• Title/Summary/Keyword: Spirals

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A Study on the Cestodes in yheyagya chalcogramma (해산어류 명태(Theragra chalcogramma)에 기생하는 조충류 조사)

  • 주종필
    • Parasites, Hosts and Diseases
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    • v.22 no.1
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    • pp.85-95
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    • 1984
  • This study was performed to investigate the intestinal parasites (especially cestoda) in the guts of Theragra chalcogramma in Korea. The cestode larvae collected were morphologically observed and measured, and at the same time, microscopical study was done with the section slides of the cestode larvae. They were identified on the basis of the descriptions by Schmidt and Yamaguti. The results obtained in this study are as follows: 1. The cestode larvae were identified as Khawia sinesis, Eulacistorhynchus chiloscyllius, Tentacularia coryphaenga, Pssudonybelinia odontasantha and Nybelinia Zingualis. These are new species reported in Korea. 2. The characteristics of Khawia sinesis are its scolex lacking loculi and broad, fat and fimbriate shape. Its neck is not separated from the body but a little constricted. 3. Eulacistorhynchus chiloscyzzius is characterized by fairly long and acraspedote scolex. The bulbs are long; retractor muscles are attached to bases of the bulbs. The two bothridia are oval or round in shape and lacking posterior notch. The tentacles are long and poeciloacanthus; double chainette present. 4. Tentacularia coryphaenea is characterized by its long craspedote and subcylindrical scolex. The bothridia are separated, without free borders and spinous. The tentacles are short, slender, armed with solid hooks in spirals, similar except the base of tentacle. The tentacle sheaths are not twisted. The bulbs are ellipsoidal. 5. Pseudonybelinia odontacantha is characterized by its craspedote scolex. The tentacles are inserted near anterior margin of bothridia and armed with hooks in spirals ascending left to right. The hooks are similar, throughout tentacle, with feeble curve and provided with a tooth-like protuberance on the ventral side. The bulbs are three times longer than its width. The posterior margins of bothridia have a pair of eversible ciliated pits; or fossettes. 6. Nybelinia lingualis is characterized by its short and craspedote scolex. The bothridia are separated, with free boarders. The tentacles are cylindrical, armed with solid and similar hooks in quincunxes.

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The temperature and density distribution of molecular gas in a galaxy undergoing strong ram pressure: a case study of NGC 4402

  • Lee, Bumhyun;Chung, Aeree
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.1
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    • pp.77.2-77.2
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    • 2015
  • Galaxies are known to evolve passively in the cluster environment. Indeed, much evidence for HI stripping has been found in cluster galaxies to date, which is likely to be connected to their low star formation rate. What is still puzzling however, is that the molecular gas, which is believed to be more directly related to star formation, shows no significant difference in its fraction between the cluster population and the field galaxies. Therefore, HI stripping alone does not seem to be enough to fully understand how galaxies become passive in galaxy clusters. Intriguingly, our recent high resolution CO study of a subsample of Virgo spirals which are undergoing strong ICM pressure has revealed a highly disturbed molecular gas morphology and kinematics. The morphological and kinematical peculiarities in their CO data have many properties in common with those of HI gas in the sample, indicating that strong ICM pressure in fact can have impacts on dense gas deep inside of a galaxy. This implies that it is the molecular gas conditions rather than the molecular gas stripping which is more responsible for quenching of star formation in cluster galaxies. In this study, using multi transitions of 12CO and 13CO, we investigate the density and temperature distributions of CO gas of a Virgo spiral galaxy, NGC 4402 to probe the physical and chemical properties of molecular gas and their relations to star formation activities.

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Effects of Initial Conditions on Transient Responses in Dynamic Simulation of FOWT (초기 조건이 부유식 풍력터빈 동역학 해석의 과도응답에 미치는 영향)

  • Song, Jin-Seop;Rim, Chae-Whan;Moon, Seok-Jun;Nam, Yong-Yun
    • Journal of Ocean Engineering and Technology
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    • v.28 no.4
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    • pp.288-293
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    • 2014
  • The IEC standard for onshore or offshore wind turbines requires additional dummy simulations (at least 5 s) for the transient responses due to initial conditions. An increase in the dummy time causes a considerable increase in the computational cost considering multiple design spirals with several thousand design load analysis cases. A time of 30 s is typically used in practical simulations for a wind turbine design with a fixed platform. However, 30 s may be insufficient for floating offshore wind turbines (FOWT) because the platforms have lower natural frequencies, and the transient responses will last much longer. In this paper, an initial condition application algorithm is implemented for WindHydro, and the appropriate dummy simulation time is investigated based on a series of dynamic simulations of a FOWT. As a result, it is found that more than 300 s is required for the platform to have stationary motion after the initial transient responses for the FOWT under the conditions considered.

