45 results on '"Young-Su Lee"'
Search Results
2. Two new records of mealybugs (Coccomorpha: Pseudococcidae) on succulent plants (Crassulaceae) from Korea
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Jinyeong Choi, Young-Su Lee, Hee-A Lee, and Seunghwan Lee
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New records ,Phenacoccus solani ,Succulent plants ,Taxonomy ,Vryburgia distincta ,Ecology ,QH540-549.5 - Abstract
Phenacoccus solani Ferris, 1918 and Vryburgia distincta (De Lotto, 1964) are herein reported occurring on succulent plants (Echeveria spp.) in South Korea. Both species have not been documented from South Korea except for quarantine inspection reports. In this study, diagnoses, descriptions, and photographs of the two species are provided with general information about their host plants and distributions.
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- 2021
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3. Effects of Dangguixu-san in patients with acute lateral ankle sprain: a randomized controlled trial
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Jae-Hong Kim, Cham-Kyul Lee, Eun-Yong Lee, Myoung-Rae Cho, Young-Su Lee, and Jeong-Soon Lee
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Ankle sprain ,Dangguixu-san ,Herbal medicine ,Randomized controlled trial ,Medicine (General) ,R5-920 - Abstract
Abstract Background Dangguixu-san (DS), a herbal extract, is widely used in Korean medicine to treat pain and swelling caused by ankle sprain. However, there is insufficient evidence regarding the effects of DS on ankle sprains. Accordingly, we assessed the efficacy and safety of DS for the treatment of acute lateral ankle sprain (ALAS). Methods This study was a multicenter (two Korean hospitals), randomized, double-blind, placebo-controlled, parallel-arm clinical trial with a 1:1 allocation ratio that included a per-protocol analysis and sub-analysis based on symptom severity. Forty-eight participants (n = 28 at Semyung University Korean Medicine Hospital in Chungju; n = 20 at DongShin University Gwangju Korean Medicine Hospital) with grade I or II ALAS that occurred within 72 h before enrollment were randomized to a DS (n = 24) or placebo (n = 24) group. Both groups received acupuncture treatment once daily for 5 consecutive days and the trial medication (DS/placebo capsule) three times a day for 7 consecutive days. Primary (visual analog scale [VAS] scores for pain) and secondary (Foot and Ankle Outcome Scores [FAOS], edema, and European Quality of Life Five-Dimension-Five-Level Scale [EQ-5D-5L] scores) outcome measures were recorded at baseline (week 0), the end of the intervention (week 1), and 4 weeks after treatment completion (week 5). Results Forty-six participants completed the trial (n = 23 each). Changes in VAS scores, FAOS Symptom/Rigidity, and FAOS Ache from week 1 to week 5 showed significant differences between the two groups. Sub-analyses showed significant differences in changes of FAOS Ache (week 0 to week 5) and VAS scores, total FAOS, and EQ-5D-5L scores (week 1 to week 5) between the two subgroups (grade II). There were no adverse events and significant negative changes in clinical laboratory parameters in both groups. Conclusions Overall, the results of this study are in favor of DS combined with acupuncture and suggest that DS combined with acupuncture is a safe treatment with positive long-term effects in terms of pain reduction and symptom alleviation in patients with grade I or II ALAS. Trial registration Clinical Research Information Service KCT0002374 . Registered on July 11, 2017; retrospectively registered.
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- 2021
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4. Stability for the Mixed Type of Quartic and Quadratic Functional Equations
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Young-Su Lee, Soomin Kim, and Chaewon Kim
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Mathematics ,QA1-939 - Abstract
We establish the general solutions of the following mixed type of quartic and quadratic functional equation: f(2x+y)+f(2x-y)=4f(x+y)+4f(x-y)+2f(2x)-8f(x)-6f(y). Moreover we prove the Hyers-Ulam-Rassias stability of this equation under the approximately quartic and the approximately quadratic conditions.
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- 2014
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5. Stability in Generalized Functions
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Young-Su Lee
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Mathematics ,QA1-939 - Abstract
We consider the following additive functional equation with 𝑛-independent variables: ∑𝑓(𝑛𝑖=1𝑥𝑖∑)=𝑛𝑖=1𝑓(𝑥𝑖∑)+𝑛𝑖=1𝑓(𝑥𝑖−𝑥𝑖−1) in the spaces of generalized functions. Making use of the heat kernels, we solve the general solutions and the stability problems of the above equation in the spaces of tempered distributions and Fourier hyperfunctions. Moreover, using the mollifiers, we extend these results to the space of distributions.
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- 2011
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6. Stability of a Quadratic Functional Equation in the Spaces of Generalized Functions
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Young-Su Lee
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Mathematics ,QA1-939 - Abstract
Making use of the pullbacks, we reformulate the following quadratic functional equation: f(x+y+z)+f(x)+f(y)+f(z)=f(x+y)+f(y+z)+f(z+x) in the spaces of generalized functions. Also, using the fundamental solution of the heat equation, we obtain the general solution and prove the Hyers-Ulam stability of this equation in the spaces of generalized functions such as tempered distributions and Fourier hyperfunctions.
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- 2008
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7. Stability of Cubic Functional Equation in the Spaces of Generalized Functions
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Soon-Yeong Chung and Young-Su Lee
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Mathematics ,QA1-939 - Abstract
In this paper, we reformulate and prove the Hyers-Ulam-Rassias stability theorem of the cubic functional equation f(ax+y)+f(ax−y)=af(x+y)+af(x−y)+2a(a2−1)f(x) for fixed integer a with a≠0,±1 in the spaces of Schwartz tempered distributions and Fourier hyperfunctions.
