• Title/Summary/Keyword: Short-cut method

Search Result 104, Processing Time 0.026 seconds

An Analysis on the Cryogenic Distillation Process for $^{13}CH_4$ Separation from LNG by Short-Cut Method (Short-Cut 방법에 의한 LNG 성분에서 $^{13}CH_4$초저온 증류 공정 분석)

  • Lee Youngchul;Song Taekyoong;Cho ByungHak;Baek Youngsoon;Song KyuMin
    • Journal of the Korean Institute of Gas
    • /
    • v.9 no.2 s.27
    • /
    • pp.22-27
    • /
    • 2005
  • In this study, we analyze computational simulation of cryogenic distillation process to separate $^{13}CH_4$ and $^{12}CH_4$ from LNG by using the cryogenic energy. Used computational simulation program is made Smoker's equation and FUG(Fenske-Underwood-Gilliland)'s method by short-cut method. Generally speaking, the technology of carbon isotope separation is studied by many methods, especially the separation by cryogenic distillation process is commercialized because of many merits.

  • PDF

Control Method for Cut-out of Shorted Load in the Auxiliary Power Supply (보조전원장치의 단락부하 차단기 개방을 위한 제어방법)

  • 황광철;조국춘;최종묵
    • Proceedings of the KSR Conference
    • /
    • 1998.11a
    • /
    • pp.249-254
    • /
    • 1998
  • This paper describes the control methods to cut out the NFB(No Fuse Breaker) of shorted load in the auxiliary power supply, Generally, when the short-circuit occurs in the load of the auxiliary power supply, the auxiliary power supply stops the operation according to the protection sequence. Finally, the other auxiliary power supply stops the operation by the same fault, To resolve this problem, we suggest the control method to trip the NFB of shorted load. That is, when the short circuit occurs, the controller changes control mode from voltage mode to current mode without the operation of output contactor(SIVK) in the auxiliary power supply. The auxiliary power supply provides a large current for the short-circuit load. After some time, the NFB of the short-circuit load is cut off and the auxiliary power supply Provides stable voltage for the loads except for the short-circuit load.

  • PDF

Performance Evaluation of Short-cut Tunneling Schemes in Optimized Path Method over Mobile IP Networks (이동 IP의 최적경로 방식에서 단거리 터널링 기법의 성능평가)

  • 변태영;이경훈
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.8 no.1
    • /
    • pp.65-73
    • /
    • 2004
  • In this paper, we propose a tunnel establishment scheme using Next Hop Resolution Protocol over mobile IP networks, which consist of LAN-based IP networks and ATM-based IP networks. As a basic idea, we use the shortest path algorithm to establish a short-cut tunnel between HA and FA. Also, we classify methods for establishing a short-cut tunnel into four cases considering the locations of HA, FA, CN and MN. To confirm the advantages of our schemes, which deliver packets using short-cut tunnel in optimized path method over mobile IP networks, we performed mathematical analysis and simulation, compared proposed schemes with existing IP routing method in terms of transmission delay between CN and MN. The simulation results show that our scheme have superior performance to that of existing IP routing mechanism, because the store-and-forward delay which occurred in IP routing mechanism is considerably reduced in short-cut tunnel over ATM networks.

The Effect of Hair Style for Impression Formation (Hair Style이 인상형성(印象形成)에 미치는 영향(影響))

  • Yoon, So-Young;Yoo, Tai-Soon
    • Journal of Fashion Business
    • /
    • v.5 no.3
    • /
    • pp.73-84
    • /
    • 2001
  • The purpose of this study is to apply fundamental data of impression formation research by analysing and observing the various facial image that can be effected from hair style as well as be helpful for choosing suitable hair style for T.P.O in modern society. This study targeted 305 college women in Daegu and Gyung-book area. Hair Style Image Scale(HSIS)was used the scale of seven point modified the S-D(Semantic Differential) method. The analysis of impression formation effect of hair style using SPSS WIN package have completed from the principal component analysis by Varimax perpendicular rotation method and ANOVA was used to recognize the difference in impression formation according to hair style change. In the case of statistical difference was appeared, LSD post-verification was applied for that. The conclusions of this study is as followed ; 1. The factors of impression formation effected by hair style were classified as goodwill factor, refinement factor, elegance factor and individuality factor. 2. In terms of goodwill factor, long hair style showed highest level and short cut hair, bobbed hair in an order. In refinement factor, there was no difference between short cut hair and bobbed hair and both of them was higher than long hair. In elegance factor, long hair was highest and bobbed hair was lowest. In individuality factor, short cut hair and bobbed hair higher than long hair and no difference between short cut hair and bobbed hair.

