67 results on '"Ah-Young Song"'
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2. Enhanced Carbon Dioxide Capture from Diluted Streams with Functionalized Metal–Organic Frameworks
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Andrzej Gładysiak, Ah-Young Song, Rebecca Vismara, Madison Waite, Nawal M. Alghoraibi, Ammar H. Alahmed, Mourad Younes, Hongliang Huang, Jeffrey A. Reimer, and Kyriakos C. Stylianou
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Chemistry ,QD1-999 - Published
- 2024
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3. Voice and Experience: Forming Counter-Narratives through Personal Poetry
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Ah-Young Song
- Abstract
While teaching in Taiwan, Ah-Young Song found that asking students for midterm self-reflections helped them to be more attuned to their distinct educational trajectories and that their comments provided useful insights into adjustments that could be made as a teacher. This article describes how two of those English language learners from the creative writing unit approached a poetry writing assignment and used the occasion to advance biographical counternarratives, positioned against assumptions made by adult figures in their lives. The writers, despite being regarded as less capable, supplanted imposed narratives with more self-empowering conceptions of identity grounded in a recognition of their ability to exceed expectations.
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- 2019
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4. Water-Assisted Transformation of Aluminum Alloys to Ceramic Nanowires and Aerogels
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Fujia Wang, Zhijian Sun, Samik Jhulki, Wenbin Fu, Kostiantyn Turcheniuk, Billy Johnson, Doyoub Kim, Crystal Jain, Ah-Young Song, Yawei Zhang, Kaixi Chen, Aashray Narla, Wenqiang Hu, Dov Wallack, Chingping Wong, and Gleb Yushin
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General Chemical Engineering ,Biomedical Engineering ,General Materials Science - Published
- 2023
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5. Characterization of Chemisorbed Species and Active Adsorption Sites in Mg–Al Mixed Metal Oxides for High-Temperature CO2 Capture
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Alicia Lund, G. V. Manohara, Ah-Young Song, Kevin Maik Jablonka, Christopher P. Ireland, Li Anne Cheah, Berend Smit, Susana Garcia, and Jeffrey A. Reimer
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General Chemical Engineering ,Materials Chemistry ,General Chemistry - Published
- 2022
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6. Synthesis of Mg Alkoxide Nanowires from Mg Alkoxide Nanoparticles upon Ligand Exchange
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Shunrui Luo, Kostiantyn Turcheniuk, Lihua Chen, Ah-Young Song, Wenqiang Hu, Xiaolei Ren, Zifei Sun, Rampi Ramprasad, and Gleb Yushin
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General Materials Science - Abstract
We report on a new synthesis pathway for Mg
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- 2022
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7. Ginsenoside F1 Promotes Cytotoxic Activity of NK Cells via Insulin-Like Growth Factor-1-Dependent Mechanism
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Hyung-Joon Kwon, Heejae Lee, Go-Eun Choi, Soon Jae Kwon, Ah Young Song, So Jeong Kim, Woo Seon Choi, Sang-Hyun Hwang, Sun Chang Kim, and Hun Sik Kim
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natural killer cell ,ginsenoside ,cytotoxicity ,cancer surveillance ,IGF-1 ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Ginsenosides are the principal active components of ginseng and are considered attractive candidates for combination cancer therapy because they can kill tumors and have favorable safety profiles. However, the overall benefit of ginsenosides remains unclear, particularly in cancer immunosurveillance, considering the controversial results showing repression or promotion of immune responses. Here we identify a potentiating role of ginsenoside F1 (G-F1) in cancer surveillance by natural killer (NK) cells. Among 15 different ginsenosides, G-F1 most potently enhanced NK cell cytotoxicity in response to diverse activating receptors and cancer cells. G-F1 also improved cancer surveillance in mouse models of lymphoma clearance and metastatic melanoma that rely on NK cell activity. G-F1-treated NK cells exhibited elevated cytotoxic potential such as upregulation of cytotoxic mediators and of activation signals upon stimulation. NK cell potentiation by G-F1 was antagonized by insulin-like growth factor (IGF)-1 blockade and recapitulated by IGF-1 treatment, suggesting the involvement of IGF-1. Thus, our results suggest that G-F1 enhances NK cell function and may have chemotherapeutic potential in NK cell-based immunotherapy. We anticipate our results to be a starting point for further comprehensive studies of ginsenosides in the immune cells mediating cancer surveillance and the development of putative therapeutics.
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- 2018
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8. Structural Design through Test and Analysis of Structure Equipped with Vibration Isolator System
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Ah-Young Song, Sung-Hwan Yim, Byung-Oh Kwon, Dae-Hee Han, and Hye-Jin Jung
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- 2021
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9. Electrolyte melt infiltration for scalable manufacturing of inorganic all-solid-state lithium-ion batteries
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Ah-Young Song, Kostiantyn Turcheniuk, Haewon Lee, Xiaolei Ren, Shirley Huang, Gleb Yushin, Yiran Xiao, Alexandre Magasinski, Ayush Jain, and Aashray Narla
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Materials science ,Fabrication ,Mechanical Engineering ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Cathode ,0104 chemical sciences ,law.invention ,Membrane ,chemistry ,Mechanics of Materials ,law ,Electrode ,Melting point ,General Materials Science ,Lithium ,0210 nano-technology ,Electrical conductor - Abstract
All-solid-state lithium (Li) metal and lithium-ion batteries (ASSLBs) with inorganic solid-state electrolytes offer improved safety for electric vehicles and other applications. However, current inorganic ASSLB manufacturing technology suffers from high cost, excessive amounts of solid-state electrolyte and conductive additives, and low attainable volumetric energy density. Such a fabrication method involves separate fabrications of sintered ceramic solid-state electrolyte membranes and ASSLB electrodes, which are then carefully stacked and sintered together in a precisely controlled environment. Here we report a disruptive manufacturing technology that offers reduced manufacturing costs and improved volumetric energy density in all solid cells. Our approach mimics the low-cost fabrication of commercial Li-ion cells with liquid electrolytes, except that we utilize solid-state electrolytes with low melting points that are infiltrated into dense, thermally stable electrodes at moderately elevated temperatures (~300 °C or below) in a liquid state, and which then solidify during cooling. Nearly the same commercial equipment could be used for electrode and cell manufacturing, which substantially reduces a barrier for industry adoption. This energy-efficient method was used to fabricate inorganic ASSLBs with LiNi0.33Mn0.33Co0.33O2 cathodes and both Li4Ti5O12 and graphite anodes. The promising performance characteristics of such cells open new opportunities for the accelerated adoption of ASSLBs for safer electric transportation. All-solid-state lithium-ion batteries provide improved safety but typically suffer from high cost and low volumetric energy density. An electrolyte melt-infiltration approach offering reduced manufacturing costs and improved volumetric energy density in all solid cells is proposed.
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- 2021
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10. Textured Texts: Demonstration of Investment through Coded Weavings and Fictional Narratives
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Ah-Young Song
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Cultural Studies ,White (horse) ,media_common.quotation_subject ,05 social sciences ,050401 social sciences methods ,050301 education ,Investment (macroeconomics) ,Literacy ,Education ,Visual arts ,Race (biology) ,0504 sociology ,Work (electrical) ,Multiliteracy ,Narrative ,Sociology ,0503 education ,media_common - Abstract
This work draws from a larger research project that centres a youth summer writing programme. In this article, the author recounts the multiliteracy experiences of a white student who found creativ...
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- 2020
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11. An Ethico-Onto-Epistemological Approach to Literacy Research
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Ah-Young Song
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Linguistics and Language ,Research methodology ,media_common.quotation_subject ,05 social sciences ,050301 education ,Post structuralism ,06 humanities and the arts ,060202 literary studies ,Language and Linguistics ,Literacy ,Education ,Epistemology ,Educational research ,0602 languages and literature ,Sociology ,0503 education ,Adolescent literacy ,media_common - Abstract
Entanglements among humans, nonhuman objects, and spatial matter in a research site necessitate greater attention to the interwoven and sometimes invisible connections across relational bodies. This piece comments on how reevaluating approaches to participant observations in qualitative research can lead to better understandings of the dynamic interconnectedness among participants, researchers, and observational tools. Drawing from the theory of thinking without method, this research explores the complexity of documentation in an out-of-school literacy setting and argues that ethico-onto-epistemology can highlight intersections between literacy researchers and technological attachments.
