• Food Science and Biotechnology
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• v.18 no.3
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• pp.579-585
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• 2009

Solid-phase microextraction (SPME) has gained widespread acceptance in sample pretreatment due to its solvent-free and easy-to-operate properties. SPME fibers are considered as a key part of SPME technique, since it primarily determines the extraction performance of the method including sensitivity, selectivity, and reproducibility. Generally speaking, target analyte with different chemical property requires fiber coating that has the best affinity towards it. Due to the lack of varieties of commercial fibers available currently, considerable efforts have been recently made to develop tailor-made fibers to fulfill increasing demands of different analysis. This paper concisely classify some SPME fiber preparation approaches such as sol-gel technology, physical deposition, molecularly imprinted technique, and their respective application in food safety analysis.

• Nuclear Engineering and Technology
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• v.51 no.7
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• pp.1842-1852
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• 2019

The AP1000 reactor coolant pump is a vertical shielded-mixed flow pump, is the most important coolant power supply and energy exchange equipment in nuclear reactor primary circuit system, whose steadystate and transient performance affect the safety of the whole nuclear island. Moreover, safety demonstration of reactor coolant pump is the most important step to judge whether it can be practiced, among which software simulation is the first step of theoretical verification. This paper mainly introduces the fluid-solid coupling simulation method applied to reactor coolant pump, studying the feasibility of simulation results based on workbench fluid-solid coupling technology. The study found that: for the unsteady calculations of the pure liquid media, the average head of the reactor coolant pump with bidirectional fluid-solid coupling decreases to a certain extent. And the coupling result is closer to the real experimental value. The large stress and deformation of rotor under different flow conditions are mainly distributed on impeller and idler, and the stress concentration mainly occurs at the junction of front cover plate and blade outlet. Among the factors that affect the dynamic stress change of rotor, the pressure load takes a dominant position.

• Steel and Composite Structures
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• v.43 no.3
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• pp.353-362
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• 2022

Bridge fire hazard has become a growing concern over the last decade due to the rapid increase of ground transportation of hazardous materials and resulting fire incidents. The lack of fire safety provisions in steel bridges can be a significant issue owing steel thermal properties that lead to fast degradation of steel properties at elevated temperatures. Alternatively, the development of composite action between steel girders and concrete decks can increase the fire resistance of steel bridges and meet fire safety requirements in some applications. This paper reviews the fire problem in steel bridges and the fire behavior of composite steel-concrete bridge girders. A numerical model is developed to trace the fire response of a typical bridge girder and is validated using measurements from fire tests. The selected bridge girder is composed by a hot rolled steel section strengthened with bearing stiffeners at midspan and supports. A concrete slab sitting on the top of the girder is connected to the slab through shear studs to provide full composite action. The validated numerical model was used to investigate the fire resistance of real scale bridge girders and the effect of the composite action under different scenarios (standard and hydrocarbon fires). Results showed that composite action can significantly increase the fire resistance of steel bridge girders. Besides, fire severity played an important role in the fire behavior of composite girders and both factors should be taken into consideration in the design of steel bridges for fire safety.

• The Korean Journal of Emergency Medical Services
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• v.14 no.3
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• pp.57-69
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• 2010

Purpose: This study aims to examine perceived safety management in teachers working for young children with disabilities, to grasp the state and problems of safety management and first-aid education at daycare center for young children with disabilities, and to provide basic materials to develop programs for safety management and first-aid education. Results: 1. For the perception items of accident possibility in daycare centers, career with more than 10 years had higher response in 'very high' and 'moderately high' than 'moderately or very low' and statistically significant difference was found(p < .05). 2. For the perception items of accident prevention in daycare centers, no teaches with at least college education thought that 'it was not possible to prevent' and most of them thought that 'it was totally possible to prevent' and statistically significant difference was found(p < .05). 3. For the performance level of safety management and first-aid items, forty and over(4.73) showed higher than age of 20-29(4.32) and 30-39 of age(4.26) and statistically significant difference was found(p < .05). 4. For the knowledge level of safety management and first aid items, the highest religion was found as Christian(16.96), followed by Catholic(15.33), Buddhism(14.91), and no religion(15.81) and statistically significant difference was found(p < .05). 5. For the items of confidence in safety management and first aid, performance level, and knowledge level, teachers who competed safety management and first-aid education( 4,48) had higher performance score than those who did not (4.17) and statistically significant difference was found(p < .05). 6. For the items of confidence in safety management and first aid, performance level, and knowledge level, teachers who competed first-aid education(2.77) had higher confidence than those who did not(2.35) and statistically significant difference was found(p < .05). Conclusion: The results suggest that safety management and first-aid education in teachers working for daycare center for young children with disabilities was closely correlated with knowledge and performance levels. Thus, it is necessary to provide continuous safety management and first-aid education for teachers working for day care center for young children with disabilities through regular in-service training. Also further research should be conducted with all subjects and various regions who contact with young children with disabilities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.5
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• pp.717-733
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• 2019

