• Title/Summary/Keyword: Pit dimension

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Pits Role in Embolism Repair of Populus tomentiglandulosa T. Lee

  • Chun, Su-Kyoung;Ahmed, Sheikh Ali
    • Journal of the Korea Furniture Society
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    • v.18 no.2
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    • pp.147-151
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    • 2007
  • This report explains the intervessel pit dimension of Populus tomentiglandulosa and its role in embolism repair according to proposed mechanism by Zwieniecki and Holbrook, 2000. It was found that mean contact angle ( ) of water droplets on the inner surface of vessels was $56^{\circ}$. Openings into the bordered pits were typically elliptical. The angle of the bordered pit chamber ($2{\alpha}$) was found $142.17^{\circ}$. From the capillary equation $Pmax\;=\;Gcos\;(\;+{\alpha})$, it was found that mathematically the maximum pressure 0.08MPa created by pits, can be employed to force the air within the embolized vessel into solution.

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Experimental Study on the Adjustment Processes of Minning Pit in the Dredged Channels (준설하천의 웅덩이 적응에 관한 실험적 연구)

  • Jang, Chang-Lae;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
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    • v.43 no.7
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    • pp.657-666
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    • 2010
  • The adjustment processes of mining pits in the disturbed channels by sand or gravel mining were investigated by laboratory experiments in this study. The pit migrated with speed when the river bed was steep. The pit migrated slow and steady when the pit was filling with sand, but the pit migrated with speed after the filling processes was finished. The submerged angle of repose in the pit was nearly constant during the pit was filling. The pit was filled with sand with speed as the channel slope was increased. It took time for the pit to be filled with sand as the pit dimension was increased. This meant that the disturbed channels by sand or gravel mining to adjust the new environment was dependent on the slope of the channels and the dimension of the pits. The dimensionless pit length was short and the dimensionless pit depth was shallow as the time was increased. The dimensionless pit depth was shallow, but the dimensionless pit migration speed was increased as the dimensionless shear velocity and the migration speed of the pit were increased. The dimensionless pit depth was increased with the dimensionless bar migration speed. The shape of the pit was deformed and migrated downstream in accordance with the location and shape of the biased bar front which was developed upstream.

Pitting Corrosion of Inconel Alloy 600 at Elevated Solution Temperatures

  • Park, Jin-Ju;Pyun, Su-Il
    • Journal of the Korean Electrochemical Society
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    • v.6 no.4
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    • pp.271-281
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    • 2003
  • The present article is concerned with pitting corrosion of Inconel alloy 600 at elevated solution temperatures. This article first summarized the previous works on the characteristics and the growth models of oxide film grown on alloy 600 at elevated solution temperatures. Thereafter, this article reviewed previous works on the morphological study on pitting corrosion of alloy 600 as functions of solution temperature and such anion additives as thiosulphate, sulphate, nitrate and bicarbonate ions in terms of pit morphology and its fractal dimension.

ON THE PRINCIPAL IDEAL THEOREM

  • Chang, Gyu-Whan
    • Bulletin of the Korean Mathematical Society
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    • v.36 no.4
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    • pp.655-660
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    • 1999
  • Let R be an integral domain with identity. In this paper we will show that if R is integrally closed or if t-dim $R{\leq}1$, then R[{$X_{\alpha}$}] satisfies the principal ideal theorem for each family {$X_{\alpha}$} of algebraically independent indeterminates if and only if R is an S-domain and it satisfies the principal ideal theorem.

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Morphological Variation of Vessel Elements in the Korean Diffuse-porous Woods (한국산(韓國産) 주요(主要) 산공재(散孔材)의 도관요소(導管要素) 형태변이(形態變異))

  • Park, Byung-Dae;Park, Sang-Jin
    • Journal of the Korean Wood Science and Technology
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    • v.15 no.3
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    • pp.1-13
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    • 1987
  • This study was carried out to investigate the variations of dimension and exterior shape of vessel elements, morphology of spiral thickening and ray-vessel pit in korean diffuse-porous woods (56 species, 18 families), The tangential pore diameter and vessel element length was increased, whereas the pore number per unit area($1mm^2$) was decreased from pith outwards. The tangential pore diameter was decreased but the length of vessel element was not changed from earlywood to latewood within an annual ring. However, the dimensional variations of vessel element was not able to be recognized among relative positions in peripheral variation. The exterior shape of vessel element could be classified into four types; Type 1 is without tail, Type 2 with ligulate tail, Type 3 with broad taper tail and Type 4 with the very short length between perforations. The distribution frequency of Type 2 and 3 was relatively high in comparision with the others. According to the prominence, distribution position and branched shape, the spiral thickenings could be divided into five types. The spiral thickenings occurred 52% in the species observed. Thus it was doubtful to consider the simple presence of spiral thickening as diagnostic index in diffuse-porous woods. The morphology of ray-vessel pit could be grouped as reticulate, scalariform, oval, linear and coalescent type. Most of species examined showed oval and linear type.

