Improved reversible redox cycles on MTiOx (M=Fe, Co, Ni, and Cu) particles afforded by rapid and stable oxygen carrier capacity for use in chemical looping combustion of methane

Kwak, B.S.,Park, N.K.,Ryu, S.O.,Baek, J.I.,Ryu, H.J.,Kang, M. Elsevier 2017 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.309 No.-

In this study, rutile TiO<SUB>2</SUB> particles (MTiOx) incorporating 3d-metals, with their electrons more than half-filled, are synthesized for use in the chemical looping combustion of methane. The specific structures are obtained by doping the M-sites with Fe, Co, Ni, and Cu (FeTiOx, CoTiOx, NiTiOx, and CuTiOx), and they have the same M/Ti molar ratio of 1.0. XRD, SEM, CH<SUB>4</SUB>-TPD, TGA, and BET techniques were used to characterize the prepared materials. The XRD results confirmed that all of the prepared materials possessed pure hexagonal phases in the case of Co1Ti1Ox and Ni1Ti1Ox and mixed formations composed of metal oxides and rutile TiO<SUB>2</SUB> in the case of Fe1Ti1Ox and Cu1Ti1Ox. The CH<SUB>4</SUB>-TPD and H<SUB>2</SUB>-TPR analyses showed that the highest adsorption is obtained on CuTiOx, in particular on Cu1.5Ti1Ox. The oxygen carrier capacities of the samples were measured in H<SUB>2</SUB> (FR)/air (AR) and CH<SUB>4</SUB>-CO<SUB>2</SUB> (FR)/air (AR) redox systems at 850<SUP>o</SUP>C using TGA analysis. Their variability was shown to be associated with the different doping elements and doping concentrations. In particular, the Cu1.5Ti1Ox material in the CH<SUB>4</SUB>-CO<SUB>2</SUB> (FR)/air (AR) redox system exhibits oxygen uncoupling behaviour, leading to improved capture and release of oxygen compared to the other materials.

食品 中 殘留農藥에 관한 硏究 : Monitoring Program for Pesticide Residues in Food

元敬豊,洪茂基,郭寅信,李熹德,朴建相,尹熙俓,文在辰,姜仁鎬 국립보건연구원 1994 국립보건원보 Vol.31 No.2

Overview of KSTAR research progress and future plans toward ITER and K-DEMO

Park, H.K.,Choi, M.J.,Hong, S.H.,In, Y.,Jeon, Y.M.,Ko, J.S.,Ko, W.H.,Kwak, J.G.,Kwon, J.M.,Lee, J.,Lee, J.H.,Lee, W.,Nam, Y.B.,Oh, Y.K.,Park, B.H.,Park, J.K.,Park, Y.S.,Wang, S.J.,Yoo, M.,Yoon, S.W.,B IOP 2019 Nuclear fusion Vol.59 No.11

<P>A decade-long operation of the Korean Superconducting Tokamak Advanced Research (KSTAR) has contributed significantly to the operation of superconducting tokamak devices and the advancement of tokamak physics which will be beneficial for the ITER and K-DEMO programs. Even with limited heating capability, various conventional as well as new operating regimes have been explored and have achieved improved performance. As examples, a long pulse high-confinement mode operation with and without an edge-localized mode (ELM) crash was well over 70 and 30 s, respectively. The unique capabilities of KSTAR allowed it to improve the capability of controlling harmful instabilities, and they have been instrumental in uncovering much new physics. The highlights are that the L/H transition threshold power is sensitive to the resonant magnetic perturbation (RMP) and insensitive to non-resonant magnetic perturbation. Co-<I>I</I> <SUB>p</SUB> offset rotation dominated by an electron channel predicted by general neoclassical toroidal viscosity theory was confirmed. Improved heat dispersal in a divertor system using three rows of rotating RMP was demonstrated and predictive control of the ELM-crash with <I>a priori</I> modeling was successfully tested. In magnetohydrodynamic physics, validation of the full reconnection model (i.e. <I>q</I> <SUB>0</SUB>  >  1 right after the sawtooth crash) and self-consistent validation of the anisotropic distribution of turbulence amplitude and flow in the presence of the 2/1 island with theoretical models were achieved. The turbulence amplitude induced by RMP was linearly increased with the slow RMP coil current ramp-up time (i.e. the magnetic diffusion time scale). The <I>D</I> <SUB> <I>α</I> </SUB> spikes (i.e. ELM-crash amplitude) was linearly decreased with the turbulence amplitude and not correlated with the perpendicular electron flow. In the turbulence area, a non-diffusive ‘avalanche’ transport event and the role of a quiescent coherent mode in confinement were studied. To accommodate the anticipation of a higher performance of the KSTAR plasmas with the increased heating powers, a new divertor/internal interface with a full active cooling system will be implemented after a full test of the new heating (neutral beam injection II and electron cyclotron heating) and current drive (CD) (Helicon and lower hybrid CD) systems. An upgrade plan for the internal hardware, heating systems and efficient CD system may allow for a long pulse operation of higher performance plasmas at <I>β</I> <SUB>N</SUB>  >  3.0 with <I>f</I> <SUB>bs</SUB> ~ 0.5 and <I>T</I> <SUB>i</SUB>  >  10 keV.</P>