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- 2007
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8. Structural Diversity and Trends in Properties of an Array of Hydrogen-Rich Ammonium Metal Borohydrides
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Lars H. Jepsen, Jakob B. Grinderslev, Radovan Černý, Torben R. Jensen, Young Whan Cho, Kasper T. Møller, and Young-Su Lee
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Coordination sphere ,Hydrogen ,010405 organic chemistry ,chemistry.chemical_element ,Crystal structure ,ddc:500.2 ,010402 general chemistry ,Borohydride ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Electronegativity ,Metal ,chemistry.chemical_compound ,chemistry ,Chemical physics ,visual_art ,visual_art.visual_art_medium ,Dihydrogen bond ,Density functional theory ,Physical and Theoretical Chemistry - Abstract
Metal borohydrides are a fascinating and continuously expanding class of materials, showing promising applications within many different fields of research. This study presents 17 derivatives of the hydrogen-rich ammonium borohydride, NH4BH4, which all exhibit high gravimetric hydrogen densities (>9.2 wt % of H2). A detailed insight into the crystal structures combining X-ray diffraction and density functional theory calculations exposes an intriguing structural variety ranging from three-dimensional (3D) frameworks, 2D-layered, and 1D-chainlike structures to structures built from isolated complex anions, in all cases containing NH4+ countercations. Dihydrogen interactions between complex NH4+ and BH4- ions contribute to the structural diversity and flexibility, while inducing an inherent instability facilitating hydrogen release. The thermal stability of the ammonium metal borohydrides, as a function of a range of structural properties, is analyzed in detail. The Pauling electronegativity of the metal, the structural dimensionality, the dihydrogen bond length, the relative amount of NH4+ to BH4-, and the nearest coordination sphere of NH4+ are among the most important factors. Hydrogen release usually occurs in three steps, involving new intermediate compounds, observed as crystalline, polymeric, and amorphous materials. This research provides new opportunities for the design and tailoring of novel functional materials with interesting properties.
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- 2020
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9. Ammine Lanthanum and Cerium Borohydrides, M(BH4)3· nNH3; Trends in Synthesis, Structures, and Thermal Properties
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Young-Su Lee, Lars H. Jepsen, Torben R. Jensen, Morten B. Ley, Young Whan Cho, Mathias Jørgensen, Jakob B. Grinderslev, and Jørgen Skibsted
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010405 organic chemistry ,Chemistry ,chemistry.chemical_element ,010402 general chemistry ,Borohydride ,01 natural sciences ,0104 chemical sciences ,Inorganic Chemistry ,Metal ,Hydrogen storage ,Crystallography ,Cerium ,chemistry.chemical_compound ,visual_art ,visual_art.visual_art_medium ,Lanthanum ,Orthorhombic crystal system ,Physical and Theoretical Chemistry ,Isostructural ,Monoclinic crystal system - Abstract
Ammine metal borohydrides show potential for solid-state hydrogen storage and can be tailored toward hydrogen release at low temperatures. Here, we report the synthesis and structural characterization of seven new ammine metal borohydrides, M(BH4)3·nNH3, M = La (n = 6, 4, or 3) or Ce (n = 6, 5, 4, or 3). The two compounds with n = 6 are isostructural and have new orthorhombic structure types (space group P21212) built from cationic complexes, [M(NH3)6(BH4)2]+, and are charge balanced by BH4-. The structure of Ce(BH4)3·5NH3 is orthorhombic (space group C2221) and is built from cationic complexes, [Ce(NH3)5(BH4)2]+, and charge balanced by BH4-. These are rare examples of borohydride complexes acting both as a ligand and as a counterion in the same compound. The structures of M(BH4)3·4NH3 are monoclinic (space group C2), built from neutral molecular complexes of [M(NH3)4(BH4)3]. The new compositions, M(BH4)3·3NH3 (M = La, Ce), among ammine metal borohydrides, are orthorhombic (space group Pna21), containing molecular complexes of [M(NH3)3(BH4)3]. A revised structural model for A(BH4)3·5NH3 (A = Y, Gd, Dy) is presented, and the previously reported composition A(BH4)3·4NH3 (A = Y, La, Gd, Dy) is proposed in fact to be M(BH4)3·3NH3 along with a new structural model. The temperature-dependent structural properties and decomposition are investigated by in situ synchrotron radiation powder X-ray diffraction in vacuum and argon atmosphere and by thermal analysis combined with mass spectrometry. The compounds with n = 6, 5, and 4 mainly release ammonia at low temperatures, while hydrogen evolution occurs for M(BH4)3·3NH3 (M = La, Ce). Gas-release temperatures and gas composition from these compounds depend on the physical conditions and on the relative stability of M(BH4)3·nNH3 and M(BH4)3
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- 2020
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10. The mechanism of Mg2+ conduction in ammine magnesium borohydride promoted by a neutral molecule
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Yigang Yan, Bjørk Hammer, Mathias Jørgensen, Wilke Dononelli, Young-Su Lee, Young Whan Cho, Radovan Černý, Torben R. Jensen, and Jakob B. Grinderslev
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Materials science ,Hydrogen bond ,Magnesium ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Electrolyte ,ddc:500.2 ,Conductivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Borohydride ,01 natural sciences ,0104 chemical sciences ,Ion ,Bond length ,Crystallography ,chemistry.chemical_compound ,chemistry ,Density functional theory ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Light weight and cheap electrolytes with fast multi-valent ion conductivity can pave the way for future high-energy density solid-state batteries, beyond the lithium-ion battery. Here we present the mechanism of Mg-ion conductivity of monoammine magnesium borohydride, Mg(BH4)2·NH3. Density functional theory calculations (DFT) reveal that the neutral molecule (NH3) in Mg(BH4)2·NH3 is exchanged between the lattice and interstitial Mg2+ facilitated by a highly flexible structure, mainly owing to a network of di-hydrogen bonds, N-Hδ+-δH-B and the versatile coordination of the BH4- ligand. DFT shows that di-hydrogen bonds in inorganic matter and hydrogen bonds in bio-materials have similar bond strengths and bond lengths. As a result of the high structural flexibiliy, the Mg-ion conductivity is dramatically improved at moderate temperature, e.g. σ(Mg2+) = 3.3 × 10-4 S cm-1 at T = 80 °C for Mg(BH4)2·NH3, which is approximately 8 orders of magnitude higher than that of Mg(BH4)2. Our results may inspire a new approach for the design and discovery of unprecedented multivalent ion conductors.
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- 2020
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11. Ammonia-assisted fast Li-ion conductivity in a new hemiammine lithium borohydride, LiBH4·1/2NH3
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Young-Su Lee, Yigang Yan, Young Whan Cho, Jakob B. Grinderslev, Mathias Jørgensen, Radovan Černý, and Torben R. Jensen
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Inert ,Materials science ,Inorganic chemistry ,Metals and Alloys ,General Chemistry ,ddc:500.2 ,Conductivity ,Catalysis ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ion ,Metal ,Molten state ,Ammonia ,chemistry.chemical_compound ,Viscosity ,chemistry ,TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY ,Lithium borohydride ,visual_art ,Materials Chemistry ,Ceramics and Composites ,visual_art.visual_art_medium - Abstract
Hemiammine lithium borohydride, LiBH4·1/2NH3, is characterized and a new Li+ conductivity mechanism is identified. It exhibits a Li+ conductivity of 7 × 10-4 S cm-1 at 40 °C in the solid state and 3.0 × 10-2 S cm-1 at 55 °C after melting. The molten state of LiBH4·1/2NH3 has a high viscosity and can be mechanically stabilized in nano-composites with inert metal oxides and other hydrides making it a promising battery electrolyte.
