Subbiah Jeeva, Nam-Il Kim, In‐Kwon Jang, Tae‐Jin Choi,
... for more papers by this authorNam-Il Kim, Nam-Il Kim Molecular Science Division, Bioneer Corporation, Daejeon, 306-220 ... for more papers by this authorNam-Il Kim, Nam-Il Kim Molecular Science Division, Bioneer Corporation, Daejeon, 306-220 ...
Tópico(s): Insect symbiosis and bacterial influences
2012 - Wiley | Aquaculture Research
Dongwook Lim, Sangjin Kim, Nam Il Kim, Euntaek Oh, Sang Eun Shim, Sung‐Hyeon Baeck,
Herein, interfacially coupled Ni/Ni(OH)2 nanocomposites are successfully prepared using a facile one-step hydrothermal route with addition of various amounts of hydrazine and then applied as bifunctional catalysts for overall water splitting. The reconfiguration of electrons at the metal and semiconductor interface and well-tuned compositions between Ni and Ni(OH)2 significantly promote activities for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Owing to the synergistic ...
Tópico(s): Advanced Photocatalysis Techniques
2020 - American Chemical Society | ACS Sustainable Chemistry & Engineering
Kyong-Chol Kim, Nam-Il Kim, Tao Jiang, Jong-Chol Kim, Chol I. Kang,
Boron compounds are widely used in more than 300 different industries, including glass, ceramics, and energy. The world’s boron consumption increases gradually, but the world's boron reserves are limited to about 1.2 billion tons, and only a few boron minerals are commercially valuable. As a result, the price of boron compounds continues to increase. In order to satisfy the increasing demand for boron, it is very important to recover boron from various boron-containing solutions. Several metal ions, ...
Tópico(s): Plant Micronutrient Interactions and Effects
2023 - Elsevier BV | Hydrometallurgy
Flame behavior in an annular diverging tube (ADT) consisting of an outer quartz tube and a tapered inner core column was investigated as a basic model for small combustion devices of various combustion space scales. Flames can be stabilized at suitable locations where the mean flow velocity is matched to the spatial average propagation velocity (SAPV). Transient variations of wall temperature and the SAPV were compared for various experimental parameters: inner core materials, burner configurations, ...
Tópico(s): Fire dynamics and safety research
2011 - Elsevier BV | Fuel
Kyong-Chol Kim, Tao Jiang, Nam Il Kim, Cholu Kwon,
The effects of the ball-to-powder diameter ratio (BPDR) and the shape of the powder particles on EDEM simulation results and time in the planetary ball mill was investigated. BPDR was varied from 1 to 40/3 by changing the powder particle diameter from 8 to 0.6 mm. The size and shape of the powder particles do not give a significant change in both the ball motion pattern and simulation results when BPDR is over 20/3. It can be assumed that the kinetic energy of the ball has nothing to do with the ...
Tópico(s): Iron and Steelmaking Processes
2021 - Elsevier BV | Journal of the Indian Chemical Society
Seung-Gon Kim, Takeshi Yokomori, Nam Il Kim, Sudarshan Kumar, Shingo Maruyama, Kaoru Maruta,
This paper reports experimental and numerical investigations on the combustion characteristics of a lean methane–air mixture in a heated porous sand bed. The porous bed consisted of sand (SiO2) particles with a mean particle diameter of 0.56 mm. The horizontally placed quartz tube was heated externally to initiate the combustion reaction in the porous bed combustor. The stabilized flame location curve as a function of averaged mixture velocity was obtained for various equivalence ratios. Contrary ...
Tópico(s): Combustion and Detonation Processes
2006 - Elsevier BV | Proceedings of the Combustion Institute
Ohyung Kwon, Hyung Giun Kim, Min Ji Ham, Wonrae Kim, Gun-Hee Kim, Jae‐Hyung Cho, Nam Il Kim, Kangil Kim,
Tópico(s): Industrial Vision Systems and Defect Detection
2018 - Springer Science+Business Media | Journal of Intelligent Manufacturing
Moon‐Young Kim, Hee‐Taek Yun, Nam-Il Kim,
An improved numerical method to exactly evaluate 14 × 14 dynamic and static element stiffness matrices is proposed for the spatial free vibration and stability analysis of nonsymmetric thin-walled straight beams subjected to eccentrically axial loads. Firstly equations of motion and force-deformation relations are rigorously derived from the total potential energy for a uniform beam element with nonsymmetric thin-walled cross-section. Next a system of linear algebraic equations with nonsymmetric matrices ...