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- 2020
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12. Analytically Confirm Displacement Interference in the Barrel of the Reconnaissance Equipment under Vibration
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Hye-Jin Jung, Dae-Hee Han, Byung-Oh Kwon, Sung-Whan Yim, Hyun Su Jung, and Ah-Young Song
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Physics ,Vibration ,Interference (communication) ,Acoustics ,Barrel (horology) ,Spectral density ,Displacement (vector) - Published
- 2020
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13. Conversion of Mg‐Li Bimetallic Alloys to Magnesium Alkoxide and Magnesium Oxide Ceramic Nanowires
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Aashray Narla, Ah-Young Song, Shunrui Luo, Doyoub Kim, Alexandre Magasinsky, Gleb Yushin, and Kostiantyn Turcheniuk
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Materials science ,010405 organic chemistry ,Magnesium ,Alloy ,Nanowire ,chemistry.chemical_element ,General Chemistry ,engineering.material ,010402 general chemistry ,01 natural sciences ,Catalysis ,Grain size ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Phase (matter) ,visual_art ,Alkoxide ,visual_art.visual_art_medium ,engineering ,Ceramic ,Bimetallic strip - Abstract
Technologically important composites with enhanced thermal and mechanical properties rely on the reinforcement by the high specific strength ceramic nanofibers or nanowires (NWs) with high aspect ratios. However, conventional synthesis routes to produce such ceramic NWs have prohibitively high cost. Now, direct transformation of bulk Mg-Li alloys into Mg alkoxide NWs is demonstrated without the use of catalysts, templates, expensive or toxic chemicals, or any external stimuli. This mechanism proceeds through the minimization of strain energy at the boundary of phase transformation front leading to the formation of ultra-long NWs with tunable dimensions. Such alkoxide NWs can be easily converted in air into ceramic MgO NWs with similar dimensions. The impact of the alloy grain size and Li content, synthesis temperature, inductive and steric effects of alkoxide groups on the diameter, length, composition, ductility, and oxidation of the produced NWs is discussed.
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- 2019
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14. Conversion of Mg‐Li Bimetallic Alloys to Magnesium Alkoxide and Magnesium Oxide Ceramic Nanowires
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Shunrui Luo, Kostiantyn Turcheniuk, Ah‐Young Song, Aashray Narla, Doyoub Kim, Alexandre Magasinsky, and Gleb Yushin
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General Medicine - Published
- 2019
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15. Cycle stability of conversion-type iron fluoride lithium battery cathode at elevated temperatures in polymer electrolyte composites
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Gleb Yushin, Kostiantyn Turcheniuk, Alexandre Magasinski, Ah-Young Song, Yiran Xiao, Qiao Huang, Xiaolei Ren, and Doyoub Kim
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Materials science ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,01 natural sciences ,Energy storage ,law.invention ,Metal ,chemistry.chemical_compound ,law ,General Materials Science ,chemistry.chemical_classification ,Mechanical Engineering ,General Chemistry ,Polymer ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Decomposition ,Cathode ,Lithium battery ,0104 chemical sciences ,chemistry ,Chemical engineering ,Mechanics of Materials ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Fluoride - Abstract
Metal fluoride conversion cathodes offer a pathway towards developing lower-cost Li-ion batteries. Unfortunately, such cathodes suffer from extremely poor performance at elevated temperatures, which may prevent their use in large-scale energy storage applications. Here we report that replacing commonly used organic electrolytes with solid polymer electrolytes may overcome this hurdle. We demonstrate long-cycle stability for over 300 cycles at 50 °C attained in high-capacity (>450 mAh g−1) FeF2 cathodes. The absence of liquid solvents reduced electrolyte decomposition, while mechanical properties of the solid polymer electrolyte enhanced cathode structural stability. Our findings suggest that the formation of an elastic, thin and homogeneous cathode electrolyte interphase layer on active particles is a key for stable performance. The successful operation of metal fluorides at elevated temperatures opens a new avenue for their practical applications and future successful commercialization. Metal fluoride conversion cathodes are promising for low-cost Li-ion batteries but suffer from poor performance at elevated temperatures. By replacing organic electrolytes with solid polymer electrolytes, long-cycle stability at 50 °C with high-capacity FeF2 cathodes is demonstrated.
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- 2019
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16. Scalable Pore Engineering Strategy for Promoting Ion Transport and Rate Capability in Thick Li-Ion Battery Electrodes
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Doyoub Kim, Gleb Yushin, Alexandre Magasinski, Yueyi Sun, Baolin Wang, Aashray Narla, Seung-Hun Lee, Hana Yoo, Samik Jhulki, Ah-Young Song, Jinho Hah, Ting Zhu, and Alexander Alexeev
- Abstract
Since the first commercialization of lithium-ion batteries (LIBs) in the early 1990s, previous research has been extensive on electrode material development. Due to its high volumetric energy and power densities and its low cost, the LIBs have aided in the widespread adoption of advanced mobile electronic devices, slowly spurred the market penetration of electric vehicles (EVs) globally and been incorporated in household energy storage systems to promote efficient use of renewable energy1,2. Unfortunately, after rapid improvements in LIB technology, the present progress in increasing energy density and reducing the costs of LIBs has been slow. To overcome the performance limitations on the material side, increasing the nickel (Ni) content of layered lithium nickel cobalt aluminum oxide (NCA) and lithium nickel cobalt manganese oxide (NCM) cathode materials and blending silicon with graphite anode materials have shown promise3,4,5. On the manufacturing side, there is a push to use thicker and denser electrodes and increase areal capacity loadings from 3-4 mAh/cm2 to 5-7 mAh/cm2 to reduce the mass and volume fraction of inactive materials and thus reduce costs and improve the energy density and specific energy of LIB cells beyond about 700 Wh/L and 250 Wh/kg, respectively6.-8 . Unfortunately, the characteristic Li+ ion diffusion time is proportional to the square of the average diffusion path through the electrode, which depends on both the electrode thickness and the tortuosity. As a result, the charging time and power performance characteristics in high-loading, dense electrodes may become undesirably poor. Herein, we report on several manufacturing pathways to create straight channel pores within electrodes to accelerate electrolyte wetting and facilitate rapid ion transport to overcome these rate limitations. References: Armand, M. & Tarascon, J.-M. Building Better Batteries. Nature 451, 652–657 (2008). Larcher, D. & Tarascon, J.-M. Towards greener and more sustainable batteries for Electrical Energy Storage. Nature Chemistry 7, 19–29 (2014). Manthiram, A., Knight, J. C., Myung, S.-T., Oh, S.-M. & Sun, Y.-K. Nickel-rich and lithium-rich layered oxide cathodes: Progress and perspectives. Advanced Energy Materials 6, 1501010 (2015). Liu, W. et al. Nickel-rich layered lithium transition-metal oxide for high-energy lithium-ion batteries. Angewandte Chemie International Edition 54, 4440–4457 (2015). Eshetu, G. G. et al. Production of high-energy Li-ion batteries comprising silicon-containing anodes and insertion-type cathodes. Nature Communications 12, (2021). Kuang, Y., Chen, C., Kirsch, D. & Hu, L. Thick electrode batteries: Principles, opportunities, and challenges. Advanced Energy Materials 9, 1901457 (2019). Patry, G., Romagny, A., Martinet, S. & Froelich, D. Cost modeling of lithium‐ion battery cells for Automotive Applications. Energy Science & Engineering 3, 71–82 (2014). Turcheniuk, K., Bondarev, D., Amatucci, G. G. & Yushin, G. Battery materials for low- cost electric transportation. Materials Today 42, 57–72 (2021).