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- 2020
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12. Microscopic Origin of Universal Quasilinear Band Structures of Transparent Conducting Oxides
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Youngho Kang, Sang Ho Jeon, Young-Woo Son, Young-Su Lee, Myungkwan Ryu, Sangyoon Lee, and Seungwu Han
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- 2012
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13. Low temperature formation of Mg2FeH6 by hydrogenation of ball-milled nano-crystalline powder mixture of Mg and Fe
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Julien O. Fadonougbo, Jin-Yoo Suh, Jae-Hyeok Shim, Jee-Yun Jung, Young Whan Cho, and Young-Su Lee
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Materials science ,Mechanical Engineering ,Metallurgy ,Kinetics ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Chemical engineering ,Mechanics of Materials ,Transmission electron microscopy ,lcsh:TA401-492 ,Process control ,General Materials Science ,lcsh:Materials of engineering and construction. Mechanics of materials ,Particle size ,0210 nano-technology ,Thermal analysis ,Ternary operation ,Ball mill ,Powder mixture - Abstract
Low temperature formation of Mg2FeH6 is demonstrated by hydrogenation of Mg-Fe elemental powder mixture at a temperature as low as 350 °C which is lower than the conventional process temperature, 500 °C. To enable the low temperature synthesis, the powder mixture of Mg and Fe has been prepared by high energy ball milling using different process control agents (PCAs). A systematic study on the ball milling and hydrogenation conditions has been carried out to maximize the yield of the ternary line compound. The hydrogenation conditions together with the particle size of the starting materials turn out to play a significant role in the hydrogenation kinetics of the system. An optimized condition has demonstrated a significant hydrogenation as well as a robust cycling ability at low temperature which suggests the strong potential of the process for practical applications. Keywords: Metal hydrides, Hydrogen solid-state storage, Thermal analysis, Transmission electron microscopy, Cycling ability
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- 2017
14. OFDM receivers using oversampling with rational sampling ratios
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Young-Su Lee and Bo-Seok Seo
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Business ,Electronics and electrical industries ,Engineering and manufacturing industries - Published
- 2009
15. Crystal Structures and Energy Storage Properties of Ammine Sodium Decahydro- closo-decaboranes (Na2B10H10· nNH3, n = 1, 2)
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Mathias Jørgensen, Bjarne R. S. Hansen, Young-Su Lee, Torben R. Jensen, and Young Whan Cho
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Materials science ,Sodium ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,Electrolyte ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Energy storage ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Metal ,General Energy ,chemistry ,visual_art ,Thermal ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry ,0210 nano-technology - Abstract
Metal closo-boranes show remarkable thermal and chemical stabilities, making them appealing candidates for a wide range of applications, such as electrolytes in electrochemical batteries and ammonia storage for indirect hydrogen storage. Furthermore, owing to the large size and nonspherical geometry of the anion (e.g., B10H10 2- or B12H12 2-), metal closo-boranes display a rich structural diversity and thermal polymorphism. Here, we present the synthesis, characterization, and structural determination of the ammoniated metal closo-boranes, Na2B10H10·nNH3 (n = 1, 2). The thermal decomposition of Na2B10H10·2NH3 was investigated with synchrotron radiation in situ powder X-ray diffraction and simultaneous thermogravimetric analysis, differential scanning calorimetry, and mass spectrometry, revealing a reversible ammonia storage capacity of 15 wt % below 150 °C. Additionally, ionic conductivities of 2.7 × 10-8 (RT) and 4.7 × 10-8 S/cm (30 °C) for Na2B10H10·2NH3 and Na2B10H10·NH3, respectively, were measured with electrochemical impedance spectroscopy. A lower Na+ conductivity compared to the parent compound, Na2B10H10, is explained by an anchoring effect of ammonia in the rigid framework of the B10H10 2--anions.
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- 2019
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16. The mechanism of Mg2+ conduction in ammine magnesium borohydride promoted by a neutral molecule.
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Yigang Yan, Dononelli, Wilke, Jørgensen, Mathias, Grinderslev, Jakob B., Young-Su Lee, Young Whan Cho, Černý, Radovan, Hammer, Bjørk, and Jensen, Torben R.
- Abstract
Light weight and cheap electrolytes with fast multi-valent ion conductivity can pave the way for future high-energy density solid-state batteries, beyond the lithium-ion battery. Here we present the mechanism of Mg-ion conductivity of monoammine magnesium borohydride, Mg(BH
4 )2 ·NH3 . Density functional theory calculations (DFT) reveal that the neutral molecule (NH3 ) in Mg(BH4 )2 ·NH3 is exchanged between the lattice and interstitial Mg2+ facilitated by a highly flexible structure, mainly owing to a network of di-hydrogen bonds, N–Hδ+ ⋯−δ H–B and the versatile coordination of the BH4 − ligand. DFT shows that di-hydrogen bonds in inorganic matter and hydrogen bonds in bio-materials have similar bond strengths and bond lengths. As a result of the high structural flexibiliy, the Mg-ion conductivity is dramatically improved at moderate temperature, e.g. σ(Mg2+ ) = 3.3 × 10−4 S cm−1 at T = 80 °C for Mg(BH4 )2 ·NH3 , which is approximately 8 orders of magnitude higher than that of Mg(BH4 )2 . Our results may inspire a new approach for the design and discovery of unprecedented multivalent ion conductors. [ABSTRACT FROM AUTHOR]- Published
- 2020
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17. Lithium Ion Disorder and Conduction Mechanism in LiCe(BH4)3Cl
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Torben R. Jensen, Young Whan Cho, Young-Su Lee, and Morten B. Ley
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Diffraction ,HYDROGEN STORAGE MATERIAL ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,01 natural sciences ,Molecular physics ,Ion ,WAVE BASIS-SET ,Molecular dynamics ,Computational chemistry ,LIBH4 ,Physical and Theoretical Chemistry ,Diffusion (business) ,BOROHYDRIDE ,COMPLEX HYDRIDES ,Chemistry ,TOTAL-ENERGY CALCULATIONS ,021001 nanoscience & nanotechnology ,Thermal conduction ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,General Energy ,METAL ,Lithium ,NA ,0210 nano-technology ,RB ,CS - Abstract
We investigate the diffusion mechanism of Li ions in LiCe(BH4)3Cl, which exhibits fast Li ion conduction. It was previously shown that eight Li ions partially occupy the 12d Wyckoff sites in the I43m structure and the Li ion diffusion takes place via jumping through the three-dimensional network of the 12d sites. In this study, we employ first-principles nudged elastic band simulation to elucidate the diffusion mechanism and discover that the Li ion does not directly jump to the neighboring 12d site, but instead passes through the closest 6b site. Moreover, the 6b site turns out to be another stable Li ion site, not just a transient point during a jump event. The occupation of the 6b site and the Li ion diffusion mechanism were assured by first-principles molecular dynamics simulations. The partial occupancy of the 12d site and 6b site at 500 K is approximately 1/2 and 1/3, respectively. The experimental diffraction data can be consistently interpreted. The peculiar crystal structure of LiCe(BH4)3Cl allo...