  • PDF

Development of Stage-Cut Method for medium depth Shaft in Korea (국내 중저심도(20~80m) 수직구에 적합한 Stage-Cut 공법 개발)

  • Hong, Chang-Soo;Lee, Ji-Su;Hwang, Dae-Jin
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.09a
    • /
    • pp.1522-1529
    • /
    • 2009
  • When a shaft is excavated in Korea, the mechanized method such as RBM(Raise Boring Machine) or RC(Raise Climber) is used independently of depth. But usually, the mechanized method is useful for the deep depth. On the contrary, when the depth of shaft is short, the cost of excavation increase. So in the case of shaft constructon less than 100m, we need to consider more suitable method of shaft construction such as Stage-cut which is one of blasting methods. Stage-Cut is widely used in the field of shaft construction in Japan as a tool of rock excavation. The main purpose of this study is to provide technical guidance for design and construction of shafts in rock, using Stage-cut method which is suitable for 20m~80m depth shaft. In this study, Blasting tests was performed in field, according to rock classification. Finally, the stage-cut method which is suitable for the geology of Korea was developed.

  • PDF

Study on a Noval Simulation Method of Wind Power Generation System Using PSCAD/EMTDC (PSCAD/EMTDC를 이용한 풍력발전시스템의 새로운 시뮬레이션 방법에 관한 연구)

  • 한상근;박민원;유인근
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.52 no.6
    • /
    • pp.307-315
    • /
    • 2003
  • This paper proposes a novel simulation method of WPGS (Wind Power Generation System). The rotation speed control method of turbine under variable wind speed using the pitch control is proposed. Moreover, when wind speed exceeds the cut-out wind speed, the turbine will be stopped by controlling pitch angle to 90$^{\circ}$, otherwise it will be controlled to steady-state operation. For the purpose of effective simulation, the SWRW (Simulation method for WPGS using Real Weather condition) is used for the utility interactive WPGS simulation in this paper, in which those of three topics for the WPGS simulation: user-friendly method, applicability to grid-connection and the utilization of the real weather conditions, are satisfied. It is impossible to consider the real weather conditions in the WPGS simulation using the EMTP type of simulators and PSPICE, etc. External parameter of the real weather conditions is necessary to ensure the simulation accuracy. The simulation of the WPGS using the real weather conditions including components modeling of wind turbine system is achieved by introducing the interface method of a non-linear external parameter and FORTRAN using PSCAD/EMTDC in this paper. The simulation of long-term, short-term, over cut-out and under cut-out wind speeds will be peformed by the proposed simulation method effectively. The efficiency of wind power generator, power converter and flow of energy are analyzed by wind speed of the long-term simulation. The generator output and current supplied into utility can be obtained by the short-term simulation. Finally, transient-state of the WPGS can be analyzed by the simulation results of over cut-out and under cut-out wind speeds, respectively.

A simple method to produce fragment seedstock for aquaculture of Pterocladiella capillacea (Gelidiales, Rhodophyta)

  • Choi, Chang Geun;Lee, Ju Il;Hwang, Il Ki;Boo, Sung Min
    • ALGAE
    • /
    • v.36 no.4
    • /
    • pp.327-332
    • /
    • 2021
  • Raw material of gelidioid red algae yielding high-quality agar has been in short supply due to overharvesting, but in situ farming of gelidioids has not been practical due to their slow growth. To produce vegetative seedstock of a cosmopolitan species, Pterocladiella capillacea, we investigated the number and length of regenerated branches arising from sectioned fragments during 3 weeks of laboratory culture at 10, 15, 20, and 25℃. All sectioned fragments formed axis-like branches mostly from the upper cut edge and stolon-like branches mostly from the lower cut edge, showing a high capacity of regeneration and intrinsic bipolarity. At 20℃, the number of regenerated branches increased to 2.74 ± 1.29 on the upper cut edge and 4.26 ± 2.66 on the lower cut edge. Our study reveals that the use of fragments bearing regenerated branches as seedstock can be a simple method to initiate fast propagation for mass cultivation in the sea or outdoor tank.

