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Probing galactic and intergalactic magnetic fields using Faraday tomography (optionally title in Korean in parentheses)

  • Ideguchi, Shinsuke;Takahashi, Keitaro;Akahori, Takuya;Ryu, Dongsu
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.31.1-31.1
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    • 2015
  • For probing magnetic fields in the universe, rotation measure (RM) have been often used. RM allows us to obtain the information of integrated (or averaged) magnetic fields along a line of sight (LOS). On the other hand, the new technique so-called Faraday tomography will be used in practical in the near future thanks to the wide-band polarimetry by Square kilometre Array and/or its precursors. The technique allows us to obtain so-called Faraday dispersion function (FDF). FDF is the distribution function of magnetic fields and polarized sources along a LOS. Because of this fact, it is expected that the studies of magnetic fields associated with various astronomical objects will progress dramatically. Since FDF also includes information of cosmic-rays and thermal electrons, the investigation of FDF may advance the studies of dynamics of external galaxies and/or the star formation activities. We have studied the potentials of Faraday tomography such as a tool to probe the intergalactic magnetic field associated with filaments of galaxies in the large scale structure. We have also studied the realistic FDFs of galaxies for understanding global magnetic field, cosmic-ray and thermal electrons of external galaxies. In the talk, we briefly introduce the Faraday tomography technique and report the results related to the Faraday tomography.

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Application of Acoustic Emission Technique for On-Line Monitoring of Quench in Racetrack Superconducting Coil at Cryogenic Environment (음향방출기법을 이용한 극저온 환경하에서 초전도 계자코일의 퀀칭탐지 적용에 관한 연구)

  • Lee, Min-Rae;Gwon, Yeong-Gil;Lee, Jun-Hyeon;Son, Myeong-Hwan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.4 s.175
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    • pp.858-865
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    • 2000
  • It is well recently recognized that quench is one of the serious problems for the integrity of superconducting magnets, which is mainly attribute to the rapid temperature rising in the magnet due to some extrinsic factors such as conductor motion, crack initiation etc. In order to apply acoustic emission(AE)echnique effectively to monitor and diagnose superconducting magnets, it is essential to identify the sources of acoustic emission. In this paper, an acoustic emission technique has been used to monitor and diagnose quenching phenomenon in racetrack shaped superconducting magnets at cryogenic environment of 4.2K. For these purposes special attention was paid to detect AE signals associated with the quench of superconducting magnets. The characteristics of AE parameters have been analyzed by correlating with quench number, winding tension of superconducting coil and charge rate by transport current. In addition, the source location of quench in superconducting magnet was also discussed on the basis of correlation between magnet voltage and AE energy.

In vitro Antiviral Activities of Korean Marine Algae Extracts against Fish Pathogenic Infectious Hematopoietic Necrosis Virus and Infectious Pancreatic Necrosis Virus

  • Kang, So-Young;Kim, Seok-Ryel;Oh, Myung-Joo
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.1074-1078
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    • 2008
  • To investigate the antiviral activity of marine algae against fish pathogenic viruses, which are often the causes of viral disease in aquaculture, the 80% methanolic extracts of 21 species collected from the coast of Korea were screened for their in vitro antiviral activities on infectious hematopoietic necrosis virus (IHNV) and infectious pancreatic necrosis virus (IPNV), using a flounder spleen (FSP) cell-line. Among them, Monostroma nitidum (10 ${\mu}g/mL$) exhibited the strongest inactivation on IHNV, showing a 2 log reduced virus titre as compared to the control in the determination of direct virucidal activity. In addition, Polysiphonia morrowii (100 ${\mu}g/mL$) remarkably reduced the virus titres of treated cells by 2-2.5 log, for both IHNV and IPNV, in the determination of cellular protective activity, implying the existence of substances that may modulate innate host defense mechanisms against viral infections. These results reveal that some marine algae could be promising candidates as sources of antiviral agents or as health-promoting feeds for aquaculture.

