• Journal of the Korean Vacuum Society
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• v.13 no.1
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• pp.9-13
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• 2004

Perylene is an interesting material known to have P-type and N-type characteristics at the same time. We prepared perylene thin-films in ultrahigh vacuum with two different deposition rates of 0.1 $\AA$/s and 1.0 $\AA$/s in order to study the dependence of film characteristics on the growth condition. The smaller average grain size with larger surface coverage as well as the better crystallinity were observed on the perylene film prepared under 1.0 $\AA$/s deposition rate in x-ray diffraction (XRD) and atomic force microscopy (AFM) study. For studying electrical property of the film, perylene organic thin-film transistor (OTFT) with gold contacts was fabricated on $SiO_2$/Si surface in UHV condition. The prepared perylene OTFT device shows P-type characteristic. The obtained hole mobility in the current-voltage characteristic curve was$2.23\times10^{-5}\textrm{cm}^2$/Vs.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1162-1174
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• 2010

Excavated gold brocade, often shows signs of serious damage and contamination from environmental factors such as exposure to soil or human remains. Therefore, most of the conservation procedures are focused on the consolidation of the gold thread and on cleaning with water or organic solvents. Indiscreet cleaning using solvents could damage the gold leaf, which identifies the features of fabric. There is a need to develop cleaning protocols appropriate for relics through the careful analysis of the condition of the relics. This study finds the appropriate cleaning method for the excavated gold brocade. Four different cleaning methods, vacuum cleaning, kneaded rubber eraser cleaning, immersion wet cleaning, and absorption wet cleaning were applied to the excavated gold brocade. The degree of cleaning and damage were examined depending on the cleaning methods, changes to the physical condition (before and after cleaning) were also analyzed through the surface observation. Although immersion cleaning showed the best cleaning result, this method had a risk of damage to the gold thread. Absorption wet cleaning safely eliminated the various soluble contaminants and the rotten smell of relics. Kneaded rubber eraser was suitable for the excavated gold brocade fabric because it can be applied to selective parts, intentionally excluding some sensitive parts such as the gold thread. The vacuum cleaning method required special attention because of a possibility of suctioning off loosely attached gold leaf. Dual cleaning, the kneaded rubber eraser cleaning, followed by the absorption cleaning was the most effective method to preserve and clean excavated gold brocade.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.217-217
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• 2012

Solution-processed tungsten oxide thin film with thickness of about 30 nm is prepared from ammonium tungstate. This layer is introduced into the interface between the poly(3-hexylthiophene):[6,6]-phenyl-C61-butyric acid methyl ester (P3HT:PCBM) layer and the ITO electrode to be used as an electron blocking layer. The annealed tungsten oxide thin films at $150^{\circ}C$ and $300^{\circ}C$ show amorphous phase, while the $400^{\circ}C$ -annealed tungsten oxide film shows crystalline phase. At $150^{\circ}C$ annealing temperature, the conversion efficiency is significantly improved from 0.71% to 1.42% as the condition is changed from vacuum to air atmosphere, which is related to oxidation state of tungsten in amorphous phase. For the air annealing condition, the conversion efficiency is further increased from 1.42% to 2.01% as the temperature is increased from $150^{\circ}C$ to $300^{\circ}C$, which is mainly due to the removal of the chemisorbed water. However, a slight deterioration in photovoltaic performance is observed when the temperature is increased to $400^{\circ}C$, which is ascribed to poor electron blocking ability due to the formation of crystalline phase. It is concluded that $W^{6+}$ oxidation state and amorphous nature in tungsten oxide interlayer is essential for blocking electron effectively from the active layer to the ITO electrode.

• Korean Journal of Materials Research
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• v.8 no.12
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• pp.1121-1126
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• 1998

For vacuum seated panel, stresses and displacements in the glass plate were calculated. The geometric variables for our experiment were the thickness of glass plate, the size of panel and the width of sealing line. The fracture behaviors and displacements of its under the vacuum were measured. From the measurement of strains and fracture, it was considered that the maximum stress acted at the middle of the sides of the panel. The stresses and displacement distribution of manufactured panels were greatly dependent on the width of the sealing line in the panel. The measured values are more similar to the values which were calculated from the condition of built-in edge as the width of the sealing line is larger. The measured displacement of the panel, made of 3mm thick glass plate, with size of $80\Times120\textrm{mm}^2$ and 20mm sealing line was $57\mu\textrm{m}$. This value is similar to calculated value, $54\mu\textrm{m}$, from built- in edge condition in the finite element method.

• Clinical and Experimental Pediatrics
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• v.61 no.12
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• pp.387-391
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• 2018

Purpose: Subgaleal hemorrhage (SGH) is a rare but potentially fatal condition in newborns; however, few studies have reported on this condition. We aimed to identify the clinical characteristics and prognostic factors of SGH. Methods: We retrospectively reviewed the medical records of 20 neonates diagnosed with SGH between January 2000 and June 2017. Enrolled neonates were clinically diagnosed when they had tender fluctuant scalp swelling that crossed the suture lines. Results: Among 20 neonates with SGH, 12 were boys and 7 were girls; median hospitalization duration was $9.7{\pm}6.9days$. Fourteen neonates (70%) were born via vacuum-assisted vaginal delivery, and 4 via vacuum-assisted cesarean section. Of the neonates enrolled, half of them initially showed unstable vital signs, including apnea, desaturation, and cyanosis. Ten neonates had acidosis and 3 had asphyxia (pH<7.0). Intracranial lesions associated with SGH were observed in 15 neonates (75%), including subdural hemorrhage (50%), subarachnoid hemorrhage (15%), intraventricular hemorrhage (5%), cerebral infarct (15%), skull fracture (30%), and cephalohematoma (20%). Twelve neonates (60%) required transfusion, 5 (25%) had seizures, and 3 (15%) died. Eight neonates (40%) had hyperbilirubinemia (mean total bilirubin, $13.1{\pm}7.4$). The mean follow-up period was $8.4{\pm}7.5months$. At follow-up, 10 neonates (58.8%) were healthy with normal development, whereas 7 (41.2%) had neurological deficits. Conclusion: The morbidity rate was 41.2% due to severe metabolic acidosis. Anemia, hyperbilirubinemia, low Apgar scores, and subdural hemorrhage did not affect the prognosis. The long-term outcomes of neonates with SGH are generally good. Only arterial blood pH was significantly associated with death.

