• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.3
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• pp.327-333
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• 1999

Controlled Ca impurity implanted inner crack-like pore in the high purity alumina bi-crystal had been created by micro-fabrication technique, which includes ion implantation, photo-lithography, Ar ion milling, and hot press. The morphological change and the growth od crystals formed by heat treatment in Ca doped high purity single crystal alumina, were observed using optical microscopy. The dot was developed and hexagon like crystal appeared on inner surface of crack-like pore after heat treatment. Bar type crystals, probably CaO . $6Al_2O_3$, were observed on the inner surface of 100ppm Ca implanted specimen after 1 hour heat treatment at $1,500^{\circ}C$, but this bar type crystal disappeared after 1 hour heat treatment at $1,600^{\circ}C$. This disappearance means that there should be little increase of Ca solubility limit to alumina and/or changes of diffusion coefficient of Ca in alumina around this temperature.

• The Journal of Natural Sciences
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• v.4
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• pp.179-189
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• 1991

The limit sowing time and the growth of radish cultivated in late fall were studied in relation to the effects of varieties and polyethylene film mulching. The root weight of Dehyung-Chusuk radish sowing in September 8th in Suwon was 520g but 718g in mulched plot. In Pusan the root weight of radish sowing on September 16th and harvested on November 23rd was 655g in Bekkyung and 813g in Dehyung-Chusuk variety, but more than 1000g in mulched plots of two varieties all. The effect of mulching was higher in Dehyung-Chusuk than in Bekkyung. The experimental results of Altari varieties will be recommandable in limit sowing time as around September 14th in mid-northern area and around September 18th in mid-southern area. Chonggak Altari was better than Chammat Altari in root formatiion. Two varieties all revealed good growth in the plots of sowing on September 26th in Pusan.

• Journal of Mechanical Science and Technology
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• v.19 no.7
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• pp.1393-1404
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• 2005

Fatigue crack growth and life have been estimated based on established empirical equations. In this paper, an alternative method using artificial neural network (ANN) -based model developed to predict fatigue damages simultaneously. To learn and generalize the ANN, fatigue crack growth rate and life data were built up using in-plane bending fatigue test results. Single fracture mechanical parameter or nondestructive parameter can't predict fatigue damage accurately but multiple fracture mechanical parameters or nondestructive parameters can. Existing fatigue damage modeling used this merit but limited real-time damage monitoring. Therefore, this study shows fatigue damage model using backpropagation neural networks on the basis of X -ray half breadth ratio B / $B_o$, fractal dimension $D_f$ and fracture mechanical parameters can estimate fatigue crack growth rate da/ dN and cycle ratio N / $N_f$ at the same time within engineering limit error ($5\%$).

• Journal of the Korean Ceramic Society
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• v.50 no.2
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• pp.116-121
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• 2013

Zinc crystal glaze has its limits in practical use of commercial glaze due to the controlling crystal. In order to overcome this limit, and to heighten the practical usage, this study is aimed to develop artificially controlling willemite ($Zn_2SiO_4$) zinc crystalline glaze. For this purpose, it has experimented with the effect of anatase form and rutile form using $TiO_2$ known as nucleating agent. In zinc glaze, adding $TiO_2$ resulted with anatase form becoming more effective at nucleating formation and growth of willemite than the rutile form. Furthermore, it turned out that using the $TiO_2$ - anatase form, with synthetic seeds (zinc silicate), the numbers and positions of crystals can be controlled artificially.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.3
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• pp.355-361
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• 1987

Creep and fatigue tests were carried out on crack growth properties of small surface cracks in 304 stainless steel at 538.deg.C, 593.deg. C and 650.deg. C in air, by using small plate specimens with a small artificial pit. All the data of the crack growth rate per hour obtained in the present tests were correlated with the maximum stress intensity factor, so that the applicability of linear fracture mechanics to the crack growth of surface cracks at elevated temperature was investigated. In the creep test, relatiion of .sigma.$\^$n/.t$\_$f/=C is obtained between failure time and nominal stress at each temperature level, where n has the value of 11-14 depending on the temperature level. In the creep and fatigue crack growth properties of surface cracks at the elevated temperatures, the maximum stress intensity factor, $_{4}$$\_$max/, is some extent applicable parameter to describe the surface crack growth rate under the present experimental conditions. The crack growth rate per hour increases when the holding time decreases, and creep crack growth rate per hour becomes the lowest limit of crack growth rate per hour in this tests.