유효 구동력 개념을 이용한 고상 비정질화 반응의 예측에 관한 연구

곽준섭(J. S. Kwak),지응준(E. J. Chi),최정동(J. D. Choi),박상욱(S. W. Park),소명기(M. K. So),이성만(S. M. Lee),백홍구(H. K. Baik) 한국진공학회(ASCT) 1993 Applied Science and Convergence Technology Vol.2 No.1

이원계 박막확산쌍에서 열처리 방법에 의한 고상 비정질화 반응의 경향성을 예측하기 위하여 유효 구동력 개념을 제시하였다. 고상 비정질화 반응은 두 원소의 물리적 혼합물과 비정질상간의 최대 자유에너지차로 주어지는 열역학적 구동력(ΔG_(max))과 확산원소의 원자반경에 대한 기지의 유효 침입형자리 반경의 비로 주어지는 구조적 요소(R_(m/d))가 충족될 때 일어나는 빠른 확산에 의하여 발생된다고 고찰하고, 유효 구동력 기준을 이용하여 금속/금속계 뿐만아니라 금속/실리콘 계의 고상반응에 의한 비정질상 생성 경향성을 예측하고 실험결과들과 비교하여 잘 적용됨을 보였다. 또한, 유효 구동력 기준이 금속/실리콘 계에서 비정질상의 임계 성장두께 경향성의 예측에도 잘 적용됨을 보였다. It is proposed that formation and growth of amorphous interlayer through solid state amorphizing reaction can be predicted by the concept of effective driving force. The effective driving force consists of two factors; i) the thermodynamic driving force given by maximum free energy difference between physical mixture of binary elements and amorphous interlayer (ΔG_(max)) and ii) the structural factor given by a ratio between effective radius of interstitial site in host matrix and atomic radius of diffusing species (R_(m/d)). It is shown that the the criterion of effective driving force is successfully applied in the prediction of the formation of amorphous interlayer in metal/silicon systems as well as that of metal/metal systems from the comparison of experimental data. In addition, the concept of effective driving force can be well applied to predict the growth tendency of amorphous interlayer in metal/silicon systems.

Immobilization of hemoglobin on functionalized multi-walled carbon nanotubes-poly-l-histidine-zinc oxide nanocomposites toward the detection of bromate and H₂O₂

Vilian, A.,Chen, S.M.,Kwak, C.H.,Hwang, S.K.,Huh, Y.S.,Han, Y.K. Elsevier Sequoia 2016 Sensors and actuators. B Chemical Vol.224 No.-

A novel biocompatible sensing strategy has been developed based on functionalized multi-walled carbon nanotube (f-MWCNT), poly-l-histine (P-l-His), and ZnO nanocomposite film for the immobilization of hemoglobin (Hb). The direct electron transfer properties and bioelectrocatalytic activity of the Hb in f-MWCNT-P-l-His-ZnO composite film is further investigated. The apparent heterogeneous electron transfer rate constant (k<SUB>s</SUB>) of Hb confined to f-MWCNT-P-l-His-ZnO nanocomposite is found to be 5.16s<SUP>-1</SUP> using Laviron's equation. Moreover, the surface coverage concentration (Γ) of the electroactive Hb in the f-MWCNT-P-l-His-ZnO film is estimated to be 1.88x10<SUP>-9</SUP>molcm<SUP>-2</SUP>. The fabricated electrochemical biosensor based on the immobilized Hb revealed a fast response time (<3s) with a wide linear range (4-18,000μM and 2-15,000μM) and detection limit (as low as 0.01μM and 0.30μM) for the electrocatalytic determination of a mediator-free H<SUB>2</SUB>O<SUB>2</SUB> and bromate under optimal experimental conditions. The ca. apparent Michaelis-Menten constant is 0.14mM, which indicates that the Hb has a high affinity to H<SUB>2</SUB>O<SUB>2</SUB>. The high sensitivity, good reproducibility, and long-term stability of the proposed nanocomposite film indicates that it can serve as an electrode for the development of an amperometric H<SUB>2</SUB>O<SUB>2</SUB> and bromate-based biosensor. The proposed third-generation biosensor was successfully applied to milk and urine samples for the detection of H<SUB>2</SUB>O<SUB>2</SUB> and bromate.

