• Title, Summary, Keyword: third body

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A Study on Third Body Abrasion in the Small Clearance Region Adjacent to the Contact Area

  • Kim, Hyung-Kyu;Lee, Young-Ho;Heo, Sung-Pil;Jung, Youn-Ho
    • KSTLE International Journal
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    • v.4 no.1
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    • pp.8-13
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    • 2003
  • Abrasion in fretting wear mechanism is studied experimentally with the specimens of two different shapes of spacer grid spring and fuel tubes of a nuclear fuel. Reciprocating sliding wear test has been carried out in the environment of air and water at room temperature. Especially, third body abrasion is referred to for explaining the wear region expansion found during the slip displacement increase with constant normal contact farce. It is found that the expansion behaviour depends on the contact shape. The small clearance between the tube and spring seems to be the preferable region of the wear particle accumulation, which causes third body abrasion of the non-contact area. Even in water environment the third body abrasion occurs apparently. Since the abrasion on the clearance contributes wear volume, the influence of the contact shape on the severity of third body abrasion should be considered to improve the grid spring design in the point of restraining wear damage of a nuclear fuel.

5-body dynamics in the Kepler-47 exoplanetary system: Predicting stable orbits of a third circumbinary planet

  • Hinse, Tobias Cornelius
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.2
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    • pp.83.1-83.1
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    • 2014
  • Kepler-47 is the first multi-body circumbinary planetary system detected by the Kepler space telescope. The two planets were detected by the transit method. In the discovery paper the authors report about the presence of an additional transit-like signal in their dataset which cannot be explained by a four-body (binary + 2 planets) system. Therefore it is likely that the unexplained signal could be due to a third planet. In this talk I will present recent results from a dynamical investigation of the five-body system (binary + 3 planets). We have applied the MEGNO technique to detect regions of quasi- or near quasi-periodic orbits of a hypothetical third planet. Quasi-periodic regions exists for a third planet and the long-term stability has been tested. Although the existence of a third planet is most likely to be confirmed from transit photometry we calculate transit-timing variation (TTV) signals due to the third planet which also can be used to infer its presence.

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[발표취소] Stable 5-body orbits in the Kepler-47 exoplanetary system: Predicting stable orbits of a possible third circumbinary planet

  • Hinse, Tobias Cornelius
    • The Bulletin of The Korean Astronomical Society
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    • v.39 no.1
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    • pp.81.1-81.1
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    • 2014
  • Kepler-47 is the first multi-body circumbinary planetary system detected by the Kepler space telescope. The two planets were detected by the transit method. In the discovery paper the authors report about the presence of an additional transit-like signal in their dataset which cannot be explained by a four-body (binary + 2 planets) system. Therefore it is likely that the unexplained signal could be due to a third planet. In this talk I will present recent results from a dynamical investigation of the five-body system (binary + 3 planets). We have applied the MEGNO technique to detect regions of quasi- or near quasi-periodic orbits of a hypothetical third planet. Quasi-periodic regions exists for a third planet and the long-term stability has been tested. Although the existence of a third planet is most likely to be confirmed from transit photometry we calculate transit-timing variation (TTV) signals due to the third planet which also can be used to infer its presence.

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SOME FACTORS RELATED TO MANDIBULAR THIRD MOLAR ERUPTION (하악제 3대구치의 맹출에 미치는 요소에 관한 연구)

  • Kim, Jae-Seung;Chung, Kyu-Rhim
    • The korean journal of orthodontics
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    • v.18 no.1
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    • pp.79-88
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    • 1988
  • The purpose of this study was to investigate the factors which might be related to mandibular third molar eruption and to predict the possibility of whether or not it will be erupted. The material of this study was lateral cephalometric radiograms, pantomograms and dental casts obtained from 70 patients (19 males, 51 females) ranging in age from 18.0 to 32.1 years. They were devided into erupted group and impacted group of mandibular third molars. For the comparison of each group, a total of 20 measurement items were employed and the data were analyzed by means of computer statistical method. As a result of this study, the following conclusion can be made; 1. The longer mandibular body length and narrower mandibular ramus width, the higher eruption tendency of the lower third molar, but the degree of genial angle was not related to mandibular third molar eruption. 2. The lower percentage of posterior mandibular body height to anterior mandibular body height, the higher eruption tendency of the lower third molar. 3. The total tooth size, including the lower second molar, appeared to be larger in the impacted group than in the erupted group of the lower third molar. 4. The arch length discrepancy of the impacted group was more severe in contrast with the erupted group of the lower third molar.

