• Bulletin of the Korean Chemical Society
• /
• v.30 no.3
• /
• pp.667-670
• /
• 2009

The understanding of behaviors of hydroperoxyl/superoxide anion radicals (${H_2O_2}^./{O_2}^{-.}$) generated from a photoirradiated $TiO_2$ surface is essential to improve the efficiency of $TiO_2$ photocatalytic reactions by decreasing the recombination of photoinduced electron-hole ($e^--h^+$) pairs. In contrast with previous studies, we found that ${H_2O_2}^./{O_2}^{-.}$ generated on the surface of illuminated $TiO_2$ particles are mobile. ${H_2O_2}^./{O_2}^{-.}$ formed by the photocatalysis of $TiO_2$ particles immobilized onto the inner surface of a coil-quartz tube were forced under a continuous flow through a knotted tubing reactor (KTR) and into the aqueous phase completely separated from the $TiO_2$ particles, and were measured by a chemiluminescence (CL) technique using 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[ 1,2-a]pyrazin-3-one (MCLA) as the reagent. The initial concentration of the ${H_2O_2}^./{O_2}^{-.}$ stream entering the KTR was determined by its half-life (98 s) at pH 5.8. We suggests that the efficiency of $TiO_2$ photocatalytic reactions may be further improved by utilizing the mobility of ${H_2O_2}^./{O_2}^{-.}$.

• Korean Journal of Plant Taxonomy
• /
• v.38 no.3
• /
• pp.251-270
• /
• 2008

Members of the genus Asarum of Korea were reviewed taxonomically, and classified into seven species. Among them, four species - A. koreanum, A. maculatum, A. patens and A. versicolor - were recorded as Korean endemics. The most valuable taxonomic characters in identifying the Asarum taxa were shape, size and color of the calyx tube and lobe. In addition, the presence of white spots on the adaxial surface, size and color of leaf, presence of trichome, shape and size of the stylar protuberance and thickness of the calyx lobe were also important characters. Keys to the species including descriptions and figures of floral structures of each taxon were provided here for the accurate identification of each species.

• Journal of Biomedical Engineering Research
• /
• v.22 no.6
• /
• pp.479-486
• /
• 2001

Spirometer is a medical equipment which diagnoses respiratory function by measuring 9as volume across Patient's lunes through airway. Because a little overdose of anesthesia medicine can take away Patient's life in the ventilator for a surgical operation. an exact measurement of respiring volume is very important. This Paper Presented an exact flow volume calculation method from factors having an influence on measurement and introduced a spirometry system for an anesthesia ventilato. This system, using differential Pressure sensor measured flow by mutual relation with Pressure. temperature. gas density and linearization from the 2nd order characteristics of differential pressure with flow.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.11 no.4
• /
• pp.58-67
• /
• 2003

An automotive engine cooling system is closely related with overall engine performances, such as reduction of fuel consumption, decrease of air pollution, and increase of engine life. Because of complex reaction between each component, the direct experiment, using a vehicle, takes high cost, long time, and slow response to the system change. Therefore, a computer simulation would provide the designer with an inexpensive and effective tool for design, development, and optimization of the engine cooling system over a wide range of operating conditions. In this work, it has been predicted the thermal performance of the engine cooling system in cases of stationary mode, constant speed mode, and city-drive mode by mathematical modelling of each component and numerical analysis. The components are engine, radiator, heater, thermostat, water pump, and cooling fans. Since the engine model is the most important, that is divided into eight sub-sections. The volume mean temperature of eight sub-sections are simultaneously calculated at a time. For detail calculation, the radiator and heater are also divided into many sub-sections like control volumes in finite difference method. Each sub-section is assumed to consist of three parts, coolant, tube with fin, and air. Hence it has been developed the simulation program that can be used in case of design and system configuration changes. The overall performance results obtained by the program were desirable and the time-traced tendencies of the results agreed fairly well with those of actual situations.

• Journal of Chest Surgery
• /
• v.40 no.9
• /
• pp.651-654
• /
• 2007

Tracheoinnominate artery fistula (TIF) is a very rare complication that can happen after long standing tracheostomy or insertion of an endotracheal tube and its mortality is very high. This condition requires early diagnosis and urgent management because of the life threatening results from tracheal obstruction or hypovolemic shock that is caused by massive bleeding. We report here on a case of successful tracheoplasty with using the costal cartilage, including the perichondrium, in a patient with laryngeal stricture, and this was done to preserve the trachea for the following operation to relieve the laryngeal stricture.