A Study on the Formation of Dynamism in the Modern Fashion (현대패션에 표현된 dynamism의 조형성 연구)

  • 이은숙
    • Journal of the Korea Fashion and Costume Design Association
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    • v.4 no.1
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    • pp.143-153
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    • 2002
  • Fashion has been analyzed and explained in diverse ways. Fashion, like every phase of culture, is a reflection of the Zeitgeist. In order to understand the changing fashion we must understand the changing society. For fashion of a period are expressions of the interrelation of the various elements of the culture, including the social and political values, the economic and industrial progress, art, the development of technology, etc... Particularly fashion is closely connected with a style of art. In a style of art, futurism focused on the "dynamism" resulting from super-speed and high-technology. This study aimed to review literatures, fashion magazines, web-site in order to know how the dynamism of futurism is expressed in modern fashion. The results of this study were as follows; 1. Dynamism was expressed by means of lines, colors, patterns through the eyesights visually. Asymmetrical oblique lines, zig-zag lines or bold cutting expressed the mechanical and offensive dynamism. In contrast, such lines as curves and spirals expressed the soft and natural dynamism. Primary colors or complementary contrast expressed energetic and rhythmical dynamism. The geometrical patterns and automobile wheels patterns expressed dynamism resulting from mechanical aesthetics. 2. Dynamism was expressed through repeat of lines, colors, patterns, and textiles. Particularly Vinyl material, fluorescent material, metallic material, beads, and spangle expressed a strong dynamism. On the other hand, natural materials, paper and other similar ones are used to signify the orientation towards a futuristic high-technology society.y society.

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Star Formation in Nuclear Rings of Barred-Spiral Galaxies?

  • Seo, Woo-Young;Kim, Woong-Tae
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.39.2-39.2
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    • 2013
  • We use grid-based hydrodynamic simulations to study star formation history in nuclear rings of barred-spiral galaxies. In our previous study, we concentrated on bar-only galaxies without spirals, finding that the star formation rate (SFR) in a nuclear ring exhibits a strong primary burst at early time before decreasing to below 1 $M_{\odot}/yr$ at late time. The rapid decline is caused by the paucity of the gas in the bar region, due to early massive gas inflows to the nuclear ring. Since star formation in nuclear rings is observed to be sustained for about 1-2 Gyr, this requires mechanisms to supply the gas to the bar regions. In this work, we study the effect of spiral arms on the radial gas inflows and related star formation in the nuclear rings. We show that spiral arms are efficient to remove angular momentum of the gas to cause significant gas inflows to the bar region, provided the patten speed of the arms is much smaller than that of the bar. The inflowing gas is added to a nuclear ring, making the ring SFR episodic over a long period of time. The time interval of multiple bursts of star formation is a few tens to hundred million years, with the mean peak SFR of ${\sim}5M_{\odot}/yr$, consistent with observations of M100.

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A Study on the Indonesian Ikat Textile Design (인도네시아 이캇 직물 디자인에 관한 연구)

  • 문미영
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.6
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    • pp.866-886
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    • 1995
  • The purpose of this study is to analyze the pattern and the meaning of textiles, and decorative techniques of ikat weaving and dyeing in Indonesia. The textile design also analyzes by examining the method of ikat techniques such as warp ikat, weft ikat and double ikat, and by classifying the style of regions. The most common motifs are geometric designs of spirals, meanders, straight lines, triangles, and circles which are influenced by outside world. Although these motifs or symbols have been evident since prehistoric times, their design and meaning have been continually reinterpreted as changes in the ceremonies and rituals. While motifs such as reptiles, birds, and human figures, depicted in spiral, hooked and rhomb configurations, have been identified among the most resilient features of Indonesian textile design, new meanings have been added to these ancient forms, and designs have been transformed and reinterpreted to suit local conceptions. Since textiles are a visual expression of Indcufsian life, textiles place the individual symbolically within social milieu, identifying rank, family, locality and religious affiliations. Textiles represent a link between the human and the spiritual realm, and a vehicle for the display of sacred and secular potency Ikat textiles play to embody special transforming powers and sacred mediating qualities, providing protection and evoking life-enriching forces for individuals or social group.

