• Title/Summary/Keyword: T-bar

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Prediction of Laminar Flame Thickness of Ethanol-Air Pre-Mixture (에탄올-공기 예혼합기의 층류 화염두께 예측)

  • Kwon, Soon-Ik;Kim, Sang-Jin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.11
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    • pp.1417-1423
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    • 2004
  • The thickness of laminar flame and preheat zone was computed from equation with burning velocity and the temperature profile, which is obtained by using premix code of Chemkin program for ethanol-air mixture. The computations were carried out under the unburned gas pressure 0.5bar-30bar and temperature of 300k-700K at 1.0. A difference flame thickness showed between temperature profile and equation with burning velocity. The ratio of flame thickness derived from the equation was about 45∼65% of the temperature profile, and the thickness of preheat zone was about 67.1% of the flame thickness. The flame thickness was decreased by increasing the pressure and temperature, but the effect of pressure is more significant than the effect of temperature on the flame thickness. The flame thickness was predicted by using the following equation. X(mm) = $X_{st}$ (T/300)$^{-0}$.65/(P)$^{-0}$.68/ (0.5bar$\leq$P$\leq$30bar, 300K$\leq$T$\leq$700K)K)

A Study on the Changes in Gwi-po from Tang to Jin Dynasty in China - Focusing on the connection type of Jwau-dae(左右隊) - (중국 당대~금대 목조 건축의 귀포 변천에 관한 연구 - 좌우대의 결구 유형을 중심으로 -)

  • Lee, Byung-Chun;Lee, Ho-Yeol
    • Korean Journal of Heritage: History & Science
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    • v.48 no.3
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    • pp.96-119
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    • 2015
  • This research has studied the changes of Gwi-po(轉角包) by taking the cases of China's medieval wooden buildings as objects. The purpose of the study is to examine the time-periodic transition process of Gwi-po through the cases of 71 wooden buildings which were built from Tang(唐) dynasty(AD 618~690 & 705~907) until Jin(金) dynasty(AD 1115~1234) and also designated as 'Major Historical and Cultural Sites Protected at the National Level'. This research has taken note of various frame types of Jwau-dae(左右隊), which are architectural components of Gwi-po, to study the changes and development process of Gwi-po. The results are as follows. An important factor in the transformations of Gwi-po format is the changes in perception of the craftsmen about Jwau-dae, who took charge in the building process. In the early periods, the principles of Yidou sanshen dougong(一斗三升) in constructing ancons of Gwi-po had been well-maintained, while there appeared many different types of Gwi-po in later periods, due to the usage of Jwau-dae and $Shu{\check{a}}$ $t{\acute{o}}u$(?頭) in each Chulmok of Gwi-po. Transitional types of Gwi-po, which were evolved from the earlier ones, are divided into 3 categories by different forms of Jwau-dae, placed on odd number stages. The first one is 'none-$f{\bar{a}}ng$ $t{\acute{o}}u$(無枋頭) type' of Song(AD 960~1127, 1127~1279) and Liao dynasty(AD 907~1125) buildings, which doesn't have $f{\bar{a}}ng$ $t{\acute{o}}u$(枋頭)s, for the reason that Jwau-dae(左右隊) is in direct contact with Gwihan-dae(耳限大). The second one is '$Shu{\check{a}}$ $t{\acute{o}}u$ $f{\bar{a}}ng$ $t{\acute{o}}u$(?頭枋頭) type' of Song(AD 960~1127, 1127~1279) and Jin dynasty(AD 1115~1234), that has $f{\bar{a}}ng$ $t{\acute{o}}u$(枋頭)s of Jwau-dae(左右隊) identical to $Shu{\check{a}}$ $t{\acute{o}}u$(?頭) in form. The last one is '$Xi{\check{a}}o$ $g{\check{o}}ng$ $t{\acute{o}}u$(小?頭) type' of Jin(AD 1115~1234) and Yuan dynasty(AD 1271~1368), which has $f{\bar{a}}ng$ $t{\acute{o}}u$(枋頭)s of Jwau-dae identical to $Xi{\check{a}}o$ $g{\check{o}}ng$ $t{\acute{o}}u$(小?頭) in form. The earlier forms of Gwi-po, which appeared between Tang dynasty(AD 618~690 & 705~907) and Five Dynasties periods(907~960) went through transitional forms of 'non-$f{\bar{a}}ng$ $t{\acute{o}}u$(無枋頭) type', '$Shu{\check{a}}$ $t{\acute{o}}u$ $f{\bar{a}}ng$ $t{\acute{o}}u$(?頭枋頭) type' and '$Xi{\check{a}}o$ $g{\check{o}}ng$ $t{\acute{o}}u$(小?頭) type' and finally had its form settled between Yuan(元, AD 1271~1368) and Ming(明. AD 1368~1644) dynasty periods. In Liao(遼) dynasty period(AD 907~1125), as the buildings got bigger and the tendency of longer eave-exposure was implemented, there grew a certain need to structurally reinforce Gwi-po, on which load of the whole roof is concentrated. Especially, the transition from Tōuxīn $z{\grave{a}}o$(偸心造) style to Jì xīn $z{\grave{a}}o$(計心造) style in this period had a great influence on standardization of Gwi-po, along with None-${\acute{A}}ng$(無仰) style. Furthermore, Wing-type Gong(翼型?), which developed in Liao dynasty(AD 907~1125), is also thought to have had a great influence on the transition from Tōuxīn $z{\grave{a}}o$(偸心造) style to Jì xīn $z{\grave{a}}o$(計心造) style by changing the forms of Gongs(?), such as Gwi-po. However, unlike None-${\acute{A}}ng$(無仰) style, there occurred a gradual change from '$Shu{\check{a}}$ $t{\acute{o}}u$ $f{\bar{a}}ng$ $t{\acute{o}}u$(?頭枋頭) type' to '$Xi{\check{a}}o$ $g{\check{o}}ng$ $t{\acute{o}}u$(小?頭) type' of Gwi-po in $Xi{\grave{a}}$ ${\acute{a}}ng$ style.

