• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.222-229
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• 2018

Objectives: The aim of this study was to evaluate gas concentrations such as oxygen in ginger storage tunnels, which are the causes of asphyxiation in confined spaces and suggest directions for safety and health management at ginger farms. Methods: Five farms in the Seosan and Taean areas which use underground ginger storage tunnels were chosen and examined with a walk-through survey and direct reading device for oxygen, hydrogen sulfide, ammonia, and carbon monoxide. Results: The oxygen concentration in the storage tunnels with no ventilation was found to be under 18% in summer, which may cause health effects. The concentration in those with ventilation was about 19%. The difference in temperature by measurement day had little effect on the concentration of oxygen. Conclusions: Even though some of farms had used compulsory ventilation systems, none of the farms visited possessed any direct reading device for oxygen. Warning systems using a direct reading device can be more effective, helpful, and required compared to ventilation, considering the difficulty and expense of periodical maintenance of ventilation systems and the fact that a farmer can be placed in danger when unaware of the malfunction of the ventilation system. In addition, a warning system may make farmers more cognitive of agricultural safety and health actions while a ventilation system can cause them to become passive and ignorant of workplace hazards.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.331-335
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• 2016

When a boating accident, such as a January number three, the customer's risk management issues emerged. Ships and accident risk in confined spaces such as risk management to locate the customer and dangers of probation is available. In this paper, aboard after consent to obtain information for customers to wrist to customers, webbing or portable device embedded in devices and Wireless sensor information Input was attached, disposable consumer information. Customer on board the ship setting for location analysis and positioning according to information communication protocol, ships, each customer's real-time location information on the screen, 3 the foundation of d customers on the floor Can be designed to inform. Threshold designed to reduce the error of the information to analyze the position in current position and errors. Also, to system attacks would control the situation of accident and emergency jaenanguk server with real-time information transmission of information outside the emergency during a disaster, search and Disaster relief to be possible.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.23-36
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• 2008

Polymer-clay nanocomposites, a novel organic-inorganic hybrid, attract much attention from both scientific fields and engineering fields due to their balanced improvements in mechanical properties as well as diffusion behaviors, including flame-retarding and barrier properties, with small amounts of clay. Preparation of polymer-clay nanocomposites, summarized as a process for uniform dispersion of hydrophilic layered clays in hydrophobic polymer matrixes, includes several technologies and scientific phenomena, such as surface-modifications of clay layers, physical properties of clays in liquids and dried states, polymer synthesis, polymer rheology, behaviors of polymer solutions/or monomers in the confined geometry, mechanical properties of polymers and clays. To comprehend complicated physical/chemical phenomena involved in the fabrication of nanocomposites, we reviewed physical properties of clays, structures of clays in nanocomposites, characterization of nanocomposites, the relation between morphology and physical property of nanocomposites, surveyed recent research trends, and then suggested a few strategies or methods for fabrication of nanocomposites reflecting future research directions.

• Journal of the Korean Society of Safety
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• v.36 no.1
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• pp.64-71
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• 2021

Experimental and analytical investigations are performed to explore the explosion characteristics of a hydrogen-air mixture in open atmosphere. A hydrogen-air mixture tent of total volume of 27 m³, with 40% hydrogen volume, is used to observe overpressure at a distance from the ignition source. Vapor cloud explosion analyses are performed using the TNO multi-energy model and Baker-Strehlow-Tang model. The results of these analyses are compared with experiment done from this study and references. The experimental results with and without obstacles indicate that the overpressure values measured at a distance of 4.5-21.5 m from the ignition source are about 9.4-3.6 kPa and 6.5-2 kPa, respectively. This implies that the overpressure with obstacles is approximately 1.7 times greater than that without obstacles. Analytical observation indicates that the results obtained with the Baker-Strehlow-Tang model with M_f = 0.2-0.35 are in good agreement with those of most of the previous studies, including that obtained from this study. Moreover, the TNO multi-energy model with a volume of 27 m³ well predicts the overpressure obtained from this study. Further studies should considered explosions in semi-confined spaces, which is more suitable for hydrogen refueling stations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5C
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• pp.303-312
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• 2006

This study is to evaluate the mechanical characteristics of flowable backfill and offer a guide line of mixture proportion based on soil types for constructing underground power utilities. Flowable backfill is known as soil-cement slurry, void fill, and controlled low-strength material(CLSM). The benefits of CLSM are reduced equipment costs, faster construction, re-excavation in the future, and the ability to place materials in confined spaces, which are narrow parts or perimeters of underground power cables nearly impossible for compaction. The flowable slurry mixed with 17 soils and 6 accelerated mixtures in the laboratory were evaluated for flowability and unconfined compressive strength to meet the target values of this study.

• Journal of the Korean Geotechnical Society
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• v.39 no.11
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• pp.63-70
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• 2023

Underground carbon dioxide (CO₂) storage emerges as a pivotal strategy for mitigating atmospheric CO₂ emissions and addressing global warming concerns. This study investigates techniques to optimize storage efficiency in aquifers, which stand out for their superior capacity compared to other geological layers. The focus is on the application of nonionic and anionic surfactants to enhance CO₂ storage efficiency within confined spaces. A specialized micromodel facilitating fluid flow observation was employed for the evaluation. Experimental results revealed a noteworthy minimum 40% increase in storage efficiency at the lowest injection rate when utilizing nonionic and anionic surfactants, in comparison to pure water injection. Interestingly, no significant variations in storage efficiency were observed based on the ionicity and concentration of the surfactants under investigation. These findings have implications for guiding the selection and concentration determination of surfactants in future underground CO₂ storage endeavors.

