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Performance evaluation of the use of tire-derived fuel fly ash as mineral filler in hot mix asphalt concrete

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Journal of Traffic and Transportation Engineering(English Edition) 2020年第2期7卷 249-258页

作者： Min Ju choi Yong Joo Kim Hyeok Jung Kim jae Jun Lee BILTZONE Co. Ltd.Hwaseong 18514South Korea Korea Institute o f Civil Engineering and Building Technology Goyang-Si 10223South Korea Industry-Academic Cooperation Foundation Center Hankyong National UniversityAnseong-si 17579South Korea Department of Civil Engineering Chonbuk National UniversityJeonju 54896South Korea

According to deplete natural resources and need to protect the environment,the demand of a usage of waste material has significantly *** studies are currently being carried out on the development of innovative and environmentally friendly materials for securing the safety of road users and improving the performance and durability of *** example,studies are currently being conducted on the use of waste tires as a substitute for currently used *** the development of the automobile industry,the amount of waste tire has continuously increased in accordance with the increased vehicle ***-derived fuel(TDF)has been used as a fuel source with generated TDF fly *** filler,made of fine mineral particles of a physical size passing the number 200 standard mesh sieve(75 micron),plays an important role in asphalt mixtures *** paper presents an application of TDF fly ash as filler in hot mix asphalt(HMA).In this study,the performance of TDF fly ash was confirmed through a comparison with three other mineral fillers:stone dust,cement,and hydrated *** tests including Marshall stability test,moisture sensitivity test,dynamic immersion test,and a wheel tracking test were performed to investigate the difference in the behaviors of the samples with different parameters considered in this *** results show that the mechanical performance of hot mix asphalt using TDF fly ash satisfied the quality standard specification of the Ministry of Land,Infrastructure and Transport(MOLIT),*** can be concluded that the use of TDF fly ash as a mineral filler in HMA not only satisfied the mechanical properties,but also reduced the volume of the pollutants waste in the environment.

关键词： Asphalt mixture TDF fly ash Marshal stability Moisture sensitive TSR

Stabilization of the Anatase Phase of Ti_(1-x)Sn_(x)O_(2) (x < 0.5) Nanofibers

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Nano Research 2010年第4期3卷 256-263页

作者： Kandasami Asokan jae Young Park Sunwoo choi Changhwan Chang Sang Sub Kim School of Materials Science and Engineering Inha UniversityIncheon 402-751Republic of Korea Inter-University Accelerator Centre Aruna Asaf Ali MargNew Delhi 110067India Department of Materials Test and Analysis Research Institute of Industrial Science and TechnologyPohang 790-600Republic of Korea

We experimentally investigate the stabilization of the anatase phase of Ti_(1-x)Sn_(x)O_(2)(x<0.5)nanofibers when synthesized by an electrospinning *** as-spun nanofibers became nano-grained,polycrystalline nanofibers after calcination and the diameters of the nanofibers depend on Sn *** of the anatase phase in Ti-rich compositions and incorporation of Sn ions were confirmed by X-ray diffraction,Raman,X-ray absorption near-edge structure,and photoluminescence(PL)*** from the PL study also demonstrated the tunable nature of the optical properties,with the emission maximum shifting towards higher wavelength with increasing Sn concentration.

关键词： Electrospinning nanofiber Ti_(1-x)Sn_(x)O_(2) X-ray absorption near-edge structure(XANES)

The kinetic studies of direct methane oxidation to methanol in the plasma process

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Chinese Science Bulletin 2008年第18期53卷 2783-2792页

作者： INDARTO Antonius choi jae-Wook LEE Hwaung SONG Hyung Keun Department of Chemical and Biochemical Engineering Korea UniversitySeoul 136-701KoreaClean Technology Research Center Korea Institute of Science and Technology Seoul 130-650 Korea Clean Technology Research Center Korea Institute of Science and TechnologySeoul 130-650 Korea Clean Technology Research Center Korea Institute of Science and TechnologySeoul 130-650Korea

The research outlined here includes a study of methanol production from direct methane conversion by means of thermal and plasma method. The kinetic study, derived from thermal-based approach, was carried out to investigate thoroughly the possible intermediate species likely to be presented in the process. A set of plasma experiments was undertaken by using dielectric barrier discharge (DBD), classified as non-thermal plasma, done at atmospheric pressure and room temperature. Plasma proc- ess yields more methanol than thermal process at the same methane conversion rates and methane to oxygen feed ratios. Oxidation reaction of thermal process resulted CO and CO2 as the most dominant products and the selectivity reached 19% and 68%, respectively. Moreover, more CO and less CO2 were produced in plasma process than in thermal process. The selectivity of CO and CO2 by plasma was 47% and 20%, respectively. Ethane (C2H6) was detected as the only higher hydrocarbon with a signifi- cant concentration. The concentration of ethane reached 9% of the total products in plasma process and 17% in thermal process. The maximum selectivity of methanol, the target material of this research, was 12% obtained by plasma method and less than 5% by thermal process. In some certain points, the kinetic model closely matched with the experimental results.

