• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.232-239
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• 2009

Statements of the problem: Many denture wearers occasionally use denture adhesives to improve denture retention, stability and chewing efficiency. An ideal denture adhesive is nontoxic, non-irritating, and provides comfort to the oral mucosa. Purpose: The purpose of this study was to evaluate the cytotoxicity and adhesive properties of a selected denture adhesive. Material and methods: To test cytotoxicity of the selected denture adhesive, mouse fibroblast cells were used in MTT testing. Cytotoxicity was examined according to the concentration of the denture adhesive and incubated for 1 to 4 days. To examine adhesive property, a denture base was fabricated on an edentulous dentiform. The adhesive was applied to the denture base, then tensile bond strength was measured, to evaluate the change in retention during 3 days. Results and Conclusion: 1. 1% and 2% concentration denture adhesive cream had no cytotoxicity. 2. The tensile bond strength of the group with both denture adhesive and artificial saliva was significantly higher than that of the group with only denture adhesive(P<.05). The tensile bond strength of the group with denture adhesive was significantly higher than that of with only artificial saliva(P<.05). 3. The tensile bond strength had no significant change during 1 hour, and then gradually decreased. After 1 day, it decrease to half. Within the limitation of this study, the tested denture adhesive had no cytotoxicilty and was effective in improving denture retention. The adhesive strength began to continuously decrease after 1 hour and it decreased to half at 1 day after application.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.1
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• pp.94-131
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• 2007

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2004 and 2005 has been done. Focus has been put on current status of research in the aspect of heating, cooling, air-conditioning, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD and flow visualization(PIV, PTV and LDV methods) technologies were widely applied for developing facilities and their systems. (2) The research trends of the previous two yews are surveyed as groups of natural convection, forced convection, electronic cooling, heat transfer enhancement, frosting and defrosting, thermal properties, etc. New research topics introduced include natural convection heat transfer enhancement using nanofluid, supercritical cooling performance or oil miscibility of $CO_2$, enthalpy heat exchanger for heat recovery, heat transfer enhancement in a plate heat exchanger using fluid resonance. (3) The literature for the last two years($2004{\sim}2005$) is reviewed in the areas of heat pump, ice and water storage, cycle analysis and reused energy including geothermal, solar and unused energy). The research on cycle analysis and experiments for $CO_2$ was extensively carried out to replace the Ozone depleting and global warming refrigerants such as HFC and HCFC refrigerants. From the year of 2005, the Gas Engine Heat Pump(GHP) has been paid attention from the viewpoint of the gas cooling application. The heat pipe was focused on the performance improvement by the parametric analysis and the heat recovery applications. The storage systems were studied on the performance enhancement of the storage tank and cost analysis for heating and cooling applications. In the area of unused energy, the hybrid systems were extensively introduced and the life cycle cost analysis(LCCA) for the unused energy systems was also intensively carried out. (4) Recent studies of various refrigeration and air-conditioning systems have focused on the system performance and efficiency enhancement. Heat transfer characteristics during evaporation and condensation are investigated for several tube shapes and of alternative refrigerants including carbon dioxide. Efficiency of various compressors and expansion devices are also dealt with for better modeling and, in particular, performance improvement. Thermoelectric module and cooling systems are analyzed theoretically and experimentally. (5) According to the review of recent studies on ventilation systems, an appropriate ventilation systems including machenical and natural are required to satisfied the level of IAQ. Also, an recent studies on air-conditioning and absorption refrigeration systems, it has mainly focused on distribution and dehumidification of indoor air to improve the performance were carried out. (6) Based on a review of recent studies on indoor environment and building service systems, it is noticed that research issues have mainly focused on optimal thermal comfort, improvement of indoor air Quality and many innovative systems such as air-barrier type perimeter-less system with UFAC, radiant floor heating and cooling system and etc. New approaches are highlighted for improving indoor environmental condition as well as minimizing energy consumption, various activities of building control and operation strategy and energy performance analysis for economic evaluation.