In this study, lining thickness distribution and its behind state (particularly, its void state) were analyzed using the GPR survey data performed on three currently operating NATM tunnels. Results of GPR analysis showed that void areas were mostly detected between concrete lining and primary support, particularly, near the crown of the tunnels. The lining thickness in the left-hand side of the tunnel was different from that of the right-hand side by 8.6~253.5 mm when measured in transverse direction. It was also found that longitudinal cracks were prevailed in the area lining thickness was sharply changed. Longitudinal thickness distribution at the crown was also studied and tested by performing 3 goodness-of-fit tests in order to find the most suitable thickness distribution. Normal distribution (or similar distribution) fit most suitably to the measured data if the measured average thickness was larger than designed one; Gamma and/or Inverse Gauss distribution fit to the measured data reasonably well if the measured average thickness was less than the designed value of thickness. Since actual lining thickness can be a potential index when assessing the state and safety of the unreinforced NATM tunnel lining, measuring of the lining thickness with GPR survey might be needed rather than assuming the thickness is always constant and same with the designed value.

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.1
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• pp.115-126
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• 2008

Backgrounds: The objective of school zones was to define protective areas and to keep children vulnerable to traffic accidents from the risk. The current "Rules on the Designation and Management of School Zones" included provisions on the installation of traffic safety facilities and road facilities, but they were not sufficient for children's traffic safety and there were many difficulties in applying standards to the fields. Purposes: With these problems to be solved, the present study surveyed the current state of safety facilities in school footpaths and school zones around elementary schools and suggested plans to improve them. This study studied various factors like the physical environment and the safety facilities in the school zone. Methods: The present researcher visited four elementary schools selected for this study, and surveyed safety facilities in the school zones around the elementary schools using a schedule prepared by the researcher. Results: According to the results of the case study, all of the four schools were designated as school zones, but the designation appeared nominal without sufficient safety facilities that can ensure children's safety. Based on the results of the survey, suggestions were made to improve traffic facilities in school zones and school footpaths as well as safety guidance.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.39-48
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• 2013

Recently, the using of prefabricated temporary equipments is increasing in the industrial field because it can reduce the installation and dismantling period. The various types of prefabricated temporary equipments are manufacturing with various materials in domestic and overseas countries. However, those equipments should win the safety certificate according to the "Governmental Notification about Safety Certification" which regulate the member-based safety certification. It tends to cause over performance of temporary equipments because it couldn't consider structural benefit of the prefabricated products. As the result of this study, it is concluded that the establishment of new safety certification standard for the prefabricated temporary equipments is resonable and the movable scaffold is appropriate for those prefabricated temporary equipment. The movable scaffolds are using as single structure and cannot be expands horizontally. Other types of temporary equipments are using as complex structure which can freely expand horizontally according to the main structure. From the results of the study, the standard of vertical compression performance of prefabricated movable scaffolds should be more than double the performance of single main frame. Other test items of safety certification standard should be fixed when the Notification is amended. The prefabricated temporary equipments which are adopted for the safety standard on assembled structure should be used, moved and kept in assembled state and not separated discretionally. The establishment of new standard for the assembled structure based on this study leads to the development of various types of temporary equipments using structural efficiency of prefabricated structure.

• Journal of Fisheries and Marine Sciences Education
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• v.29 no.2
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• pp.343-353
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• 2017

Nursing students who are in clinical practices under the complicated medical environment to become competent practitioners can be exposed to a variety of dangerous situations. In particular, nursing students can experience stress and compromised safety because they have difficulty in prioritizing their tasks and lack confidence in clinical and interpersonal skills. The purpose of this study is to investigate the types and characteristics of nursing students' attitudes toward the safety of clinical practices, and improve their safety related to clinical practices. A total of 40 statements about the safety of clinical practices were applied to 37 nursing students. Collected data were analyzed with the PC QUANL program. The Perception of nursing students to the safety of clinical practices was categorized into three types: 'Pursuit of perfection in overwhelming state type', 'Perseverance Patience type' and 'Cover up-meeting expectation type'. The subjects related to the safety of clinical practices need to be developed within the curriculum of nursing departments by examining the Perception of nursing students to the safety of clinical practices. In addition, a sense of responsibility shared by nursing students, educators and practitioners needs to be enhanced to improve the safety of clinical practices.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.460-477
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• 1994

There is a direct and continuing challenge to food scientists. You can increase food safety for the world.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.171-180
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• 2009