• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.4
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• pp.3991-4000
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• 1975

It is the aim of this study to investigate the influence of the factors in the sprayer nozzle for the travelling distance and to get nozzle design data in relation to the nozz1e with and without swirl plate. The factors of sprayer nozzle are composed of the spraying pressure, the helical angle of swirl plate, the helical groove depth of swirl plate, the distance of vortex chamber the slope of nozz1e cap, the curvature of nozzle cap and the hole diameter of nozz1e cap. The travelling distance and the size of sprayed particle are experimeted indoors by the factorial arrange-ment according to the 5 each level of the above factors. The results of this stupy are summarized as follows; 1. In the nozzle with swirl p1ate there were remarkable significance among factors each other, while without swirl plate were no significance. 2. The helical angle and groove depth in the nozzle with swirl plate were the highest effective factors. The effect of helical angle was very remarked in the quadratic curve with minium value. 3. The correlation betweenthe travelling distance and the sprayed particle size was no high and under 250 micron in the case with swirl plate, and there was higher correlation in the case without swirl plate. 4. The new ideal development of the swirl plate using of the most effective helical angle and groove depth will probably show the possiblities to make effective travelling distance over 8 meters and more over and to make average particle diameter under 300 micron.

• Journal of Welding and Joining
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• v.28 no.6
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• pp.28-34
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• 2010

This paper was described on investigation to prevent porosity in high speed MIG Welding of Al 6082-T6. Porosity measurement was carried out by using image analysis of micrographs with the help of an analysis software. The main parameter was arc length and torch progressive angle. The porosity ratio was increased as arc length was increased. The arc length was increased depending upon the output voltage. By proper selection of pulse waveform parameter, the stable arc of one pulse one drop was generated. The porosity ratio of optimum condition in one pulse one drop was lower than high voltage condition. When torch progressive angle was an angle of advance $10^{\circ}$, porosity ratio was minium.

• Proceedings of the KSME Conference
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• 2000.11b
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• pp.738-744
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• 2000

The breakup behaviors of impinging droplet on a hot surface are studied experimentally. The droplets are produced by the dripping method and the breakup behaviors of liquid droplet are recorded by photographs. Experimental conditions are, droplet diameter di : 2.5, 3.2 [mm], weber number : $30{\sim}140$, surface temperature : $28^{\circ}C(room\;temperature){\sim}450^{\circ}C$. Water is used to liquid. As weber number of droplet increases, a liquid sheet, which is formed after the impingement on a hot surface, is disintergrated by the dynamical effect. But at low weber number, it has effected by thermodynamical effect. The breakup behaviors of droplet are divided into three patterns with weber number and surface temperature, non-disintegration, transition and disintegration region. Further, these boundary values are affected by the hot surface temperature and weber number. SMD of breakup droplets are calculated in according to surface temperatures and weber number. The minium SMD of breakup droplets are observed at weber number 65.49, temperature $250^{\circ}C$ and weber number 99.08, temperature $350^{\circ}C$.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.55-60
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• 2012

Longitudinal transmission-line modal theory is applied to analyze maximum power transfer in plasmonic grating-assisted directional couplers (P-GADC) based on silicon waveguide. By defining a coupling efficiency amenable to rigorous analytical solutions and interference between even and odd modes, the power exchange of TE modes as a function of propagation distance is evaluated. The numerical result reveals that maximum power transfer occurs at a grating period ${\Lambda}_{eq}=10.26{\mu}m$, in which the insertion loss of supermodes is equal to each other. That is, it is generally different from conventional phase-matching condition or minium gap condition of GADC.

• The Journal of the Petrological Society of Korea
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• v.20 no.4
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• pp.243-250
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• 2011

This study considers the historical eruption record in 1702 from the volcanological point of view, which is presumed to have occurred from Mt. Baegdusan volcano. The minium volume of erupted materials is estimated to be $1.2km^3$ when calculated with an empirical formula using an isopach line obtained from two points 140 km away from the vent. The 1702 eruption was a paroxysmal one with VEI of 5. The historical record described a deposition of wind-modified fallout ash by movement of hot ash cloud. To prepare for the future eruption, we have to analyze historical literatures and understand characteristics of volcano.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.1
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• pp.1-9
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• 1999

This study was performed to investigate the deinkability of Korean old newspaper(KONP) and the properties of newsprint made from deinked pulp with some addition of virgin pulp. When the samples of composed of 50% Australian old magazine(AuOMG) and 50% KONP were compared with the samples 50% AuOMG and 50% AuONP, the yield, opacity, strength properties of the former were high, but its brightness was low. When the mixing ratio of AuOMG : AuONP : KONP was 30:20:50, the brightness and strength properties were obtained the similar or better than those obtained samples having other mixing ratio. The brightness and opacity of samples made from deinked pulp with the some addition of TMP and BKP can meet the minium qualifications of brightness and opacity specified by Japanese Industrial Standard. The samples, which DIP, TMP, and KP were mixed with the ratio of the 85:10:5 and 90:5:5, maintained higher brightness and strength comparing to the samples containing higher amount of virgin pulp. Since the newsprint samples made from KONP was not inferior to those from imported old newspaper, the more use of KONP in producing newsprint is recommended.