• Journal of radiological science and technology
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• v.39 no.1
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• pp.51-57
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• 2016

Acoustic noise during magnetic resonance imaging (MRI) is the main source for patient discomfort. we report our preliminary experience with this technique in neuroimaging with regard to subjective and objective noise levels and image quality. 60 patients(29 males, 31 females, average age of 60.1) underwent routine brain MRI with 3.0 Tesla (MAGNETOM Tim Trio; Siemens, Germany) system and 12-channel head coil. Q-$T_2$ and $T_2$ sequence were performed. Measurement of sound pressure levels (SPL) and heart rate on Q-$T_2$ and $T_2$ was performed respectively. Quantitative analysis was carried out by measuring the SNR, CNR, and SIR values of Q-$T_2$, $T_2$ and a statistical analysis was performed using independent sample T-test. Qualitative analysis was evaluated by the eyes for the overall quality image of Q-$T_2$ and $T_2$. A 5-point evaluation scale was used, including excellent(5), good(4), fair(3), poor(2), and unacceptable(1). The average noise and peak noise decreased by $15dB_A$ and $10dB_A$ on $T_2$ and Q-$T_2$ test. Also, the average value of heartbeat rate was lower in Q-$T_2$ for 120 seconds in each test, but there was no statistical significance. The quantitative analysis showed that there was no significant difference between CNR and SIR, and there was a significant difference (p<0.05) as SNR had a lower average value on Q-$T_2$. According to the qualitative analysis, the overall quality image of 59 case $T_2$ and Q-$T_2$ was evaluated as excellent at 5 points, and 1 case was evaluated as good at 4 points due to a motion artifact. Q-$T_2$ is a promising technique for acoustic noise reduction and improved patient comfort.

• Journal of Christian Education in Korea
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• v.67
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• pp.195-227
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• 2021

In a situation where it is difficult to plan face-to-face worship or assembly-type evangelism due to the continuation of the corona pandemic, it seems that evangelism is not a way to present the gospel, but to strengthen the gospel life. This is the era of evangelism as a spiritual care where the church can comfort those who are struggling and share the gospel naturally by accompanying them, and the time has come to set and practice various ministry directions that combine Christian education and counseling. At this time, this paper aims to analyze not only in the area of counseling, but also studies and papers on professional ministry through a convergence and complex approach between Christian education and counseling. This study focused on the papers on practical trials and cases. The research contents to be dealt with include the concept and understanding of counseling in Christian education, the application of counseling as various Christian education methods, and the development of programs necessary for the field. In addition, the purpose of this study is to analyze what kind of trend characteristics the subjects developed in advance show, what kind of trend characteristics research methodologies were used in the preceding studies, and what are the issues and tasks of Christian education and counseling based on the subject and method analysis. This study aims to analyze various influences on Korean society by meta-analyzing the discourse and issues of Christian education and counseling developed in the field of Christian education in Korea and suggest the convergence and direction of counseling in the field of Christian education in the future. First, many studies should be conducted to lay a systematic and clearer theoretical foundation for the convergence and complex approach of Christian education and counseling. Second, various studies on the understanding and psychological evaluation of learners based on psychology should be conducted. Finally, research on various counseling techniques should be conducted in Christian education counseling, and in particular, various studies on the application and practice of Christian education counseling using basic counseling theory should be conducted. The author also hope that studies on effectiveness verification based on utilization cases will be actively carried out to develop counseling programs that can help our neighbors who are struggling during the coronavirus era and provide direction for Christian education counseling.

• Journal of agricultural medicine and community health
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• v.47 no.3
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• pp.166-180
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• 2022

Objective: This study evaluated the effects of a non-face-to-face obesity management program, implemented during the pandemic. Methods: The non-face-to-face obesity management program used the Intervention mapping protocol (IMP). The program was put into effect over the course of eight weeks, from September 14 to November 13, 2020 in 48 overweight and obese adults, who applied to participate through the Daegu Citizen Health Support Center. Results: IMP was first a needs assessment was conducted; second, goal setting for behavior change was established; third, evidence-based selection of arbitration method and performance strategy was performed; fourth, program design and validation; fifth, the program was run; and sixth, the results were evaluated. The average weight after participation in the program was reduced by 1.2kg, average WC decreased by 3cm, and average BMI decreased by 0.8kg/m² (p<0.05). The results of the health behavior survey showed a positive improvement in lifestyle factors, including average daily intake calories, fruit intake, and time spent in walking exercise before and after participation in the program. A statistically significant difference was seen (p<0.05). The satisfaction level for program process evaluation was high, at 4.57±0.63 point. Conclusion: The non-face-to-face obesity management program was useful for obesity management for adults in communities, as it enables individual counseling by experts and active participation through self-body measurement and recording without restriction by time and place. However, the program had some restrictions on participation that may relate to the age of the subject, such as skill and comfort in using a mobile app.