• Nuclear Engineering and Technology
• /
• v.31 no.5
• /
• pp.506-511
• /
• 1999

The pilot system for radioactive liquid laundry waste was developed with treatment capacity, 1ton/hr and set up in the Yong Kwang unit #4. The system is composed of tank module, RO systems and a UV/$H_2O$$_2$photo-oxidation unit. The RO system consists of the BW unit (low-pressure RO for brackish water desalination) and the SW unit (high-pressure RO for seawater desalination). The BW unit possesses 4 RO membranes and it can reduce the feed water volume down to 1/10. This concentrated feed water can be reduced again up to 1/10 in its volume in the SW unit composed of 4 RO membranes. The UV/$H_2O$$_2$ photo-oxidation process unit was used for the detergent degradation. The operation of the pilot system was carried out and verified in its capability through the continuous operation and concentration operation using the actual liquid waste from the power plant. The design criteria and data for industrialization were yielded. The efficiency of the UV/$H_2O$$_2$ photo-oxidation process and the optimum operational procedure were evaluated. The decontamination factors for radioactive cobalt and cesium were measured. This on-site test showed the experimental result in the DF$\geq$300 and volume reduction factor$\geq$100.

• The Journal of Korean Physical Therapy
• /
• v.14 no.2
• /
• pp.234-249
• /
• 2002

This study was performed, using c-fos and Substance P, to investigate the effect of GaAlAs laser on acute pain model induced by wound in lumbar region's spinal level. The test group was divided into control and experimental group. Control group is shamed group(c-fos and substance P expression after non-irradiation by a GaAlAs laser), The experimental group was divided into two subgroups: one is experimental group I (c-fos expression after irradiation by a GaAlAs laser), and the other is experimental group II (substance P expression after irradiation by a GaAlAs laser). The results of this study were as following: 1. The numbers of c-fos immunoreactive neuron in spinal cord was increased markedly 1 day after wound, and decreased gradually from 1 day to 2 days in wound with GaAlAs laser irradiation. 2. The changes of the average percentages of substance P immunoreactive neurons in spinal cord was increased markedly 1 day after wound, and decreased gradually from 1 day to 2 days in wound with GaAlAs laser irradiation. Therefore, decreasing the changes of c-fos and substance P expression after irradiation by a GaAlAs laser indicates and GaAlAs laser have effect on pain control.

• Korean Journal of Materials Research
• /
• v.21 no.11
• /
• pp.592-595
• /
• 2011

It is well known that modified 9Cr-1Mo steel has a low thermal expansion and high thermal conductivity with excellent high temperature properties compared to austenitic stainless steel. For these advantages, the steel is very popular for the boiler tube of thermal power plants. Normalizing is commonly utilized to obtain martensite in this steel, which shows an unusual toughness for martensite. However, some accidents related to this steel have been reported recently, opening the necessity for further study. As a particular behavior of the steel, an abrupt drop of the impact value has been identified upon tempering at 750$^{\circ}C$ for about 1 hour. It is well known that $Fe_3C$ forms during autotempering and turns to $Cr_2C$ at an early stage and then transforms to $Cr_{23}C_6$. In this study, the cause of the abrupt drop of the impact value was investigated with an impact test, microstructural observation, nanodiffraction and phase analyses using instruments such as optical and transmission electron microscopes (TEM) with an extraction carbon replica of the carbides. The analyses revealed that the $M_2C$ that formed when retained for about 1 hour at 750$^{\circ}C$ causes a drastic decrease in the mechanical properties. The sharp drop in mechanical properties, however, disappeared as the $M_2C$ transformed into $M_{23}C_6$ with longer retention.

• Journal of Ocean Engineering and Technology
• /
• v.30 no.5
• /
• pp.349-355
• /
• 2016

Divinycell, which functions as both insulation and a supporting structure, is generally applied in the NO96-type liquefied natural gas (LNG) insulation system. Polymer-material-based Divinycell, which has a high strength and low weight, has been widely used in the offshore, transportation, wind power generation, and civil engineering fields. In particular, this type of material receives attention as an insulation material because its thermal conductivity can be lowered depending on the ambient temperature. However, it is difficult to obtain research results for Divinycell, even though the component materials of the NO96-type LNG cargo containment system, such as 36% nickel steel (invar steel), plywood, perlite, and glass wool, have been extensively studied and reported. In the present study, temperature and strain-rate dependent compressive tests on Divinycell were performed. Both the quantitative experimental data and elastic recovery are discussed. Finally, the mechanical characteristics of Divinycell were compared to the results of polyurethane foam insulation material.

• Women's Health Nursing
• /
• v.16 no.2
• /
• pp.126-136
• /
• 2010

Purpose: This study was done to evaluate factors affecting active early detection behaviors of breast cancer and performance rate of breast self examination (BSE), physical examination and mammography. Methods: The participants were 264 women from an outpatient breast clinic of a university hospital and materials were collected from March 2007 to February 2008 using a structured questionnaire. The data were analyzed using $x^2$ test, logistic analysis. Results: The rate for BSE was 58.3%, for physical examination, 55.3% and for mammography experience, 63.4%. Women with all of these active early detection behaviors accounted for 31.8% of the participants. Various factors such as age, income, marital status, and menopause showed increased significant performance rate. The explanation power of logistic model was 48.5%, and was significant for age, income and health belief. Factors related to high performance rate were being over 40 years of age, high income and high health belief score. Conclusion: Active early detection behaviors were not high in spite of marked increases in breast cancer incidence. Encouragement for women practicing early detection behavior is important, but there is also a need to develop interest and support for the low performance group. More sustained education and public relations are needed to further improve active early detection behavior.

