• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.8 s.239
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• pp.927-933
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• 2005

Boiling heat transfer characteristics of liquid nitrogen in a stainless steel plain tube and wire coil inserted tubes were investigated. The test tubes, which had an inner diameter of 10.6 m and a length of 1.65 m, were horizontally located. Five wire coils having different pitch and thickness were inserted into the plain tube. The pitches of the wire coils were 18.4, 27.6, and 36.8 m, and the thickness was 1.5, 2.0, and 2.5 mm respectively. Tests were conducted at a saturation temperature of $-191^{\circ}$, mass fluxes from 58 to 105 kg/$m^2s$, and heat fluxes from 22.5 to 32.7 kw/$m^2$. A direct heating method was used to apply heat to the test section. The boiling heat transfer coefficients of liquid nitrogen were represented as a function of vapor quality, which showed significant drop at the dryout vapor quality. The maximum heat transfer enhancement using the wire coil inserted tubes over the plain tube was $174\%$ for 'Wire 3' having a thickness of 2.5 mm and a pitch of 18.4 mm.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.40 no.4
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• pp.59-65
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• 2008

Electrochemical properties of pulp fiber could be modified by LbL(Layer-by-Layer) multilayering. Salt concentration and pH affect the conformation and ionization degree of polyelectrolyte. In this study, therefore, we intended to evaluate the effect of pH and salt concentration in polyelectrolyte multilayering on the electrochemical properties of pulp fiber. The pH of the stock was varied to 4, 7, and 10. Salt concentration was controlled at 0.001, 0.003, and 0.005 M of NaCl. Higher zeta potential was obtained when pulp fibers were multilayered at the condition of higher pH and higher salt concentration. The final zeta potential of pulp fiber after multilayering was dependent on the adsorption ratio of polyelectrolyte and the initial zeta potential of fibers.

• The Journal of Korean Obstetrics and Gynecology
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• v.31 no.4
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• pp.188-196
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• 2018

Objectives: This study is to report the clinical effectiveness of the complex Korean medicine therapy on a postoperative endometriosis patient's hypoestrogenic side effects who is treated with GnRH-agonist injection. Methods: The patient in this case was diagnosed with endometriosis and has been treated with GnRH-a injection after laparoscopic operation. The patient complained hot flash and sweating mainly after GnRH-a treatment. The patient received complex Korean medicine therapy during 10 days admission period. The clinical effects were evaluated through KI (Kupperman's Index) and SF-36 (36 item Short Form Health Survey). Results: After the complex Korean medicine therapy, the various clinical symptoms including hot flash and sweating were improved. Also, the quality of life was enhanced. Conclusions: This case report shows that the complex Korean medicine therapy was effective for treating hypoestrogenic side effects occurred after GnRH-a treatment in postoperative endometriosis patient.

• Journal of the Korean Chemical Society
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• v.17 no.2
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• pp.130-135
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• 1973

The rate-constants of hydrolysis of 3, 4-methylenedioxyphenylmethylenemalononitrile are determined by ultraviolet spectrophotometry at various pH and a rate equation which can be applied over wide pH range is obtained. The rate equation reveals that below pH 5.0 and above pH 9.0, the hydrolysis is initiated by the addition of water and hydroxide ion respectively. However, at pH 6.0-8.0 the competitive addition of water and hydroxide ion occurs. The catalytic contribution of hydroxide ion and water can be fully explained by the rate equation obtained.

• The Journal of Korean Obstetrics and Gynecology
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• v.33 no.4
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• pp.1-22
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• 2020

Objectives: The purpose of this review is to evaluate the efficacy of moxibustion for stress urinary incontinence (SUI) in women. Methods: For relevant randomized controlled trials (RCTs), we searched the following databases from their inception to September 1, 2020: The Cochrane Library, PubMed, EMBASE, Chinese National Knowledge Infrastructure Database (CNKI), Koreanstudies Information Service System (KISS), Research Information Sharing Service (RISS), and National Digital Science Library (NDSL). The key search terms were 'stress urinary incontinence' and 'moxibustion'. Data extraction and assessment of risk of bias were conducted by two authors independently. Results: A total of 11 RCTs were finally included in this systematic review. In all studies, moxibustion treatment was applied as an adjuvant therapy to the conventional treatment, and the most common conventional treatment was pelvic floor muscle training (PFMT). The treatment group (conventional treatment plus moxibustion) showed statistically more significant effect than the control group (conventional treatment only) in various evaluation indicators including urinary incontinence frequency, 1 hour urine pad test, quality of life, the clinical efficacy rate, and pelvic muscle strength. Conclusions: In this study, we investigated the efficacy of moxibustion as an adjuvant therapy for female SUI patients. Further studies are needed to supplement the safety of moxibustion and the evaluation of moxibustion dose.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.29 no.5
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• pp.213-219
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• 2017