Study on Original Design Features of First Ladies' Evening Dresses - Comparison of Jacqueline's Styles and Later First Ladies' Styles -

  • Lee, Young-Jae
    • Journal of Fashion Business
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    • v.16 no.3
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    • pp.95-106
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    • 2012
  • Jacqueline Kennedy Onassis (July 28, 1929 - May 19, 1994) was served as First Lady of the United States in the early 1960s. Her fashion styles are analyzed into the elements of designs, and the features of Jackie look are assorted. A variety of sources about women's suits for the 21st century are suggested in the research. Jackie's taste in fashion, her fashion image are searched. In addition, after Jackie, other nine fashionable First Ladies' evening dresses are compared to Jackie's dresses so as to see if there are similarities between their styles. Based on this data, the typical First Lady's look is classifiable. The purpose of this study is to furnish the industry with basic information which helps create high value fashion design. Most of Jackie's evening dresses had the straight - sheath silhouettes, and the round or bateau necklines without collars. Pale tones like white predominated in her dresses, and patternless colorful silk, silky and bright texture of cloth was used for the dresses. Elegance and classic represented her image. Design features of Jackie look are the straight silhouette, the simple line excluded adornments, and the fine quality of cloth. There has been little change in other nine First Ladies' evening dresses since Jackie. They weren't influenced by the vogue at that time, but they kept the style the way Jackie did. Jackie style is the beginning of the typical first lady look, that is.

The Analysis of Environmental Impact Load by Fibrous Raw Materials and Wet-end Additives in Papermaking Process (제지공정 섬유상 원재료 및 공정 첨가제의 환경오염 부하 분석)

  • Kim, Hyoung-Jin;Shin, Dong-Uk
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.37 no.3
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    • pp.50-58
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    • 2005
  • It is generally known that paper industry is the second largest industry in the use of process water, and also have the highest environmental impact load in the contaminant sources. Paper is produced from the mixtures composed of 1% fibrous raw materials and 99% water. The optimum use of process water effects on the quality properties of paper and the environmental impact load of waste water treatment. In this research, the kinds of fibrous raw material & additives used in the paperboard production line were investigated, and the quantification of environmental loads and the environmental effects of process water on COD potential were evaluated. The NBDCODs were also analyzed from process water by the method of waste water treatment in paper mill and applied for the optimum use of recycling water, and zero effluent process. In the fibrous raw materials, KOCC caused the highest COD potentials, and sack paper & UKP was comparatively low. The NBDCOD of KOCC largely reduced after biological treatment because of easily biodegradable properties, but AOCC contained non-biodegradable materials. In chemical additives, COD was high in turns of rosin>starch>deaeration agent>dye, NBDCOD greatly reduced in starch and deaeration agent. In the case of 2 kinds of paperboard product, the COD potentials was mainly high in starch, AOCC and KOCC.

The Research of Pseudolite technology by comparison with each applications for marine applications (해양분야 응용을 위한 의사위성 실내항법기술의 적용 대상별 비교 연구)

  • Shim, Woo-Seong;Suh, Sang-Hyun;Lee, Sang-Jeong;Park, Chan-Sik;Ki, Chang-Don
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.05a
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    • pp.6-11
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    • 2002
  • A term of GNSS(Global Navigation Satellite System) is widely used to represent a navigation method for global area using satellite in space orbit 1his system can provide accurate and continuous position, and timing sources synchronized to UTC. There are, however, certain disadvantage that system can not operate without line of sight environment to satellite, or system failure of either satellite or control station. It is the pseduolite technology for using indoor and also for back-up equipment of foreign system failure. Especially, ocean applications widely use the GNSS system for navigation, surveying, timing, and management of traffic, so, system failure of GNSS will be very critical problem to affect many aspects of ocean field. In this paper, we experimented the pseudolite technology for several application field to compare the result in different environment. We used the common CDGPS algorithm for in-door navigation and experimented in ocean engineering basin with metallic wall and gymnasiums with concrete wall. We also investigated the comparison result and considerations for ocean applications of pseudolite technology.

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Influence of an Aspect Ratio of Rectangular Channel on the Cooling Performance of a Multichip Module

  • Choi, Min-Goo;Cho, Keum-Nam
    • Journal of Mechanical Science and Technology
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    • v.14 no.3
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    • pp.350-357
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    • 2000
  • Experiments were performed by using PF-5060 and water to investigate the influence of an aspect ratio of a horizontal rectangular channel on the cooling characteristics from an in-line $6{\times}1$ array of discrete heat sources which were flush mounted on the top wall of the channel. The experimental parameters were aspect ratio of rectangular channel, heat flux of simulated VLSI chip, and channel Reynolds number. The chip surface temperatures decreased with the aspect ratio at the first and sixth rows, and decreased more rapidly at a high heat flux than at a low heat flux. The measured friction factors at each aspect ratio for both water and PF-5060 gave a good agreement with the values predicted by the modified Blasius equation within ${\pm}7%$. The Nusselt number increased as the aspect ratio decreased, but the increasing rate of Nusselt number reduced as the aspect ratio decreased. A 5:1 rectangular channel yields the most efficient cooling performance when the heat transfer and pressure drop in the test section were considered simultaneously.