关键词：等离子体热采方法部分氧化甲烷甲醇

Development of a skill assessment tool for the Korea operational oceanographic system

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Acta Oceanologica Sinica 2013年第9期32卷 74-81页

作者： CHO Kyoung-Ho choi Jin-Yong JEONG Sang-Hun choi Jung-Woon KWON jae-Il PARK Kwang-Soon Coastal Disaster Research Center Korea Institute of Ocean Science and Technology

A standard skill assessment （SA） tool was developed and implemented to evaluate the performance of op- erational forecast models in the Korea operational oceanographic system. The SA tool provided a robust way to assess model skill in the system by comparing predictions and observations, and involved the com- putation of multiple skill metrics including correlation and error skills. User- and system-based acceptance criteria of skill metrics were applied to determine whether predictions were acceptable for the system. To achieve this, the tool produced a time series comparison plot, a skill score table, and an advanced sum- marized diagram to effectively demonstrate the multiple skill scores. Moreover, the SA was conducted to evaluate both atmospheric and hydrodynamic forecast variables. For the atmospheric variables, acceptable error criteria were preferable to acceptable correlation criteria over short timescales, since the mean square error overwhelmed the observation variance. Conversely, for the hydrodynamic variables, acceptable root mean square percentage error （e.g., perms） criteria were preferable to acceptable error （e.g., erms） criteria owing to the spatially variable tidal intensity around the Korean Peninsula. Furthermore, the SA indicated that predetermined acceptance error criteria were appropriate to satisfy a target central frequency （fc） for which errors fell within the specified limits （i.e., the .fc equals 70%）.

关键词： skill assessment tool operational forecast system Korea operational oceanographic system

Novel extended C-m models of flow stress for accurate mechanical and metallurgical calculations and comparison with traditional flow models

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Journal of Magnesium and Alloys 2022年第9期10卷 2516-2533页

作者： Man Soo Joun Mohd Kaswandee Razali jae Dong Yoo Min Cheol Kim Jeong Muk choi ReCAFT Gyeongsang National UniversityGraduate School of Mechanical and Aerospace EngineeringJinju 52828South Korea Gyeongsang National University Graduate School of Mechanical and Aerospace EngineeringJinju 52828South Korea MFRC Research CenterJinju 52818South Korea Jinhap Daejeon 34302South Korea

Here,we developed novel extended piecewise bilinear power law(C-m)models to describe flow stresses under broad ranges of strain,strain rate,and temperature for mechanical and metallurgical calculations during metal forming at elevated *** traditional C-m model is improved upon by formulating the material parameters C and m,defined at sample strains and temperatures as functions of the strain *** coefficients are described as a linear combination of the basis functions defined in piecewise patches of the sample strain and temperature domain.A comparison with traditional closed-form function flow models revealed that our approach using the extended piecewise bilinear C-m model is superior in terms of accuracy,ease of use,and adaptability;additionally,the extended C-m model was applicable to numerical analysis of mechanical,metallurgical,and microstructural ***,metallurgy-related values can be calculated directly from the flow stress *** the proposed model was developed for materials at elevated temperatures,it can be applied over a broad temperature range.

关键词： Flow stress Power law model Piecewise bilinear function Numerical analysis Microstructural prediction Peak strain

Removal of arsenate and arsenite from aqueous solution by waste cast iron

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Journal of Environmental Sciences 2012年第4期24卷 589-595页

作者： Nag-Choul choi Song-Bae Kim Soon-Oh Kim jae-Won Lee Jun-Boum Park Department of Rural Systems Engineering Seoul National UniversitySeoul 151-921Republic of Korea Department of Earth and Environmental Sciences and Research Institute of Natural Science Gyeongsang National UniversityJinju 660-701Republic of Korea JIU Corporation 154-3 Samsung-dongGangnam-guSeoul 135-879Republic of Korea Department of Civil and Environmental Engineering Seoul National UniversitySeoul 151-742Republic of Korea

The removal of As（III） and As（V） from aqueous solution was investigated using waste cast iron, which is a byproduct of the iron casting process in foundries. Two types of waste cast iron were used in the experiment： grind precipitate dust （GPD） and cast iron shot （CIS）. The X-ray diffraction analysis indicated the presence of Fe~ on GPD and CIS. Batch experiments were performed under different concentrations of As（III） and As（V） and at various initial pH levels. Results showed that waste cast iron was effective in the removal of arsenic. The adsorption isotherm study indicated that the Langmuir isotherm was better than the Freundlich isotherm at describing the experimental result. In the adsorption of both As（III） and As（V）, the adsorption capacity of GPD was greater than CIS, mainly due to the fact that GPD had higher surface area and weight percent of Fe than CIS. Results also indicated the removal of As（III） and As（V） by GPD and CIS was influenced by the initial solution pH, generally decreasing with increasing pH from 3.0 to 10.5. In addition, both GPD and CIS were more effective at the removal of As（III） than As（V） under given experimental conditions. This study demonstrates that waste cast iron has potential as a reactive material to treat wastewater and groundwater containing arsenic.