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- 2016
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18. Solid state synthesis, structural characterization and ionic conductivity of bimetallic alkali-metal yttrium borohydrides MY(BH4)4 (M = Li and Na)
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Ki-Ho Park, Young-Su Lee, Morten B. Ley, Elsa Roedern, Young Whan Cho, Torben R. Jensen, and Jørgen Skibsted
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DECOMPOSITION ,Inorganic chemistry ,chemistry.chemical_element ,Ionic bonding ,THERMAL-PROPERTIES ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,AUGMENTED-WAVE METHOD ,DENSITY-FUNCTIONAL THEORY ,X-RAY-DIFFRACTION ,Formula unit ,LIBH4 ,Ionic conductivity ,General Materials Science ,Isostructural ,Bimetallic strip ,Renewable Energy, Sustainability and the Environment ,Chemistry ,LISC(BH4)(4) ,General Chemistry ,Yttrium ,B-11 MAS-NMR ,021001 nanoscience & nanotechnology ,Alkali metal ,0104 chemical sciences ,HYDROGEN-STORAGE MATERIALS ,Physical chemistry ,Lithium ,0210 nano-technology ,Y(BH4)(3) - Abstract
Two bimetallic borohydrides, lithium yttrium tetraborohydride, LiY(BH4)4, and sodium yttrium tetraborohydride, NaY(BH4)4, have been synthesized by thermal treatment and quenching of ball-milled precursors. LiY(BH4)4 crystallizes in the space group P2c and NaY(BH4)4 in C2221 and the compounds are isostructural to LiSc(BH4)4 and NaSc(BH4)4, respectively. Both LiY(BH4)4 and NaY(BH4)4 are built from the complex anions of [Y(BH4)4]−. The unit cell volumes per formula unit of the bimetallic compounds LiY(BH4)4 and NaY(BH4)4 are significantly larger compared to those of the constituent components (14% and 7.5% unit cell expansion, respectively), which may contribute to the mobility of the Li+ and Na+ cations. The ionic conductivities of LiY(BH4)4 and NaY(BH4)4 at room temperature, measured by impedance spectroscopy, are σ = 1.26 × 10−6 and 6.92 × 10−7 S cm−1 respectively, and are improved compared to those of the precursors. DFT calculations were used to optimize the structures and identify a possible mechanism for the Na ion mobility. In addition, they provide the basis for assignment of the 11B NMR parameters determined by 11B MAS NMR for the two boron sites in NaY(BH4)4.
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- 2016
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19. Ammine Calcium and Strontium Borohydrides: Syntheses, Structures, and Properties
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Flemming Besenbacher, Lars H. Jepsen, Ram S. Sarusie, Young Whan Cho, Radovan Černý, Torben R. Jensen, and Young-Su Lee
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Metal borohydride ,Reaction mechanisms ,General Chemical Engineering ,Alkaline earth metals ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,Borohydrides ,ddc:500.2 ,010402 general chemistry ,Borohydride ,01 natural sciences ,Metal ,chemistry.chemical_compound ,X-Ray Diffraction ,Ammonia ,Spectroscopy, Fourier Transform Infrared ,Environmental Chemistry ,Molecule ,General Materials Science ,Thermal stability ,Boron ,Alkaline earth metal ,Strontium ,Molecular Structure ,Structure elucidation ,Hydrogen storage ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,General Energy ,chemistry ,Powder diffraction ,visual_art ,X-ray crystallography ,visual_art.visual_art_medium ,Calcium ,0210 nano-technology ,Powder Diffraction ,Hydrogen - Abstract
A new series of solvent- and halide-free ammine strontium metal borohydrides Sr(NH3 )n (BH4 )2 (n=1, 2, and 4) and further investigations of Ca(NH3 )n (BH4 )2 (n=1, 2, 4, and 6) are presented. Crystal structures have been determined by powder XRD and optimized by DFT calculations to evaluate the strength of the dihydrogen bonds. Sr(NH3 )(BH4 )2 (Pbcn) and Sr(NH3 )2 (BH4 )2 (Pnc2) are layered structures, whereas M(NH3 )4 (BH4 )2 (M=Ca and Sr; P21 /c) are molecular structures connected by dihydrogen bonds. Both series of compounds release NH3 gas upon thermal treatment if the partial pressure of ammonia is low. Therefore, the strength of the dihydrogen bonds, the structure of the compounds, and the NH3 /BH4 (-) ratio for M(NH3 )n (BH4 )m have little influence on the composition of the released gasses. The composition of the released gas depends mainly on the thermal stability of the ammine metal borohydride and the corresponding metal borohydride.
