs. Then, he had to edit and peer review the analysis and consult with graphic designers to obtain desired pictures of rheumatoid figures. “All these processes took a long time, but interacting with peer reviewers was particularly helpful in advancing this article,” said Bae. Bae stresses the importance of enhancing research on drug repositioning. Drug repurposing, also called as drug repositioning, is applying and utilizing existing medicine to develop into rheumatoid remedies. This technique significantly curtails the cost and time to invent new drugs that target rheumatoid diseases, because existing drugs have already been approved for its pharmacodynamics. Also, the development of precision medicine, which therapeutically targets for personalized rheumatoid state, is being accelerated. “Rheumatoid arthritis does not signal the body in a unique way- it feels more like a cold in the beginning. But alerting oneself to get regular health checks may help to prevent the threatening disease." Bae's ultimate goal is to develop and contribute to organic and personalized rheumatoid arthritis drug invention. His efforts to contribute to the field of rheumatology are prominent, just like his favorite poem, 'The Road Not Taken', by Robert Frost. “Reminding yourself of the original attitude and always trying your best will undoubtedly lead you to success,” advised Bae. Kim Ju-hyun kimster9421@hanyang.ac.kr Photos by Choi Min-ju

2017-03 14 Important News

[Academics]Way to Improve Korean Healthcare Ecosystem by U-healthcare System

Professor Lee Chang-won of School of Business is an expert in the field of healthcare management. From his years at graduate school in the United States, Lee became interested in telemedicine, so-called ubiquitous healthcare (u-healthcare) that can provide healthcare service and treatments to its patients regardless of time and location. After coming back to Korea, Lee started to study more deeply about healthcare management and also wrote a paper on how to effectively and efficiently allocate hospital resources. One of his most recent paper, “Improving healthcare quality: A technological and managerial innovation perspective,” specifically researched on quality characteristics of u-healthcare services for a health care service that influences users’ (hospital staffs) usage intentions. Prof.Lee is an expert in the field of healthcare management. The background of u-healthcare system starts with the aging society, a society with more than 7 percent of people who are older than 65 in a whole population. Such social changes have become a serious problem in many countries. In Korea as well, due to the increasing life expectancies and lowering birth rate, there are increasing number of elderlies. Societal aging influence on nearly every factor that affect an individual’s life quality, from economic growth, labor markets, housing, and health. To be more specific, it leads to reduction of productive workforce, while the costs of healthcare for the elderly greatly increases. Thus, it became crucial for the Korean government’s policy makers to initiate an innovative IT-based healthcare system to help people get access to qualified, but more affordable healthcare services. “In the case of patients who need regular medicine subscription or examination, it is unnecessary for them to visit hospitals every time. I think the u-healthcare system will be useful for both patients who requires long-term care and who lives far away from hospitals,” said Professor Lee. “There are various identified quality characteristics of u-health care. It includes, connectivity, compatibility, complexity, perceived benefit, and perceived trust. It was our purpose of the study to research on how such characteristics actually influence on the usage attention of hospital staffs,” explained Professor Lee. Thus, it is crucial for Korea’s policy makers to understand usage intentions of its stakeholders to later plan and implement the system better. To do so, Prof. Lee and his team did an empirical research on the 142 staff (physicians, nurses, technicians, and administrative staff) of hospitals in Korea. They used multiple survey methods via both online and offline to collect the needed data. The survey included about 3-4 pages of questions to understand their wiliness for new u-healthcare. The graph shows the overall framework of the research done in the paper. (Photo courtesy of Prof. Lee) The result showed several interesting connection or relevance between the characteristics of u-healthcare and usage intention of hospital staffs. First, it showed positive relationships with connectivity, compatibility and performance expectancy. It explained how an individual expects themselves to perform better with u-healthcare system when one has an ability to connect with u-healthcare system anytime anywhere. On the other hand, complexity and performance expectancy showed negative responses from the staffs. If a system is complex and difficult, taking more time to handle easily, it showed that their expectancy of performance is likely to reduce. “There were also quite high conservative responses from some of the staffs from the concern that u-healthcare is more accessible and affordable to patients,” said Prof Lee. “However, this study identifies benefits of u-healthcare system. Thus, it is a new task for us to suggest a new solution for people who are reluctant to adopt and use new technologies,” added Prof. Lee. Last but not least, Prof. Lee shared some more thoughts about the future of healthcare industry or management. “I feel that there are still misconceptions about “managing” healthcare and hospitals, people easily think that those two concepts of hospital and management cannot go along since management is all about seeking a private interest of a business organization. I think we definitely need a change of recognition,” said Prof. Lee. According to him, healthcare business or management should be more comprehensively compromised on consensus made among key players of healthcare ecosystem. “Managing an organization is not about promoting an interest of a certain group of people, but it is about considering the purpose (or mission) of every individual organization resulting in making a better society,” concluded Prof. Lee. Prof. Lee will continuously strive to develop better hospital ecosystem in Korea. Yun Ji-hyun uni27@hanyang.ac.kr Photos by Kim Yoon-soo