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Orbital Elements Evolution Due to a Perturbing Body in an Inclined Elliptical Orbit

  • Rahoma, W.A
    • Journal of Astronomy and Space Sciences
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    • v.31 no.3
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    • pp.199-204
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    • 2014
  • This paper intends to highlight the effect of the third-body in an inclined orbit on a spacecraft orbiting the primary mass. To achieve this goal, a new origin of coordinate is introduced in the primary and the X-axis toward the node of the spacecraft. The disturbing function is expanded up to the second order using Legendre polynomials. A double-averaged analytical model is exploited to produce the evolutions of mean orbital elements as smooth curves.

REDISCUSSION OF PER100 CHANGE OF THE CLOSE BINARY V65l CASSIOPEIAE (근접쌍성 V651 Cas의 공전주기 변화의 재논의)

  • 김천휘;이재우;이충욱;이동주;강영운
    • Journal of Astronomy and Space Sciences
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    • v.19 no.1
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    • pp.47-56
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    • 2002
  • Observations of times of minimum lights of the eclipsing binary V65l Cas were carried out on the three nights from November 21-23, 2000. From our observations a total of seven new times of minimum lights was obtained. Through the analysis of photoelectric and CCD times of minima of V65l Cas including ours, the light time orbit due to a third body, which was propose by Kim & Lee (2000), was confirmed and improved. The resultant values for the period, semi-amplitude, and eccentricity of the light-time orbit were $6.^{y}3,\;0.^{d}0013$, and 0.78, respectively. The deduced marts range of the third body is . If the third body is $0.09M_{\odot}\;{\leq}\;M_3\;{\leq}\;0.20M_{\odot}\;for\;i_3\;{\geq}\;30^{\circ}$. If the third body suggested in V65l Cas system exists really and is a main-sequence star, it is located at the end of the main-sequence.

Antibiotics in third molar surgery, justifiable or not?

  • Alrashdan, Mohammad S.;Park, Jong-Chul;Lee, Ju-Hwan;Yoo, Myung-Sook;Pang, Kang-Mi;Kim, Soung-Min;Lee, Jong-Ho
    • Journal of Korean Dental Science
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    • v.2 no.2
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    • pp.46-52
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    • 2009
  • Objectives : The purpose of this study was to evaluate the significance of antibiotics in reducing postoperative infection rates and other complications following third molar surgery. Patients and methods : Two groups of patients underwent surgical extraction of third molars. The antibiotics group, n=21, received a third generation cephalosporin antibiotic for 5 days, starting from the day of surgery. The non-antibiotics group, n=26, didn't receive any antibiotics and only received analgesics to control postoperative pain. Body temperature and hematologic findings including WBC, neutrophils, lymphocytes and monocytes counts were compared between the two groups at three intervals, preoperatively, 24 hours and 7-10 days postoperatively. Pain and swelling during the follow up period were also recorded in both groups and compared in the second part of the study. Results : In the first part of the study, comparison of body temperature, CBC components (except WBCs) showed no significant difference between the two groups during the follow up period. All parameters were within the normal range at all intervals, which indicated absence of infection. In the second part, 38% of patients in the antibiotic group, compared to 54% of the non-antibiotics group, had one or more complications during the follow up period. However, three patients from the antibiotic group compared to one from the nonantibiotics group reported having a swelling of some degree. Conclusion : Based on our objective parameters (body temperature and CBC components), both groups showed no signs of infection during the follow up period. However, the results related to pain and swelling were less conclusive, probably due to small number of patients included in the study. Accordingly, we are unable to provide definite recommendations on antibiotics use in third molar surgery.

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The Growth Analysis of the Crawfish (Cambaroides similis Koelbel) (Crustacea) 2. Relative Growth (가재(Cumbaroides similis Koelbel)의 상대성장 분석)

  • 연근성;노용태정병균
    • The Korean Journal of Zoology
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    • v.35 no.2
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    • pp.231-239
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    • 1992
  • For the analysis of the relative grouch of six body pans, such as carapace width. abdominal length, abdominal width, cheliped length, second pereiopod length and third pereiopod length, to the carapace length of crayfish (Comboroides similis Koelbel), the equation Y = bXa were applied. The results were as follows: 1. In the relative srourth of each body part to the carapace length, abdominal width and abdomial length in both sexes showed as positive allometrv, the third pereiopod length in both sexes as isometry and the rest shouted as negative. The least coefficient of the relative growth was found in cheliped length in female (0.9300).2. The grolwth gradient of each body part to the carapace length in each sex revealed decreasing pattern in abdominal length and third pereiopod length in both sexes and the abdominal width in male with the growth centers on the initial growth period. and the rest showed increasing pattern with the growth centers on the 6th growvth period except the abdomini,d uridth in female on the 3rd growth period.

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