Tópico(s): Vibration and Dynamic Analysis
2003 - Elsevier BV | Computers & Structures
Kyong-Chol Kim, Tao Jiang, Yingzhe Xu, Nam Il Kim, Hak-Son Jin, Jong-Chol Kim,
We have studied the change of the specific surface area of the ground powder and the dynamics of balls and powders with several milling parameters such as the ball to powder ratio, the size of balls, the filling ratio, and the rotational speed of the vial in the mechanical activation process of boron concentrate by high-energy planetary ball mill. The results have shown that the ball movement regime for good grinding efficiency of the planetary ball mill is “cascading” or light “cataracting”, and ...
Tópico(s): Energetic Materials and Combustion
2020 - Elsevier BV | Powder Technology
Young Ok Kim, Chul Woo Yang, Sun Ae Yoon, Kyung Ah Chun, Nam Il Kim, Jang Sang Park, Byung Soo Kim, Yong‐Soo Kim, Yoon Sik Chang, Byung Kee Bang,
Blood flow imaging using color doppler has proven effective in predicting graft failures in hemodialysis patients, but its effect on native arteriovenous fistulas (AVF) is not well known. This study was performed to investigate whether measurements of the access blood flow can be used as predictors of an early failure of a native AVF in hemodialysis patients. Fifty-three consecutive patients who received native AVF operations were included in this study. Access blood flow was measured at 1 week after ...
Tópico(s): Vascular anomalies and interventions
2001 - Karger Publishers | American Journal of Nephrology
Young Ok Kim, Ho Cheol Song, Sun Ae Yoon, Chul Woo Yang, Nam Il Kim, Yeong Jin Choi, Eun Jung Lee, Wan Young Kim, Yoon Sik Chang, Byung Kee Bang,
Tópico(s): Vascular anomalies and interventions
2003 - Elsevier BV | American Journal of Kidney Diseases
Young-Jin Yoon, Gyeongmin Choe, Nam Il Kim, Joon‐Young Lee, In So Kweon,
We present surface normal estimation using a single near infrared (NIR) image. We are focusing on reconstructing fine-scale surface geometry using an image captured with an uncalibrated light source. To tackle this ill-posed problem, we adopt a generative adversarial network, which is effective in recovering sharp outputs essential for fine-scale surface normal estimation. We incorporate the angular error and an integrability constraint into the objective function of the network to make the estimated ...
Tópico(s): Computer Graphics and Visualization Techniques
2016 - Springer Science+Business Media | Lecture notes in computer science
This paper presents a flexural-torsional analysis of shear flexible thin-walled sandwich I-beams with functionally graded materials (FGMs). The transverse shear and warping shear deformations are considered in this study. Based on the power law distribution of volume fraction of ceramic or metal, the mechanical properties of beam such as Young's and shear moduli are assumed to continuously vary in the thickness direction. The locations of center of gravity and shear center for FG beams are derived. ...
Tópico(s): Structural Analysis and Optimization
2016 - Elsevier BV | Composites Part B Engineering
This paper presents the geometrically nonlinear isogeometric analysis of functionally graded material (FGM) plates based on the first-order shear deformation theory considering the physical neutral surface. According to the power law distribution of volume fraction of constituents, the material properties of plate are assumed to vary through the thickness. The transverse shear correction factor is evaluated through the energy equivalence and the geometric nonlinearity is accounted for von Kármán ...
Tópico(s): Railway Engineering and Dynamics
2016 - Elsevier BV | Composite Structures
Tan-Tien Nguyen, Nam-Il Kim, Jaehong Lee,
Tópico(s): Structural Load-Bearing Analysis
2016 - Elsevier BV | Composites Part B Engineering
Yongjin Jung, Min-Jung Lee, Nam Il Kim,
Flame propagation characteristics of hydrogen-air mixtures were investigated using an improved annular stepwise diverging tube (ASDT). An infrared detectable camera was used to visualize flame behaviors. Flame propagation velocity (FPV) was examined using the variation of equivalence ratio (or premixing ratio) and flow rate. Conclusively, it was found that hydrogen-air flames have critical FPVs that are not significantly affected by the channel gap scales. The critical FPVs were measured over a range ...
