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91.
Kyoungo Nam Hyunki Park Kihak Im Dongjin Kim Heejae Ahn Jaehyuk Lee Jaewhan Moon Emma Watson Robert Shaw 《Fusion Engineering and Design》2013,88(6-8):701-704
The purpose-built, ITER tokamak assembly tools, which are to be provided by Korea, should be designed to meet: the assembly plan, space reservations, safety standards, simple operations, efficient maintenance, and so on. It is very important that the ITER assembly tools are able to lift and transfer ITER components or their sub-assemblies to their assembled position safely. Furthermore, the lifting tools will lift and handle very heavy loads that can be more than 1200 tonnes sometimes. Therefore, the ITER lifting tools must be designed to endure these heavy load conditions with regard to their structural integrity. Also, these designs should be verified through an appropriate method. The preliminary design of the sector lifting tool and associated lifting attachments are introduced in this paper. The sector lifting tool was designed especially to lift and handle various ITER components by adjusting the lifting centre. The structural analysis results using ANSYS are described considering the heaviest load condition. The results of the analysis show that; all stresses applied on the lifting tool are lower than the allowable stress of the applied material. 相似文献
92.
Jun Ho Yeom Keeman Kim Young Seok Lee Hyoung Chan Kim Sangjun Oh Kihak Im Charles Kessel 《Fusion Engineering and Design》2013,88(6-8):742-745
A conceptual design study for a steady-state Korean fusion DEMO reactor (K-DEMO) has been initiated. Two peculiar features need to be noted. First, the major radius is designed to be just below 6.5 m, considering practical engineering feasibilities. But still, high magnetic field at the plasma center around 8 T is expected to be achieved by using current state-of-the-art high performance Nb3Sn strand technology. Second, a two-stage development plan is being considered. In the first stage, K-DEMO will demonstrate a net electricity generation but will also act as a component test facility. Then, after a major upgrade, K-DEMO is expected to show a net electric generation on the order of 300 MWe and the competitiveness in cost of electricity (COE). Feasibility of such a practical, near-future demonstration reactor is studied in this paper, based on a zero dimensional system analysis code study. It was shown that a net electric generation on the order of 300 MWe can be achieved below the optimistic βN limit of 5. The elongation of K-DEMO is around 1.8 with single null configuration. Detailed optimization process and the resultant various plasma parameters are described. 相似文献
93.
Yonghyun Kim Huiwen Liu Yi Liu Boa Jin Hao Zhang Wenjing Tian Chan Im 《Frontiers of Chemical Science and Engineering》2021,15(1):187-197
Cesium lead halide perovskite(CsPbX3,X=Cl,Br,I)quantum dots(QDs)and their partly Mn2+-substituted QDs(CsPb1–xMnxX3)attract considerable attention owing to their unique photoluminescence(PL)efficiencies.The two types of QDs,having different PL decay dynamics,needed to be further investigated in a form of aggregates to understand their solid-state-induced exciton dynamics in conjunction with their behaviors upon degradation to achieve practical applications of those promising QDs.However,thus far,these QDs have not been sufficiently investigated to obtain deep insights related to the long-term stability of their PL properties as aggregated solid-states.Therefore,in this study,we comparatively examined CsPbX3-and CsPb1–xMnxX3-type QDs stocked for>50 d under dark ambient conditions by using excitation wavelength-dependent PL quantum yield and time-resolved PL spectroscopy.These investigations were performed with powder samples in addition to solutions to determine the influence of the inter-QD interaction of the aged QD aggregates on their radiative decays.It turns out that the Mn2+-substituted QDs exhibited long-lasting PL quantum efficiencies,while the unsubstituted CsPbX3-type QDs exhibited a drastic reduction of their PL efficiencies.And the obtained PL traces were clearly sensitive to the sample status.This is discussed with the possible interaction depending on the size and distance of the QD aggregates. 相似文献
94.
Homogeneous 2D MoTe2 p–n Junctions and CMOS Inverters formed by Atomic‐Layer‐Deposition‐Induced Doping 下载免费PDF全文
June Yeong Lim Atiye Pezeshki Sehoon Oh Jin Sung Kim Young Tack Lee Sanghyuck Yu Do Kyung Hwang Gwan‐Hyoung Lee Hyoung Joon Choi Seongil Im 《Advanced materials (Deerfield Beach, Fla.)》2017,29(30)
Recently, α‐MoTe2, a 2D transition‐metal dichalcogenide (TMD), has shown outstanding properties, aiming at future electronic devices. Such TMD structures without surface dangling bonds make the 2D α‐MoTe2 a more favorable candidate than conventional 3D Si on the scale of a few nanometers. The bandgap of thin α‐MoTe2 appears close to that of Si and is quite smaller than those of other typical TMD semiconductors. Even though there have been a few attempts to control the charge‐carrier polarity of MoTe2, functional devices such as p–n junction or complementary metal–oxide–semiconductor (CMOS) inverters have not been reported. Here, we demonstrate a 2D CMOS inverter and p–n junction diode in a single α‐MoTe2 nanosheet by a straightforward selective doping technique. In a single α‐MoTe2 flake, an initially p‐doped channel is selectively converted to an n‐doped region with high electron mobility of 18 cm2 V?1 s?1 by atomic‐layer‐deposition‐induced H‐doping. The ultrathin CMOS inverter exhibits a high DC voltage gain of 29, an AC gain of 18 at 1 kHz, and a low static power consumption of a few nanowatts. The results show a great potential of α‐MoTe2 for future electronic devices based on 2D semiconducting materials. 相似文献
95.