This study investigated the thermal conductivity of $CO_2$ gas mixtures in order to ascertain the effects of particular impurities in $CO_2$ in pipeline transportation. We predicted the thermal conductivity of three $CO_2$ gas mixtures ($CO_2+N_2$, $CO_2+H_2S$, and $CO_2+CH_4$) by utilizing three different methods : Chung et al., TRAPP, and the REFPROP model. We validated predictions by comparing the estimated results with 216 experimental data for $CO_2+CH_4$, $CO_2+N_2$, and $CO_2+C_2H_6$. Following $CO_2$ transportation conditions, we observed that the model developed by Chung et al. showed the lowest mean deviation of 3.07%. Further investigations were carried out on the thermal conductivity of $CO_2$ gas mixtures based on the Chung et al. model including the effects of the operation parameters of pressure, temperature, and mole fraction of impurities.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.254-261
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• 2004

Traditionally, electrical power systems had formed the vertically integrated industry structures based on the economics of scale. However, power systems have been recently reformed to increase their energy efficiency. According to these trends, the Korean power industry underwent partial reorganization and competition in the generation market was initiated in 2001. In competitive electric markets, accurate load data is one of the most important issues to maintaining flexibility in the electric markets as well as reliability in the power systems. In practice, the measuring load data can be uncertain because of mechanical trouble, communication jamming, and other issues. To obtain reliable load data, an efficient evaluation technique to adjust the missing load data is required. This paper analyzes the load pattern of historical real data and then the tuned ARIMA (Autoregressive Integrated Moving Average), PCHIP (Piecewise Cubic Interpolation) and Branch & Bound method are applied to seek the missing parameters. The proposed method is tested under a variety of conditions and also tested against historical measured data from the Korea Energy Management Corporation (KEMCO).

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.199-202
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• 2014

The bioconversion of cellulosic biomass hydrolyzates consisting mainly of glucose and xylose requires the use of engineered Saccharomyces cerevisiae expressing a heterologous xylose pathway. However, there is concern that a fungal xylose pathway consisting of NADPH-specific xylose reductase (XR) and $NAD^+$-specific xylitol dehydrogenase (XDH) may result in a cellular redox imbalance. However, the glycerol biosynthesis and glycerol degradation pathways of S. cerevisiae, termed here as the glycerol cycle, has the potential to balance the cofactor requirements for xylose metabolism, as it produces NADPH by consuming NADH at the expense of one mole of ATP. Therefore, this study tested if the glycerol cycle could improve the xylose metabolism of engineered S. cerevisiae by cofactor balancing, as predicted by an in-silico analysis using elementary flux mode (EFM). When the GPD1 gene, the first step of the glycerol cycle, was overexpressed in the XR/XDH-expressing S. cerevisiae, the glycerol production significantly increased, while the xylitol and ethanol yields became negligible. The reduced xylitol yield suggests that enough $NAD^+$ was supplied for XDH by the glycerol cycle. However, the GPD1 overexpression completely shifted the carbon flux from ethanol to glycerol. Thus, moderate expression of GPD1 may be necessary to achieve improved ethanol production through the cofactor balancing.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.3
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• pp.10-22
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• 2021

Purpose: This study aims to be used as a reference for setting the direction of university major education & policy. Research design, data and methodology: The satisfaction survey were nine major curriculum surveys for each college, targeting students enrolled in a university. One university consisted of 9 colleges and 49 departments or majors. The survey period is approximately one month. Results: The highest item in the major curriculum reflects the educational goal of the department, with a score of 3.95. Conversely, the lowest item is 3.65 points, indicating that the major curriculum offers a wide range of subjects to choose from. As the questions are higher than the average score (3.83 points), the major curriculum is helping me grow my competency through academic achievement (3.90 points), the major curriculum is helping me set my career and finding a job (3.88 points), The major curriculum suggests specific performance standards for judging the achievement of a set target competency (3.88 points), and the major curriculum reflects social demands and changes (3.85 points). Conclusions: Students want that their major education faithfully reflects the educational goals of their major and that major education helps their ability to grow for academic achievement.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.4
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• pp.537-548
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• 2020

Currently, radioactive waste for disposal has been restricted to low and intermediate level radioactive waste generated during operation of nuclear power plants, and these radioactive wastes were managed and disposed of the 200 L and 320 L of steel drums. However, it is expected that it will be difficult to manage a large amount of decommissioning waste of the Kori unit 1 with the existing drums and transportation containers. Accordingly, the KORAD is currently developing various and large-sized containers for packaging, transportation, and disposal of decommissioning waste. In this study, the radiation exposure doses of workers and the public were evaluated using RADTRAN computational analysis code in case of the domestic on-road transportation of new package and transportation containers under development. The results were compared with the domestic annual dose limit. In addition, the sensitivity of the expected exposure dose according to the change in the leakage rate of radionuclides in the waste packaging was evaluated. As a result of the evaluation, it was confirmed that the exposure dose under normal and accident condition was less than the domestic annual exposure dose limit. However, in the case of a number of loading and unloading operations, working systems should be prepared to reduce the exposure of workers.