식육중 잔류항생물질 검사방법에 관한 연구(Ⅱ) : Tetracycline계의 확인시험 Identification of tetracyclines

이철원,김소희,장영미,곽효선,백선영,최병희,이경옥 국립보건연구원 1994 국립보건원보 Vol.31 No.2

약용작물을 가해하는 주요해충의 분포현황

곽준수,김창수,송영은,김주,한종현,신민교,송호준 대한본초학회 1997 大韓本草學會誌 Vol.12 No.1

This study performed for surveying insect pests which are distributing on medicinal plants in Korea. On the basis of pre-submitted data which were reported artificially, we analyzed the data and arranged the catalogue for surveying on medicinal plants in Korea. We classified it by family centering with host plants and arranged the catalogue of main insect pests by plants. The major results are as follow ; 1. The main insect pests which inflict injuries on medicinal plants showed totals on 539 species in 3 phyla, 4 classes, 14 orders and 105 families. 2. By population, arthopods were topped with 489 species (2 phyla, 11 order and 91 families) followed by nemathelminthes 47 species (1 phylum, 2 orders and 12 families), mollusca 3 species (1 phylum, 1 order and 3 families) etc. 3. Crops which showed relatively wide in host range are as follows ; Tylenchus sp. of nemathelminthes was recorded in 38 species of medicinal plants, Acusta despecta of mollusca was in 25 plants, two-spotted spider mite was in 47, tea-red spider mite was in 46, differentiate grasshopper was in 44, cotton aphid was in 23, and Sitochroa verticalis was in 33 plants.

Idiopathic Respiratory Distress Syndrome의 2例

郭景魯,金顯宇,李敏子,李謹洙 金原出版 1970 小兒科 Vol.11 No.7

거주지역에 따른 유아의 기호도 조사

곽동경,이혜상,박신정,최은희,홍완수,장미라 대한영양사협회 1998 대한영양사협회 학술지 Vol.4 No.1

The purpose of this study was to evaluate the preference trend of children in the child-care centers in relation to certain environmental factors such as size of the residing town. This evaluation was conducted using questionnaire survey where the mother of each child was required to complete a preference questionnaire including 83 food items. Statistical data analysis was completed using SAS package program. The results of this survey showed the followings : 1. Generally, the preference level of the children living in large cities were higher than those of medium cities except in case of vegetables, while the preference level of the children living in large cities were higher than those of rural area except in case of hard-boiling(jorim) and vegetables. The subjects showed high preferences to bulgogi(4.53), pork-cutlet(4.52), fried chicken(4.51), jajangmyone(4.45), kimgui(4.43), roasted fish(4.31), kim-bab(4.17), roasted ham(4.13). 2. There was a tendency that a la carte, bread and noodles received higher preference scores. Items of Korean style soup attained higher preference scores than stew(ggigae). The preference scores of fried, broiled or pan-fried items(jun) were higher than those of other items such as seasoned vegetables(namool). 3. The preference scores of children (routinely or occasionally) skipping breakfast or supper were generally low. There was no significant difference according to the existence of mother's job except in case of steamed or pan-fried items, provided that the preference scores of the children whose mother had a job were slightly higher in general. Further, there was no significant difference according to the size of the monthly income of the household except stew, provided that the preference scores of the children whose household had lower income were slightly higher in general.

사슴의 행동과 heart rate에 관한 연구

곽완섭,이상무,전병태,문상호,김창원,김경훈,太田 實 건국대학교 자연과학연구소 1998 建國自然科學硏究誌 Vol.9 No.1

꽃사슴의 heart rate를 안정적이며 지속적으로 기록하기 위해 고안한 본 telemetry system, 특히 자체 제작하여 활용한 electrode 와 transmitter 의 부착 방법 등은 매우 유용한 방법임이 입증되었다. 개발된 방법으로 heart rate를 측정, 행동과의 관계를 검토한 바, 행동의 변화는 곧 heart rate 의 변동으로 이어지기 때문에 방목사슴의 행동추정에 heart rate 의 측정치가 유효한 지표가 될 수 있음이 입증되었다. 또한 꽃사슴은 1일중 standing 시간이 70%로 면양과 똑같은 비율이었으며, 채식시간이 매우 짧은(170분/일) 경향을 나타내었는데 이것은 집약적 사육 조건하에서 꽃사슴의 채식특성이 아닌가 생각된다. In order to make consistent and reliable records of heart rate of deer, the telemetry system was modified in electrode and in attaching transmitter. This method was highly effective. The heart rate measured by this modification had a high correlationship with the change of deer behavior. The heart rate was a good prediction index of deer behavior on the pasture. In addition, the standing time of sika deer was 70% of daily hours, which was similar to that of sheep. Also, the short eating time(17- min/day) was attributed to the unique eating characteristics of deer under the intensive feeding condition.