关键词： waste cast iron arsenic removal sorption batch experiment

Bioinspired Multi-material Polyjet-printed Frog Robot for Synchronous and Asynchronous Swimming

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Journal of Bionic Engineering 2023年第3期20卷 923-933页

作者： Afaque Manzoor Soomro jae-Wook Lee Fida Hussain Memon Faheem Ahmed Kashif Hussain Kyung Hyun choi Department of Mechatronics Engineering Jeju National UniversityJeju63243South Korea Department of Electrical Engineering Sukkur IBA UniversitySukkur65200Pakistan

This paper proposes the bioinspired soft frog robot. All printing technology was used for the fabrication of the robot. Polyjet printing was used to print the front and back limbs, while ultrathin filament was used to print the body of the robot, which makes it a complete soft swimming robot. Dual thrust generation approach has been proposed by embedding the main muscle and antagonistic muscle in all the limbs, which enables it to attain high speed (18 mm/s), significant control to swim in dual mode (synchronous and asynchronous modes). To achieve the swimming motion of frog, four SMA (BMF 300) muscle wires were used. The frog robot is named as (FROBOT). The hind limbs are 60 mm long and 10 mm thick on average, while the front limbs are 35 mm long and 7 mm thick. Model-based design and rigorous analysis of the dynamics of real frogs have allowed FROBOT to be developed to swim at a level that is remarkably consistent with real frogs. Electrical and mechanical characteristics have been performed. In addition, the test data were further processed using TRACKER to analyze angle, displacement and velocity. FROBOT (weighs 65 g) can swim at different controllable frequencies (0.5–2 Hz), can rotate in any direction on command from custom built LabVIEW software allowing it to swim with speed up to 18 mm/s on deep water surface (100 cm) with excellent weight balance.

关键词： Bioinspired Soft robotics Frog FROBOT Asynchronous swimming

Absorption-Dominant mmWave EMI Shielding Films with Ultralow Reflection using Ferromagnetic Resonance Frequency Tunable M-Type Ferrites

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Nano-Micro Letters 2023年第6期15卷 1-23页

作者： Horim Lee Seung Han Ryu Suk Jin Kwon jae Ryung choi Sang‑bok Lee Byeongjin Park Composites Research Division Korea Institute of Materials Science797 ChangwondaeroSeongsan‑GuChangwonGyeongsangnam‑Do 51508Republic of Korea

Although there is a high demand for absorption-dominant electromagnetic interference(EMI) shielding materials for 5G millimeter-wave(mmWave) frequencies, most current shielding materials are based on reflection-dominant conductive materials. While there are few absorption-dominant shielding materials proposed with magnetic materials, their working frequencies are usually limited to under 30 GHz. In this study, a novel multi-band absorption-dominant EMI shielding film with M-type strontium ferrites and a conductive grid is proposed. This film shows ultralow EMI reflection of less than 5% in multiple mmWave frequency bands with sub-millimeter thicknesses, while shielding more than 99.9% of EMI. The ultralow reflection frequency bands are controllable by tuning the ferromagnetic resonance frequency of M-type strontium ferrites and composite layer geometries. Two examples of shielding films with ultralow reflection frequencies, one for 39 and 52 GHz 5G telecommunication bands and the other for 60 and 77 GHz autonomous radar bands, are presented. The remarkably low reflectance and thinness of the proposed films provide an important advancement toward the commercialization of EMI shielding materials for 5G mmWave applications.

关键词： 5G communication MmWave EMI shielding M-type ferrites

The secretory products of Trichomonas vaginalis decrease fertilizing capacity of mice sperm in vitro

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Asian Journal of Andrology 2015年第2期17卷 319-323,I0012页

作者： jaesook Roh Young-Su Lim Min-Young Seo Yuri choi jae-Sook Ryu Department of Anatomy and Cell Biology Laboratory of Reproductive Endocrinology College of Medicine Hanyang University Seoul Korea Department of Anesthesiology and Pain Medicine St. Mary's Hospital Catholic University Incheon Korea Department of Environmental Biology and Medical Parasitology College of Medicine Hanyang University Seoul Korea.

Trichomonas vaginalis infection is one of the most prevalent sexually transmitted infections in humans and is now recognized as an important cause of infertility in men. There is little information about the effect of extracellular polymeric substances （EPS） from T. vaginalis on sperm, but previous reports do not provide a conclusive description of the functional integrity of the sperm. To investigate the impact of EPS on the fertilizing capacity of sperm, we assessed sperm motility, acrosomal status, hypo-osmotic swelling, and in vitro fertilization rate after incubating the sperm with EPS in vitro using mice. The incubation of sperm with EPS significantly decreased sperm motility, viability, and functional integrity in a concentration and time-dependent manner. These effects on sperm quality also resulted in a decreased fertilization rate in vitro. This is the first report that demonstrates the direct negative impact of the EPS of T. vaginalis on the fertilization rate of sperm in vitro. However, further study should be performed using human sperm to determine if EPS has similar negative impact on human sperm fertilizing capacity in vitro.

关键词： extracellular polymeric substances fertilization sperm Trichomonas vaginalis