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A Pilot Study of Evaluating the Reliability and Validity of Pattern Identification Tool for Insomnia and Analyzing Correlation with Psychological Tests (불면증 변증도구 신뢰도와 타당도 평가 및 심리검사와의 상관성에 대한 초기연구)

  • Jeong, Jin-Hyung;Lee, Ji-Yoon;Kim, Ju-Yeon;Kim, Si-Yeon;Kang, Wee-Chang;Lim, Jung Hwa;Kim, Bo Kyung;Jung, In Chul
    • Journal of Oriental Neuropsychiatry
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    • v.31 no.1
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    • pp.1-12
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    • 2020
  • Objectives: The purpose of this study was to evaluate the reliability and validity of the instrument on pattern identification for insomnia (PIT-Insomnia) and verify the correlation between PIT-Insomnia and psychological tests. Methods: Two evaluators examined the pattern identification of the participants who met insomnia disorder diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorder, Fifth Edition (DSM-5) and took the Insomnia Severity Index (ISI) score over 15 once manually and twice using the PIT-Insomnia to measure the inter-rater and test-retest reliability. We also conducted the following surveys: the Pittsburgh Sleep Quality Index (PSQI), the Korean version of Beck's depression inventory (K-BDI), the Korean version of the State-Trait Anxiety Inventory (STAI-K), the Korean Symptom checklist-95 (KSCL-95), and the EuroQol-5 dimension (EQ-5D), to measure concurrent validity and correlation between the PTI-Insomnia and psychological tests. Results: 1. The test-retest reliability analysis of the pattern identification results showed moderate agreement, and test-retest reliability analysis of each pattern identification score showed agreements from poor to moderate. 2. The inter-rater reliability analysis of the pattern identification results via manual showed slight agreement, when analysis was performed with calibration, the inter-rater reliability analysis of the pattern identification results via manual showed fair agreement. 3. The concordance analysis between results via manual and the PIT-Insomnia showed poor agreement, when the analysis was performed with calibration, concordance analysis showed fair agreement. 4. The concordance analysis between the PIT-Insomnia and the PSQI showed positive linear correlation. 5. The concordance analysis between the PIT-Insomnia and the PSQI, K-BDI, STAI-K, KSCL-95, and EQ-5D showed that non-interaction between the heart and kidney have positive linear correlation with the K-BDI, anxiety item of KSCL-95, dual deficiency of the heart-spleen have positive linear correlation with somatization item of KSCL-95, paranoia item of KSCL-95, heart deficiency with timidity have positive linear correlation with stress vulnerability item of KSCL-95, parania item of KSCL-95, phlegm-fire harassing the heart have positive linear correlation with K-BDI, paranoia item of KSCL-95, depressed liver qi transforming into fire have positive linear correlation with the anxiety item of KSCL-95, parania item of KSCL-95, all pattern identification have negative linear correlation with EQ-5D. Conclusions: The PIT-Insomnia has moderate agreement of reliability and reflects the severity of insomnia since it has some concurrent validity with the PSQI. There are some correlations between the PTI-Insomnia with specific psychological tests, so we could suggest it can be used appropriately in the clinical situation.

A Study of Coloration of Topaz(I): Mineralogical and Chemical Study on the Topaz Selected from Some Localities of the World (토파즈의 人工着色 處理를 위한 硏究(I) : 世界 主要 産地別 토파즈의 鑛物學的 및 化學的 特性)

  • Han, Yi-Kyeong;Park, Maeng-Eon;Jang, Yong-Nam
    • Journal of the Mineralogical Society of Korea
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    • v.5 no.2
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    • pp.109-121
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    • 1992
  • For the purpose of mineralogical and chemical study on the topazes from various localities of world(Brzail, China, India, Nigeria and Sri Lanka), electron microprobe analysis(EPMA), neutron activation analysis(NAA), X-ray diffractometry, Raman spectroscopy, etch test, scanning electron microscopy, refractive index, specific gravity, fluid inclusion were performed. The chemical composition in topaz was discussed along with its physical and structural properties. Variations in the unit-cell dimension and physical properties of topaz were found to have a close relations in the unit-cell dimension and physical properties of topaz were found to have a close relationship with extent of substitution of $OH^-\;for\;F^-$. According to neutron activation analyses, the trace elements had no effects on the physical properties of topaz. Raman spectra showed that the peaks of topaz were different in intensity from one locality to another. Etching defects in topaz includes negative crystal defect o point-bottom pit(India, Nigeria) and net work defect of curl-bottom pit(Brazil, China). Fluid inclusions in topaz may be classiffied into liquid $CO_2$-bearing inclusion, gaseous inclusion, halite, sylvite-bearing inclusion and liquid inclusion. The results of this study can be useful to devising artificial coloring methods for topaz with different mineralogical compositions.

