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81.
Kim Jeongeun Kim Sukwha Kim Seongheui Lee Euehun Heo Yoonjeong Hwang Cheol-Yong Choi Yun-Young Kong Hyoun-Joong Ryu Hyeongju Lee Hyeongsuk 《Intelligent Service Robotics》2021,14(5):729-739
Intelligent Service Robotics - This study aims to analyze the concept of companion robots for older adults from the perspective of nursing. This study employed a concept analysis. The literature... 相似文献
82.
Niranjan Sitapure Hyeonggeon Lee Francisco Ospina-Acevedo Perla B. Balbuena Sungwon Hwang Joseph Sang-II Kwon 《American Institute of Chemical Engineers》2021,67(1):e17073
Li metal anode is the “Holy Grail” material of advanced Lithium-ion-batteries (LIBs). However, it is plagued by uncontrollable dendrite growth resulting in poor cycling efficiency and short-circuiting of batteries. This has spurred a plethora of research to understand the underlying mechanism of dendrite formation. While experimental studies suggest that there are complex physical and chemical interactions between heterogeneous solid-electrolyte interphase (SEI) and dendrite growth, most of the studies do not reveal the mechanisms triggering these interactions. To deal with this knowledge gap, we propose a multiscale modeling framework which couples kinetic Monte Carlo and Molecular Dynamics simulations. Specifically, the model has been developed to account for (a) heterogeneous SEI, (b) dendrite-SEI interactions, and (c) effect of electrolyte on Li electrodeposition and potential dendrite formation. This allows the proposed computational model to be extended to various electrolytes and SEI species and generate results consistent with previous experimental studies. 相似文献
83.
Hong-Sik Hwang Jill K. Winkler-Moser Brent Tisserat Rogers E. Harry-O'kuru Mark A. Berhow Sean X. Liu 《Journal of the American Oil Chemists' Society》2021,98(1):73-87
The food industry is seeking natural antioxidants for edible oils that have comparable activity to synthetic counterparts. In this study, Osage orange extract (OOE) rich in osajin (42.9%) and pomiferin (30.0%) was obtained after hexane extraction of the fruit, and its antioxidant activity was examined in stripped soybean oil (SBO) and fish oil (FO), in which antioxidants and polar compounds were removed. The antioxidant activity of OOE was compared with commercial natural antioxidants (i.e., rosemary extract and mixed tocopherols) and a synthetic antioxidant, butylated hydroxytoluene (BHT), during storage at 25 and 40 °C. The 0.1% OOE had stronger antioxidant activity than 0.1% rosemary extract and 0.1% mixed tocopherols in both oils at 25 and 40 °C. Its activity was similar to 0.02% BHT in SBO and was similar or slightly stronger than 0.02% BHT in FO. When OOE was studied at 0.05, 0.1, and 0.2%, there was a weak dose–response in SBO but a stronger dose–response in FO. Headspace volatile analysis using solid phase micro-extraction (SPME) combined with GC–MS indicated that 0.1% OOE was very effective in preventing the formation of volatile oxidation products in both oils. Although it should be further tested for safety before the actual use, this study shows that OOE can be developed as an antioxidant for edible oils. 相似文献
84.
The ability to trap precise quantities of cells or particles into confined areas has numerous applications for biological purposes. In particular, single cell trapping has received considerable attention because it permits the study of heterogeneity in a population, while trapping larger groups of cells have been used to form aggregates. Among several methods, the use of microwell offers a simple platform to capture cells or particles using hydrodynamic forces. This review examines the use of microwells in both static and microfluidic environments, and the application of microfluidic geometric arrays for trapping. This paper discusses the design and fabrication methods of microwells and compares the trapping and release techniques used in both static and microfluidics‐integrated microwells. Finally, we will summarize novel microfluidic geometric arrays used to capture cells or particles through hydrodynamic trapping. 相似文献
85.
Jeong-Sun Oh Joon-Hyung An Sun-Ok Lee Yeon-Hum Yun Bo-An Kang Sang-Bok Kim Kyu-Seog Hwang 《Metals and Materials International》2002,8(5):459-462
We prepared zirconia thin films on (100) Si wafer by using a chemical solution deposition with a zirconium naphthenate as
a starting material. The films were pyrolyzed at 500°C for 10 min and finally annealed for 30 min in air at 500°C. Amorphous
films after annealing had no distinct structure and were uniform along the cross section line.In vitro formation of the calcium phosphate was evaluated by the field emission-scanning electron microscope, energy dispersive X-ray
spectrometer and Fourier transform infrared spectroscopy. 相似文献
86.