• Clean Technology
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• v.15 no.4
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• pp.253-257
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• 2009

The waste solution discharged form the LCD(Liquid Crystal Display) manufacturing process contains phosphoric acid, nitric acid, acetic acid and metal ions such Al and other impurities. In this study, vacuum evaporation and diffusion dialysis was developed to commercialize an efficient system for recovering the high-purity phosphoric acid and manufacturing monoammonium phosphate. By vacuum evaporation, almost 99% of nitric and acetic acid was removed. Also, by diffusion dialysis, about 97.5% of Al was removed. Monoammonium phosphate was manufactured from purified phosphoric acid and ammonium hydroxide. In order to get the optimum manufacturing condition, the molar ratio of ammonium hydroxide and phosphoric acid, pH and temperature was controlled. Using this optimum condition, we obtained the recovery rate of monoammonium phosphate of about 90%.

• 보존과학연구
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• s.35
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• pp.45-55
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• 2014

The small dining tables which are made of bamboo were deteriorated condition when those were excavated from Mado shipwreck No.1. Therefore, preliminary test was conducted for consolidation (Sucrose, Dammar gum, Cetyl alcohol and Polyethylene glycol 4000) then impregnated and vacuum freeze dried. After the test, since the treatment with vacuum freeze drying using an aqueous solution of PEG 4000 keep the shape well the most and present bright colour, waterlogged archaeological bamboo conserved with vacuum freeze drying using an aqueous solution of PEG 4000. One bamboo table consolidated with soluble PEG 4000 from 10% to 40%, then vacuum freeze dried. Another impregnated with soluble PEG 4000 from 10% to 70%. After that, it was separated and held in polycarbonate sheet for preventing bending during dry. The small dining tables are the three dimensional shapes and have some loss. Therefore the mounting for support tables were necessary which are made of acrylic sheet. It keep the table shape and make it convenient for storage and handling.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.1819-1824
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• 2014

The vacuum-glazing panel is a panel that keeps two glasses completely sealed in a vacuum condition. It is the high function insulation material of having the wall level minimizing the heat loss by the conduction and convection heat transmission coefficient. The edge sealing is a very important process of vacuum glass on the strength, thickness and air tightness. In this study, by using the hydrogen mixture gas torch, two sheets of glass was sealing in the furnace. The thickness and strength of the glass according to the process parameters is measurement and analysis, and predicting the edge sealing strength of glass by using taguchi method of experiment. We verified the validity of the experiment by checking the error rate through additional experiment.

• Archives of design research
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• v.18 no.4 s.62
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• pp.155-164
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• 2005

In contrast with product design field, some designers who work in furniture field tend to do their own studio works as well as typical designing part. Especially in the small furniture studios for the limited quantity batch production, custom made or handmade craft furniture which is finished with high quality, the propensity for their own production is more obvious than in the big furniture companies in this case. In this kind of small-scale furniture studios, they have more chance to create the various formative works and 'curved shape' is one of the most important elements to form creative pieces. Except by caning, it is very difficult to make curved wooden shape because of own characteristic of wood. Therefore, the special techniques of bending wood are essential to formative furniture production and vacuum press system is introduced as a main subject for the bending wood method in this study. Especially for the designers who work as makers as well at the small furniture studios, the value of vacuum press system on efficiency and productivity of work was sought by testing and improving the method of wood bending techniques. According to this practical searching, ideally sufficient condition on vacuum pressing work was founded as a result on this study.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.8
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• pp.404-410
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• 2006

Toward the practical applications, on operation of conduction-cooled HTS SMES at temperatures well below 40[K] should be investigated, in order to take advantage of a greater critical current density of HTS and considerably reduce the size and weight of the system. In order to take advantage of a greater critical current density of high temperature superconducting (HTS) and considerably reduce the size and weight of the system, conduction-cooled HTS superconducting magnetic energy storage (SMES) at temperatures well below 40[K] should be investigated. This work focuses on the breakdown and flashover phenomenology of dielectrics exposed in air and/or vacuum for temperatures ranging from room temperature to cryogenic temperature. Firstly, we summarize the insulation factors of the magnet for the conduction cooled HTS SMES. And Secondly a surface flashover as well as volume breakdown in air and/or vacuum with two kind insulators has been investigated. Finally, we will discuss applications for the HTS SMES including aging studies on model coils exposed in vacuum at cryogenic temperature. The commercial application of many conduction-cooled HTS magnets, however, requires refrigeration at temperatures below 40[K], in order to take advantage of a greater critical current density of HTS and reduce considerably the size and weight of the system. The magnet is driven in vacuum condition. The need to reduce the size and weight of the system has led to the consideration of the vacuum as insulating media. We are studying on the insulation factors of the magnet for HTS SMES. And we experiment the spacer configure effect in the dielectric flashover characteristics. From the results, we confirm that our research established basic information in the insulation design of the magnet.