2017-03 06 Important News

[Academics]Spin-Orbit Interaction and Holographic Theory

Physics is an indispensable domain to invest in as it generates fundamental knowledge for technological infrastructure and future advancements. Accentuating the importance of the field, Professor Sin Sang-jin (Department of Physics) puts strenuous effort into enlightening unresolved physical phenomena. In his paper "Character Of Matter in Holography: Spin-orbit Interaction," Sin elaborated the relationship between holographic theory and spin-orbit interaction using graphite to decode the enigma. String theory and spin-orbit interaction Physical phenomena relating to the notion of gravity can be explained through Einstein’s general theory of relativity at a macroscopic level. However, narrowing down the matter and studying at a microscopic level, the so-called quantum gravity theory must enter the picture. Among other quantum gravity theories, the prime candidate that is attracting much interest is string theory, which states that the smallest particle of matter is not a point molecule but a vibrating string, which cannot be decomposed further. String theory focuses on holographic duality (also known as gauge/gravity duality) as a novel method of approaching and connecting a range of subjects, including quantum gravity. The movement and interaction between the electronic system are not holistically mastered by physicists, rendering the strongly correlated electronic system cryptic. By employing the holographic theory, which states that the description volume of space could be encoded on a lower-dimensional boundary to the region, can explain not only electron-to-electron interaction but also lattice-electron interaction. Of the interactions of electrons, spin-orbit interaction is what Sin sheds light on. Sin describes the complexity of the relationships between several theories. Spin-orbit interaction is a type of particle interation which causes shifts in an electron’s energy level caused by the electromagnetic interaction between the electron’s spin and the magnetic field. This field is generated by the electron’s orbit around the nucleus. The big question here was to figure out how to fit this interaction into the holographic theory, which connects to another phenomenon called anomalous hall effect. This effect is the traversing of electric current in the magnetic field perpendicular to the current, with no electromagnetic force applied. What is peculiar is the aberration; perpendicular traversing would happen only when electromagnetic force is applied. To find the answer to this puzzle, Sin applied the magnetization curve of graphite to the spin-orbit interaction, which fitted suitably. This was because the magnetization curve of graphite was well-depicted by the strong interaction between electrons. Uncountable layers of graphene make up graphite, corresponding to the strongly interacting temperature and density. The ultimate goal of Sin’s research is to construct a solid theory of physics for novel materials. In the process, string theory and holographic theory are incorporated to the core concept. “This particular research paper at hand merely managed to link the notion with spin-orbit interaction, which could be compared to just one tree out of an entire forest. I aim to theorize the strongly-correlated electronic system,” noted Sin. “Many say there aren't any phenomena which can’t be explained with theories formed 100 years ago. This isn't true in my view. Physicists today still cannot explain matters with the strongly correlated electronic system. There is no end to physics and its exploration,” added Sin. Sin asserts that physics is the base of all phenomena. Jeon Chae-yun chaeyun111@hanyang.ac.kr Photos by Choi Min-ju

