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Pre-Flashover of Alumina in Vacuum (진공 중에서 알루미나의 플래쉬오버)

  • Choi, Yong-Sung;Lee, Kyung-Sup
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.06a
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    • pp.375-376
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    • 2008
  • The flashover of insulators in vacuum is the main factor to limit the performance of insulation in vacuum insulation system. It is believed that the pre-flashover phenomena would play a very important role in the procedure of the flashover in the interface between the insulators and vacuum. This paper is mainly concerned on the pre-flashover phenomena of Alumina insulators in vacuum. There are 24 different types of alumina insulators were tested with a 0.7/4 ${\mu}s$ pulsed voltage under a $1\times10^{-4}$Pa vacuum. The observed pre-flashover phenomena were classified and the pre-flashover characteristics were concluded. It is useful to study further on the flashover mechanism in vacuum.

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Treatment Efficacy on Oral Malodor according to Pre-treatment Volatile Sulfur Compound Level (구취의 심도에 따른 치료 효과에 대한 비교 연구)

  • 이상구;고홍섭;이승우
    • Journal of Oral Medicine and Pain
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    • v.23 no.3
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    • pp.263-270
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    • 1998
  • Considering various factors contributing oral malodor, the accurate prediction of prognosis is very important to both clinician and patients. The present study has been performed to invetigate the relationship between treatment effeicacy and pre-treatment volatile sulfur compounds (VSC) level. Ninety patients were divided into three groups, A(<150ppb), B(150< <200ppb), and C(>200ppb) groups, according to pre-treatment VSC level detected by Halimeter, and each group included 30 patients. Routine therapeutic measures for oral were provided to each patient which consisted of oral prophylaxis, tooth brushing and flossing instruction, tongue scraping by proper device, and gargling of 0.25% ZnCl2 Solution. The group with high pre-treatment VSC level (>150ppb) showed significant reduction of VSC level at 1 and 3 weeks after. However, the group with low pre-treatment VSC level (<150ppb) did not show any significant reduction during the experimental periods. Collectively, the results suggested that patients with high pre-treatment VSC level show better prognosis.

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A Wafer Pre-Alignment System Using One Image of a Whole Wafer (하나의 웨이퍼 전체 영상을 이용한 웨이퍼 Pre-Alignment 시스템)

  • Koo, Ja-Myoung;Cho, Tai-Hoon
    • Journal of the Semiconductor & Display Technology
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    • v.9 no.3
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    • pp.47-51
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    • 2010
  • This paper presents a wafer pre-alignment system which is improved using the image of the entire wafer area. In the previous method, image acquisition for wafer takes about 80% of total pre-alignment time. The proposed system uses only one image of entire wafer area via a high-resolution CMOS camera, and so image acquisition accounts for nearly 1% of total process time. The larger FOV(field of view) to use the image of the entire wafer area worsen camera lens distortion. A camera calibration using high order polynomials is used for accurate lens distortion correction. And template matching is used to find a correct notch's position. The performance of the proposed system was demonstrated by experiments of wafer center alignment and notch alignment.

A Lifestyle Communication Tool: Association of E-cigarette Use and Pre-diabetes

  • Nilanga Aki Bandara;Tanisha Vallani;Xuan Randy Zhou;Senara Hansini Palihawadane;Rochelle Gamage;Miles Mannas;Jay Herath
    • Journal of Preventive Medicine and Public Health
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    • v.56 no.4
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    • pp.384-387
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    • 2023
  • The aim of this study was to present a framework for clinicians to use when discussing electronic cigarette (e-cigarette) use and its association with pre-diabetes. A communication tool was designed using evidence-based strategies from the academic literature. A four-step framework is presented, which includes: step (1) helping patients to understand the association between e-cigarette use and pre-diabetes; step (2) the synergistic health impacts of e-cigarette use and pre-diabetes; step (3) management of diabetes-related lifestyle factors; and step (4) stages of change assessment related to e-cigarette reduction. This communication tool provides support for clinicians to discuss the risk of pre-diabetes associated with e-cigarette use. Moving forward, implementation and evaluation of this model are needed.

