• Title/Summary/Keyword: DIAMETER GROWTH

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Micro-Porous Ceramics Using directionally $MgAl_2O_4/MgO$ eutectic crystals

  • Lee, Jong-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.15 no.6
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    • pp.229-233
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    • 2005
  • Novel process was tried to obtain micro-porous ceramic body containing continuous pore channel. $MgAl_2O_4/MgO$ eutectic fibers and rods have been grown successfully by the micro-pulling-down method, and the microstructures and optical characterizations of grown crystals were performed. $MgAl_2O_4/MgO$ eutectic fibers of $0.3{\sim}1mm$ in diameter and about 500 mm in length, and the rods having 5 mm in diameter with approximately 60 mm in length have been grown with the $6{\sim}120mm/hr$ of growth speed. The eutectic fibers showed homogeneous microstructure in which MgO fiber aligned to the growth direction in the $MgAl_2O_4$ (spinel) matrix. The grown crystals looked semitransparency under naked eyes. Optical and orientational characterizations were performed. The second phase of MgO (periclase) was easily removed by selective etching with hydrochloric acid, and then porous bodies were obtained.

The growth and structure of CNTs dependent on the catalysts using thermal CVD

  • Lee, Tae-Jae;Lyu, Seung-Chul;Choi, Sang-Kyu;Lee, Cheol-Jin;Lee, Jin-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.670-673
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    • 2002
  • We have investigated the catalyst effect on the growth and structure of CNTs using thermal chemical vapor deposition. The respective growth rate of CNTs shows that the performance of catalysts is in the order of nickel (Ni)>cobalt (Co)>iron (Fe). The average diameter of CNTs follows the sequence of Fe, Co, and Ni catalysts. The structure of CNTs reveals almost same morphology regardless of catalyst but the crystallinity of CNTs is largely dependent on catalyst. The crystallinity of CNTs synthesized from Fe catalyst is higher than that from Ni or Co catalyst. We demonstrate that the growth rate, the diameter, and the crystallinity of CNTs can be manipulated by selecting the catalysts.

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Cross- and Double-Resistance of Benomyl-Resistant Botryosphaeria dothidea (Benomyl에 저항성인 사과 겹무늬썩음병균의 교차 및 이중저항성)

  • 이창은;박석희
    • Korean Journal Plant Pathology
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    • v.10 no.4
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    • pp.270-276
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    • 1994
  • Mycelial growth resistant isolates of Botryosphaeria dothidea to benomyl showed 99~79% spore germination on the PSA media supplemented with 200~2,100 $\mu\textrm{g}$/ml of carbendazim and thiophanate-methyl to manifest the high cross-resistance in spore germination. Mycelial growth, 23~9 mm in colony diameter, also manifested the high cross-resistance of mycelial growth together with similarity of spore forming cross-resistance. Benomyl resistant isolates BR1, BR2 and BR3, grew 23~10 mm in colony diameter at 330~3,000 $\mu\textrm{g}$/ml of captafol, captan and oxine-copper showing the high double resistance of mycelial growth and spore formation with minor difference. However, within concentration range of the 3 fungicides tested, germinations of all the tested isolates were completely suppressed to show no double-resistance in the fungal spore germination.

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Modelling of transport phenomena and meniscus shape in Czochralski growth of silicon material

  • Bae, Sun-Hyuk;Wang, Jong-Hoe;Kim, Do-Hyun
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.5
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    • pp.454-458
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    • 1999
  • Hydrodynamic Thermal Capilary Model developed previously has been modified to study the transport phenomena in the Czochralski process. Our analysis is focused on the heat transfer in the system, convection in the melt phase, and the meniscus and interface shape. Four major forces drive melt flow in the crucible, which include thermal buoyancy force in the melt, thermocapillary force along the curved meniscus, crucible rotation and crystal rotation. Individual flow mechanism due to each driving force has been examined to determine its interaction with the meniscus and interface shape. A nominal 4-inch-diameter silicon crystal growth process is chosen as a subject for analysis. Heater temperature profile for constant diameter crystal is also present as a function of crystal height or fraction solidified.

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Development of Allometry and Individual Basal Area Growth Model for Major Species in Korea (우리나라 주요수종의 Allometry와 개체목 흉고단면적 생장모델 개발)

  • Choi, Jung-Kee
    • Journal of Forest and Environmental Science
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    • v.27 no.1
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    • pp.47-54
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    • 2011
  • Allometry and basal area equations were developed with various tree measurement variables for the major species; Quercus variabilis, Quercus mongolica, Pinus koraiensis and Larix leptolepis in Korea. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, and crown width), relative size (relative diameter and relative height) as well as competition measures (competition index, crown class, and live crown ratio).

Automatic diameter control system for Czochralski growth (자동직경제어 Czochralski 성장장치의 제작)

  • Han, J.Y.;Park, S.S.;Lee, S.K.;Ma, D.J.;Kim, Y.H.;Lee, S.H.
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.4 no.4
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    • pp.356-362
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    • 1994
  • We developed a computer controlled Czochralski puller which automated entire crystal growing processes. Crystal weighing technique was employed for an automatic diameter control. The performance of the system was evaluated by the growth of $LiNbO_3$ single crystals.