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- 2022
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17. Multifunctional Microparticles with Stimulation and Sensing Capabilities for Facile NK Cell Activity Assay
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Jinho Kim, Ah Young Song, Yerin Shin, Yujin Baek, SoonHo Kweon, Jung Min Kim, Junsang Doh, Duck Cho, Hun Sik Kim, and Jeehun Park
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Chemokine ,medicine.medical_treatment ,Cell ,Bioengineering ,02 engineering and technology ,01 natural sciences ,Flow cytometry ,Interferon-gamma ,medicine ,Cytotoxicity ,Instrumentation ,Fluid Flow and Transfer Processes ,biology ,medicine.diagnostic_test ,Chemistry ,Process Chemistry and Technology ,010401 analytical chemistry ,Innate lymphoid cell ,021001 nanoscience & nanotechnology ,Flow Cytometry ,Immunity, Innate ,0104 chemical sciences ,Cell biology ,Granzyme B ,Killer Cells, Natural ,medicine.anatomical_structure ,Cytokine ,biology.protein ,Cytokines ,Cytokine secretion ,0210 nano-technology - Abstract
Natural killer (NK) cells are a subset of innate lymphoid cells playing an important role in immune surveillance and early defense against infection and cancer. They recognize and directly kill infected or transformed cells. At the same time, they produce various cytokines and chemokines to regulate other immune cells. NK cell activity can be a useful marker for health screenings because impaired NK cell functions may indicate a more susceptible environment for infection or tumor development. Currently, most NK cell activity assays are focused on measuring either cytokine secretion, in particular, interferon γ (IFN-γ), or cytotoxicity against target cells such as K562, thus only providing partial information on NK cell activity. In order to develop a comprehensive test for measuring NK cell function, cytotoxicity and cytokine secretion ability should be measured simultaneously. In addition, current NK cell assays are performed by stimulating NK cells with cocktails of cytokines, antibody-coated beads, or live target cells. In this study, we developed multifunctional microparticles for NK cell activity assay (MNAs) that allow simultaneous stimulation and sensing various NK cell activities, including cytokine secretion and cytotoxicity. The surfaces of MNAs are decorated with multiple functional biomolecules, including antibodies that stimulate NK cells by engaging NK cell activating receptors, antibodies that can capture cytokines secreted by NK cells, and a peptide sensor that reacts with granzyme B, a key molecule released by NK cells for cytotoxicity. The performances of MNAs are assessed using flow cytometry and live cell imaging. NK cell activity is measured by simply mixing MNAs with NK cells and performing flow cytometry, and the results are comparable to those measured by standard NK cell activity assays.
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- 2021
18. Transformation of bulk alloys to inorganic nanowires
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Danni Lei, Jim Benson, Ah-Young Song, Shunrui Luo, Gleb Yushin, Alexandre Magasinski, Fujia Wang, and Kostiantyn Turcheniuk
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- 2020
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19. Long cycle stability of conversion metal fluoride cathodes in polymer electrolytes
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Do-Youb Kim, Alexandre Magasinski, Yiran Xiao, Ah-Young Song, Gleb Yushin, Dmitry Bondarev, Xiaolei Ren, Qiao Huang, and Kostiantyn Turcheniuk
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- 2020
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20. Kokumi Taste Active Peptides Modulate Salt and Umami Taste
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Jie Qian, Shobha Mummalaneni, Vijay Lyall, Mee-Ra Rhyu, Ah-Young Song, Hee-Jin Son, Eun-Young Kim, Yi-Seul Kim, and John R. Grider
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0301 basic medicine ,Taste ,Salt (chemistry) ,lcsh:TX341-641 ,Stimulation ,Peptide ,Umami ,salty ,Pharmacology ,Article ,kokumi ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,amiloride-insensitive salt taste pathway ,Benzamil ,chorda tympani ,Animals ,Humans ,Channel blocker ,Sodium Chloride, Dietary ,chemistry.chemical_classification ,Nutrition and Dietetics ,Sodium ,Glutamate receptor ,Fishes ,Taste Perception ,Taste Buds ,umami ,Korean soy sauce ,Electrophysiological Phenomena ,Rats ,030104 developmental biology ,chemistry ,Models, Animal ,lcsh:Nutrition. Foods and food supply ,030217 neurology & neurosurgery ,Food Science - Abstract
Kokumi taste substances exemplified by g-glutamyl peptides and Maillard Peptides modulate salt and umami tastes. However, the underlying mechanism for their action has not been delineated. Here, we investigated the effects of a kokumi taste active and inactive peptide fraction (500-10,000 Da) isolated from mature (FIIm) and immature (FIIim) Ganjang, a typical Korean soy sauce, on salt and umami taste responses in humans and rodents. Only FIIm (0.1&ndash, 1.0%) produced a biphasic effect in rat chorda tympani (CT) taste nerve responses to lingual stimulation with 100 mM NaCl + 5 mM benzamil, a specific epithelial Na+ channel blocker. Both elevated temperature (42 °, C) and FIIm produced synergistic effects on the NaCl + benzamil CT response. At 0.5% FIIm produced the maximum increase in rat CT response to NaCl + benzamil, and enhanced salt taste intensity in human subjects. At 2.5% FIIm enhanced rat CT response to glutamate that was equivalent to the enhancement observed with 1 mM IMP. In human subjects, 0.3% FIIm produced enhancement of umami taste. These results suggest that FIIm modulates amiloride-insensitive salt taste and umami taste at different concentration ranges in rats and humans.
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- 2020
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21. Preservation of red pepper flakes using microwave-combined cold plasma treatment
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Ah Young Song, Yeong Ji Oh, Jung Eun Kim, and Sea C. Min
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0303 health sciences ,Nutrition and Dietetics ,biology ,030309 nutrition & dietetics ,Chemistry ,fungi ,Bacillus cereus ,Food preservation ,food and beverages ,Aspergillus flavus ,04 agricultural and veterinary sciences ,biology.organism_classification ,Ascorbic acid ,040401 food science ,Spore ,Dihydrocapsaicin ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Cereus ,Pepper ,Food science ,Agronomy and Crop Science ,Food Science ,Biotechnology - Abstract
Red pepper flakes are often contaminated with various microorganisms; however, any technologies aiming to decontaminate the flakes should also maintain their quality properties. This study investigated the effect of microwave-combined cold plasma treatment (MCPT) at different microwave power densities on microbial inactivation and preservation of red pepper flakes. Red pepper flake samples inoculated with spores of Bacillus cereus or Aspergillus flavus and without inoculation were subjected to MCPT at 900 W for 20 min at either low microwave power density (LMCPT, 0.17 W m-2 ) or high microwave power density (HMCPT, 0.25 W m-2 ).; Results: The numbers of B. cereus and A. flavus spores on red pepper flakes after LMCPT and HMCPT were initially reduced by 0.7 ± 0.1 and 1.4 ± 0.3 log spores cm-2 and by 1.5 ± 0.3 and 1.5 ± 0.2 log spores cm-2 respectively and remained constant for 150 days at 25 °C. Immediately after HMCPT, the concentrations of capsaicin and ascorbic acid in the flakes were significantly lower than in untreated samples; however, no difference in concentration was detected during storage. Neither LMCPT nor HMCPT affected the antioxidant activity or color of the flakes during storage. LMCPT also did not affect the sensory properties and the concentrations of capsaicin and dihydrocapsaicin of the flakes, indicating its suitability in preserving their quality properties.; Conclusion: MCPT may provide an effective non-thermal treatment for food preservation which can improve the microbial safety and stability of red pepper flakes while maintaining intact their qualitative properties. © 2018 Society of Chemical Industry.; © 2018 Society of Chemical Industry.
- Published
- 2018
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22. Development of Anti-Insect Microencapsulated Polypropylene Films Using a Large Scale Film Coating System
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Jaejoon Han, Seacheol Min, Ah Young Song, Ha Young Choi, and Eun Song Lee
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0106 biological sciences ,Polypropylene ,Thermogravimetric analysis ,Materials science ,04 agricultural and veterinary sciences ,Polyethylene ,040401 food science ,01 natural sciences ,Polyvinyl alcohol ,Cinnamaldehyde ,chemistry.chemical_compound ,Film coating ,Low-density polyethylene ,0404 agricultural biotechnology ,chemistry ,Chemical engineering ,010608 biotechnology ,Emulsion ,Food Science - Abstract
Films containing microencapsulated cinnamon oil (CO) were developed using a large‐scale production system to protect against the Indian meal moth (Plodia interpunctella). CO at concentrations of 0%, 0.8%, or 1.7% (w/w ink mixture) was microencapsulated with polyvinyl alcohol. The microencapsulated CO emulsion was mixed with ink (47% or 59%, w/w) and thinner (20% or 25%, w/w) and coated on polypropylene (PP) films. The PP film was then laminated with a low‐density polyethylene (LDPE) film on the coated side. The film with microencapsulated CO at 1.7% repelled P. interpunctellamost effectively. Microencapsulation did not negatively affect insect repelling activity. The release rate of cinnamaldehyde, an active repellent, was lower when CO was microencapsulated than that in the absence of microencapsulation. Thermogravimetric analysis exhibited that microencapsulation prevented the volatilization of CO. The tensile strength, percentage elongation at break, elastic modulus, and water vapor permeability of the films indicated that microencapsulation did not affect the tensile and moisture barrier properties (P> 0.05). The results of this study suggest that effective films for the prevention of Indian meal moth invasion can be produced by the microencapsulation of CO using a large‐scale film production system. Low‐density polyethylene‐laminated polypropylene films printed with ink incorporating microencapsulated cinnamon oil using a large‐scale film production system effectively repelled Indian meal moth larvae. Without altering the tensile and moisture barrier properties of the film, microencapsulation resulted in the release of an active repellent for extended periods with a high thermal stability of cinnamon oil, enabling commercial film production at high temperatures. This anti‐insect film system may have applications to other food‐packaging films that use the same ink‐printing platform.