Optimal Phase of Dynamic Computed Tomography for Reliable Size Measurement of Metastatic Neuroendocrine Tumors of the Liver: Comparison between Pre- and Post-Contrast Phases

  • Huh, Jimi;Park, Jisuk;Kim, Kyung Won;Kim, Hyoung Jung;Lee, Jong Seok;Lee, Jong Hwa;Jeong, Yoong Ki;Shinagare, Atul B.;Ramaiya, Nikhil H.
    • Korean Journal of Radiology
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    • v.19 no.6
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    • pp.1066-1076
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    • 2018
  • Objective: The reliability of size measurements of liver metastases from neuroendocrine tumors (NETs) on contrast-enhanced computed tomography (CT) phases made by different readers may be hampered due to transient, variable rim enhancement in arterial phase (AP) or portal venous phase (PVP) images. We aimed to assess the reliability of tumor size measurements in pre- and post-contrast scans. Materials and Methods: The study coordinator selected target lesions according to Response Evaluation Criteria in Solid Tumors 1.1 guidelines in 44 consecutive patients with pathologically confirmed NET liver metastases. Two blinded readers measured the longest diameters of target lesions on pre-contrast, AP, and PVP images twice with a 4-week interval. Inter- and intra-observer agreements were evaluated using Bland-Altman plots and 95% limit of agreement (LOA) calculations. Results: Of the 79 target lesions (approximate mean size of 3 cm), 45 showed rim enhancement. Inter-observer agreement assessed based on LOA was highest in pre-contrast CT images (-6.1-5.7 mm), followed by PVP (-7.9-7.1 mm) and AP (-8.5-7.4 mm) images. Intra-observer agreement showed the same trend: -2.8-2.9 mm and -2.9-2.9 mm for readers 1 and 2, respectively, on pre-contrast CT, -2.8-2.9 mm and -3.0-3.2 mm, respectively, on PVP, and -3.2-4.2 mm and -3.4-3.2 mm, respectively, on AP images. Mean tumor diameters differed significantly among the phases in the following increasing order: pre-contrast CT, PVP, and AP images. Conclusion: There was better inter- and intra-observer agreement in size measurements of NET liver metastases on pre-contrast scans than on AP and PVP scans. Pre-contrast CT may be the optimal for measuring NET liver metastases if its accuracy is proven.

Different Mechanisms of Induced Systemic Resistance and Systemic Acquired Resistance Against Colletotrichum orbiculare on the Leaves of Cucumber Plants

  • Jeun, Yong-Chull;Park, Kyung-Seok;Kim, Choong-Hoe
    • Mycobiology
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    • v.29 no.1
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    • pp.19-26
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    • 2001
  • Defense mechanisms against anthracnose disease caused by Colletotrichum orbiculare on the leaf surface of cucumber plants after pre-treatment with plant growth promoting rhizobacteria(PGPR), amino salicylic acid(ASA) or C. orbiculare were compared using a fluorescence microscope. Induced systemic resistance was mediated by the pre-inoculation in the root system with PGPR strain Bacillus amylolquefaciens EXTN-1 that showed direct antifungal activity to C. gloeosporioides and C. orbiculare. Also, systemic acquired resistance was triggered by the pre-treatments on the bottom leaves with amino salicylic acid or conidial suspension of C. orbiculare. The protection values on the leaves expressing SAR were higher compared to those expressing ISR. After pre-inoculation with PGPR strains no change of the plants was found in phenotype, while necrosis or hypersensitive reaction(HR) was observed on the leaves of plants pre-treated with ASA or the pathogen. After challenge inoculation, inhibition of fungal growth was observed on the leaves expressing both ISR and SAR. HR was frequently observed at the penetration sites of both resistance-expressing leaves. Appressorium formation was dramatically reduced on the leaves of plants pre-treated with ASA, whereas EXTN-1 did not suppress the appressorium formation. ASA also more strongly inhibited the conidial germination than EXTN-1. Conversely, EXTN-1 significantly increased the frequency of callose formation at the penetration sites, but ASA did not. The defense mechanisms induced by C. orbiculare were similar to those by ASA. Based on these results it is suggested that resistance mechanisms on the leaf surface was different between on the cucumber leaves expressing ISR and SAR, resulting in the different protection values.

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Quality Characteristics and Quantification of Acetaldehyde and Methanol in Apple Wine Fermentation by Various Pre-Treatments of Mash

  • Won, Seon Yi;Seo, Jae Soon;Kwak, Han Sub;Lee, Youngseung;Kim, Misook;Shim, Hyoung-Seok;Jeong, Yoonhwa
    • Preventive Nutrition and Food Science
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    • v.20 no.4
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    • pp.292-297
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    • 2015
  • The objective of this study was to compare the effects of adding lactic acid and pectinase, and chaptalization for the quality of apple wine and the production of hazardous compounds (methanol and acetaldehyde). The pH of all of the samples was below 4; therefore, mash seemed to be fermented without any issue. Total acidity was the highest in sample A due to lactic acid addition. Pre-treated groups (samples B, C, and D) showed higher total acidities than that of the control (P<0.05). Pre-treatments might influence the production of organic acids in apple wines. The control and pectinase added sample (sample B) had the lowest alcohol contents. Adding lactic acid produced more alcohol, and chaptalized samples produced more alcohol due to the addition of sugar. Adding pectinase with and without chaptalization was not effective for producing more alcohol. The control sample had significantly higher acetaldehyde content (2.39 mg/L) than the other samples (1.00~2.07 mg/L); therefore, pre-treatments for apple wine fermentation produced a lower amount of acetaldehyde. Among the pre-treated samples, samples C and D showed the lowest acetaldehyde content of 1.00 mg/L and 1.16 mg/L, respectively. On the other hand, a significantly higher amount of methanol was generated for sample A (1.03 mg/L) and sample D (1.22 mg/L) than that of the control (0.82 mg/L) (P<0.05). Adding lactic acid or chaptalization was effective in reducing methanol and acetaldehyde in apple wines.