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Physiological Response of Tetrapleura tetraptera (Schum. and Thonn.) Taub. to Soil Textural Class, Moisture and Light Intensity

  • Akinyele, Adejoke O.;Wakawa, Lucky Dartsa
    • Journal of Forest and Environmental Science
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    • v.33 no.2
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    • pp.97-104
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    • 2017
  • Investigation was carried out on response of Tetrapleura tetraptera (Schum. and Thonn.) to soil, water and light with the view of its domestication and introduction to different ecological regions. The experiment was arranged in a factorial experiment of $3{\times}3{\times}3$ in a completely randomized design (CRD) with three replicates. The factors were: soil textural class (Loamy sand, Sand and Sandy clay loam), watering regime (daily, twice a week and once a week) and light intensity (100%, 75% and 50%). Soil textural classes had significant influence on collar diameter, stem height, number of leaflets, root/shoot ratio and relative growth rate of Tetrapleura seedlings. Seedlings grown on loamy sand recorded the highest mean value- 2.28 mm for collar diameter, stem height- 12.9 cm, number of leaflets- 19.9, chlorophyll b- $0.34mg\;mL^{-1}$, leaf relative water content- 27.4% and relative growth rate- $0.037mg\;g^{-1}\;day^{-1}$. Watering regime had significant influence on the collar diameter of Tetrapleura. Seedlings watered daily recorded the highest mean value- 2.25 mm for collar diameter. Light intensity significantly influenced collar diameter and root/shoot ratio. Seedlings exposed to 100% light intensity recorded higher mean value for collar diameter- 2.28 mm and root/shoot ratio- 1.481 cm. The interaction between soil textural class and light intensity significantly affected collar diameter, stem height and number of leaflets. Higher mean value for collar diameter (2.47 mm) stem height (13.25 cm) and number of leaflets (21.16) were recorded while the interaction between soil textural class, light intensity and watering regime was significant for only number of leaflets. Tetrapleura exhibited some level of tolerance to different soil texture, drought and light intensity. Therefore, Tetrapleura has the potentials to be raised in different ecological zones characterized by difference in soil, rainfall and amount of sunshine.

Growth Degree of Quercus Community Plantations for Effective Vegetation Restoration (효과적인 식생복원을 위한 참나무류 군락 식재의 생장량에 관한 연구)

  • Mi-Jin Kim;Eun-Suk Cho;Hee-Jeong Jeong;Dong-gil Cho
    • Journal of Environmental Science International
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    • v.32 no.3
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    • pp.161-171
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    • 2023
  • The present study evaluated growth factors affecting oak community plantations through literature review and a field survey. Specifically, 41 related literature sources were analyzed and field surveys were conducted to collect growth data. Previous studies were analyzed to identify variables with high frequency of use. The frequency of use was in the order of tree size > environment > planting density > forest age. Analysis of factors impacting height and diameter growth revealed that the growth rate of species other than Quercus variabilis was negative in the field survey. This may be because of differences between the actual trees planted and specifications in the construction drawings, which may be attributed to the site conditions and decisions made by the project subject during construction. Furthermore, simple linear regression analysis was conducted with time, height at planting, density, and species code as the independent variables and growth rate as the dependent variable. A strong positive linear correlation was noted between height and diameter. This work builds a foundation for developing a forest restoration model and simulation program based on a regression model derived from the four variables tested.

Alterations in Growth and Morphology of Ganoderma lucidum and Volvariella volvaceae in Response to Nanoparticle Supplementation

  • Singh, Swarnjeet;Kuca, Kamil;Kalia, Anu
    • Mycobiology
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    • v.48 no.5
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    • pp.383-391
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    • 2020
  • Use of nanoparticles (NPs) in several commercial products has led to emergence of novel contaminants of air, soil and water bodies. The NPs may exhibit greater ecotoxicity due to nano-scale dependent properties over their bulk counterparts. The present investigation explores the effect of in vitro supplementation of TiO2, silica and silver NPs on radial growth and ultrastructural changes in the hyphae and spores of two mushroom genera, Ganoderma lucidum and Volvariella volvaceae. A concentration dependent decrease in radial growth on NP amended potato dextrose agar medium was recorded. However, in comparison to control, there was decrease in radial diameter on supplementation with TiO2 NPs while an increase was recorded for silica and silver NPs amendments as compared to their bulk salts at same concentrations after 48 h of incubation. Optical microscopy studies showed decrease in the number of spores while increase in spore diameter and thinning of hyphal diameter on NPs supplementation. Scanning electron microscopy analysis of fungal growth showed presence of deflated and oblong spores in two fruiting strains of Ganoderma while Volvariella exhibited decreased sporulation. Further, hyphal thinning and branching was recorded in response to NP amendments in both the test mushrooms. Enhancement of protein content was observed on NP compared to bulk supplementation for all cultures, concentrations and hours of incubation except for TiO2 NPs. Likewise, bulk and NP supplementations (at 100 mg L-1) resulted in enhanced laccase activity with occurrence of laccase specific protein bands on SDS-PAGE analysis.

Early Growth and Development of Eye in Dotted Gizzard Shad, Konosirus punctatus (전어, Konosirus punctatus의 초기 성장 및 눈 발달)

  • Park, In-Seok;Im, Soo-Yeon;Seol, Dong-Won;Lee, Jin-Hwan;Hur, Jun-Wook;Jeong, Gwan-Sik
    • Development and Reproduction
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    • v.10 no.2
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    • pp.93-96
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    • 2006
  • The total length, head length, head height, eye diameter, retina thickness, and lens diameter of the dotted gizzard shad, Konosirus punctatus, showed positive allometric relationships between hatching and 30 days post-hatching (dph). The increase in total length relative to head length and head height, head length growth relative to eye and lens diameter, head height growth relative to eye diameter and lens diameter, and thickness of the retina relative to eye diameter, lens diameter, head length, and head height were showed allometric relationships. The eyes were formed completely at 9 dph. At this age, the eye has a lens, an optic nerve fiber layer, a ganglion cell layer, an inner plexiform layer, an inner nuclear layer, an outer plexiform layer, an outer nuclear layer, an outer limiting membrane, a rod and cone layer, and an epithelial layer. The essential demands that must be met by the retina in this species pertain to light sensitivity and spatial resolution.

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