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Two-Ann Microstrip Spiral Antenna with a Circular Aperture on the Ground Plane for Generating a Circularly Polarized Conical Beam (코니컬 빔을 가지는 접지면에 원형 슬롯이 있는 양팔 마이크로스트립 스파이럴 안테나)

  • 오대영;김명기;박익모
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.9
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    • pp.851-857
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    • 2002
  • A two-arm microstrip spiral antenna with a circular aperture on the ground plane that generates a circularly polarized conical beam is presented in this paper. We obtained circularly polarized conical beam by using two spirals that are excited in-phase from the microstrip feed lines. The main beam directions of the conical beam from the broadside are approximately 40$^{\circ}$ in the range from 5 GHz to 6.5 GHz, and 58$^{\circ}$ from 9 GHz to 11 GHz. Since the proposed antenna has omni-directional conical beam pattern, it is suitable for use in mobile communication systems.

APPLICATIONS OF SELF-REFERENCING METHOD TO THE VIRGO CLUSTER SPIRALS

  • Chung, Eun-Jung;Kim, Hyo-Young;Rhee, Myung-Hyun
    • Journal of The Korean Astronomical Society
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    • v.38 no.4
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    • pp.371-384
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    • 2005
  • Self-referencing method in revised-OTFTOOL is a new method in On-The-Fly(OTF) observation mode. It uses the source free regions of the observed frame as references instead of the OFFs references. We already analyzed and discussed its proprieties and advantages in the previous paper. In this paper, we make a statistical study about the self-referencing method by applying it to OTF mapping data of 27 Virgo spiral galaxies. We found that the self-referencing method solves the crooked baseline problem for every datacube. It straightens the baseline, and conserves the emissions. Compared with other data processing, the median filtering task 'mwflt' in AIPS, to use self-referencing method is more effective and safe not only to straighten the baseline but also to conserve the emission. For the strong CO galaxies, the data obtained by self-referencing method shows scarcely any difference from those reduced by conventional OFFs references and AIPS median filtering in the range of uncertainties. Undetected CO emissions in datacubes of conventional OFFs references are also not detected in those of self-referencing method. The self-referencing method is expected to save the observing time and simplify data reduction processes. Besides this, using self-referencing method will offer emission-free references more safely.

A Study on the Flow Characteristics of Desktop Personal Computer by In-Out Fan (흡.배기 팬에 의한 Desktop Personal Computer 내부의 유동특성에 관한 연구)

  • Lee, Haeng-Nam;Park, Gil-Moon;Jung, Han-Byul
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.6
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    • pp.665-671
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    • 2007
  • The purpose of this study is to find out a flow characteristics required by the design of a computer case and to provide information about the preliminary data of cooling efficiency of CPU and a flow inside of a case. We examined a flow characteristic-suction a tracing particle occurred from a surge tand installed at an inlet into a computer case and moving it to a exit duct-experimentally by using PIV. The experimental device was consists of a fan inflowing and discharging the air into the computer case and a slot installed with a CPU cooling ran add-on, and analyzed the data of Re-stress distribution, velocity distribution, and kinetic energy distribution. This research will make a great contribution to improvement of the efficiency and performance of notebook, workstation, server, and all the design of electronic devices using large scale integrated(LSI) as well as usual computers.

Crystal Growth and Solid Solution of Hexagonal Ferrites (육방정 페라이트의 고용성 및 단결정 육성 연구)

  • 강진기;박병규;정수진
    • Journal of the Korean Ceramic Society
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    • v.23 no.3
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    • pp.78-86
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    • 1986
  • single crystals of various hexagonal ferrites were grown by a flux technique. For the growing experiment platinum crucibles of size 40 cc and a horizontal siliconit tube furnace were used. Charges consisted of the flux of BaO(SrO)/$B_2O_3$ and the composition of crystals in the system of BaO $(SrO)-Fe_2O_3-ZnO$. The BaO(SrO)/$B_2O_3$ molar ratio of the flux were varied from 1 to 3. Crystals up to 12.5mm in diameter were grown by slow cooling of melts from a maximum temperature of 1, 30$0^{\circ}C$or 1, 350$0^{\circ}C$ to 95$0^{\circ}C$ or 1, 00$0^{\circ}C$ The grown crystals exhibited a tabular hexagonal habits with very well developed ba-sal planes and narrow pyramidal faces of {1011} {1012} and {0001}. For the identification of the grown crystals X-ray diffraction studies were carried out. The effects of va-riations in flux ratio flux percentage and cooling rate on the quality of the grown crystals were studied. Cry-stal habits hillocks etch steps and growth spirals were observed by optical microscope. Magnetic properties of single crystals were measured.

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