• Journal of the Korean Society of Safety
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• v.29 no.4
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• pp.34-41
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• 2014

The goal of this study is to investigate some crack behaviors which affect the crack propagation angle at the planar solid oxide fuel cell with cracks under the fabricating and operating temperature and analyze the stresses by 3 steps processing on the solid oxide fuel cell. Currently, there are lots of researches of the performance improvement for fuel cells, and also for the more powerful efficiency. However, the planar solid oxide fuel cell has demerits which the electrode materials have much brittle properties and the thermal condition during the operating process. It brings some problems which have lower reliability owing to the deformation and cracks from the thermal expansion differences between the electrolyte, cathode and anode electrodes. Especially the crack in the corner of the electrodes gives rise to the fracture and deterioration of the fuel cells. Thus it is important to evaluate the behavior of the cracks in the solid oxide fuel cell for the performance and safety operation. From the results, we showed the stress distributions from the cathode to the anode and the effects of the edge crack in the electrolyte and the slant crack in the anode. Futhermore the crack propagation angle was expected according to the crack length and slant angle and the variation of the stress intensity factors for the each fracture mode was shown.

• Analytical Science and Technology
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• v.26 no.3
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• pp.190-198
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• 2013

Ambers have been used mostly as beads, jewelry and ornaments from ancient times and excavated as a buried artifact. When excavated, they are severely weathered to be cracked, exfoliated and disintegrated. Monitoring of changes in composition of amber according to weathering is very important for diagnosing the condition of amber and applying conservation materials and techniques. In this study, we tried to find the components of amber by analyzing amber with pyrolysis/GC/MS. The changes in the composition of pyrolzates after artificial ageing for 60 days under heat and oxygen were also observed. Abietic acid was detected as a main component of fresh amber and monoterpene, alkene, aromatic hydrocarbon were detected as major pyrolyzates. Changes with artificial ageing was estimated by comparing the peak area ratio of 23 components, and it was found that abietic acid abruptly decreased in the presence of heat and oxygen together, revealing that oxygen is a key factor to the deterioration of amber. It was also tried to understand the weathered surface of original amber gemstone based on the result of this ageing experiment.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.197-204
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• 2004

The temporary power installations are to be used for temporarily supplying power during work at construction sites and have a minimum of protective devices to differ from permanent installations. There are many risk factors caused by loose working environments, deterioration of installations at construction sites. To analyze risk factors of temporary power installations, the investigation and the questionnaire were carried out side by side for power receiving system patch and panel boards, and were performed by researcher, the related expert, engineer of Korea Electrical Safety Corporation all over the country. The objects were variable such as an airport, an apartment, a municipal playground As a result, there are many problems such as a bad lock, poor protection of charging department. Solvable methods are improvement of the related regulation safety education, safety check and so on. In the future, the analytical data can be applied to prevent the electrical shock at construction site, and can be used to stabilize electrical installations.

• Mycobiology
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• v.45 no.4
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• pp.240-254
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• 2017

Cereal grains are the most important food source for humans. As the global population continues to grow exponentially, the need for the enhanced yield and minimal loss of agricultural crops, mainly cereal grains, is increasing. In general, harvested grains are stored for specific time periods to guarantee their continuous supply throughout the year. During storage, economic losses due to reduction in quality and quantity of grains can become very significant. Grain loss is usually the result of its deterioration due to fungal contamination that can occur from preharvest to postharvest stages. The deleterious fungi can be classified based on predominance at different stages of crop growth and harvest that are affected by environmental factors such as water activity ($a_w$) and eco-physiological requirements. These fungi include species such as those belonging to the genera Aspergillus and Penicillium that can produce mycotoxins harmful to animals and humans. The grain type and condition, environment, and biological factors can also influence the occurrence and predominance of mycotoxigenic fungi in stored grains. The main environmental factors influencing grain fungi and mycotoxins are temperature and $a_w$. This review discusses the effects of temperature and $a_w$ on fungal growth and mycotoxin production in stored grains. The focus is on the occurrence and optimum and minimum growth requirements for grain fungi and mycotoxin production. The environmental influence on aflatoxin production and hypothesized mechanisms of its molecular suppression in response to environmental changes are also discussed. In addition, the use of controlled or modified atmosphere as an environmentally safe alternative to harmful agricultural chemicals is discussed and recommended future research issues are highlighted.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.3
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• pp.66-70
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• 2009

Paper cultural heritages usually experienced the chemical and the physical deterioration because of various factors including preservation environment and the property of their materials. General restoration technology for paper cultural heritages is the lining. The application of the lining paper and the lining technology has varied depending on researcher's experiences. Therefore, each lining material and technology must be evaluated to develop a standard guide for preservation and restoration of paper cultural heritages. To date, various analysis techniques using lining paper, in terms of their materials, have been applied to analyses of causes and condition of damages, but it is difficult to develop a standard restoration treatment method of paper cultural heritages because it varies by their material. The Hanf, is made frrr the mulberry, is generally used for the lining in Korea.edt is required that the cr, in terms properties and general properties of Hanf, is used for lining papers, are evaluated to develop a standard guide for their restoration.ed this study, the general properties of several lining papers(Hanf), especially dimensave bility, were evaluated as part of the standardization of lining papers. The result have varied depending on the pulping chemical and the manufacturers. the basis weight, thickness and tensale strength of lining papers is bigger the paper treated by natural ash than the paper treated by sodium carbonate.ed case of formation, folding endurance, and dimensave bility, the paper treated by sodium carbonate showed better properties than those of the paper treated by natural ash.