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- 2018
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23. 'Meta-Talk' as a Composition Tool: Promoting Reflective Dialogue During the Drafting Process
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Ah-Young Song
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060201 languages & linguistics ,Cultural Studies ,Multimedia ,Process (engineering) ,05 social sciences ,Metalinguistics ,050301 education ,Citizen journalism ,06 humanities and the arts ,computer.software_genre ,0602 languages and literature ,Composition process ,Pedagogy ,ComputingMilieux_COMPUTERSANDEDUCATION ,Sociology ,0503 education ,computer ,Composition (language) - Abstract
This article argues for expanded opportunities for metalinguistic dialogue and written response rounds in order to better understand students' needs. Encouraging students to reflect on their compositions can invite multiple stylistic approaches and inform a more participatory composition process. The writing explores theoretical underpinnings, makes a case for metalinguistic dialogue, and remarks on the use of written exchanges between students and teachers.
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- 2017
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24. ¿Y tú quién eres? Interviews as Project-Based Learning at a Multicultural College Community
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Adrián Gras-Velázquez, Julia Chindemi-Vila, and Ah-Young Song
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- 2019
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25. Progressive Impairment of NK Cell Cytotoxic Degranulation Is Associated With TGF-β1 Deregulation and Disease Progression in Pancreatic Cancer
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Eunsung Jun, Ah Young Song, Ji-Wan Choi, Hyeon Ho Lee, Mi-Yeon Kim, Dae-Hyun Ko, Hyo Jeong Kang, Seong Who Kim, Yenan Bryceson, Song Cheol Kim, and Hun Sik Kim
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lcsh:Immunologic diseases. Allergy ,Cytotoxicity, Immunologic ,pancreatic cancer ,Immunology ,Peripheral blood mononuclear cell ,Cell Degranulation ,Flow cytometry ,Transforming Growth Factor beta1 ,TGF-β1 ,Pancreatic cancer ,Biomarkers, Tumor ,medicine ,Humans ,Immunology and Allergy ,Cytotoxic T cell ,Original Research ,natural killer cells ,medicine.diagnostic_test ,business.industry ,Degranulation ,Cancer ,medicine.disease ,NKG2D ,Killer Cells, Natural ,Pancreatic Neoplasms ,Immunosurveillance ,Disease Progression ,Cancer research ,cytotoxicity ,prognosis ,lcsh:RC581-607 ,business - Abstract
Natural killer (NK) cells are key effectors in cancer immunosurveillance and can be used as a prognostic biomarker in diverse cancers. Nonetheless, the role of NK cells in pancreatic cancer (PC) remains elusive, given conflicting data on their association with disease prognosis. In this study, using conventional K562 target cells and complementary engineered target cells providing defined and synergistic stimulation for NK cell activation, a correlation between impaired NK cell cytotoxic degranulation and PC progression was determined. Peripheral blood mononuclear cells (PBMCs) from 31 patients with newly diagnosed PC, 24 patients with non-malignant tumors, and 37 healthy controls were analyzed by flow cytometry. The frequency, phenotype, and effector functions of the NK cells were evaluated, and correlations between NK cell functions and disease stage and prognosis were analyzed. The results demonstrated that effector functions, but not frequency, of NK cells was progressively decreased on a per-cell basis during PC progression. Impaired cytotoxic degranulation, but not IFN-γ production, was associated with clinical features indicating disease progression, such as high serum CA19-9 and high-grade tumors. Significantly, this impairment correlated with cancer recurrence and mortality in a prospective analysis. Furthermore, the impaired cytotoxic degranulation was unrelated to NKG2D downregulation but was associated with increased circulating and tumor-associated TGF-β1 expression. Thus, NK cell cytotoxic activity was associated with PC progression and may be a favorable biomarker with predictive and prognostic value in PC.
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- 2019
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26. Critical Media Literacies in the Twenty-First Century: Writing Autoethnographies, Making Connections, and Creating Virtual Identities
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Ah-Young Song
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Multimedia ,Communication ,05 social sciences ,Media studies ,Twenty-First Century ,050301 education ,computer.software_genre ,Education ,Social integration ,Critical theory ,Ethnography ,Media literacy ,0501 psychology and cognitive sciences ,Sociology ,Computer-mediated communication ,0503 education ,computer ,Global education ,Cultural pluralism ,050104 developmental & child psychology - Published
- 2017
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27. Comparison of effectiveness of edible coatings using emulsions containing lemongrass oil of different size droplets on grape berry safety and preservation
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Yoon Ah Oh, Ah Young Song, Yeong Ji Oh, Kyung Bin Song, Jin Sung Won, and Sea C. Min
- Subjects
0301 basic medicine ,030109 nutrition & dietetics ,Chromatography ,Antioxidant ,medicine.medical_treatment ,04 agricultural and veterinary sciences ,engineering.material ,040401 food science ,law.invention ,Chitosan ,Pascalization ,03 medical and health sciences ,chemistry.chemical_compound ,0404 agricultural biotechnology ,chemistry ,Coating ,law ,Emulsion ,engineering ,medicine ,Particle ,Food science ,Essential oil ,Food Science ,Mesophile - Abstract
Effects of lemongrass oil (LO) droplet size in the LO/chitosan emulsion on the emulsion's coating effectiveness in improving microbiological safety and preserving grape berries ( Vitis vinifera L. × V. labruscana Bailey) were investigated. LO was homogenized with a chitosan solution (1 g/100 g) and Tween 20 (0.25 g/100 g) by high shear mixing (HSM; 10,000 rpm, 1 min) or dynamic high pressure processing (DHP; 103–172 MPa, 1–3 passes), forming LO coating emulsions. The particle sizes of the HSM and DHP emulsions were 461.9–632.6 nm and 204.2–378.8 nm, respectively. DHP emulsions were more stable than HSM emulsions. Compared with the HSM emulsion, the DHP emulsion coating resulted in higher initial inhibition of Salmonella typhimurium ; greater growth inhibition of total mesophilic aerobes, yeasts, and molds; and retention of color, total soluble solid content, and antioxidant activity during storage at 25 °C ( P Salmonella and preserving grape berries, compared with the coating with larger droplets.
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- 2017
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28. Direct potentiation of NK cell cytotoxicity by 8-azaguanine with potential antineoplastic activity
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Ah Young Song, Nayoung Kim, Hun Sik Kim, Inki Kim, Sojung Park, Hye-Ran Park, Woo Seon Choi, and Ji-Wan Choi
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0301 basic medicine ,Cytotoxicity, Immunologic ,Immunology ,Antineoplastic Agents ,Cytoplasmic Granules ,Lymphocyte Activation ,Granzymes ,Chemical library ,Small Molecule Libraries ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Amphotericin B ,Fluoxetine ,Immunology and Allergy ,Humans ,Immunologic Factors ,Cytotoxicity ,Cells, Cultured ,Pharmacology ,Cytolytic granule ,biology ,Perforin ,Azaguanine ,Long-term potentiation ,Killer Cells, Natural ,030104 developmental biology ,chemistry ,Granzyme ,030220 oncology & carcinogenesis ,Hematologic Neoplasms ,biology.protein ,Cancer research ,8-Azaguanine ,Drug Screening Assays, Antitumor ,Conjugate - Abstract
This study identified 8-azaguanine (8-AG) as a novel immunomodulatory drug (IMiD) through a high-throughput screen of the Preswick Chemical Library in a model of human NK cell cytotoxicity against blood cancer cells. 8-AG, originally developed as an antineoplastic agent, significantly increased the cytotoxicity of NK cells and was superior in this activity to previously known IMiDs, such as fluoxetine and amphotericin B, identified from the same library. IFN-γ expression was also slightly increased by 8-AG. Mechanistically, 8-AG increased conjugate formation between NK and target cells and subsequent cytolytic granule polarization, but not calcium mobilization, regulation of activating receptors, or expression of perforin or granzyme B. Thus, the antineoplastic activity of 8-AG should be re-evaluated in light of this novel potentiating effect on NK cells.