2017-02 28 Important News

[Academics][Researcher of the Month] Blue Ocean of Materials Science

Conspicuous or not, our surroundings play a crucial role in navigating our health, holding accountability for small and big degenerations for mankind’s physical wellbeing. Among all, two indispensable elements in our life, air and water, have slow and accumulative effect on the health of the population. Professor Kim Ki-hyun (Department of Civil and Environmental Engineering), whose studies focus on environmental pollution, delineated the means of applying advanced materials in his review paper “Carbon nanotubes: a novel material for multifaceted applications in human healthcare.” Carbon nanotubes in biotechnology As modern material technology has been advancing considerably, its application seems ever-expanding in diverse fields, with nanomaterials as the convenient and indispensable companion. Based on a research paper conducted by other scholars, Kim wrote another, centralizing on the uses of carbon nanotubes (CNT), an emerging nanomaterial that is seeing the light in the biomedical and environmental fields. Its application is versatile: drug delivery, sensing, water purification, composite materials, and bone scaffolds. More specifically, CNTs could be used to alleviate myocardial infarction by enlarging clogged blood vessels, expediting drug delivery, and organizing bone structures in needed parts. Kim outlines his review paper on the application of carbon nanotubes in the biomedical field. Despite all the medical benefits, advanced materials including CNT also have the potential to bring adverse effects. As alien substances could disturb immune or antibody responses, the body functions to react against them. Especially, in case of new materials, unprecedented resistance could occur, and thus their potential impacts must be taken into consideration through attentive examination for possible toxicity. Nonetheless, as long as the criteria are met, CNT and other materials could spark revolutionary breakthroughs that would change the future of mankind. “I think that endless developments are yet to come in the field of materials science to help other research fields like environment and human health flourish. Better materials in terms of cost efficiency and functional effectiveness would be improved while there is yet no limits to such developments. Materials science and nanomaterials would not only be fruitful in biomedical fields but also environmentally,” commented Kim. His interest in new materials are extended toward environmental progress, starting with the sensing of pollutants and purifying polluted medium. The blue ocean Materials science could often be referred to as the 'blue ocean' since there are more to be discovered than what has been excavated so far. On top of this, collaboration with environmental issues is not conventional. Kim is involved in research for integrated environmental monitoring technology, digitizing and managing air, water, and soil pollution. He is looking forward to fuse newly unveiled materials in his research, hoping to bring a constructive result to lay a bridge between materials science and environmental engineering. To set an example, metal-organic frameworks (MOFs) could be used to mitigate environment pollution: volatile organic compounds (VOC) in the air spawns odor while propagating carcinogens if transferred into the human body through the respiratory system. As the material for sensing or removing such hazardous pollutants, MOFs are regarded as one of the highly promising solutions. What is to be underscored here is the infinite possibility of combination of the materials, which are not only capable of being used alone but also of being employed in cooperation with other materials. Kim's research will continue to be centered around mitigating environmental pollution with newly excavated materials. Jeon Chae-yun chaeyun111@hanyang.ac.kr Photos by Choi Min-ju

2017-02 24

[Academics]Research Institute Expands Cooperation With Africa

Hanyang University Institute for Euro-African Studies recently signed an MOU, the first among domestic universities, with government institutions and universities in Tanzania and Morocco. Hanyang University will support the training of experts in Africa and advancement of Korean SMEs. The Institute signed an MOU with major economic ministries, including Tanzania Trade Development Agency, Tourism and Investment Office, University of Dar es Salaam, and Ardhi University, on May 13th. In particular, the Tourism Authority of Tanzania has decided to appoint Hanyang University Institute for Euro-African Studies as the Korean Goodwill Ambassador to Tanzania. Prior to this, the Institute sought to cooperate with the Ministry of Urban Policy and Development in Morocco last December and signed a MOU with Mohamed V. University of Rabat the capital of Morocco. After the agreement, the Institute joined Nanjing University, China and Meiji University, Japan to co-host the Asia-Africa Cooperation International Conference. The two-way agreement with Tanzania and Moroccan agencies and universities signifies the expansion of their foundations for training regional experts on Africa and opens the way into the African market for small-to-medium Korean enterprises as well as academic exchanges. Kim Sung-soo, a professor in the Department of Political Science and International Studies, said on December 22, "The agreement has an economic significance in addition to academic significance." He added, “The entry of Korean SMEs to Africa will also greatly help Korea's economy. " ▲Prof. Kim Sung-soo