- Published
- 2015
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20. Complex hydrides for hydrogen storage – new perspectives
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Lars H. Jepsen, Flemming Besenbacher, Jens-Erik Jørgensen, Young-Su Lee, Yaroslav Filinchuk, Mikael Sloth, Masoud Rokni, Jens Oluf Jensen, Martin Dornheim, Young Whan Cho, Morten B. Ley, José M. Bellosta von Colbe, Torben R. Jensen, and UCL - SST/IMCN/MOST - Molecules, Solids and Reactivity
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Materials science ,Hydrogen ,chemistry.chemical_element ,Nanotechnology ,Borohydrides ,02 engineering and technology ,Energy carriers ,010402 general chemistry ,Hydrogen densities ,01 natural sciences ,7. Clean energy ,Hydrogen storage ,Materials Science(all) ,General Materials Science ,SDG 7 - Affordable and Clean Energy ,ddc:620.11 ,Flexibility (engineering) ,Energy carrier ,business.industry ,Mechanical Engineering ,Renewable energies ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Environmentally friendly ,0104 chemical sciences ,Renewable energy ,chemistry ,Structural flexibilities ,13. Climate action ,Mechanics of Materials ,Future perspectives ,Complex hydrides ,Biochemical engineering ,0210 nano-technology ,business - Abstract
Since the 1970s, hydrogen has been considered as a possible energy carrier for the storage of renewable energy. The main focus has been on addressing the ultimate challenge: developing an environmentally friendly successor for gasoline. This very ambitious goal has not yet been fully reached, as discussed in this review, but a range of new lightweight hydrogen-containing materials has been discovered with fascinating properties. State-of-the-art and future perspectives for hydrogen-containing solids will be discussed, with a focus on metal borohydrides, which reveal significant structural flexibility and may have a range of new interesting properties combined with very high hydrogen densities. © 2014 Elsevier Ltd.
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- 2014
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21. Synthesis, Crystal Structure, Thermal Decomposition, and 11B MAS NMR Characterization of Mg(BH4)2(NH3BH 3)2
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Jørgen Skibsted, Young Whan Cho, Flemming Besenbacher, Kasper T. Møller, Yaroslav Filinchuk, Torben R. Jensen, Young-Su Lee, Voraksmy Ban, and Lars H. Jepsen
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Reaction mechanism ,Chemical shift ,Thermal decomposition ,Crystal structure ,Borane ,Borohydride ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Metal ,chemistry.chemical_compound ,Crystallography ,General Energy ,chemistry ,visual_art ,Melting point ,visual_art.visual_art_medium ,Physical and Theoretical Chemistry - Abstract
A metal borohydride–ammonia borane complex, Mg(BH4)2(NH3BH3)2 was synthesized via a solid-state reaction between Mg(BH4)2 and NH3BH3. Different mechanochemical reaction mechanisms are observed, since Mg(BH4)2(NH3BH3)2 is obtained from α-Mg(BH4)2, whereas a mixture of Mg(BH4)2(NH3BH3)2, NH3BH3, and amorphous Mg(BH4)2 is obtained from γ-Mg(BH4)2. The crystal structure of Mg(BH4)2(NH3BH3)2 has been determined by powder X-ray diffraction and optimized by first-principles calculations. The borohydride groups act as terminal ligands, and molecular complexes are linked via strong dihydrogen bonds (
- Published
- 2014
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22. LiCe(BH4)3Cl, a New Lithium-Ion Conductor and Hydrogen Storage Material with Isolated Tetranuclear Anionic Clusters
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Morten B. Ley, Young-Su Lee, Young Whan Cho, Yaroslav Filinchuk, Jørgen Skibsted, Raphaël Janot, Torben R. Jensen, and Dorthe Bomholdt Ravnsbæk
- Subjects
Chemistry ,General Chemical Engineering ,Neutron diffraction ,General Chemistry ,Borohydride ,Ion ,Hydrogen storage ,chemistry.chemical_compound ,Crystallography ,Paramagnetism ,Octahedron ,Cubane ,Materials Chemistry ,Density functional theory - Abstract
Mechanochemical synthesis using CeCl 3-MBH 4 (M = Li, Na or K) mixtures are investigated and produced a new compound, LiCe(BH 4) 3Cl, which crystallizes in a cubic space group I43m, a = 11.7204(2) A. The structure contains isolated tetranuclear anionic clusters [Ce 4Cl 4(BH 4) 12] 4- with a distorted cubane Ce 4Cl 4 core, charge-balanced by Li + cations. Each Ce atom coordinates three chloride ions and three borohydride groups via the I• 3- BH 3 faces, thus completing the coordination environment to an octahedron. Combination of synchrotron radiation powder X-ray diffraction (SR-PXD), powder neutron diffraction and density functional theory (DFT) optimization show that Li cations are disordered, occupying 2/3 of the 12d Wyckoff site. DFT calculation indicates that LiCe(BH 4) 3Cl is stabilized by higher entropy rather than lower enthalpy, in accord with the disorder in Li positions. The structural model also agrees well with the very high lithium ion conductivity measured for LiCe(BH 4) 3Cl of 1 A - 10 -4 Scm -1 at T = 20 °C. In situ SR-PXD reveals that the decomposition products consist of LiCl, CeB 6 and CeH 2. The Sieverts measurements show that 4.7 wt % H 2 is released during heating to 500 °C. After rehydrogenation at 400 °C and p(H 2) = 100 bar for 24 h an amount of 1.8 wt % H 2 is released in the second dehydrogenation. The 11B MAS NMR spectra of the central and satellite transitions for LiCe(B(D/H) 4) 3Cl reveal highly asymmetric manifolds of spinning sidebands from a single 11B site, reflecting dipolar couplings of the 11B nuclear spin with the paramagnetic electron spin of the Ce 3+ ions. © 2012 American Chemical Society.
- Published
- 2012
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23. Superstability of generalized cauchy functional equations
- Author
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Soon-Yeong Chung and Young-Su Lee
- Subjects
Cauchy problem ,Algebra and Number Theory ,Applied Mathematics ,Cauchy functional equation ,lcsh:Mathematics ,Mathematical analysis ,Mathematics::Analysis of PDEs ,Cauchy distribution ,lcsh:QA1-939 ,d'Alembert's formula ,stability ,superstability ,Elliptic partial differential equation ,Functional equation ,Applied mathematics ,Cauchy boundary condition ,C0-semigroup ,Hyperbolic partial differential equation ,Analysis ,Mathematics - Abstract
In this paper, we consider the stability of generalized Cauchy functional equations such as Especially interesting is that such equations have the Hyers-Ulam stability or superstability whether g is identically one or not. 2000 Mathematics Subject Classification: 39B52, 39B82.
