http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mg 其他 複合材料의 强化材 量 및 分布에 따른 機械的性質特性
안선규,하홍수,김영직,임병수 成均館大學校 科學技術硏究所 1997 論文集 Vol.48 No.1
The effect of different SiC particle size and weight fraction in Mg/SiC particle MMC on the mechanical properties has been investigated. In this study, different particle sizes of 7㎛, 20㎛ and 50㎛ were prepared with various weight fraction of 10wt.%, 20wt.% and 30wt.% for sample preparation. By tension tests, the properties of ultimate tensile stress, yield stress and % elongation were observed and by tension-tension fatigue tests, whose procedures are standardized in ASTM standard 647E-93, the ΔK vs, da/dN curves were also obtained. Finally, the crack propagation paths were observed by optical microscope.
Kim Jin-Ju,Park Jae-Hyun,Kim Hyeok,Sim Woo-Sup,Hong Seokbeom,Choi Yeon-Jik,Kim Hyo-Jin,Lee Soon Min,Kim Dongha,Kang Sun-woong,Ban Kiwon,Park Hun-Jun 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-
Despite recent progress in medical and endovascular therapy, the prognosis for patients with critical limb ischemia (CLI) remains poor. In response, various stem cells and growth factors have been assessed for use in therapeutic neovascularization and limb salvage in CLI patients. However, the clinical outcomes of cell-based therapeutic angiogenesis have not provided the promised benefits, reinforcing the need for novel cell-based therapeutic angiogenic strategies to cure untreatable CLI. In the present study, we investigated genetically engineered mesenchymal stem cells (MSCs) derived from human bone marrow that continuously secrete stromal-derived factor-1α (SDF1α-eMSCs) and demonstrated that intramuscular injection of SDF1α-eMSCs can provide long-term paracrine effects in limb ischemia and effectively contribute to vascular regeneration as well as skeletal muscle repair through increased phosphorylation of ERK and Akt within the SDF1α/CXCR4 axis. These results provide compelling evidence that genetically engineered MSCs with SDF-1α can be an effective strategy for successful limb salvage in limb ischemia.
Kim, Chan-Mi,Dharmaiah, Peyala,Kim, Hyo-Seob,Koo, Jar-Myung,Yoon, Jae-Sik,Hong, Hyun-Seon,Hong, Soon-Jik PAS 2017 ARCHIVES OF METALLURGY Vol.62 No.2
<P>The objective of this particular study was to recover valuable metals from waste plasma display panels using high energy ball milling with subsequent acid dissolution. Dissolution of milled (PDP) powder was studied in HCl, HNO3, and H2SO4 acidic solutions. The effects of dissolution acid, temperature, time, and PDP scrap powder to acid ratio on the leaching process were investigated and the most favorable conditions were found: (1) valuable metals (In, Ag, Mg) were recovered from PDP powder in a mixture of concentrated hydrochloric acid (HCl: H2O = 50:50); (2) the optimal dissolution temperature and time for the valuable metals were found to be 60 degrees C and 30 min, respectively; (3) the ideal PDP scrap powder to acid solution ratio was found to be 1:10. The proposed method was applied to the recovery of magnesium, silver, and indium with satisfactory results.</P>
A truncated adaptive transmission scheme for hybrid multicarrier CDMA/FDM systems in forward link
Kim, Hong Jik,Song, Iickho,Lee, Jumi,Kim, Sun Yong IEEE 2005 IEEE Transactions on Vehicular Technology VT Vol.54 No.3
A truncated adaptive transmission scheme for the hybrid multicarrier CDMA/FDM system is considered in forward link. In the proposed scheme, a data substream is transmitted over the subchannels of which the channel gains are greater than a given threshold, based on the feedback information from the mobile station. We analyze the performance of the proposed system when orthogonal and random signature sequences are used in single- and multiple-cell environment. In the single-cell environment, when orthogonal signature sequences are used, the proposed scheme outperforms the adaptive FH/DS system as well as the conventional MC DS/CDMA system, and accommodates more users than the adaptive FH/DS system while maintaining the orthogonality between users. In the multiple-cell environment also, the proposed scheme has better performance characteristics than the adaptive FH/DS system when orthogonal or random codes are used as spreading sequences.
The Mierostruetural Evolution and Mechanical Properties of Atomized Al-xFe-yCr Alloys
Kim, Taek Soo,Chun, Byong Sun,Kim, Kyeoung Hwan,Kim, Hong Moule,Hong, Soon Jik 대한금속재료학회(대한금속학회) 1999 METALS AND MATERIALS International Vol.5 No.3
Relation between the microstucture and mechanical property of Al-xFe-yCr alloy, with various types, volume fractions and sizes of dispersoids, has been studied. 'The alloys contain high concentrations of transition elements(Cr, Fe) which form thermally stable precipitates in the aluminium matrix. High temperature tensile tests were performed to investigate the possibility of elevated temperature applications. Oxidation of powder surface during atomizing strengthens the bulk extrudates by providing the obstacle layer. The oxide layer is very chemically and thermally stable and prevent the coarsening of the intermediate compounds. X-ray diffraction shows that the volume fraction of the α-Al matrix and the intermetallic compounds in the extrudates are changed depending on the composition of alloying elements. The extrudates exhibit a fine microstructures.
Kim, Hyeok-Gyu,Kim, Hong-Jik,Lee, Myong-Hwa,Kim, Jong-Ho Korean Society for Atmospheric Environment 2014 Asian Journal of Atmospheric Environment (AJAE) Vol.8 No.2
There have been a lot of efforts to keep permissible emission standards and to reduce the amount of emitted air pollutants. There are several air pollution control equipments, however, wet scrubber is used to remove particulate matters and gaseous pollutants simultaneously, even if it has low collection efficiency in the particle size less than $5.0{\mu}m$. To overcome this problem, we introduced a spray tower scrubber with an electrospray system which a high voltage was indirectly applied. We found that collection efficiency of fine particles in the electrospray system was improved by increasing electrical field strength and the ratio of liquid-gas flow rate (from 41% to 84% for $0.3{\mu}m$ particles). In addition, a number of small droplets generated from an electrospray system led high collection efficiency, resulting from electrostatic attraction between droplets and particles and higher collision frequency. Therefore, we can conclude that the introduction of an electrospray system is quite effective to increase the particle removal efficiency of a spray tower scrubber.