2017-02 20 Important News

[Academics]Redefining Warfare for Cyberspace Battle

Professor Eun. (Photo courtesy of Eun) Since the early 2010s, there have been reports in the media about the rising number of cyberattacks. One of the most notable incidents is the US and Israel's joint cyber assaults at Iran's nuclear facilities using the Stuxnet worm virus. The attacks focused on destroying the operation system of the installations instead of military offense. Hearing this, Professor Eun Yong-soo (Department of Political Science & International Studies) started to question the adaptability of the traditional concept of war to modern cyberattacks. The first Asian to become the editor-in-chief of the Routledge series, "International Relations (IR) Theory and Practice in Asia", Eun specializes in IR theory. His paper, "Cyberwar: Taking Stock of Security and Warfare in the Digital Age" discusses the necessity to reformulate the concept of war in the Information Era. This paper was published in International Studies Perspectives, a SSCI indexed and internationally recognized academic journel of the International Studies Association. According to a German war theorist, Karl Clausewitz, a traditional war is caused with violent means such as destruction, by an institutionalized entity, which has a political purpose to acquire certain values like power or money. Although the concept of cyberwar can be applied to this definition, it is insufficient since there are great disparities between the virtual and the physical world. First, in the case of cyberwar, it is difficult to find who is responsible for the war. "In traditional war, we know who began the attack, and who discharged the missiles. But due to the advance of digital technology, stealthy attacks are possible by circumventing Internet Protocol (IP) addresses," explained Eun. In addition, there may be individuals who serve a government or an institutionalized organization to launch a cyberattack. Second, the damage caused by cyberwar is indirect and comprehensive, whereas harm done by traditional wars occurs directly and instantaneously. If blackout occurs in organizations such as banks and digital network, the entire city becomes disordered, negatively influencing the crime rate and crashing the stock market- and in turn, affecting the whole nation's economy to gradually collapse in the long run. Finally, cyber attacks are much easier to launch than physical assaults. Traditional warfare needs money, and much challenging, as armies need maintaining and weapons have to be launched. Moreover, such attacks are spotted on radar and satellites. By comparison, cyberattacks are carried out with ease. By simple access to the Internet, the whole information network can be destroyed. “There is a concept called 'cyberwar asymmetric paradox'. Although a nation, such as the US and South Korea, boasts high information and communication technology (ICT), its proliferation and reliance means reduced cyberwar strength, because the defense ability is decreased,” Eun specified. This means that the ubiquitous Internet may easily turn many into victims of Information War. Cyberwar asymmetric paradox increases third world countries' motivation to trigger cyberwars. Since they are less subject to shutdowns by cyberattacks due to poor infrastructure, they would remain safe from any damages caused by cyberwars compared to other developed countries. A lower mark in cyber dependence makes a country more dependent. Although the US's cyber offence is stronger than North Korea, the total cyber-strength is weaker due to high cyber dependence and low cyber defence. (Photo courtesy of Eun) “Therefore, there is a need for redefining warfare. The imbalance of power is a significant aspect when analyzing causes of war, since balance of strength may restrain the desire for war. So, when analyzing national power, it is important to consider cyber-strength as an important factor of war along with GDP and military power,” Eun concluded. According to Eun, open social consensus on the extent to calling cyberattack a war is also indispensible, because of its broad and comprehensive damage. This is also significant due to possible cases where hyper securitization can be wrongfully used as a means of acquiring political advantage, labeling every major and minor cyberattack a war. In addition, open discussion, research, and creation of a manual for cyberwar is a necessity particularly in South Korea where despite all the cyberattacks caused by North Korea and high cyber-reliance, there is a lack of academic discussion regarding the issue. Eun explains the need for open discussion and academic research on cyberwar in the modern society. Currently, Eun is planning to develop diverse research theories in the field of international politics. "The theories for academics are typically Western-oriented. They don’t depict our world and its reality," Eun argued. His project is to develop non-Western international political theories. Eun is currently writing a book about the subject, which is called "What is at Stake in Building "Non-Western" International Relations Theory?", and is leading a research project about emotions influencing international politics. "There are a lot of emotional battles going on among Korea, Japan and China. I'm interested in how the collective feelings of a group or a nation affect diplomacy," he said. Turning over conventional ideas and mainstream research methods is what interests Eun, and they usually trigger his research. "Difficulties do arise when you don't follow the mainstream. Yet, I believe that thinking differently is necessary for the development of a society. Even though diverse ideas are not easily accepted, there is a need for people to vocalize thoughts that differ from the mainstream." Eun believes that voicing diverse ideas that differ from the mainstream is important for the development of society. Jang Soo-hyun luxkari@hanyang.ac.kr Photos by Choi Min-ju