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Behavior of the tunnel under the influence of a existing building during the adjacent ground excavation (근접굴착 시 기존건물의 영향을 받는 터널의 거동)

  • Lee, Jong-Min
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.20 no.3
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    • pp.609-623
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    • 2018
  • If the ground is excavated in a depth which is deeper than the adjacent existing tunnel, the behavior of the braced wall is known to be greatly affected by the presence of the tunnel. By the way it is expected to be also affected by the structure on the ground surface, There are not many examples of studies which are conducted on this subject. As a result, largel scale model tests and analysis were conducted, to measure the behavior of the tunnel under the building whose location on the ground surface was varied during the adjacent ground excavation. For this purpose, the location of a building load was varied in 0 m, 1D, 2D on ground surface. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1 : 10 scale were performed in real construction sequences. The size of test pit was $2.0m(width){\times}6.0m(height){\times}4.0m(length)$ in dimension. As a result, it was found that the stability of the existing tunnel under the influence of the building load on the ground surface adjacent to the braced wall.

Capillary Flow in Different Cells of Thuja orientalis, Gmelina arborea, Phellodendron amurense

  • Chun, Su Kyoung
    • Journal of the Korea Furniture Society
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    • v.28 no.3
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    • pp.248-258
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    • 2017
  • A study was carried out to observe the 1% aqueous safranine solution flow speed in longitudinal and radial directions of softwood Thuja orientalis L., diffuse-porous wood Gmelina arborea Roxb., and ring-porous wood Phellodendron amurense Rupr., Longitudinal flow was considered from bottom to top while the radial flow was considered from bark to pith directions. In radial direction, ray cells and in longitudinal direction tracheids, vessel and wood fiber were considered for the measurement of liquid penetration speed at less than 12% moisture contents(MC). The variation of penetration speed for different species was observed and the reasons behind for this variation were explored. The highest radial penetration depth was found in ray parenchyma of T. orientalis but the lowest one was found in ray parenchyma of P. amurense. The average liquid penetration depth in longitudinal trachied of T. orientalis was found the highest among all the other cells. The penetration depth in fiber of G. arborea was found the lowest among the other longitudinal cells. It was found that cell dimension and also meniscus angle of safranine solution with cell walls were the prime factors for the variation of liquid flow speed in wood. Vessel was found to facilitate prime role in longitudinal penetration for hardwood species. The penetration depth in vessel of G. arborea was found highest among all vessels. Anatomical features like ray parenchyma cell length and diameter, end-wall pits number were found also responsible fluid flow differences. Initially liquid penetration speed was high and the nit gradually decreased in an uneven rate. Liquid flow was captured via video and the penetration depths in those cells were measured. It was found that even in presence of abundant rays in hardwood species, penetration depth of liquid in radial direction of softwood species was found high. Herein the ray length, lumen area, end wall pit diameter determined the radial permeability. On the other hand, vessel and fiber structure affected the longitudinal flow of liquids. Following a go-stop-go cycle, the penetration speed of a liquid decreased over time.

Behavior of Building Lower Part Passage Tunnel due to Adjacent Ground Excavation (근접굴착에 따른 건물 하부 통과 터널의 거동)

  • Lee, Jong-Min;Lee, Sang-Duk
    • Tunnel and Underground Space
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    • v.20 no.5
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    • pp.369-377
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    • 2010
  • Applied to the braced wall in order to stabilize the adjacent tunnel. A pre-load of bracing was imposed to prevent the horizontal displacement of the braced wall during the ground excavation. For this purpose, real scale model tests were conducted, without and with pre-load on braced wall. Real scale model tests were conducted, without and with building load (0 m, 1D, 2D) on ground surface. As a result, it was found that the stability of the existing tunnel adjacent to the braced wall could be greatly enhanced when the horizontal displacement of the braced wall was reduced by applying a pre-load, which was larger than the designated axial force of bracing. In this paper, the behaviors of braced wall and adjacent tunnel was studied. Model tests in 1:10 scale were performed in real construction sequences. Adjacent tunnel was 12 m in diameter and the size of test pit was 2.0 m (width) ${\times}$ 6.0 m (height) ${\times}$ 4.0 m (length) in dimension.