• Animal Systematics, Evolution and Diversity
• /
• v.19 no.1
• /
• pp.111-117
• /
• 2003

Some hydromedusae were collected from Shiwhaho (Kyonsgi-do), Korea Strait and Yeosu, Korea during years 2000-2002. They were identified into Sorsia tubulosa (M. Sars, 1835) of the order Anthomedusae, and Liriope tetraphylla (Chamisso and Eysenhardt, 1821) of the order Trachymedusae respectively. They are new to the Korean fauna. The order Trachymedusae is first recorded in Korea. The long tube-like manubrium and four marginal tentacles are characteristics of S. tubuloso. In L. tetraphylla, the four triangle-shaped gonads and their positions upon half of surface of subumbrella, the seven blind centripetal canals in a quadrant and the long fat manubrium are its distinct characteristics. Resulting from this work, the Korean hydromedusae identified so far consist of 13 species of 11 families in five orders.

• Journal of Fashion Business
• /
• v.22 no.5
• /
• pp.52-63
• /
• 2018

The purpose of this study was to explore and understand why and how elementary school students do their makeup. An interview with 13 sixth grade female students attending an elementary school in Seoul was conducted to identify the reasons, learning routes, and purchasing patterns related to their makeup purchase and use. The results of this qualitative analysis showed that the girls were influenced to start wearing makeup by friends or family members, such as sisters and mothers. The students thought that their faces were ugly before they did makeup. They thought they became more beautiful and they were pleased after makeup. Elementary school students mostly reported that they used sunscreen, sun cushion with a whitening function, and lip tint. Some students also used a concealer to cover their flaws. They learned the methods of makeup by watching YouTube videos and from friends. They showed different purchasing patterns depending on the type of cosmetics they buy. They reported that their parents often bought their basic cosmetics such as lotions, and creams, while they tend to use their own money to purchase cosmetics for makeup.

• Journal of Home Health Care Nursing
• /
• v.26 no.2
• /
• pp.180-188
• /
• 2019

Purpose: To investigate the duration of each nursing activity performed by home care nurses for non-cancer patients and the relationship between patients' palliative prognostic index (PPI) and duration of each nursing activity. Methods: Nursing activities performed for six non-cancer terminal patients were timed using a stopwatch, and 18 parameters were measured by visiting each patient thrice. The mean and standard deviations of duration for each category of nursing activities were computed. The relationship between category-specific duration of nursing activities and PPI was analyzed with Spearman's correlation and multiple regression analysis. Results: Among nursing activities, the highest greatest duration of time was spent on traffic time (11.91 min), followed by urinary catheter management (10.65 min) and insertion and management of nasogastric tube (9.03 min). In terms of nursing categories, after excluding movement time, the greatest duration of time was spent on excretion care (5.48 min), nutrition care (5.40 min), and medication (3.82 min). PPI correlated with hygiene care, excretion care, and patient and information management. Multiple regression analysis revealed that PPI increased with increasing duration of hygiene care. Conclusion: These study findings provide grounds for the increased nursing time of hygiene care for people reaching the end of life.

• Journal of Korean society of Dental Hygiene
• /
• v.21 no.1
• /
• pp.65-76
• /
• 2021

Objectives: In an aging society, the demand for dental medical institutions among the elderly is increasing. There will be an increased demand for high-quality oral health services. Therefore, the purpose of this study was to investigate factors influencing attitudes toward the elderly of Generation Z dental hygiene students. Methods: The participants in this study were 198 dental hygiene students. The survey was conducted from June 1 to 30, 2020, using a structured questionnaire. The questionnaire consisted of knowledge (24 items), attitude (20 items), and experience (11 items) of the elderly. The collection data were compared and analyzed using analysis of variance and multiple regression. Results: Factors influencing attitudes toward the elderly of dental hygiene students appeared positive in those with a lot of experience and higher knowledge of social area, in case of one grade. However, the attitude toward the elderly appears negative in those with a low knowledge of physical area. Conclusions: In order to improve Generation Z dental hygiene students' attitudes towards the elderly, it is necessary to develop a course related to the elderly and a program related to high-quality elderly contact experience opportunities. Socially, it is necessary to promote healthy elderly life through internet broadcasting and YouTube.

• Journal of Information Technology Applications and Management
• /
• v.29 no.1
• /
• pp.59-70
• /
• 2022

Recently, in platforms such as YouTube and Instagram, virtual characters resembling human life become the main characters, produce various contents, breathe with the public, and create the era of virtual humans. For example, existing game characters appear as virtual characters with unique AUs, or AI characters created by reflecting the public's preferences are actively communicating with the public through advertisements and SNS activities. As the consumption of video content through smart devices increases significantly in the post-corona era, virtual influencers are being used as all-round entertainers because there is little risk of personality controversy or production cost. there is a trend In this study, we investigated the characteristics of the case of being active as an influencer among the activities of a virtual character, and how the interactive aspect of the influencer appears by identifying the current situation through major cases. Combining this, based on the analysis of the influence of virtual influencers, the parts that producers should recognize are derived, and the differentiated characteristics of interactive virtual influencers are summarized. In addition, the difficulties of virtual influencers were investigated and problems were identified, and for the development of the content industry, a more favorable method for interaction was presented and suggestions were made to secure inner sincerity.