- Published
- 2011
24. Decomposition Reactions and Reversibility of the LiBH4-Ca(BH4)2 Composite
- Author
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Ji Young Li, Dorthe Bomholdt Ravnsbæk, Young-Su Lee, Yngve Cerenius, Jae-Hyeok Shim, Torben René Jensen, Nam Hwi Hur, and Young Whan Cho
- Published
- 2009
25. Stability of a Jensen type functional equation
- Author
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Young-Su Lee and Soon-Yeong Chung
- Subjects
Mathematics::Functional Analysis ,Algebra and Number Theory ,Mathematics::Operator Algebras ,Mathematical analysis ,Stability (learning theory) ,39B52 ,Type (model theory) ,Hyers–Ulam–Rassias stability ,Jensen functional equation ,Functional equation ,Applied mathematics ,Hyers-Ulam-Rassias stability ,39B82 ,Analysis ,Stability theorem ,Mathematics - Abstract
In this paper we consider the general solution of a Jensen type functional equation. Moreover we prove the stability theorem of this equation in the spirit of Hyers, Ulam, Rassias and G˘avruta.
- Published
- 2007
26. Cycloaddition Functionalizations to Preserve or Control the Conductance of Carbon Nanotubes
- Author
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Young-Su Lee and Nicola Marzari
- Subjects
Materials science ,General Physics and Astronomy ,chemistry.chemical_element ,FOS: Physical sciences ,Nanotechnology ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,Photochemistry ,01 natural sciences ,law.invention ,Metal ,law ,Single bond ,Condensed Matter - Materials Science ,Conductance ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,Cycloaddition ,0104 chemical sciences ,chemistry ,Covalent bond ,visual_art ,visual_art.visual_art_medium ,0210 nano-technology ,Chirality (chemistry) ,Carbon - Abstract
We identify a class of covalent functionalizations that preserves or controls the conductance of single-walled metallic carbon nanotubes. [2+1] cycloadditions can induce bond cleaving between adjacent sidewall carbons, recovering in the process the $sp^2$ hybridization and the ideal conductance of the pristine tubes. This is radically at variance with the damage permanently induced by other common ligands, where a single covalent bond is formed with a sidewall carbon. Chirality, curvature, and chemistry determine bond cleaving, and in turn the electrical transport properties of a functionalized tube. A well-defined range of diameters can be found for which certain addends exhibit a bistable state, where the opening or closing of the sidewall bond, accompanied by a switch in the conductance, could be directed with chemical, optical or thermal means., 5 pages, 6 figures, Phys. Rev. Lett., in press
- Published
- 2006
27. Aggressive osteoblastoma of the cervical vertebrae in a Turkish Angora cat.
- Author
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Hyun KIM, Young su LEE, Ki hoon KIM, Ji yong KIM, Sae jong YOO, A-jin LEE, Hwi yool KIM, and Dai jung CHUNG
- Subjects
- *
CERVICAL vertebrae , *OSTEOCHONDROMA , *TURKISH Angora cat , *VETERINARY literature , *IMMUNOHISTOCHEMISTRY , *DIAGNOSIS , *CANCER - Abstract
Aggressive osteoblastoma is a type of bone tumor rarely reported in veterinary literature. Osteoblastoma may be misdiagnosed as an osteosarcoma, which is a well-understood malignant bone tumor. Owing to poor prognosis, animals diagnosed with osteosarcoma are not always treated. In the present case, we diagnosed the tumor as aggressive osteoblastoma on the basis of macroscopic, microscopic, radiographic, and immunohistologic findings. The patient was treated via resections of the osteoblastoma and lived without metastasis for 3 years. This is the first reported case of aggressive feline osteoblastoma of the cervical vertebrae and will be useful for diagnosing and managing aggressive osteoblastoma. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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28. Coupled simulation of flow and dynamic analysis for prediction of the performance in GIS.
- Author
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Young Su Lee, Boo Hyung Bang, Hee Sub Ahn, Jong Ung Choi, and Seok Won Park
- Published
- 2013
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29. Thermodynamics and sorption reaction of some light metal borohydrides for reversible hydrogen storage.
- Author
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Young Whan Cho, Yoonyoung Kim, Young-Su Lee, Jin-Yoo Suh, and Jae-Hyeok Shim
- Published
- 2010
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30. Analyzing the Effect of a Block FEC Algorithm's Symbol Size on Energy Consumption in Wireless Sensor Networks.
- Author
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Hee Yong Youn, Minkoo Kim, Morikawa, Hiroyuki, Jong-Suk Ahn, Young-Su Lee, Jong-Hyuk Yoon, and Kang-Woo Lee
- Abstract
This paper evaluates the effect of a block Forward Error Correction (FEC) algorithm's symbol size on power consumption in wireless sensor networks (WSN). The WSN channels exhibit frequent bursty errors with a high average Bit Error Rate (BER) due to low transmission power, random deployment, and moving intermediate objects obstructing WSN communications. For resisting against the bursty errors, WSN would adopt a block FEC algorithm that restores more tainted bits than other kinds of FEC algorithms as errors become burstier since it recovers errors symbol-by-symbol not bit-by-bit. Even when the same amount of bits are allocated for FEC code, different FEC symbol size meaning different number of FEC symbols vary the packet error rate and the transmission energy over a given WSN. They also affect the computational energy since their decoding and encoding complexities depend on the number of FEC symbols per packet. The analytical evaluation based on long-term sensor traffic traces indicates that the appropriate FEC symbol size saves a sensor node's energy consumption by up-to 85 % comparing to other sizes. [ABSTRACT FROM AUTHOR]
- Published
- 2006
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- View/download PDF
31. Hydrogen-induced interactions in vanadium from first-principles calculations.
- Author
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Chuying Ouyang and Young-Su Lee
- Subjects
- *
HYDROGEN , *ATOMIC hydrogen , *ATOMS , *TETRAHEDRAL coordinates ,MAGNETIC properties of vanadium - Abstract
We present a first-principles study on hydrogen-induced interactions in vanadium, such as V-H, H-H, and vacancy-H interactions, which are relevant to the H-induced embrittlement in vanadium alloys employed as H2 purification membranes. Insertion of H at tetrahedral interstitial sites of V proceeds exothermically and lowers the energy levels of V 3d, 4s, and 4p states that form a bonding state with H 1s. However, H insertion accompanies large local atomic relaxation, thereby developing stress inside the material, which makes a good contrast with Pd where H can be added without significant structural distortion. The strength of the H-H interaction in V, which is indeed an interaction between two V-H bonding states, is negligibly small compared with that of the V-H interaction itself when the H-H distance is larger than ~2 Å. We show that six H atoms can be trapped at the six octahedral sites next to a vacancy in V. Formation of H2 molecules is energetically unfavorable, which is different from the cases of Al and W, where H2 molecules can be formed when enough H atoms are accumulated in a vacancy. Reasons behind this difference, together with the energetics of H-induced superabundant vacancy formation, are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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- View/download PDF