Properties of Natural Dyeing of Bast Fiber(Part 2) Pre mordanting dyeing of sappan wood, gardenia and gallnut (인피섬유의 천연염색 및 염색성(제 2보) 소목, 치자, 오배자의 선매염 염색)

  • Park, Myung-Ox;Yoon, Seung-Lak
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.4
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    • pp.1-14
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    • 2010
  • To investigate natural dyeing properties of bast fiber, properties of pre mordanting dyeing of sappan wood, gardenia and gallnut such as K/S values, developed color, and fastness were evaluated. Silk showed the most increased K/S values by pre mordanting treatment when Fe was uses as a mordant. The optimized amount of Fe was 3%. The colors of sappan wood was a series of YR. After pre mordanting treatment with Fe, the colors of bast fiber of mulberry and silk showed a series of RP, and the color of cotton showed a series of Y. The color of gallnut was a series of Y regardless of pre mordant treatment. Sappon wood (YR), gardenia (Y), and gallnut (Y) showed various colors such as YR, R, and RP, respectively. Sunlight fastness was not improved by pre mordanting treatment. The effect of pre mordanting treatment was not good. Especially the treatment with Al showed poor sunlight fastness.

Effects of Therapeutic Play Program on the Pre-operative Anxiety of the Preschooler (치료적 놀이 프로그램이 학령전 아동의 수술 전 불안에 미치는 효과)

  • Kim, Jong-Sun
    • Korean Parent-Child Health Journal
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    • v.12 no.2
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    • pp.119-130
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    • 2009
  • Purpose: This study was designed to examine the effects of Therapeutic Play Program on the pre-operative anxiety of the preschoolers. The design of this study is a quasi experimental study of non-equivalent control group pre-test/post-test design. Method: The subjects of this study were the hospitalized preschoolers receiving an operation in C University Hospital. These totalled 60 and were divided into a 30-person-control-group and a 30-person-experimental-group. The data was collected from June 1 to October 5, 2002. The Experimental treatment was carried out according to Therapeutic Play Program developed by Researcher. The instruments used in this study were the observational records for Hospitalized preschooler's Anxiety behavior response, pulse rate, and respiration rate of the preschooler's. The collected data were analyzed with real numbers, percentage, t-test, and $X^2$-test, using SPSS WIN 11.0 program. Result: Hypothesis, "The experimental group provided with a Therapeutic Play Program would show a lower score of the pre-operative anxiety behavior(t=13.79, p=.00), pre-operative pulse(t=4.50, p=.00) and pre-operative respiration rate(t=4.29, p=.00) response than when the control group was not provided", was supported. Conclusion: Therapeutic Play Program is determined to be useful for reducing Pre-operative anxiety of the preschoolers.

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CONSTRAINTS ON PRE-INFLATION COSMOLOGY AND DARK FLOW

  • MATHEWS, GRANT J.;LAN, N.Q.;KAJINO, T.
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.309-313
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    • 2015
  • If the present universe is slightly open then pre-inflation curvature would appear as a cosmic dark-flow component of the CMB dipole moment. We summarize current cosmological constraints on this cosmic dark flow and analyze the possible constraints on parameters characterizing the pre-inflating universe in an inflation model with a present-day very slightly open ${\Lambda}CDM$ cosmology. We employ an analytic model to show that for a broad class of inflation-generating effective potentials, the simple requirement that the observed dipole moment represents the pre-inflation curvature as it enters the horizon allows one to set upper and lower limits on the magnitude and wavelength scale of pre-inflation fluctuations in the inflaton field and the curvature parameter of the pre-inflation universe, as a function of the fraction of the total initial energy density in the inflaton field. We estimate that if the current CMB dipole is a universal dark flow (or if it is near the upper limit set by the Planck Collaboration) then the present constraints on ${\Lambda}CDM$ cosmological parameters imply rather small curvature ${\Omega}_k{\sim}0.1$ for the pre-inflating universe for a broad range of the fraction of the total energy in the inflaton field at the onset of inflation. Such small pre-inflation curvature might be indicative of open-inflation models in which there are two epochs of inflation.