- Published
- 2018
29. Preservation of red pepper flakes using microwave-combined cold plasma treatment
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Jung Eun, Kim, Yeong Ji, Oh, Ah Young, Song, and Sea C, Min
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Spores, Bacterial ,Bacillus cereus ,Plasma Gases ,Food Preservation ,Capsaicin ,Capsicum ,Microwaves ,Aspergillus flavus - Abstract
Red pepper flakes are often contaminated with various microorganisms; however, any technologies aiming to decontaminate the flakes should also maintain their quality properties. This study investigated the effect of microwave-combined cold plasma treatment (MCPT) at different microwave power densities on microbial inactivation and preservation of red pepper flakes. Red pepper flake samples inoculated with spores of Bacillus cereus or Aspergillus flavus and without inoculation were subjected to MCPT at 900 W for 20 min at either low microwave power density (LMCPT, 0.17 W mThe numbers of B. cereus and A. flavus spores on red pepper flakes after LMCPT and HMCPT were initially reduced by 0.7 ± 0.1 and 1.4 ± 0.3 log spores cmMCPT may provide an effective non-thermal treatment for food preservation which can improve the microbial safety and stability of red pepper flakes while maintaining intact their qualitative properties. © 2018 Society of Chemical Industry.
- Published
- 2018
30. Cold Oxygen Plasma Treatments for the Improvement of the Physicochemical and Biodegradable Properties of Polylactic Acid Films for Food Packaging
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Sea C. Min, Yoon Ah Oh, Si Hyeon Roh, Ji Hyeon Kim, and Ah Young Song
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Materials science ,Weight change ,chemistry.chemical_element ,Nanotechnology ,04 agricultural and veterinary sciences ,02 engineering and technology ,Biodegradation ,equipment and supplies ,021001 nanoscience & nanotechnology ,040401 food science ,Oxygen ,Contact angle ,Food packaging ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Polylactic acid ,chemistry ,Chemical engineering ,Ultimate tensile strength ,0210 nano-technology ,Photodegradation ,Food Science - Abstract
The effects of cold plasma (CP) treatment on the physicochemical and biodegradable properties of polylactic acid (PLA) films were studied. The PLA films were exposed to CP for 40 min at 900 W and 667 Pa using oxygen as the plasma-forming gas. The tensile, optical, and dynamic mechanical thermal properties, surface morphology, printability, water contact angle, chemical structure, weight change, and biodegradability properties of the films were evaluated during storage for up to 56 d. The tensile and optical properties of the PLA films were not significantly affected by CP treatment (CPT; P > 0.05). The surface roughness and water contact angle of PLA films increased by CPT and further increased during storage for 56 d. The printability of the PLA films increased following CPT and remained stable throughout the storage period. CP-induced hydrophilicity was also sustained during the storage period. The PLA films lost 1.9% of their weight after CPT, but recovered 99.5% of this loss after 14 d in storage. Photodegradation, thermal, and microbial biodegradable properties of the films were significantly improved by CPT (P < 0.05). Accelerated biodegradation of CP-treated PLA sachets with and without cheese was observed in compost. These results demonstrate the potential of CPT for modifying the stiffness, water contact angle, and chemical structure of PLA films and improving the printability and biodegradability of the films for food packaging.
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- 2015
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31. Cold plasma treatment for microbial safety and preservation of fresh lettuce
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Deog-Hwan Oh, Jung Eun Kim, Ah Young Song, Yeong Ji Oh, Kyung Bin Song, and Sea C. Min
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endocrine system ,Salmonella ,Microbial safety ,endocrine system diseases ,Plasma treatment ,Biology ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,digestive system diseases ,Microbiology ,medicine ,heterocyclic compounds ,Food science ,neoplasms ,Escherichia coli ,Food Science ,Biotechnology - Abstract
Cold plasma treatment (CPT) was investigated for inhibition of foodborne pathogens and extension of fresh lettuce storage life. Lettuce samples were treated with CP at 400 W and 900 W for 10 min for assessment of the effects of CPT on inhibition of Escherichia coli O157:H7 and Salmonella Typhimurium, and on physicochemical and sensory properties of lettuce. N2, an N2-O2 mixture, and He effectively formed CP against both pathogens. CPT inhibited both pathogens on lettuce by up to 2.8 log CFU/g. The Weibull model adequately described the degree of microbial inhibition using CPT. N2-CPT did not affect the sensory properties of lettuce. N2-CPT resulted in a bacteriostatic effect against growth of E. coli O157:H7 but did not affect physicochemical properties of lettuce during storage. CPT demonstrated potential for improving the microbial safety of vegetables without loss of physicochemical or sensory properties.
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- 2015
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32. Development of Microencapsulated Cinnamon Oil-coated Polypropylene Film Using a Pilot-plant Scale Film Coating System
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Sea C. Min, Ah Young Song, and Yoon Ah Oh
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Polypropylene ,chemistry.chemical_compound ,Film coating ,Pilot plant ,Materials science ,chemistry ,Scale (ratio) ,Composite material ,Cinnamon Oil ,Food Science - Published
- 2015
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33. Hollow titanium dioxide spheres as anode material for lithium ion battery with largely improved rate stability and cycle performance by suppressing the formation of solid electrolyte interface layer
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Baohua Li, Yanjie He, Zhiqun Lin, Beibei Jiang, Di Yang, Yan-Bing He, Ah-Young Song, Yingkui Yang, Cuiping Han, and Mengye Wang
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chemistry.chemical_classification ,Anatase ,Materials science ,Renewable Energy, Sustainability and the Environment ,Nanoparticle ,Nanotechnology ,General Chemistry ,Electrolyte ,Electrochemistry ,Lithium-ion battery ,Amorphous solid ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,Titanium dioxide ,General Materials Science ,Alkyl - Abstract
By subjecting amorphous titanium dioxide (TiO2) colloidal spheres as a scaffold to a two-step external template-free hydrothermal treatment, anatase TiO2 hollow spheres with an average diameter of 410 nm and shell thickness of 65 nm were successfully yielded. Such hollow TiO2 nanostructures possessed a large surface area, abundant active sites and reduced Li ion diffusion path and thus were highly favorable for use in TiO2-based lithium ion batteries (LIB). Electrochemical measurements revealed that as-prepared TiO2 hollow spheres exhibited specific discharge capacities of 296, 185, 118, 66 and 37 mA h g−1 at 0.1 C, 1 C, 2 C, 5 C and 10 C, respectively. This is in sharp contrast to the considerably lower values obtained in TiO2 solid nanoparticles (i.e., 182, 119, 81, 43 18 mA h g−1 at discharge rates of 0.1 C, 1 C, 2 C, 5 C and 1 0 C, respectively). Interestingly, TiO2 hollow spheres showed a large irreversible capacity loss and relatively low cycling performance due to the residual chemisorbed water in TiO2 and hydroxyl groups present on the TiO2 surface. A solid electrolyte interface (SEI) layer composed primarily of Li2CO3, lithium alkyl carbonates and organic phosphates was thus formed on the surface of hollow TiO2 spheres, thereby leading to an increased internal cell impedance and the decreased rate and cycling performance. The subsequent high-temperature annealing effectively removed chemisorbed water and hydroxyls on the TiO2 surface. As a consequence, annealed TiO2 hollow spheres rendered markedly improved rate stability and cycle performance in the resulting TiO2-based LIBs. The specific discharge capacities at rates of 5 C and 10 C were 77 mA h g−1 and 50 mA h g−1, which are considerably larger than those obtained from as-prepared TiO2 hollow spheres. Moreover, compared to only 42.1% for as-prepared hollow TiO2 spheres, a capacity retention as high as 93.5% over 200 cycles at 1 C was achieved for annealed hollow TiO2 spheres.