• Korean Journal of Occupational Health Nursing
• /
• v.28 no.4
• /
• pp.253-261
• /
• 2019

Purpose: This study aimed to identify the influence of job stress, compassion satisfaction, and resilience on depression of nurses. Methods: One hundred seventy six nurses working at one tertiary hospital in one metropolitan city were included. The data collection was conducted from September 1st to October 1st, 2018, using a structured, self-reported questionnaire. The collected data were analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression. Results: The $M{\pm}SD$ age of 170 subjects was $29.62{\pm}5.59$. Depression had significant negative correlations with compassion satisfaction (r=-.50, p<.001) and resilience (r=-.56, p<.001), and a positive correlation with job stress (r=.42, p<.001). In the multiple regression analysis, marital status (${\beta}=-.15$, p=.015), job stress (${\beta}=-.00$, p<.001) and resilience (${\beta}=-5.47$, p<.001) had a significant effect on depression. The explanatory power of the subject's marital status, leisure life, job stress, compassion satisfaction, and resilience on depression was 44.1% (F=27.62, p<.001). Conclusion: The study results showed that single status, low job stress, high resilience may decrease depression of nurses. Reducing job stress and improving resilience of nurses will virtually contribute to reduce their depression that can influence on not only nurses' health status but also their performance and qualitative caring for patients.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.14 no.5
• /
• pp.369-374
• /
• 2021

Apartment recently built in kitchen is made is made because the gas hose with built-in ways invisible inside the sink. In this case, if the gas leaks, it is a dangerous method that can accumulate inside the sink and lead to an explosion. In this study, since the hose connected between the gas range and the intermediate valve is inside the sink, it is not possible to test for gas leaks, so a valve system that can easily check for gas leaks using a pressure sensor was studied. As for the pressure measurement method, the pressure of the hose connecting the intermediate valve and the gas range was measured so that data could be collected and analyzed using the I2C communication method. In addition, the calculation of the gas pressure supplied to the home was investigated for the atmospheric pressure error for the value calculated by adding the average value of the gas gauge pressure of 22.46 mbar at the inlet of the gas meter to the atmospheric pressure. A valve system was developed to detect minute gas leaks.

• Journal of Korean society of Dental Hygiene
• /
• v.19 no.3
• /
• pp.437-448
• /
• 2019

Objectives: The purpose of this study was to suggest an effective instruction method for dental hygiene students by determining the degree of importance and satisfaction that they attach to the courses. Methods: Data obtained from a survey that was conducted on 654 dental hygiene students were analyzed. Statistical Package for the Social Sciences version 23.0 was used for the statistical analysis. A paired t-test was conducted to detect the differences between the degree of importance that the respondents attached to the courses and the degree of satisfaction they achieved. A comparative analysis of the two was performed using the IPA analysis. Results: Regarding the items, the respondents found the environment most important, followed by the content, method, perspective, and assessment. Regarding satisfaction, they were most satisfied with the environment, followed by the perspective, method, content, and assessment. Regarding the importance of ideal teaching, the respondents gave the highest priority to 'a class in which the core content is summarized, emphasized, and explained.' The satisfaction was the highest toward 'PowerPoint-based classes in which the core content is well-organized.' Based on the results of the IPA analysis, the respondents regarded 16 items as requiring maintenance and continuous efforts, 12 items as low priority, and 4 items as requiring excessive efforts and timely improvement. Conclusions: An ideal class requires the instructor to utilize various teaching methods that would enable the students to comprehend the detailed teaching content and elicit active interaction and feedback from the students through easy-to-understand lectures that are appropriate for students.

• The Journal of Korean Institute of Information Technology
• /
• v.16 no.12
• /
• pp.57-68
• /
• 2018

A system to prevent disasters by collecting and analyzing environmental information such as road surface sedimentation, sinkholes, collapse risk of bridges, temperature and humidity around tram station is continuously monitored by monitoring the condition of road surface when constructing tram which is one of the urban railways. In this paper, we propose a wireless network security management system for tram roads based on LPWA that can recognize risk factors of road surface, bridge and tram station of tram in advance and prevent risk. The proposed system consists of a sensor node that detects the state of the tram road surface, a gateway that collects sensor information, and a safety management system that monitors the safety and environmental conditions of the tram road surface, and applies the low power long distance communication technology. As a result of comparing the proposed system with the LTE system in the field test, it was confirmed that there is no significant difference between the sensor information value and the critical alarm level in the monitoring system.

• Design & Manufacturing
• /
• v.14 no.4
• /
• pp.71-77
• /
• 2020

Various manufacturing technologies, including over-molding and insert-injection molding, are used to produce hybrid plastics and metals. However, there are disadvantages to these technologies, as they require several steps in manufacturing and are limited to what can be reasonably achieved within the complexities of part geometry. This study aims to determine a practical approach for producing metal/plastic hybrid components by combining plastic injection molding and metal die casting to create a new hybrid metal/plastic molding process. The integrated metal/plastic hybrid injection molding process developed in this study uses the proven method of multi-component technology as a basis to combine plastic injection molding with metal die casting into one integrated process. In this study, the electrical conductivity and ampacity were verified to qualify the new process for the production of parts used in electronic devices. The electrical conductivity was measured, contacting both sides of the test sample with constant pressure, and the resistivity was measured using a micro ohmmeter. Also, the specific conductivity was subsequently calculated from the resistivity and contact surface of the conductor path. The ampacity defines the maximum amount of current a conductive path can carry before sustaining immediate or progressive deterioration. The manufactured hybrid multi-components were loaded with increasing currents, while the temperature was recorded with an infrared camera. To compare the measured infrared images, an electro-thermal simulation was conducted using commercial CAE software to predict the maximum temperature of the power loaded parts. Overall, during the injection molding process, it was demonstrated that multifunctional parts can be produced for electric and electronic applications.