CHARACTERIZATIONS OF PARTITION LATTICES

  • Yoon, Young-Jin
    • Bulletin of the Korean Mathematical Society
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    • v.31 no.2
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    • pp.237-242
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    • 1994
  • One of the most well-known geometric lattices is a partition lattice. Every upper interval of a partition lattice is a partition lattice. The whitney numbers of a partition lattices are the Stirling numbers, and the characteristic polynomial is a falling factorial. The set of partitions with a single non-trivial block containing a fixed element is a Boolean sublattice of modular elements, so the partition lattice is supersolvable in the sense of Stanley [6]. In this paper, we rephrase four results due to Heller[1] and Murty [4] in terms of matroids and give several characterizations of partition lattices. Our notation and terminology follow those in [8,9]. To clarify our terminology, let G, be a finte geometric lattice. If S is the set of points (or rank-one flats) in G, the lattice structure of G induces the structure of a (combinatorial) geometry, also denoted by G, on S. The size vertical bar G vertical bar of the geometry G is the number of points in G. Let T be subset of S. The deletion of T from G is the geometry on the point set S/T obtained by restricting G to the subset S/T. The contraction G/T of G by T is the geometry induced by the geometric lattice [cl(T), over ^1] on the set S' of all flats in G covering cl(T). (Here, cl(T) is the closure of T, and over ^ 1 is the maximum of the lattice G.) Thus, by definition, the contraction of a geometry is always a geometry. A geometry which can be obtained from G by deletions and contractions is called a minor of G.