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- 2015
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34. Development of Anti-Insect Microencapsulated Polypropylene Films Using a Large Scale Film Coating System
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Ah Young, Song, Ha Young, Choi, Eun Song, Lee, Jaejoon, Han, and Sea C, Min
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Insecta ,Drug Compounding ,Food Packaging ,Temperature ,Moths ,Polypropylenes ,Permeability ,Polyethylene ,Food Preservation ,Insect Repellents ,Larva ,Polyvinyl Alcohol ,Tensile Strength ,Oils, Volatile ,Animals ,Humans ,Emulsions ,Acrolein - Abstract
Films containing microencapsulated cinnamon oil (CO) were developed using a large-scale production system to protect against the Indian meal moth (Plodia interpunctella). CO at concentrations of 0%, 0.8%, or 1.7% (w/w ink mixture) was microencapsulated with polyvinyl alcohol. The microencapsulated CO emulsion was mixed with ink (47% or 59%, w/w) and thinner (20% or 25%, w/w) and coated on polypropylene (PP) films. The PP film was then laminated with a low-density polyethylene (LDPE) film on the coated side. The film with microencapsulated CO at 1.7% repelled P. interpunctella most effectively. Microencapsulation did not negatively affect insect repelling activity. The release rate of cinnamaldehyde, an active repellent, was lower when CO was microencapsulated than that in the absence of microencapsulation. Thermogravimetric analysis exhibited that microencapsulation prevented the volatilization of CO. The tensile strength, percentage elongation at break, elastic modulus, and water vapor permeability of the films indicated that microencapsulation did not affect the tensile and moisture barrier properties (P0.05). The results of this study suggest that effective films for the prevention of Indian meal moth invasion can be produced by the microencapsulation of CO using a large-scale film production system.Low-density polyethylene-laminated polypropylene films printed with ink incorporating microencapsulated cinnamon oil using a large-scale film production system effectively repelled Indian meal moth larvae. Without altering the tensile and moisture barrier properties of the film, microencapsulation resulted in the release of an active repellent for extended periods with a high thermal stability of cinnamon oil, enabling commercial film production at high temperatures. This anti-insect film system may have applications to other food-packaging films that use the same ink-printing platform.
- Published
- 2017
35. Understanding Li‐Ion Dynamics in Lithium Hydroxychloride (Li 2 OHCl) Solid State Electrolyte via Addressing the Role of Protons
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Ah-Young Song, Johannes Leisen, Lamartine Meda, Oleg Borodin, Gleb Yushin, Yiran Xiao, and Kostiantyn Turcheniuk
- Subjects
Materials science ,Solid-state nuclear magnetic resonance ,chemistry ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Ionic conductivity ,chemistry.chemical_element ,General Materials Science ,Lithium ,Solid state electrolyte ,Ion transporter ,Ion - Published
- 2020
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36. Flexible Nanofiber‐Reinforced Solid Polymer Lithium‐Ion Battery
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Ah-Young Song, Kostiantyn Turcheniuk, Kyounghwa Kim, Gleb Yushin, Qiao Huang, Xiaolei Ren, Yiran Xiao, and Fujia Wang
- Subjects
chemistry.chemical_classification ,Infiltration (hydrology) ,General Energy ,Materials science ,chemistry ,Reinforced solid ,Nanofiber ,Polymer ,Composite material ,Lithium-ion battery - Published
- 2019
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37. An evaluation of the factor structure of the change assessment inventory for domestic violence among Korean batterers
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Jae Yop Kim and Ah Young Song
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South Korea -- Social aspects ,Abusive men -- Laws, regulations and rules ,Intervention (Civil procedure) -- Analysis ,Family violence -- Cases ,Company legal issue ,Government regulation ,Sociology and social work - Published
- 2009
38. Synthesis and magnetic properties of multifunctional CoPtAu nanoparticles
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Ji Hyun Min, Jun Hua Wu, Ah Young Song, In Tak Jeon, Jae-Seon Ju, and Young Keun Kim
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Cobalt alloys -- Magnetic properties ,Cobalt alloys -- Structure ,Gold alloys -- Magnetic properties ,Gold alloys -- Structure ,Platinum -- Magnetic properties ,Transmission electron microscopes -- Usage ,X-rays -- Diffraction ,X-rays -- Usage ,Physics - Abstract
The synthesis and magnetic properties of multifunctional CoPtAu alloy nanoparticles of three compositions by a modified polyol process are described. The x-ray diffraction and transmission electron microscopy analyses have shown the formation of the alloy nanostructure comprising Au-rich and Pt-rich nanophases, with a narrow distribution of particle sizes and have provided the structural arrangements.
- Published
- 2009
39. Three-dimensional kinematic analysis of pelvic and lower extremity differences during trunk rotation in subjects with and without chronic low back pain
- Author
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Ah Young Song, Paul S. Sung, Hang Jin Jo, and Yoon Hyuk Kim
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Adult ,Male ,medicine.medical_specialty ,Rotation ,Posture ,Physical Therapy, Sports Therapy and Rehabilitation ,Thigh ,Pelvis ,medicine ,Postural Balance ,Humans ,Orthodontics ,business.industry ,Biomechanics ,Middle Aged ,Low back pain ,Trunk ,Sagittal plane ,Biomechanical Phenomena ,Transverse plane ,medicine.anatomical_structure ,Lower Extremity ,Chronic Disease ,Physical therapy ,Female ,medicine.symptom ,business ,Low Back Pain - Abstract
Objective To investigate three-dimensional angular changes of the pelvis and lower extremities during trunk axial rotation in subjects with and without chronic low back pain (LBP). Design Repeated-measures design. Participants Thirty volunteers participated in the study (15 with LBP, 15 without LBP). The mean age of the subjects was 44 (standard deviation 15.8) years (range 27 to 63 years). Main outcome measures All participants were asked to perform five sets of axial trunk rotation activities with a bar in a standing position. The outcome measures included three-dimensional rotational angles of the pelvis and lower extremities (foot, calf and thigh). Results The angular change of the pelvis in the sagittal plane differed between subjects with and without LBP ( P = 0.03). There were no significant differences in angular changes of the lower extremities in the frontal and transverse planes between groups. Conclusions The angular change of the pelvis in the sagittal plane differed significantly between groups. Further research is needed to investigate the three-dimensional characteristics of biomechanical and neuromuscular aspects in subjects with LBP.
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- 2012
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40. Phospholipid-driven long-range ordering of Fe3O4 nanoparticles
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Hyeun Hwan An, Hyung Soo Ahnn, Jung Hoon Kim, Young Keun Kim, Ah-Young Song, Chong Seung Yoon, and Dae Hoon Kwon
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Range (particle radiation) ,Spin coating ,Materials science ,Superlattice ,General Physics and Astronomy ,Nanoparticle ,Nanotechnology ,Surfaces and Interfaces ,General Chemistry ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Chemical engineering ,Particle-size distribution ,Monolayer ,Molecule ,Self-assembly - Abstract
N-(1-(2,3-dioleoyloxy)propyl)-N,N,N-trimethylammonium chloride (DOTAP) lipid molecules were used to drive the self-assembly of pre-fabricated Fe 3 O 4 nanoparticles (∼10 nm in size) into a tightly packed hexagonal array by spin coating. In spite of the relatively wide particle size distribution of the pre-fabricated nanoparticles, the nanoparticles encapsulated by the DOTAP lipid molecules were self-assembled into a two-dimensional superlattice over a large area because the monolayer of DOTAP molecules attached to the particles surface provided the force necessary to anchor the nanoparticles on the substrate surface during spin coating as well as the force necessary to hold the particles together. It is expected that the proposed method can be easily scalable to an industrial process and be also adapted to different nanoparticle systems by appropriate selection of the encapsulating lipid molecules.
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- 2011
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41. Synthesis and Magnetic Properties of Multifunctional Fe$_{3}$O$_{4}$-AuPt Core-Shell Nanoparticles
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Ji Sung Lee, Jun Hua Wu, Ah-Young Song, Reasmey P. Tan, Ji Hyun Min, and Young Keun Kim
- Subjects
Materials science ,Nanostructure ,Chemical engineering ,Ferromagnetism ,Surface plasmon ,X-ray crystallography ,Nanoparticle ,Nanotechnology ,Particle size ,Electrical and Electronic Engineering ,Surface plasmon resonance ,Electronic, Optical and Magnetic Materials ,Superparamagnetism - Abstract
This paper describes the synthesis and magnetic properties of multifunctional Fe3O4-AuPt core-shell nanoparticles. The Fe3O4-AuPt core-shell nanoparticles were synthesized by a one-pot polyol process in two consecutive steps from Fe, Au, and Pt precursors. The structural characterization and property analysis proves the formation of the core-shell nanostructure fusing the multifunctionality in a single entity. The TEM observation shows that the Fe3O4-AuPt core-shell nanoparticles are highly crystalline and uniform in size distribution, with an averaged particle size of ~12.5 nm in diameter, whereas the X-ray diffraction patterns provide further substantiation. The surface plasmon resonance arising from the AuPt nano-shell was revealed by UV-vis spectroscopy, while the magnetic measurements by VSM and PPMS demonstrate the well-defined superparamagnetic and/or soft-ferromagnetic behavior of the Fe3O4-AuPt core-shell nanoparticles.