2017-02 14

[Academics]Transition of PDA Crystals

In the 21st century, nanoscience is coming into the limelight, as more sophisticated technologies are urgently in need to solve crimes or enhance the quality of life. Here is the leader of the Institute of Nano Science and Technology (INST) of Hanyang University- Kim Jong-man, professor at the Department of Chemical Engineering, who is currently leading the field of nanoscience. In the paper “Photoinduced reversible phase transition of azobenzene-containing polydiacetylene crystals,” Kim revealed how an azobenzene-containing supramolecular polydiacetylene (PDA) crystal undergoes a photo-induced reversible red-to-blue phase transition accompanied by crystal tearing. Kim reveals the reversible phase transition that azobenzene-containing PDA crystals undergo. Polydiacetylene, also called as PDA, is an organic polymer that conducts electricity, which is created by the polymerization of substituted diacetylene. PDA is a commonly used compound in the scientific field, considering its multiple applications- from development of organic films to immobilizations of other molecules. Recently, Kim and his research team have found out that when azobenzene, a synthetic crystalline organic compound, is incorporated to PDAs, it showed grand responsiveness to ultraviolet (UV) radiation. “The ultimate goal of this research was to find out what kind of changes the azobenzene-containing PDA crystal undergoes when exposed to UV rays. The result was phenomenal, as crystal tearing was detected in the vulnerable areas of its crystalline structure,” said Kim. Photo-isomerization of azobenzene is a form of light-induced molecular motion, which simply means the compound is capable of absorbing light. When azobenzene is incorporated into PDA crystals, crystal tearing occurred, along with red-to-blue color phase transition between frail crystal structures. These measured up to about 25 degrees in angle. When the UV exposure was removed, the crystalline structure returned to its original state. The video above shows the reversible phase transition of azobenzene-containing PDA crystal, and its crystalline tearing, along with red-blue transition. (Video courtesy of Kim) The graph above shows the angle of crystal tearings when the UV is turned on and off. (Photo courtesy of Kim) “This crystal-tearing phenomenon was a startling finding, because in the beginning, our team only expected color changes, not alternations in the structure. This six month-long experiment proved that light, such as UV rays, can be used as remote controls to regulate nano-compounds,” mentioned Kim. A remote control of nano-particles using lights is called an ‘actuator’, and Kim is hoping to enhance the sophistication of its design based on this experiment. PDA is an intriguing compound, due to its scientifically academic characteristic and practicality. PDAs can bear several colors, mostly red and blue, which is a rare phenomenon found in an organic compound. When certain physical or chemical pressure is applied to PDAs, they usually change their color from red to blue. When the pressure is removed, the color will change back from blue to red, which is called the reversible transition phase. Using this reversibility, Kim discovered various practical applications of PDAs, such as the ‘Forged Gasoline Identification Kit’ or the 'Pore Map', which identifies inherent pore structures. Kim explains various applications of polydiacetylenes. “It is my ultimate goal to develop sensitive sensors using PDAs that can be applied to carbon nanotubes or lung cancer detectors,” added Kim. Carbon nanotubes are allotropes of carbon that are useful in a lot of areas, such as nanotechnology, optics, electronics and material sciences. The lung cancer detector that Kim desires to formulate is designed based on the fact that human breaths consist of about 40 kinds of volatile organic compounds (VOC). Among the VOCs, there is a compound called toluene, which lung cancer patients possess three times more than normal people in their breaths. Based on this, Kim longs to create a kit that can verify whether a test taker is ill or not, just by breathing into the kit. “These practical applications do have restrictions, since the area they are used for are sensitive- economically and security-wise. As a professor, I'm more interested in enhancing the academic foundation of material science, especially PDAs, for the future of nanotechnology,” said Kim. “I want my students and trainees to become scientists, not technicians. While technicians do what they are told to do, scientists ponder upon new ideas and move forward creatively. This approach will allow the futures of our students - including science - to shine.” "Becoming a questioning scientist, instead of a passive technician, is key to the bright future of science." Kim Ju-hyun kimster9421@hanyang.ac.kr Photos by Kim Youn-soo