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Production of Herbicide-resistant Transgenic Plants from Embryogenic Suspension Cultures of Cucumber (오이의 배발생 현탁 배양세포로부터 제초제 저항성 형질전환 식물체 생산)

  • 우제욱;정원중;최관삼;박효근;백남긴;유장렬
    • Korean Journal of Plant Tissue Culture
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    • v.28 no.1
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    • pp.53-58
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    • 2001
  • To develop herbicide-resistant cucumber plants (Cucumis sativus L. cv Green Angle) embryogenic suspension cultures were co-cultured with Agrobacterium tumefaciens strain LBA4404 carrying a disarmed binary vector pGA-bar. The T-DNA region of this binary vector contains the nopalin synthase/neomycin phosphotransferase Ⅱ (npt Ⅱ) chimeric gene for kanamycin resistance and the cauliflower 35S/phosphinothricin acetyltransferase (bar) chimeric gene for phosphinothricin (PPT) resistance, After co-cultivation for 48 h, embryogenic calli were placed on maturation media containing 20 mg/L PPT. Approximately 200 putatively transgenic plantlets were obtained in hormone free media containing 40 mg/L PPT. Northern blot hybridization analysis confirmed the expression of the bar gene that was integrated into the genome of five transgenic plants. Transgenic cucumber plants were grown to maturity. Mature plants in soil showed tolerance to the commercial herbicide (Basta) of PPT at the manufacturer's suggested level (3 mL/L).

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Nonlinear Finite Element Analysis of Steel Composite Girders (합성형 거더의 3차원 비선형 거동해석)

  • 주영태;강병수;성원진;박대열;이용학
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.11a
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    • pp.173-176
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    • 2003
  • Progressive failure analysis of steel composite double T-beam is performed to investigate the mechanical effects of steel composite fabricated in the webs of double-T beam to replace concrete placing forms. The analysis is based on nonlinear finite element scheme considering material nonlinearities of concrete, reinforcing bar and PS steel. Four-parameter strength envelope defines the hardening and softening phenomena of concrete with consideration of the various levels of confining pressures. Rankine maximum strength criterion defines the elasto-plasticity of PS steel and reinforcing bar, and Von Mises $J_2$ failure criterion for steel plate which wraps the concrete webs of double T-beam. A 6m long two-span steel composite double T-beam is analyzed and compared with the experimental results.

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A Performance Test on Exterior T-type Joint for RCS Composite System (철근콘크리트 기둥 철골 보의 합성구조 외부형 접합부 구조성능에 관한 연구)

  • 양승렬;이상호;김병국;정하선;김종락;최완철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.977-982
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    • 2000
  • As a newly structural system, RCS composite system has been researched last two decades. However mechanism of exterior T-type joint for RCS composite system is not well known. This research is focus on the exterior T-type joint for RCS composite system. Specimens are designed by the ASCE guideline, tested and compared with the inner RCS joint. Test variables include face bearing plate(FBP), extended face bearing plate(E-FBP) and U-bar. The tests indicate that the strength of exterior T-type joint is higher than that of the guideline by ASCE. The U-bar has a significant effect on the joint strength and absorbing the strain energy.

Experimental analysis of geomorphic changes in weir downstream by behavior of alternate bar upstream (보 상류 교호사주의 거동에 따른 하류 지형변화에 대한 실험적 분석)

  • Lee, KyungSu;Jang, Chang-Lae;Kim, GiJung
    • Journal of Korea Water Resources Association
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    • v.52 no.spc2
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    • pp.801-810
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    • 2019
  • This study analyzes the impact on geomorphic changes downstream due to alternate bars developed weir upstream through laboratory experiments. The disturbance, such as a spur in the side wall, of the flow at the inlet of the channel triggers the development of alternate bar upstream at the beginning of the experiment, and gradually moved downstream with keeping their shapes over time. The bed in the downstream of weir in the mid of channel scoured due to the scarcity of sediment inflow because weir upstream traps it. Moreover, bar migration speed decreases as the bars approaches to the weir with time. However, as time increases, the alternate bars upstream migrate over the weir, and sediment in the eroded bed of the weir downstream are deposited. The phase of the bar upstream changes oppositely after passing through the weir. The phase of the bar downstream changes rapidly as the shape of alternate bar is clear upstream, which is affected by the strong disturbance. The phase of bar changes, and the bar migration speed decreases gradually with time, and finally stopped due to forcing effects on the bar by the disturbance. The faster the reaction of alternate bar with a long spur, the larger the bar height formed downstream and the shorter the bar length. This means that the larger the forcing effect of bar, the more it affects the bar migration. In addition, although the size of the alternate bar increases over time, the bar doesn't migrate downstream and a forced bar is generated.