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- 2009
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42. Comparison of Endothelium-Dependent Vasorelaxation of Crude Ginsenosides from Mountain-Grown Ginseng and Red Ginseng
- Author
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Jun-Gyo In, Young Joo Lee, Ah-Young Song, and Mee-Ra Rhyu
- Subjects
Biological activity ,Plant Science ,Propranolol ,Biology ,Pharmacology ,Nitric oxide ,Nitric oxide synthase ,Atropine ,chemistry.chemical_compound ,Ginseng ,chemistry ,Biochemistry ,Muscarinic acetylcholine receptor ,medicine ,biology.protein ,Cyclooxygenase ,medicine.drug - Abstract
Mountain-grown ginseng (Panax ginseng C. A. Meyer; Sansam in Korean) is believed to possess more potent biological activity than red ginseng. This study examined the endothelium-dependent vasorelaxant effects and possible mechanisms of crude ginsenosides from adventitious roots of Korean mountain-grown ginseng (GS-ARMG) and red ginseng (GS-RG) in isolated rat aorta pre-contracted with norepinephrine. GS-ARMG (0.03–3.0 mg/mL) produced transient acute relaxation in a concentration-dependent manner, with a maximum relaxation (mean ± SEM) of 90 ± 9% and a median effective concentration (EC50) of 0.09 ± 0.07 mg/mL. GS-ARMG displayed about 25-fold more potent activity than GS-RG (maximum relaxation 50 ± 4%, EC50 2.34 ± 1.30 mg/mL). Relaxations induced by both GS-ARMG (1.0 mg/mL) and GS-RG (1.0 mg/mL) were nearly abolished by endothelial ablation or pre-treatment with N G -nitro-l-arginine, a nitric oxide synthase inhibitor, or by methylene blue, a soluble guanylate cyclase inhibitor. These inhibitory effects, however, revealed different sensitivity of GS-ARMG and GS-RG; the maximum relaxations attained were 30–38% and 13–17% that of untreated preparations, respectively, but indomethacin and cyclooxygenase inhibitors did not affect the response. None of the receptor antagonists, atropine, diphenhydramine, [D-Pro2, D-Trp7, 9]-substance P, or propranolol, caused any significant inhibition to GS-ARMG-induced relaxation; however, atropine or propranolol caused a 10% reduction in the relaxation, suggesting possible involvement of a muscarinic receptor or a β-adrenoceptor in the GS-ARMG-induced relaxation. These results demonstrate that GS-ARMG produces endothelium-dependent relaxation of isolated rat aorta similar to that of GS-RG; increased nitric oxide production and increased vascular levels of cGMP in endothelial cells could contribute to the relaxation. However, GS-ARMG has more potent activity than GS-RG to relax isolated rat aorta though an active substance(s), which might be higher in mountain-grown ginseng due to the growing conditions on mountains or the processing during manufacture of GS-ARMG. These factors may contribute to understanding the biological beneficial effects of mountain-grown ginseng.
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- 2009
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43. Cold Oxygen Plasma Treatments for the Improvement of the Physicochemical and Biodegradable Properties of Polylactic Acid Films for Food Packaging
- Author
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Ah Young, Song, Yoon Ah, Oh, Si Hyeon, Roh, Ji Hyeon, Kim, and Sea C, Min
- Subjects
Plasma Gases ,Polymers ,Polyesters ,Food Packaging ,Water ,Biodegradable Plastics ,Oxygen ,Soil ,Food Storage ,Cheese ,Food Preservation ,Tensile Strength ,Lactic Acid ,Hydrophobic and Hydrophilic Interactions - Abstract
The effects of cold plasma (CP) treatment on the physicochemical and biodegradable properties of polylactic acid (PLA) films were studied. The PLA films were exposed to CP for 40 min at 900 W and 667 Pa using oxygen as the plasma-forming gas. The tensile, optical, and dynamic mechanical thermal properties, surface morphology, printability, water contact angle, chemical structure, weight change, and biodegradability properties of the films were evaluated during storage for up to 56 d. The tensile and optical properties of the PLA films were not significantly affected by CP treatment (CPT; P0.05). The surface roughness and water contact angle of PLA films increased by CPT and further increased during storage for 56 d. The printability of the PLA films increased following CPT and remained stable throughout the storage period. CP-induced hydrophilicity was also sustained during the storage period. The PLA films lost 1.9% of their weight after CPT, but recovered 99.5% of this loss after 14 d in storage. Photodegradation, thermal, and microbial biodegradable properties of the films were significantly improved by CPT (P0.05). Accelerated biodegradation of CP-treated PLA sachets with and without cheese was observed in compost. These results demonstrate the potential of CPT for modifying the stiffness, water contact angle, and chemical structure of PLA films and improving the printability and biodegradability of the films for food packaging.
- Published
- 2015
44. Ion Conductivities: Protons Enhance Conductivities in Lithium Halide Hydroxide/Lithium Oxyhalide Solid Electrolytes by Forming Rotating Hydroxy Groups (Adv. Energy Mater. 3/2018)
- Author
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Gleb Yushin, Marco Olguin, Anirudh Ramanujapuram, Punith Upadhya, Alexandre Magasinski, Yiran Xiao, Kostiantyn Turcheniuk, Ah-Young Song, Jim Benson, Lamartine Meda, and Oleg Borodin
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,Halide ,chemistry.chemical_element ,02 engineering and technology ,Solid state electrolyte ,021001 nanoscience & nanotechnology ,Ion ,Antiperovskite ,chemistry.chemical_compound ,chemistry ,X-ray crystallography ,Fast ion conductor ,Hydroxide ,General Materials Science ,Lithium ,0210 nano-technology - Published
- 2018
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45. Protons Enhance Conductivities in Lithium Halide Hydroxide/Lithium Oxyhalide Solid Electrolytes by Forming Rotating Hydroxy Groups
- Author
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Lamartine Meda, Gleb Yushin, Ah-Young Song, Alexandre Magasinski, Yiran Xiao, Marco Olguin, Punith Upadhya, Jim Benson, Oleg Borodin, Kostiantyn Turcheniuk, and Anirudh Ramanujapuram
- Subjects
Materials science ,Renewable Energy, Sustainability and the Environment ,Inorganic chemistry ,chemistry.chemical_element ,Halide ,02 engineering and technology ,Solid state electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Antiperovskite ,chemistry ,X-ray crystallography ,Fast ion conductor ,Hydroxide ,General Materials Science ,Lithium ,0210 nano-technology - Published
- 2017
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46. Influence of Protons on the Lithium Transport Mechanism in Antiperovskite Solid Electrolytes from Molecular Dynamics Simulations
- Author
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Oleg Borodin, Marco Olguin, Ah-Young Song, Yiran Xiao, Kostiantyn Turcheniuk, Anirudh Ramanujapuram, Jim Benson, Alexandre Magasinski, Lamartine Meda, and Gleb Yushin
- Abstract
Battery energy storage has become a critical component of civil and military operations because of the rapidly growing demands in consumer electronics, electric vehicles and the power-consuming systems carried by soldiers on the battlefield. Currently utilized batteries are flammable and suffer from an insufficient high specific energy, which poses major safety issues creating a tactical burden for the soldiers. The use of solid state batteries may offer enhanced safety and increased energy density. Previous modeling studies of the superionic lithium-rich anti-perovskites conductors focused on Li3OX (X = Cl, Br) structures and reported a variety of the charge transport mechanisms ranging from the low-barrier three-atom hop mechanism involving vacancies, Li hops to the nearest neighbor, Li interstitial dumbbells, and diffusion of the Li+ interstitials in LiCl-deficient Li3OCl that outnumber vacancies by 2–3 orders of magnitude as predicted by the shell model. It is, however, quite challenging to completely remove protons from these anti-perovskite conductors during synthesis, highlighting the importance of understanding the influence of protons on conductivity and electrochemical properties for these superionic lithium-rich anti-perovskite conductors.(1, 2) Born-Oppenheimer molecular dynamics (BOMD) simulations of Li2+xOH1-xCl (0≤x≤1) solid electrolytes were performed in order to gain insights into the mechanism of lithium transport and the influence of H concentration, complementing previous modeling studies of H-free antiperovskites. The simulation cell was comprised of 320 atoms. Density Functional Theory (DFT) calculations were performed with the QUICKSTEP module of the CP2K code, which implements the dual Gaussian and Plane Waves (GPW) method. The gamma point supercell approach was used in combination with 3-dimensioanl Periodic Boundary Conditions (PBC). Calculations were performed using the spin-polarized Perdew-Burke-Ernzerhof (PBE) exchange correlation functional with Grimme’s D3 dispersion correction. BOMD simulations predicted a significant enhancement of the lithium diffusion with the increased fraction of protons in agreement with experimental data. The lithium transport mechanism was found to be closely coupled with the rotation of a relatively short OH-group within the protonated electrolytes. Moreover, lithium jump events were found to be highly-correlated. Figure 1a shows a snapshot of the simulation box. In order to gain further insight into the transport mechanics, the motion of the fastest lithium cations in Li2.5OH0.5Cl solid electrolyte are highlighted with different colors. Overlap between trajectories of the fastest lithium cations shown by red arrows is indicative of the highly-correlated fashion of the lithium jumps.