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Field Evaluation of Mungbean Recombinant Inbred Lines against Mungbean Yellow Mosaic Disease Using New Disease Scale in Thailand

  • Akhtar, Khalid P.;Kitsanachandee, R.;Srinives, P.;Abbas, G.;Asghar, M.J.;Shah, T.M.;Atta, B.M.;Chatchawankanphanich, O.;Sarwar, G.;Ahmad, M.;Sarwar, N.
    • The Plant Pathology Journal
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    • v.25 no.4
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    • pp.422-428
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    • 2009
  • Studies were conducted to identify the sources of resistance in mungbean recombinant inbred lines (RILs) in Thailand against mungbean yellow mosaic disease (MYMD). 146 mungbean RILs in $F_8$ series were evaluated in a field including resistant parent NM-10-12-1 and susceptible parent KPS 2 during summer 2008 under high inoculum pressure. The RILs were subsequently scored for disease symptom severity ratings (DSSR) using a new scale. Observations regarding DSSR and % disease index (%DI) showed that the tested RILs responded differently to the disease. A large number of RILs (132) were found highly susceptible, 12 were susceptible, 3 were tolerant and one was resistant. Overall screening results showed that three RILs, viz. line no. 30, 100 and 101 had minimum DSSR and % disease index thus they are good source of resistance to MYMD in spite of high disease pressure and can therefore be used directly as varieties to manage the disease in Thailand.

The Study on Efficiency Improvement of Thermal Storage Tank for Solar Combined Heating System (태양열 난방 일체형 복합시스템의 축열조 효율개선에 관한 연구)

  • Lyu, Nam-Jin;Ko, Kwang-Soo;Han, Yu-Ri;Park, Youn-Cheol
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.11a
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    • pp.188-192
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    • 2006
  • This study is conducted to improve efficiency of thermal storage tank. The thermal storage tank was designed to store heat energy that obtained from solar or the others heat sources. However, it has difficulties in storing heat with uniform temperature through the entire tank with respect to vertical direction. This kind of maldistribution of the supplied heat to the storage tank effects on the system performance. In this study is focused on utilization of the thermal stratification to improve thermal comfort for people in the house. To enhance temperature stratification of the tank, a distributor was designed and Installed in the middle of the tank. The distributor is supplies hottest water to the top side of the tank which is very close to inlet of the supply line to the heating load. The hottest water that is accumulated on top side of the tank is firstly supplied to the load with higher temperature. Reminder water takes a little time to warming up until desired supply temperature reached. This kind alternating selection of the supply temperature is improve thermal comfort with moderated system performance.

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A Conveyor Algorithm for Complete Consistency of Materialized View in a Self-Maintenance (실체 뷰의 자기관리에서 완전일관성을 위한 컨베이어 알고리듬)

  • Hong, In-Hoon;Kim, Yon-Soo
    • IE interfaces
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    • v.16 no.2
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    • pp.229-239
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    • 2003
  • The On-Line Analytical Processing (OLAP) tools access data from the data warehouse for complex data analysis, such as multidimensional data analysis, and decision support activities. Current research has lead to new developments in all aspects of data warehousing, however, there are still a number of problems that need to be solved for making data warehousing effective. View maintenance, one of them, is to maintain view in response to updates in source data. Keeping the view consistent with updates to the base relations, however, can be expensive, since it may involve querying external sources where the base relations reside. In order to reduce maintenance costs, it is possible to maintain the views using information that is strictly local to the data warehouse. This process is usually referred to as "self-maintenance of views". A number of algorithm have been proposed for self maintenance of views where they keep some additional information in data warehouse in the form of auxiliary views. But those algorithms did not consider a consistency of materialized views using view self-maintenance. The purpose of this paper is to research consistency problem when self-maintenance of views is implemented. The proposed "conveyor algorithm" will resolved a complete consistency of materialized view using self-maintenance with considering network delay. The rationale for conveyor algorithm and performance characteristics are described in detail.