32. Hypertrophic Cardiomyopathy Attributable to Mitochondrial DNA Mutation Diagnosed by Pathology and Gene Sequencing.
- Author
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Young Choi, Jeong-Hwa Lee, Mei Nu Cui, Young Su Lee, Mi-Hyang Jung, Jeong-Eun Yi, Hae Ok Jung, Ho-Joong Youn, Choi, Young, Lee, Jeong-Hwa, Cui, Mei Nu, Lee, Young Su, Jung, Mi-Hyang, Yi, Jeong-Eun, Jung, Hae Ok, and Youn, Ho-Joong
- Published
- 2016
- Full Text
- View/download PDF
33. Stability of Quartic Functional Equations in the Spaces of Generalized Functions.
- Author
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Young-Su Lee and Soon-Yeong Chung
- Subjects
- *
NUMERICAL solutions to functional equations , *QUARTIC equations , *STABILITY (Mechanics) , *FUNCTION spaces , *THEORY of distributions (Functional analysis) , *HYPERFUNCTIONS - Abstract
We consider the general solution of quartic functional equations and prove the Hyers-Ulam- Rassias stability. Moreover, using the pullbacks and the heat kernels we reformulate and prove the stability results of quartic functional equations in the spaces of tempered distributions and Fourier hyperfunctions. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
34. Stability of Cubic Functional Equation in the Spaces of Generalized Functions.
- Author
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Young-Su Lee and Soon-Yeong Chung
- Subjects
- *
FUNCTIONAL equations , *THEORY of distributions (Functional analysis) , *SCHWARTZ distributions , *HYPERFUNCTIONS , *HOMOMORPHISMS , *BANACH spaces , *PARTIAL differential equations , *MATHEMATICAL research , *MATHEMATICAL analysis - Abstract
The article focuses on the stability of cubic functional equation in the spaces of generalized functions. It is proved that the Hyers-Ulam-Rassias stability theorem cubic functional equation of the cubic functional equation f ( ax + y ) + f ( ax - y ) = af ( x + y ) + af ( x - y ) + 2a(a2 - 1 ) f ( x ) for fixed integer a with a ≠ 0, ± 1 in the spaces of Schwartz tempered distributions and Fourier hyperfunctions. It is mentioned that in 1940, questions concerning the stability of group homomorphisms was solved by Hyers, assuming that G1 and G2 are Banach spaces. It is said that in 1978, Rassias generalized Hyers' result to the unbounded Cauchy difference.
- Published
- 2007
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- View/download PDF
35. Preparation and Properties of Transparent Glass-Ceramics in x K 2 O-(33.3- x )BaO-16.7TiO 2 -50SiO 2 Glasses.
- Author
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Hoi Kwan Lee, Young Su Lee, Bhalla, Amar S., and Won Ho Kang
- Subjects
- *
GLASS-ceramics , *HEAT treatment , *NONLINEAR optics , *THERMAL analysis , *CRYSTALLIZATION - Abstract
Transparent surface crystallized glasses have been prepared by controlled heat treatment in the system xK 2 O-(33.3-x) BaO-16.7TiO 2 -50SiO 2 (0 = x = 20 mol%), and properties were investigated. The glassy nature was analyzed by differential thermal analyses. The transparency of glass-ceramics is variable and controllable by the processing parameters like time and temperature. The c-axis orientation of surface crystallized Ba 2 TiSi 2 O 8 was observed at the bulk glass-ceramics surfaces and characterized the diffraction intensity ratio (002)/I(001). The estimated nonlinear optical susceptibility ? (3) is discussed in relation to the optical parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
36. Extinction and positivity of the solutions of the heat equations with absorption on networks
- Author
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Soon-Yeong Chung, Young-Su Lee, and Yun-Sung Chung
- Subjects
Applied Mathematics ,Mathematical analysis ,Boundary data ,Heat equation ,Heat equation with absorption ,Laplacian matrix ,Discrete heat equation ,Networks ,Laplace operator ,Graph ,Analysis ,Mathematics - Abstract
In this paper, we propose a discrete version of the following semilinear heat equation with absorption ut=Δu−uq with q>1, which is said to be the ω-heat equation with absorption on a network. Using the discrete Laplacian operator Δω on a weighted graph, we define the ω-heat equations with absorption on networks and give their physical interpretations. The main concern is to investigate the large time behaviors of nontrivial solutions of the equations whose initial data are nonnegative and the boundary data vanish. It is proved that the asymptotic behaviors of the solutions u(x,t) as t tends to +∞ strongly depend on the sign of q−1.
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- View/download PDF
37. Stability of a quadratic Jensen type functional equation in the spaces of generalized functions
- Author
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Soon-Yeong Chung and Young-Su Lee
- Subjects
Quadratic functional equation ,Generalized function ,Applied Mathematics ,Mathematical analysis ,Type (model theory) ,symbols.namesake ,Quadratic equation ,Fourier transform ,Gauss transform ,Jensen functional equation ,Functional equation ,Fundamental solution ,symbols ,Heat equation ,Stability ,Heat kernel ,Analysis ,Mathematical physics ,Mathematics - Abstract
Making use of the fundamental solution of the heat equation we find the solution and prove the stability theorem of the quadratic Jensen type functional equation 9 f ( x + y + z 3 ) + f ( x ) + f ( y ) + f ( z ) = 4 [ f ( x + y 2 ) + f ( y + z 2 ) + f ( z + x 2 ) ] in the spaces of Schwartz tempered distributions and Fourier hyperfunctions.
- Full Text
- View/download PDF
38. Stability of Quartic Functional Equations in the Spaces of Generalized Functions
- Author
-
Young-Su Lee and Soon-Yeong Chung
- Subjects
Mathematics::Functional Analysis ,Generalized function ,Partial differential equation ,Algebra and Number Theory ,Functional analysis ,lcsh:Mathematics ,Applied Mathematics ,Stability result ,lcsh:QA1-939 ,Stability (probability) ,symbols.namesake ,Fourier transform ,Ordinary differential equation ,Quartic function ,symbols ,Applied mathematics ,Analysis ,Mathematics - Abstract
We consider the general solution of quartic functional equations and prove the Hyers-Ulam-Rassias stability. Moreover, using the pullbacks and the heat kernels we reformulate and prove the stability results of quartic functional equations in the spaces of tempered distributions and Fourier hyperfunctions.