(2) We will also discuss changes of band gaps and band alignments that were calculated using DFT hybrid functionals as markers for electrochemical stability. We anticipate that our findings will reduce the existing confusions and show new avenues for tuning solid electrolyte compositions for further improved Li-ion conductivities. Different aspects of this work were supported by NASA Minority University Research and Education Project (MUREP; NASA grant NNX15AP44A and interagency agreement NND16AA29I with ARL for modeling) and ARPA-E (grant DE-AR0000779). References 1. Y. Li, W. Zhou, S. Xin, S. Li, J. Zhu, X. Lü, Z. Cui, Q. Jia, J. Zhou, Y. Zhao and J. B. Goodenough, Angew. Chem. Int. Ed., 55, 9965 (2016). 2. A.-Y. Song, Y. Xiao, K. Turcheniuk, A. Ramanujapuram, J. Benson, A. Magasinski, M. Oguin, L. Meda, O. Borodin and G. Yushin, (submitted)(2017). Figure 1. A snapshot from MD simulations of Li2.5(OH)0.5Cl (a). Trajectories of the fastest Li+ cations during 10 ps BOMD run of Li2.5OH0.5Cl SSE using different colors to denote distinct Li+ (b). Red arrows show overlap between the Li+ trajectories that is indicative of the Li+ correlated motion for the fastest moving Li+. Figure 1
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- 2017
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47. Indian meal moth (Plodia interpunctella)-resistant food packaging film development using microencapsulated cinnamon oil
- Author
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In-Hah, Kim, Ah Young, Song, Jaejoon, Han, Ki Hwan, Park, and Sea C, Min
- Subjects
Cinnamomum zeylanicum ,Polyethylene ,Drug Compounding ,Larva ,Food Packaging ,Animals ,Plant Oils ,Moths ,Polypropylenes - Abstract
Insect-resistant laminate films containing microencapsulated cinnamon oil (CO) were developed to protect food products from the Indian meal moth (Plodia interpunctella). CO microencapsulated with polyvinyl alcohol was incorporated with a printing ink and the ink mixture was applied to a low-density polyethylene (LDPE) film as an ink coating. The coated LDPE surface was laminated with a polypropylene film. The laminate film impeded the invasion of moth larvae and repelled the larvae. The periods of time during which cinnamaldehyde level in the film remained above a minimum repelling concentration, predicted from the concentration profile, were 21, 21, and 10 d for cookies, chocolate, and caramel, respectively. Coating with microencapsulated ink did not alter the tensile or barrier properties of the laminate film. Microencapsulation effectively prevented volatilization of CO. The laminate film can be produced by modern film manufacturing lines and applied to protect food from Indian meal moth damage.The LDPE-PP laminate film developed using microencapsulated cinnamon oil was effective to protect the model foods from the invasion of Indian meal moth larvae. The microencapsulated ink coating did not significantly change the tensile and barrier properties of the LDPE-PP laminate film, implying that replacement of the uncoated with coated laminate would not be an issue with current packaging equipment. The films showed the potential to be produced in commercial film production lines that usually involve high temperatures because of the improved thermal stability of cinnamon oil due to microencapsulation. The microencapsulated system may be extended to other food-packaging films for which the same ink-printing platform is used.
- Published
- 2014
48. A kinematic analysis of relative stability of the lower extremities between subjects with and without chronic low back pain
- Author
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Dongchul C. Lee, Yoon Hyuk Kim, Hang Jin Jo, Ah Young Song, Paul S. Sung, and Kyung Lee
- Subjects
Adult ,Male ,medicine.medical_specialty ,medicine.medical_treatment ,Kinematics ,Weight-Bearing ,Disability Evaluation ,Young Adult ,Physical medicine and rehabilitation ,medicine ,Group interaction ,Humans ,Orthopedics and Sports Medicine ,Young adult ,Postural Balance ,Gait Disorders, Neurologic ,Leg ,Rehabilitation ,business.industry ,Confounding ,Middle Aged ,Low back pain ,Relative stability ,Chronic low back pain ,Biomechanical Phenomena ,Physical therapy ,Surgery ,Female ,Original Article ,medicine.symptom ,Chronic Pain ,business ,Low Back Pain - Abstract
Even though a number of studies have evaluated postural adjustments based on kinematic changes in subjects with low back pain (LBP), kinematic stability has not been examined for abnormal postural responses during the one leg standing test. The purpose of this study was to evaluate the relative kinematic stability of the lower extremities and standing duration in subjects with and without chronic LBP. In total, 54 subjects enrolled in the study, including 28 subjects without LBP and 26 subjects with LBP. The average age of the subjects was 37.8 ± 12.6 years and ranged from 19 to 63 years. The outcome measures included normalized holding duration and relative kinematic stability. All participants were asked to maintain the test position without visual input (standing on one leg with his/her eyes closed and with the contra lateral hip flexed 90°) for 25 s. The age variable was used as a covariate to control confounding effects for the data analyses. The control group demonstrated significantly longer holding duration times (T = −2.78, p = 0.007) than the LBP group (24.6 ± 4.2 s vs. 20.5 ± 6.7 s). For the relative kinematic stability, there was a difference in dominance side (F = 9.91, p = 0.003). There was a group interaction between side and lower extremities (F = 11.79, p = 0.001) as well as an interaction between age and dominance side (F = 7.91, p = 0.007). The relative kinematic stability had a moderate negative relationship with age (r = −0.60, p = 0.007) in subjects without LBP. Clinicians need to understand the effects of age and relative stability, which decreased significantly in the single leg holding test, in subjects with LBP in order to develop effective rehabilitation strategies.
- Published
- 2010
49. Operationalizing Critical Digital Literacies: A Holistic Approach to Literacy Education in the Modern Age.
- Author
-
Ah-Young Song
- Subjects
LITERACY education ,COMPUTER literacy ,CRITICAL literacy ,FUNCTIONAL literacy ,HEGEMONY - Abstract
The article offers information on an approach to literacy education in the modern age. Topics include that critical digital literacies can help facilitate skills, as it is an approach that conceives of learning as a socially situated practice, informed by an individual's multiple identities, family dynamics, and fluctuating sociocultural environments; and refers to the insistence in critical theory on intensive examinations of dominant narratives and the establishment of counter-hegemonies.
- Published
- 2016
- Full Text
- View/download PDF
50. Critical Peer Reviews of Personal Narratives as Transactional Readings.
- Author
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Ah-Young Song
- Subjects
NARRATIVES ,READING ,PEER review of students - Abstract
Every transaction falls somewhere in "continuum" between aesthetic and efferent poles (Rosenblatt, 1981, p. 22), and readers are constantly resituating themselves along the spectrum, rather than remaining in a decisively aesthetic or efferent orientation. Reading, therefore, allows for an unceasing reorientation along the continuum even within a single literacy event, as students intake information and accordingly adjust their positions based on personal memories, present environmental factors, and serendipitous anchorings of their attentive mental faculties onto particular devices or words that spark involuntary emotional currents. At the heart of this essay is what happens when the transactional model of reading is applied to writing workshops and peer evaluations of personal essays in the English classroom. Following the tradition of the Critical Friends Group (CFG) model, I call the readings of peer essays critical peer reviews because they act as contributors who offer encouraging support and candid criticisms as they critically examine peers' artifacts. Critical peer reviews are built on a community of participants engaged in structured reflection, effective feedback, and constructive revisions. Importantly, critical peers do not take on hierarchical or dominant roles as assessors but become collaborative members of learning groups who rotate and serve as writer/reader, observer/participant, and artist/critic. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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