2017-02 06

[Academics][Researcher of the Month] Al-FCG Ready for Action

Professor Sun Yang-guk of the Department of Energy Engineering is February’s Researcher of the Month for his active role in exploring the field of energy engineering. In his paper, “Compositionally Graded Cathode Material with Long-Term Cycling Stability for Electric Vehicles Application”, Sun explains how adding aluminum into the cathode makes batteries last longer and become more stable compared to other rates of composition. The Al-FCG61 that Sun has developed has shown a high rate of energy efficiency even at 100% depth of discharge (DOD), which draws attention in the field. Sun explains his research with assisted diagrams. As the supply and demand of the electric vehicle is on the rise, most of the batteries in the market last from 150km to 400km, meaning that once the battery is fully charged, the car would move between the distance within. What accounts for the difference is the capacity as to how much cathode can hold up. In order for cars to go beyond 300km at least, the capacity of the cathode would have to be over 200A/h. The only problem to this is that it gets difficult to make it stable and it could blow up. There are various prototypes ranging from generation 1 to generation 4 and the study carried out in Sun's paper is on generation 3. Gradients of different components from inner to outer parts of nickel particle. (Photo courtesy of Sun) Capacity retention, which is the lifespan of a battery, would rise with 61% of nickel with FCG full concentration gradient, which is what Sun has developed in order to create a more stable and long-lasting battery that would hold a larger capacity. Within the mold, Sun has created a two-way particle that contains a high percentage of nickel inside with lower percentage of nickel on the outside. This concentration gradient is created due to the fact that nickel has its advantage of being able to increase the capacity of the battery while it makes the battery more unstable with exothermic reaction. Along with the nickel, Sun has increased the percentage of the manganese inside the particle since it has the advantage of making the cathode more stable. Depth of discharge (DOD) is the rate at which battery is either charged 60% or 100%, and this is tested before electric vehicles are sold for inspection. The average usage of an electric vehicle is at around 2,500 cycles for 10 years, and the Al-FCG has proven to be more energy efficient even at 100%. Most of the batteries do not last long at DOD100 due to the expansion of volume inside the battery. This means that the battery would lose its efficiency as time goes. Al-FCG has shown its Coulombic efficiency rate of 84.5% even at DOD100, while batteries currently in the market show an average of 50% at 2000 cycles. This new battery devised by Sun is not only more energy efficient, but more cost efficient as well. Sun wishes to make more efficient batteries. Sun is continuously researching to keep the DOD level at 100% even after 2000 cycles. With his findings, the electric vehicle industry would definitely benefit hugely in terms of cost and energy efficiency. With different materials, Sun wishes to develop other types of batteries that would bring more comfort to society. Kim Seung-jun nzdave94@hanyang.ac.kr Photos by Kim Youn-soo