Tópico(s): Advanced Combustion Engine Technologies
2016 - Elsevier BV | Combustion and Flame
Donggeun Yoo, Nam Il Kim, Sunggyun Park, Anthony S. Paek, In So Kweon,
We present an image-conditional image generation model. The model transfers an input domain to a target domain in semantic level, and generates the target image in pixel level. To generate realistic target images, we employ the real/fake-discriminator as in Generative Adversarial Nets [6], but also introduce a novel domain-discriminator to make the generated image relevant to the input image. We verify our model through a challenging task of generating a piece of clothing from an input image of a ...
Tópico(s): Advanced Image Processing Techniques
2016 - Springer Science+Business Media | Lecture notes in computer science
This paper presents the general shear flexible thin-walled beam theory to study the coupled vibration characteristics of sandwich I-beams made of functionally graded materials (FGMs). This model accounts for the structural coupling coming from the material anisotropy and the transverse shear and the restrained warping induced shear deformation. The mechanical properties of beam such as Young's and shear moduli and material density are assumed to be continuously graded through the wall thickness according ...
Tópico(s): Structural Analysis and Optimization
2016 - Elsevier BV | Composites Part B Engineering
Alexander A. Konnov, Akram Mohammad, Ratna Kishore Velamati, Nam Il Kim, Chockalingam Prathap, Sudarshan Kumar,
Accurate measurement and prediction of laminar burning velocity is important for characterization of premixed combustion properties of a fuel, development and validation of new kinetic models, and calibration of turbulent combustion models. Understanding the variation of laminar burning velocity with thermodynamic conditions is important from the perspective of practical applications in industrial furnaces, gas turbine combustors and rocket engines as operating temperatures and pressures are significantly ...
Tópico(s): Combustion and Detonation Processes
2018 - Elsevier BV | Progress in Energy and Combustion Science
Hye Jin Jang, Gyu Min Jang, Nam Il Kim,
Tópico(s): Fire dynamics and safety research
2018 - Elsevier BV | Proceedings of the Combustion Institute
Geun‐Tae Yun, Woo‐Bin Jung, Myung Seok Oh, Gyu Min Jang, Jieung Baek, Nam Il Kim, Sung Gap Im, Hee‐Tae Jung,
Both high static repellency and pressure resistance are critical to achieving a high-performance omniphobic surface. The cuticles of springtails have both of these features, which result from their hierarchical structure composed of primary doubly reentrant nanostructures on secondary microgrooves. Despite intensive efforts, none of the previous studies that were inspired by the springtail were able to simultaneously achieve both high static repellency and pressure resistance because of a general ...
Tópico(s): Adhesion, Friction, and Surface Interactions
2018 - American Association for the Advancement of Science | Science Advances
Nam Il Kim, Dongwook Lim, Yeji Choi, Sang Eun Shim, Sung‐Hyeon Baeck,
Water splitting system by transition metal-based catalysts has drawn much attention in renewable energy storage and conversion system. In this study, β-Ni(OH)2 nanoplates with abundant oxygen vacancies were synthesized via the hydrothermal method followed by a partial reduction reaction in a mild hydrogen atmosphere, and applied to the oxygen evolution reaction (OER) in an alkaline solution. The β-Ni(OH)2 nanoplates prepared by partial reduction in a hydrogen atmosphere at 100 °C exhibited a current ...
Tópico(s): Supercapacitor Materials and Fabrication
2019 - Elsevier BV | Electrochimica Acta
Seongmin Son, Jin Young Heo, Nam Il Kim, Aqil Jamal, Jeong Ik Lee,
Recent climate initiatives had initiated a wave of reducing CO2 emissions for power generation. Many countries have been striving to develop and deploy low carbon emission technologies for power generation through efficiency improvement and use of renewable energy. For the regions that gain sufficient amount of solar to make solar power attractive overall, the challenge of intermittency still poses an issue for the electricity grid. The complementary role of natural gas power for the incoming renewables ...
Tópico(s): Chemical Looping and Thermochemical Processes
2019 - Elsevier BV | Energy Conversion and Management
Dongwook Lim, Hyungseok Kong, Nam-Il Kim, Chaewon Lim, Wha‐Seung Ahn, Sung‐Hyeon Baeck,
Abstract Herein, mesoporous NiFe 2 O 4 spinel nanoparticles with abundant oxygen vacancies are successfully prepared by a simple hydrothermal method followed by mild H 2 reduction and used as catalysts for the oxygen evolution reaction. Compared with the pristine and air‐treated NiFe 2 O 4 , the H 2 ‐treated NiFe 2 O 4 shows a much lower overpotential of 389 mV at a current density of 10 mA cm −2 . The H 2 ‐treated NiFe 2 O 4 also indicates substantial long‐term stability even after 1000 cyclic tests. ...