• Journal of Korea Foundry Society
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• v.23 no.4
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• pp.187-194
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• 2003

The effect of rare earth elements (R.E)(from 0.0 to 0.04%) on the microstructure formation and mechanical properties of thin-wall ductile iron castings were investigated. Tensile strength and hardness were decreased with an addition of up to 0.03% rare-earth elements. After addition of more than 0.03%, those were increased. Graphite nodule sizes were the finest, nodule count was the highst regardless of thickness and volume fraction of ferrite was the largest when that was 0.02%. However, the nodule count was decreased with increasing R.E. Futhermore. nodule size increased with increasing thickness and the volume fraction of ferrite decreased as that was increased. Nodularity was increased regardless of the thickness as that was increased. The castings of minium thickness up to 3 mm was possible without the formation of chill.

• Journal of the Korean Applied Science and Technology
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• v.16 no.1
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• pp.95-103
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• 1999

In the separation of toluene/n-heptane mixture by the emulsion type liquid membrane in a batch system, the effect of surfactants on the separation factor and membrane stability were studied over the surfactant concentration ranging from 0.1 to 1.5 wt% at the contact time of 5 and 10 minutes and the settling time 5 and 10 minutes. The surfactants used were triethanol amine lauryl sulfate. The separation factor reached its maximum value at the surfactant concentration of 0.5 wt%. It was found that the percentage of membrane breakup reached its minium values and the separation factor showed its maximum value at the surfactant concentration of 0.5 wt%, which confirmed that efficient separation could be effect when emulsion liquid membrane were stable because of low membrane break up.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.23 no.1
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• pp.37-48
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• 2020

This study was aimed to design core areas applied by the global conservation criteria to promote the public awareness to the protected areas and the value cognition of the Key Biodiversity Areas (KBAs), targeting the Mt Seorak, according to the designation of globally important biodiversity areas. As a method for carrying out this study, the biota were cataloged through literature reviews and field trips. With applied by the Global Red List criteria of the International Union for Conservation of Nature (IUCN), only nine species were categorized in the studied area; plants were classified into six species as follows: Megaleranthis saniculifolia ohwi, Bupleurum euphorbioides Nakai, Hanabusaya asiatica Nakai, Thuja koraiensis Nakai, Leontopodium leiolepis Nakai, Androsace cortusaefolia Nakai, fish was classified one species as follow: Pungitius sinensis Tanaka, and the mammal was classified as two species as follows: Hydropotes inermis, Naemorhedus caudatus. According to the occupation area (EoO, Extent of Occurrence) and Minimum Viable Population(MVP), the size of protected area was 234.56㎢ for plants, 235.07㎢ for mammals, and 0.14㎢ for fish, and the Key Biodiversity Area (KBA) of Mt. Seolak suggested as 286.72㎢.

• Journal of the Korean Wood Science and Technology
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• v.50 no.3
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• pp.193-217
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• 2022

The Wooden Seated Amitabha Buddha Triad and Altarpiece have not been the subjects of definitive species identification and scientific analysis. In this study, visual investigation, portable X-ray fluorescence (p-XRF), species identification, and lacquer layer observations were carried out to determine the original materials and conservation status. Cracks, exfoliation and discoloration were detected during the visual investigation. The p-XRF data indicated that chrome oxide green, malachite, gold, cadmium red, cinnabar, minium, hematite, lead white, ink stick (Carbon), and copper were used for pigments and the coronet accessory. Tilia spp., Abies spp., and Pinus spp. were identified from both the Buddha Triad and Altarpiece. Finally, lacquer layer analyses of the base layer, lacquer layer, orange pigment layer, and gold leaf layer observed modern synthetic pigments likely used in previous conservation. As the Korean Cultural Heritage Charter and the International Charter for the Conservation and Restoration of Monuments and Sites clearly state that objects of cultural heritage must be conserved using their original materials, future conservation of these objects should utilize the data obtained in this study to employ traditional materials. Furthermore, a deterioration map diagnosis can be applied together with the obtained analysis data to understand the conservation status of and inform an appropriate and authentic conservation treatment for the Buddha Triad and Altarpiece.