Jooho Hwang Chun-Hong Park Chan-Hong Lee Seung-Woo Kim 《International Journal of Machine Tools and Manufacture》2006,46(7-8):801-810
This paper describes an estimation and correction method for the two-dimensional (2D) position errors of a planar XY stage that is driven along the Y-axis by two linear motors. The 2D position errors of the stage were estimated and corrected based on measured motion errors from a conventional laser interferometer system. To compensate for the planar XY stage 2D position errors, corrections were introduced for the yaw, perpendicular, straightness and 1D position errors along each axis, which are predominantly caused by linear scale, yaw, and pitching motion errors. The effect of the motion error corrections was evaluated by diagonal measurements based on the ISO230-6 standard and six different 1D position error measurements along the X and Y-axes. By applying error motion corrections, the diagonal systematic deviation at the center point was improved from 499.7 μm to 1.16 μm, and the estimated maximum 2D position errors were improved to −0.263 and 0.530 μm in the X and Y directions, respectively. The diagonal systematic deviation at a corner point was 1.23 μm and the estimated maximum difference between the corner and center points improved from −2.603 and 2.603 μm to −0.05 and 0.12 μm in the X and Y directions respectively. 相似文献
87.
A new approach using a neural network to process the features of the cutting force signal for the recognition of tool breakage in face milling is proposed. The cutting force signal is first compressed by averaging the cutting force signal per tooth. Then, the average cutting force signal is passed through a median filter to extract the features of the cutting force signal due to tool breakage. With the back propagation training process, the neural network memorizes the feature difference of the cutting force signal between with and without tool breakage. As a result, the neural network can be used to classify the cutting force signal with or without tool breakage. Experiments show this new approach can sense tool breakage in a wide range of face milling operations. 相似文献
88.
Ahn Kyu-Hong Hwang Jong-Hyuk Song Kyung-Guen Jung Yong-Ho Cho Eul-Saeng Lim Byung-Ran Kim Kwang-Soo 《Metals and Materials International》2004,10(2):167-170
The performance of an attached growth wastewater treatment process was investigated in an effort to improve nitrogen removal
efficiency. Recycled Yakult (lactic acid fermentation drink) bottles made of polystyrene were used as a biofilm media. The
use of Yakult bottles as a biofilm media has been attempted by numerous researchers in Japan for the removal of solids and
organics. However, these studies focused only on the removal of solids and organics. This study extended their application
to the removal of nitrogen for domestic sewage treatment. Yakult media was placed in a reactor with 70% apparent reactor volume
in a conventional A/O process. The bottom of the Yakult media was removed, and randomly filled Yakult media were effectively
able to reduce the flow in tanks, resulting in an increase in the contact time between pollutants and microorganisms. With
higher HRT, the nitrogen removal efficiency was increased by up to 83% with 12 hr of HRT. Nitrification appeared to be the
limiting factor of nitrogen removal at an HRT that is less than 12 hr, indicating that the Yakult process requires more retention
time to achieve nitrification compared to other biofilm processes. The removal efficiencies of organics and solids were high
regardless of the change of operational parameters.
This article is based on a presentation in “The 7th Korea-China Workshop On Advanced Materials” organized by the Korea-China
Advanced Materials Cooperation Center and the China-Korea Advanced Materials Cooperation Center, held at Ramada Plaza Jeju
Hotel, Jeju Island, Korea on August 24–27, 2003. 相似文献
89.
Hyoun Woo Kim Kwang-sik Kim Woon-suk Hwang Rafael Reif 《Metals and Materials International》2002,8(5):463-467
We investigated the effect of the rinsing and drying technique on the oxygen and carbon concentration on a silicon surface.
Rinsing in deionized water increased the interfacial oxygen concentration and helped generate defects. Blow-drying was more
efficient than spin-drying in reducing interfacial oxygen concentration. Exposure to the atmosphere was detrimental to obtaining
high crystallinity in the epitaxial layer. We evaluated the effectiveness of the cleaning process by observing the grown epilayer
and the epilayer/substrate interface. 相似文献
90.
Galvanic coupling effect on the corrosion of SiC-reinforced aluminum alloy-matrix composites was investigated in a sodium chloride solution. The potentiodynamic polarization measurement indicated that pitting potentials of metal matrix composites (MMCs) and AA2124 matrix alloy were similar, and pitting potential of MMCs was almost same as corrosion potential, while pitting susceptibility of MMCs was higher than that of AA2124 alloy. Galvanic current by formation of galvanic couple between SiCw and matrix reveals very low value because of large cathodic polarization of SiC. However, by increasing potential of matrix to pitting potential by this galvanic couple and thus, forming pits easily at the weak passive film near SiC reinforcing phase preferentially, it is concluded that pitting susceptibility of MMCs increases highly than AA2124 alloy of matrix composition. 相似文献