- Full Text
- View/download PDF
39. Stability of quadratic functional equations in generalized functions
- Author
-
Young-Su Lee
- Subjects
Generalized function ,Partial differential equation ,Algebra and Number Theory ,Independent equation ,Differential equation ,Applied Mathematics ,Mathematical analysis ,MathematicsofComputing_NUMERICALANALYSIS ,Examples of differential equations ,ComputingMethodologies_SYMBOLICANDALGEBRAICMANIPULATION ,Functional equation ,Riccati equation ,Applied mathematics ,Binary quadratic form ,Analysis ,Mathematics - Abstract
In this paper, we consider the following generalized quadratic functional equation with n-independent variables in the spaces of generalized functions
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- View/download PDF
40. On the stability of a mixed type functional equation in generalized functions
- Author
-
Young-Su Lee
- Subjects
Bernoulli differential equation ,Partial differential equation ,Algebra and Number Theory ,Differential equation ,Applied Mathematics ,Mathematical analysis ,First-order partial differential equation ,Separation of variables ,Integro-differential equation ,Functional equation ,Riccati equation ,Applied mathematics ,Analysis ,Mathematics - Abstract
We reformulate the following mixed type quadratic and additive functional equation with n-independent variables
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- View/download PDF
41. Ethyl Formate Fumigation for Controlling Two Major Aphid Pests, Aphis spiraecola and Aphis gossypii, on Passion Fruit, from Cultivation to Post-Harvest Storage
- Author
-
Jeong Oh Yang, Dongbin Kim, Young Su Lee, Ki-Jeong Hong, Byung-Ho Lee, and Min-Goo Park
- Subjects
ethyl formate ,cultivation ,passion fruit trees ,post-harvest passion fruits ,Aphis spiraecola ,Aphis gossypii ,Science - Abstract
Tropical and subtropical crops are being increasingly cultivated in South Korea, leading to an increase in damage by exotic insect pests. Consequently, ethyl formate (EF) is currently being considered for quarantine and pre-shipment fumigation. In this study, we evaluated the effectiveness of EF fumigation for controlling Aphis spiraecola Patch and Aphis gossypii Glover, two representative quarantine pests on passion fruit (“Pink Bourbon”) during greenhouse cultivation and post-harvest storage. The efficacy of EF against both aphids in terms of the lethal concentration causing 50% mortality (LCt50%) and LCt99% was 1.36–2.61 g h/m3 and 3.73–7.55 g h/m3 under greenhouse conditions (23 °C), and 1.37–2.02 g h/m3 and 3.80–14.59 g h/m3 post-harvest (5 °C), respectively. EF at 4 g/m3 for 4 h resulted in 100% mortality of A. spiraecola, which was more resistant to EF, without causing phytotoxic damage to the trees in a 340 m3 greenhouse. Post-harvest fruit fumigation at 10 g/m3 for 4 h in a mid-size (0.8 m3) fumigation chamber resulted in complete disinfection. Moreover, the EF level decreased below the EF threshold within 10 min after natural ventilation in the greenhouse. Therefore, our results suggest EF fumigation as an effective method for controlling A. spiraecola and A. gossypii.
- Published
- 2024
- Full Text
- View/download PDF
42. MPEG4 AVC/H.264 decoder with scalable bus architecture and dual memory controller.
- Author
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Hae-Yong Kang, Kyung-Ah Jeong, Jung-Yang Bae, Young-Su Lee, and Seung-Ho Lee
- Published
- 2004
- Full Text
- View/download PDF
43. Polarization diversity with directional antennas for indoor environments.
- Author
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Sun Hak Hong, Young Su Lee, Myung Sun Choi, and Young Joong Yoon
- Published
- 1999
- Full Text
- View/download PDF
44. Effects of host plant on the development and reproduction of Agrotis ipsilon (Lepidoptera: Noctuidae) on horticultural crops
- Author
-
Young Su Lee, Hee-A Lee, Gil-Hah Kim, and Sunghoon Baek
- Subjects
Agrotis ipsilon ,Host effect ,Host fitness ,Horticultural crop ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
One of cosmopolitan pest, Agrotis ipsilon (Lepidoptera: Noctuidae), causes serious economic damages in horticultural crops. This pest is difficult to manage and causes irreversible damage because its larvae stay in the ground at day and cut the plant stems at night. Thus, this study compared the host fitness of A. ipsilon among nine major horticultural crops in Korea. Among the nine crops, the population of A. ipsilon failed to complete its development in spinach, cucumber, melon, and kidney bean. The host effects on development and reproduction of A. ipsilon were further investigated in the remained five crops (i.e., napa cabbage, soybean, perilla, corn, and pepper). Host plants significantly (P
- Published
- 2023
- Full Text
- View/download PDF
45. Dispersal and oviposition patterns of Lycorma delicatula (Hemiptera: Fulgoridae) during the oviposition period in Ailanthus altissima (Simaroubaceae)
- Author
-
Minhyung Jung, Jung-Wook Kho, Do-Hun Gook, Young Su Lee, and Doo-Hyung Lee
- Subjects
Medicine ,Science - Abstract
Abstract The spotted lanternfly (SLF), Lycorma delicatula (Hemiptera: Fulgoridae), has the potential to become a global pest and is currently expanding its range in the United States. In this study, we investigated the dispersal patterns of SLF in Ailanthus altissima during its oviposition period in South Korea using a fluorescent marking system. Oviposition patterns of SLF were then analyzed by surveying egg masses in A. altissima patches. The recapture rate of fluorescent-marked SLF rapidly decreased to 30% within the first two weeks. During the oviposition period, seven cases of among-patch dispersal of SLF adults were observed. The minimum distance that SLF could have traveled to achieve these among-patch dispersal events ranged from 10 to 1740 m, with most events spanning under 60 m. Also, the number of A. altissima trees on which fluorescent marked SLF were detected increased until September. Based on the egg mass survey, a total of 159 egg masses were detected from 38 out of 247 A. altissima trees. Furthermore, 79.2% of egg masses were located
- Published
- 2022
- Full Text
- View/download PDF
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