• The Journal of Pediatrics of Korean Medicine
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• v.35 no.1
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• pp.18-29
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• 2021

Objectives The purpose of this study is to provide evidence of treatment of growth disorder Methods We have reviewed clinical studies of growth disorder in children and adolescent through 6 databases until February, 2020. The searching keywords were "short stature OR dwarfism OR growth disorder" AND "acupuncture OR electric acupuncture OR electroacupuncture OR moxibustion OR herb medicine OR cupping OR Korean medicine OR oriental medicine OR chuna OR pharmacopuncture OR qigong OR traditional medicine OR traditional Korean medicine OR Korean medicine". There was no limit to time and language. Results As a result of the initial search, a total of 270 papers from six domestic databases were found. Among these papers, 156 papers were selected after excluding duplicated papers, and 109 of them were further excluded after checking the title and the abstract. Additionally, 28 papers were excluded by reviewing the full text. The author, year, number of patients, treatment, evaluation tools, and results of a total of 19 papers were included in this study and were summarized. 90.5% of the studies have shown that herbal remedies have improved childhood growth. Conclusions Random control studies and large-scale observational studies are needed in future to show high-quality evidence for the treatment of Korean medicine in pediatric growth.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.87-94
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• 1997

One of the general properties of adsorption on multilayer is that the amount of adsorbing particles is not saturated. As another important property, in many cases, the amount of adsorbed particles is linearly proportional to the pressure of gases above the layers, at sufficiently low pressure, which is known to be Henry's experimental law. A purpose of this paper is to show qualitatively, in terms of a theory, that an adsorption on multilayer lbeys Henry's law at the region of low pressure. For this, we introduce a simple multilayer adsorption model and establish an adsorption isotherm for the given model, which is analyzed in the limit of low pressure.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.239.2-239.2
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• 2015

Graphene is a most interesting material due to its unique and outstanding properties. However, semi-metallic properties of graphene along with zero bandgap energy structure limit further application to optoelectronic devices. Recently, many researchers have shown that band gap can be induced in the Bernal stacked bilayer graphene. Several methods have been used for the controlled growth of the Bernal staked bilayer graphene, but it is still challenging to control the growth process. In this paper, we synthesize the large area Bernal stacked bilayer graphene using multi heating zone low pressure chemical vapor deposition (LPCVD). The synthesized bilayer graphenes are characterized by Raman spectroscopy, optical microscope (OM), scanning electron microscopy (SEM). High resolution transmission electron microscopy (HRTEM) is used for the observation of atomic resolution image of the graphene layers.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.154-162
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• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.

• Corrosion Science and Technology
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• v.10 no.4
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• pp.151-155
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• 2011

The iron oxide particles could be resulted from the corrosion of the circulating water system of a power plant. Because it may be one of the trouble materials which affect the power generation efficiency due to the deposition on steam generator tube and turbine blade, the continuous observation of its concentration is very important. The laser induced break-down detection (LIBD) technology was applied to monitor continuously the concentration of corrosion products with the detection limit of ppb level. The measurement system consists of a Nd:YAG pulsed laser, a polarizing beam splitter, a flow-type sample cell, an acoustic emission sensor, a high speed data acquisition board, a personal computer, etc.. The performance test results confirmed that this technology can be effective to monitor the corrosion product concentration of the circulating water system of a power plant.