Tópico(s): Advanced battery technologies research
2019 - Wiley | ChemNanoMat
Nam Il Kim, Sumin Kim, Jaehong Lee,
In this study, an efficient damage detection technique using the differential evolution (DE) algorithm and vibration data is proposed to properly detect the locations and extents of multiple damages of truss structures. The general equilibrium equations in which the reaction forces at notes are taken into account are considered. The compatibility equations in terms of forces are presented using the singular value decomposition (SVD) technique and then the extended equations of motion are developed ...
Tópico(s): Vibration and Dynamic Analysis
2019 - Elsevier BV | Applied Acoustics
Dongwook Lim, Hyungseok Kong, Chaewon Lim, Nam Il Kim, Sang Eun Shim, Sung‐Hyeon Baeck,
Spinel-type nickel cobaltite with numerous oxygen vacancies is successfully synthesized by hydrothermal and thermal reduction using hydrogen. The effects of oxygen vacancies on the electrochemical activity and stability for the oxygen reduction reaction are investigated. The prepared catalyst displays significantly enhanced oxygen reduction reaction (ORR) catalytic performance under alkaline conditions, which is comparable to that of commercial Pt/C. The oxygen-deficient NiCo2O4 exhibits a very high ...
Tópico(s): Supercapacitor Materials and Fabrication
2019 - Elsevier BV | International Journal of Hydrogen Energy
Laminar burning velocities of premixed flames provide essential data in combustion studies. To facilitate an in situ monitoring in the field, a method using the annular diverging tube (ADT) and its improved version of the annular stepwise diverging tube (ASDT) were introduced in previous studies. Although the reliability and applicability of these methods has been verified, additional improvements are necessary for the field application. In this study, an assembled annular stepwise diverging tube ( ...
Tópico(s): Fire dynamics and safety research
2013 - Elsevier BV | Combustion and Flame
R. A. White, Carlos E. Donayre, Irwin Walot, Jonathan D. Woody, Nam Il Kim, George E. Kopchok,
Assessment of the long-term function of endografts to exclude abdominal aortic aneurysm (AAA) includes determination of aneurysm dimensions and morphologic changes that occur after implantation. This study reports the dimensional analysis of patients treated with AneuRx bifurcated endoprostheses with postintervention, 1-year (n = 51), 2-year (n = 28), and 3-year (n = 10) postimplantation contrast computed tomography data.Maximal diameter (D) and cross-sectional area (CSA) of the AAA were measured from axial ...
Tópico(s): Aortic Disease and Treatment Approaches
2001 - Elsevier BV | Journal of Vascular Surgery
R. A. White, Carlos E. Donayre, Irwin Walot, Maurice Lippmann, Jonathan D. Woody, James Lee, Nam Il Kim, George E. Kopchok, T J Fogarty,
Objective: The objective of this study was to analyze a single-center experience in which descending thoracic aortic aneurysms (TAAs) were treated with a new self-expanding endovascular prosthesis (Medtronic AVE). Methods: Twenty-six patients (13 men, 13 women) with American Society of Anesthesiology grades II to IV and ages ranging from 53 to 92 years (average, 74 years) consented as part of a Phase I Food and Drug Administration–approved trial. Treated lesions included TAAs that were 5 to 10 cm in ...
Tópico(s): Infectious Aortic and Vascular Conditions
2001 - Elsevier BV | Journal of Vascular Surgery
Tuan Ngoc Nguyen, Nam-Il Kim, Jaehong Lee,
This paper aims to present the mixed finite element method for the static analysis of nanobeams. The size-dependent effect of nanostructures is taken into consideration by nonlocal continuum theory. The governing equation is derived for Euler–Bernoulli beam theory incorporated with nonlocal theory. The present mixed finite element method is first introduced to overcome the concentrated loading problem of nonlocal beam which is a major limitation of the regular finite element formulation. Numerical ...
Tópico(s): Microstructure and mechanical properties
2015 - Elsevier BV | Finite Elements in Analysis and Design