A Study on the Usage of Miào(廟) and Gōng(宮) in Zhou Dynasty through the Mentions to Them in the Scripture Sentences of 『Chūn-qiū(春秋)』 - In the Process of Investigating the Existence of Zhou Dynasty's System to Regulate the Number of Zōng-miào(宗廟) 【1/2】 (『춘추』 경문에서의 묘(廟)·궁(宮) 언급을 통한 주대(周代)의 그 쓰임 사례 일고찰 - 주대의 묘수제(廟數制) 실재 여부에 대한 궁구 과정에서 【1/2】-)

  • Seo, Jeong-Hwa
    • The Journal of Korean Philosophical History
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    • no.57
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    • pp.57-90
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    • 2018
  • In this discussion, as a way to verify the existence of the system to regulate Zhou dynasty's $z{\bar{o}}ng-mi{\grave{a}}o$(宗廟) numbers, the discussion was focused on '$mi{\grave{a}}o$ (廟)' and '$g{\bar{o}}ng$(宮)' in the records of "$Ch{\bar{u}}n-qi{\bar{u}}$(春秋)". As for the parts where the contents of scripture sentences were not specific, the context of the case was investigated through the writings in "$Zu{\breve{o}}-zhu{\grave{a}}n$(左傳)" and other materials. In the cases of the usage of the letter, '$mi{\grave{a}}o$(廟 : a ruler's house, a nation's royal court)', in the scripture sentences in "$Ch{\bar{u}}n-qi{\bar{u}}$(春秋)", the followings need to be noticed. In $t{\grave{a}}i-mi{\grave{a}}o$(太廟) of State $L{\check{u}}$(魯), nationwide events and a ruler's political ancestral rite, $d{\grave{i}}$(?) ritual, were performed, and fancy tools for ancestral rites used in those rituals were equipped. As for the $z{\bar{o}}ng-mi{\grave{a}}o$(宗廟) of a ruler of those times, a ritual of royal court, $ch{\acute{a}}o$(朝) rite, was performed. The usage case of the letter, '$g{\bar{o}}ng$(宮 : house)', is as the following. In $g{\bar{o}}ng$(宮) where a ruler's personal family lived was a family ancestral rite for them carried out. The record about the ornate decorating for the $hu{\acute{a}}n-g{\bar{o}}ng$ house(桓宮), which can be said to have been the political base of $s{\bar{a}}n-hu{\acute{a}}n-sh{\grave{i}}$(三桓氏), three politically noble families of State $L{\check{u}}$(魯), is outstanding. The $x{\bar{i}}-g{\bar{o}}ng$ house(西宮) during $X{\bar{i}}-g{\bar{o}}ng$(魯 僖公)'s reign and a $x{\bar{i}}n-g{\bar{o}}ng$ house(新宮 : a newly built house) destroyed by fire at the third year of $Ch{\acute{e}}ng-g{\bar{o}}ng$(魯 成公), are assumed to have been a ruler's another house, such as the $ch{\check{u}}-g{\bar{o}}ng$ house(楚宮) in which $Xi{\bar{a}}ng-g{\bar{o}}ng$(魯 襄公) used to enjoy staying, which is different from the viewpoint that it might be a $m{\acute{i}}-g{\bar{o}}ng$ shrine(?宮 : a house constructed as a shrine for the deceased father or the deceased grand father) that had been formed since Han dynasty. It has been discussed that, regarding the records that the '$w{\check{u}}-g{\bar{o}}ng$ house(武宮) was built' and that the '$y{\acute{a}}ng-g{\bar{o}}ng$ house(煬宮) was built', certain buildings were established with the symbols of '$w{\check{u}}$(武 : martial arts and force of arms)' and '$y{\acute{a}}ng$(煬 : to burn and get rid of everything)', and the events that a lord stood as its lord continued. Therefore, its main goal was not the performance of a dutiful ancestral rite by a ruler of those times for deceased rulers, for instance, $W{\check{u}}-g{\bar{o}}ng$(魯 武公) or $Y{\acute{a}}ng-g{\bar{o}}ng$(魯 煬公), but display of certain political symbolism through the ritual. This symbolism is most obvious with the $hu{\acute{a}}n-g{\bar{o}}ng$ house(桓宮) and the $x{\bar{i}}-g{\bar{o}}ng$ house(僖宮). As a consequence, all $mi{\grave{a}}os$(廟) and $g{\bar{o}}ngs$(宮) in scripture sentences had the functions of a shrine in some part, but it has been verified that they were not the buildings set up as a shrine to follow '$z{\bar{o}}ng-mi{\grave{a}}o$(宗廟)'s number regulation system' of '$ti{\bar{a}}nz{\check{i}}-7-mi{\grave{a}}o$(天子七廟 : an emperor owns seven $mi{\grave{a}}os$(廟))' or '$zh{\bar{u}}h{\acute{o}}u-5-mi{\grave{a}}o$(諸侯五廟 : a lord owns five $mi{\grave{a}}os$(廟))'.