Short Channel Analytical Model for High Electron Mobility Transistor to Obtain Higher Cut-Off Frequency Maintaining the Reliability of the Device

  • Gupta, Ritesh;Aggarwal, Sandeep Kumar;Gupta, Mridula;Gupta, R.S.
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.7 no.2
    • /
    • pp.120-131
    • /
    • 2007
  • A comprehensive short channel analytical model has been proposed for High Electron Mobility Transistor (HEMT) to obtain higher cut-off frequency maintaining the reliability of the device. The model has been proposed to consider generalized doping variation in the directions perpendicular to and along the channel. The effect of field plates and different gate-insulator geometry (T-gate, etc) have been considered by dividing the area between gate and the high band gap semiconductor into different regions along the channel having different insulator and metal combinations of different thicknesses and work function with the possibility that metal is in direct contact with the high band gap semiconductor. The variation obtained by gate-insulator geometry and field plates in the field and channel potential can be produced by varying doping concentration, metal work-function and gate-stack structures along the channel. The results so obtained for normal device structure have been compared with previous proposed model and numerical method (finite difference method) to prove the validity of the model.

Studies on Short Term Hardening Method of Tree Seedlings for Afforestation of Cut-Rock Slope (암반절개사면 녹화용 강건묘목의 속성육묘법에 관한 연구)

  • Hong, Sung-Gak;Kim, Jong-Jin
    • Korean Journal of Environmental Agriculture
    • /
    • v.17 no.4
    • /
    • pp.358-361
    • /
    • 1998
  • This study was carried out to develop a short term hardening method of tree seedlings of Rhus chinensis Mill., Evodia daniellii Hemsley and Parthenocissus tricuspidata(Sieb. et Zucc.) Planck for afforestation on a concave and a crack of cut-rock slope. The seedlings were grown in a cylinder shaped pot made of polyvinyl net with the soil media of peatmoss, vermiculite, clay, compost, fertilizer, and absorbant(40:25:19:15:1:0.1, v:v). They were cultivated in a greenhouse for four months and in field condition for two months. During the last three months of the growing period the seedlings were hardened by periodic desiccation and irrigation in 4 to 10 days interval. The hardened seedlings showed lower leaf water potential, higher leaf osmotic pressure, and lower T/R ratio than those before the hardening. The hardened seedlings survived well on the soil medium in the concave of cut-rock slope.

  • PDF

Preparation and Characterization of Silk and Mulberry/Silk Papers

  • Lee, Ki-Hoon;Kang, Gyung-Don;Oh, Han-Jin;Ki, Chang-Seok;Kim, Jong-Wook;Park, Young-Hwan
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.13 no.1
    • /
    • pp.45-50
    • /
    • 2006
  • Papers were prepared from cut cocoons and mulberry branches, which are byproducts from sericulture industry. The long filament of silk should be cut into appropriate length in order to prepare paper and this was achieved by chemical method. By a mixture of sodium hydroxide and sodium carbonate solution, the silk filaments were cut into short fibers (less than 1 mm in length). Since the short silk fibers (sSf) could not bind each other by itself, starch and poly(ethylene oxide)(PEO) were added as a bonding agent. When starch and PEO were used in a ratio of 3:7, the silk papers had optimum mechanical properties for paper. Fibers from the skin of mulberry branches (MBF) were added to sSf to enhance the mechanical properties of pure silk paper. Bleaching of MBF was performed with a mixture of hydrogen peroxide and sodium silicate. The mechanical properties were greatly enhanced and the optimum blend ratio of MBF and sSf were 7:3. The mulberry/silk paper has good absorption property against formaldehyde, and therefore, the paper could be applied as a wall paper for preventing the sick house syndrome.