• Journal of Digital Convergence
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• v.11 no.12
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• pp.665-672
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• 2013

In radiology department, where patients with a variety of diseases receive their tests, there is a large possibility of cross contamination of nosocomial infection. Magnetic resonance imaging (MRI) tests take particularly more time than other tests do, which increases the possibility of being exposed to cross contamination. Therefore, this research examines the status of MRI equipment sterilization and investigates the bacterial distribution on head coils, which have the most frequent contact with patients, patient fixation blocks, and bores, which are confined spaces. The status of MRI equipment disinfection was examined by a survey targeting 150 employees, and the distribution of bacteria was measured in ten medical facilities. The result of bacterial distribution tests on MRI equipment showed various bacteria, including Staphylococcus, Acinetobacter, Sphingomona, Pantoea agglomeranss, Micrococcus, Bacillus, Saprophyticus, Brevundimona, and Myroidesspecies. The result of examining the stat us of MRI room disinfection showed that the disinfections of the head coil, block, and bore were implemented well, and the largest proportion was carried out once a day in the morning. The time and implementation of disinfection by the disinfection manager showed that they were implemented well when the manager was the MRI room examiner. The disinfection after examining a patient using an appropriate disinfectant is mandatory to prevent cross contamination.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.21 no.3
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• pp.240-248
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• 1999

To investigate the expression pattern of noncollagenous bone matrix proteins such as osteonectin(OSN), osteopontin(OPN) and osteocalcin(OSC) mRNA during bony healing procedure induced by guided bone regeneration method, we made artificial defects on bilateral femur of rats. Then induced bony healing by application of a nonabsorbable PTFE membrane in experimental sites and without its application in control sites for 3 weeks. The mRNA expression pattern at specimens obtained at 1, 2 and 3 weeks after operation was detected by in situ hybridization method using its antisense mRNA probes. The experimental sites revealed more rapid and favorable bony healing than control sites and new bone formation was limited within defected area by inhibitory activity of bone marrow cells. In experimental sites, the OSN and OSC mRNA were expressed strongly on osteoblasts of regenerating cortical bone at 1st week and on osteoblasts lining the trabecular bone in marrow space at 3rd week, whereas, in control sites, their expression were noted on osteoblasts lining the reactively formed sponge bones at 2nd and 3rd week. In addition, the OPN mRNA was expressed on osteoblasts and osteoclasts at sites of remodeling and osteocytes of remained trabecular bone of defected area in experimental sites and on macrophages at 1st week and osteoclasts at sites of remolding at 2nd and 3rd week in control sites. The above findings suggest that the more rapid and favorable bony healing might be induced by blocking of invading fibrous connective tissue into bony defects. And the earlier expression of OSN and OSC mRNA on osteoblasts of experimental sites suggest that the formation and resorption of regenerating bone was more rapidly progressed in confined spaces made by applicate membranes.

• Korean Institute of Interior Design Journal
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• v.20 no.3
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• pp.172-181
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• 2011

Many of penthouse apartments began to be built and distributed in Korea from the 2000s. However, we have a transformed definition from the international concept of penthouse. It seems that the penthouse apartments in Korea have a confined definition as a luxury and privileged house-we often find it out from advertisements of newly built apartments. In this thesis, therefore, it needs to make a clear and substantial definition of penthouse. And on the base of this definition, this study is intended to analyze planes of penthouse apartments which are distributed recently. It is in order to find out positive aspects of penthouse apartments and to make practical application of this analysis. The process of this study for plane-planning is as follows. Firstly, it is investigated and analyzed that external factors that have an effect on plane-planning such as locations and types of penthouse apartments. Secondly, an interior of penthouse apartments are divided into a private, public and outward area. And properties of each area through this research show the way of division and arrangement of plane. Thirdly, methods of connection between spaces is analyzed on the base of results of research for the way of partition. Finally, specific characters of penthouse apartments planning is derived from synthesis of research. In conclusion, analysis of plane-planning of penthouse apartments is summarized as follows. The majority of penthouse apartments is arranged to small portions of households and on higher stories in apartment which is situated around Han River or public parks. These external factors influence the plane-planning in both the interior and exterior way. For the exterior planning in space, it becomes important to design bays as many as possible in contact with outside in order to satisfy demands for fine prospects. It is also important to plan extra places naturally such as a terrace in order to provide virtual grounding. In the interior planning, a large size of interior induces to develop space for linking between each area, such as corridors or extra rooms. This makes it possible that the private area is linked to each other, at the same time it has its own distinctiveness according to its usage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.604-609
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• 2016

This study evaluated the long-term performance of RSR (Reinforced Subgrade for Railways) technology which increases the railway line capacity without the need for additional land. Its characteristics include the use of a short reinforcement with rigid wall, which make it possible to apply it in confined spaces. The 7m high and 40m long testbed employed to evaluate the long-term performance was designed and constructed near Jupo station on the Chang-hang line. This line, located close to a local bus route, had collapsed at the subgrade following heavy rainfall. The performance of the new type of subgrade was verified with long term measurements over a 2 year period including the surface and ground settlement, horizontal displacement of the wall, tensile strain of the reinforcement, and settlement of the rail top on the side track. Based on the results of the measurements made until now, we concluded that it had sufficient safety and serviceability for use as a railway subgrade. It is expected that RSR technology could be frequently used at sites which lack the necessary construction materials for an embankment and are located close to functional railway lines and boundaries, in order to settle civil complaints.