Reduction of Zygomatic Fractures Using the Carroll-Girard T-bar Screw

  • Baek, Ji Eun;Chung, Chan Min;Hong, In Pyo
    • Archives of Plastic Surgery
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    • v.39 no.5
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    • pp.556-560
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    • 2012
  • Zygomatic fractures are the second most common facial bone fractures encountered and treated by plastic surgeons. Stable fixation of fractured fragments after adequate exposure is critical for ensuring three-dimensional anatomic reduction. Between January 2008 and December 2010, 17 patients with zygomatic fractures were admitted to our hospital; there were 15 male and 2 female patients. The average age of the patients was 41 years (range, 19 to 75 years). We exposed the inferior orbital rim and zygomatic complex through a lateral brow, intraoral, and subciliary incisions, which allowed for visualization of the bone, and then the fractured parts were corrected using the Carroll-Girard T-bar screw. Postoperative complications such as malar asymmetry, diplopia, enophthalmos, and postoperative infection were not observed. Lower eyelid retraction and temporary ectropion occurred in 1 of the 17 patients. Functional and cosmetic results were excellent in nearly all of the cases. In this report, we describe using the Carroll-Girard T-bar screw for the reduction of zygomatic fractures. Because this instrument is easy to use and can rotate to any direction and vector, it can be used to correct displaced zygomatic bone more accurately and safely than other devices, without leaving facial scars.

ENVIRONMENT DEPENDENCE OF DISK MORPHOLOGY OF SPIRAL GALAXIES

  • Ann, Hong Bae
    • Journal of The Korean Astronomical Society
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    • v.47 no.1
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    • pp.1-13
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    • 2014
  • We analyze the dependence of disk morphology (arm class, Hubble type, bar type) of nearby spiral galaxies on the galaxy environment by using local background density (${\Sigma}_n$), projected distance ($r_p$), and tidal index (T I) as measures of the environment. There is a strong dependence of arm class and Hubble type on the galaxy environment, while the bar type exhibits a weak dependence with a high frequency of SB galaxies in high density regions. Grand design fractions and early-type fractions increase with increasing ${\Sigma}_n$, $1/r_p$, and T I, while fractions of flocculent spirals and late-type spirals decrease. Multiple-arm and intermediate-type spirals exhibit nearly constant fractions with weak trends similar to grand design and early-type spirals. While bar types show only a marginal dependence on ${\Sigma}_n$, they show a fairly clear dependence on $r_p$ with a high frequency of SB galaxies at small $r_p$. The arm class also exhibits a stronger correlation with $r_p$ than ${\Sigma}_n$ and T I, whereas the Hubble type exhibits similar correlations with ${\Sigma}_n$ and $r_p$. This suggests that the arm class is mostly affected by the nearest neighbor while the Hubble type is affected by the local densities contributed by neighboring galaxies as well as the nearest neighbor.