Jumi Yun Dae Hoon Lee Ji Sun Im Hyung-Il Kim 《Materials science & engineering. C, Materials for biological applications》2012,32(6):1564-1570
Transdermal drug delivery system (TDDS) was prepared with temperature-responsive hydrogel. The graphite was oxidized and incorporated into hydrogel matrix to improve the thermal response of hydrogel. The micro heater was fabricated to control the temperature precisely by adopting a joule heating method. The drug in hydrogel was delivered through a hairless mouse skin by controlling temperature. The efficiency of drug delivery was improved obviously by incorporation of graphite oxide due to the excellent thermal conductivity and the increased interfacial affinity between graphite oxide and hydrogel matrix. The fabricated micro heater was effective in controlling the temperature over lower critical solution temperature of hydrogel precisely with a small voltage less than 1 V. The cell viability test on graphite oxide composite hydrogel showed enough safety for using as a transdermal drug delivery patch. The performance of TDDS could be improved noticeably based on temperature-responsive hydrogel, thermally conductive graphite oxide, and efficient micro heater. 相似文献
96.
Jongseong Park Dae‐Hyeon Kim Su‐Jin Park Tae‐gon Lee Mir Im Jeong‐Seog Kim Sahn Nahm 《Journal of the American Ceramic Society》2016,99(7):2229-2232
A specimen having a stoichiometric composition of KSbO3·(KSb) calcined at 800°C has an R rhombohedral structure (RS), and changes to a Pn cubic structure (CS) when calcined at 1100°C. Finally, a <111>‐oriented rhombohedral phase is formed in the specimen calcined at 1230°C. K/Sb ratio decreases from 1.0 in RS, 0.93 in CS, and finally to 0.85 in <111>‐oriented rhombohedral phases. On the other hand, a specimen having a K‐excess composition of K1.1SbO3 calcined at 800°C shows a RS that is maintained in the K‐excess specimen calcined at 1230°C. The composition of these specimens is very close to KSb. Therefore, the RS with a space group of R is a stable form of KSbO3. The formation of Pn cubic and <111>‐oriented R phases can be explained by the evaporation of K2O during the calcination process at temperatures above 1100°C. 相似文献
97.
Fractionation of the MeOH extract of Homaxinella sp., a marine sponge, led to the isolation of a sodium salt of a new brominated FA (1), two new MG (2 and 4), and a new lysoPC (6). The geometry of the double bonds in 1 and 2 was defined by comparison of the NMR chemical shifts of the allylic carbons, nuclear Overhauser effect spectroscopy correlations
of the allylic protons, and coupling constants of the vinylic protons with those reported. Evidence mainly from NMR and MS
analyses established the planar structures of the compounds. Compounds 1, 2, 4, and 6 were evaluated for cytotoxicity against a panel of five human solid tumor cell lines. Only compound 1 showed moderate activity. 相似文献
98.
David K. Hsu Kwang-Hee Im Young-Tae Cho Jae-Woung Park Jae-Ki Sim In-Young Yang 《Journal of Mechanical Science and Technology》2002,16(3):292-301
Ultrasound waves interact strongly with the orientation and sequence of the plies in a layup when propagating in the thickness direction of composite laminates. Also the layup orientation greatly influences its properties in a composite laminate. If the layup orientation of a ply is misaligned, it could result in the part being rejected and discarded. Now, most researchers cut a small coupon from the waste edge and use a microscope to optically verify the ply sequences on important parts. This may add a substantial cost to the production since the test is both labor intensive and performed after the part is cured. A nondestructive technique would be very beneficial, which could be used to test the part after curing and requires less time than the optical test. Therefore we have developed, reduced, and implemented a novel ply-by-ply vector decomposition model for composite laminates fabricated from unidirectional plies. This model decomposes the transmission of a linearly polarized ultrasound wave into orthogonal components through each ply of a laminate. High probability is found, by comparisons between the model and tests, in characterizing cured layups of the laminates by using the proposed method. 相似文献
99.
100.
We have evaluated a multichannel transcranial magnetic stimulation (TMS) system using realistic simulations based on the boundary element method (BEM). We investigated various configurations and types of stimulation coils by means of quantitative measures such as targeting accuracy and field concentration. The simulation studies applied to four different head-brain models suggest improved coil types yielding enhanced targeting accuracy and concentrated evoked electric field distribution 相似文献