• The Journal of Internal Korean Medicine
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• v.41 no.3
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• pp.494-501
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• 2020

Objectives: Insomnia is a common condition that causes deterioration of cognitive function and physical function and has a negative impact on quality of life. Insomnia is experienced by more than one-third of the population of the world. Although sleeping pills are currently used as therapeutic agents, they have side effects, so safer treatment methods are needed. Therefore, we report a case of an outpatient who sleeps only one hour a day due to insomnia. Methods: The patient visited Korean Medicine Hospital 10 times for four weeks and was treated with Korean medicine therapies, including electroacupuncture on the back-Shu points and herbal medicine (Yukmijihwang-tang and Hwangnyeonhaedok-tang). Treatment progress was assessed using the Pittsburgh Sleep Quality Index (PSQI) and the Insomnia Severity Index (ISI). Results: After 29 days of treatment, the PSQI score decreased from 20 points and 14 points. The ISI score also decreased to decreased to 22 points from 26 points. The average daily sleeping time increased from 60 minutes to 197.1 minutes after treatment. No significant side effects were observed. Conclusions: Yukmijihwang-tang and Hwangnyeonhaedok-tang with electroacupuncture might be a recommended therapeutic option for insomnia patients.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.3231-3239
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• 2014

After 1970-80's rapid economic and urban development, nowadays the old downtown suffers from the deterioration of physical environment, outflow of its function and cavitation of population. And this phenomenon makes urban regeneration as a new paradigm in urban development. This is the case of Myeongdong area (Jungang-dong, Monsung-dong), old downtown of Cheonan around rail station, in the same way. City government has tried many regeneration/ redevelopment projects on this area but all failed due to lack of feasibility. This study intends to suggest new viable strategic regeneration scheme of this area through research and analysis of TOD development, existing condition and problems. As a result, the area needs to be considered as a node that links bus terminal complex and central market place with walkable street. For regeneration of this area, a strategic development scheme of this area is suggested deploying private capital invested rail station, underground shopping mall, transfer center, culture complex and nature park with Myeongdong street mall.

• Journal of Korean Neurosurgical Society
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• v.39 no.4
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• pp.281-285
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• 2006

Objective : The tethered cord syndrome results in progressive neurological deficits. Although it may remain controversial, many physicians recommend definitive surgery to untether the cord as soon as this condition is identified. We retrospectively evaluate the pre-operative and post-operative course of 38 tethered cord patients with spinal dysraphism in an attempt to learn the natural history of the disease and to determine the effectiveness of the surgical treatment. Methods : The medical records, operation notes and radiographs were evaluated. The follow up period ranged from 4 months to 12 years with a mean follow-up of 28.6 months. Twenty-seven patients were younger than 15 years of age. Results : At presentation, 26 of the patients were asymptomatic. In three of 11 adult symptomatic patients, their neurological deficits worsened after trauma or exercise. Improvement of motor strength was documented in two out of 5 patients. Five of nine patients with bladder symptoms improved, however, none had a complete return of their bladder function. Conclusion : Childhood patients were less symptomatic than the adult patients. Adult patients showed progression of their symptoms that were not improved even after the operation in most of the cases. Asymptomatic tethered spinal cord can be symptomatic as time passes by and even at an old age. Future research should be focused on the operative methods to prevent the delayed deterioration after surgery, rather than on the usefulness of preventive surgery in asymptomatic patients.

• Research in Community and Public Health Nursing
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• v.32 no.3
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• pp.312-324
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• 2021

Purpose: Tuberculosis is an infectious condition with a high disease burden, and the stigma in patients with tuberculosis causes negative health outcomes. The purpose of this study was to define and clarify the concept of self-stigma among patients with tuberculosis. Methods: The analysis was conducted using Walker and Avant's conceptual approach. Twenty-seven studies met the selection criteria. Results: Self-stigma in patients with tuberculosis can be defined by the following attributes: 1) self-esteem decrement; 2) fear; 3) negative emotions to oneself; 4) social withdrawal; and 5) discrimination. The antecedents identified were 1) inappropriate knowledge of tuberculosis, 2) spread of improper health information through media and social communications, 3) stereotypes and prejudices, 4) visibility due to symptoms appearing, 5) recognizing the risk of infection, and 6) low financial status. The consequences were 1) concealing the disease, 2) treatment delay, 3) poor treatment adherence, 4) poor quality of life, and 5) deterioration in or lack of social activities. Conclusion: The definition and attributes of self-stigma identified by this study can be applied to enhance the understanding of stigma in tuberculosis patients and to improve communications between healthcare providers and researchers. It can also be used to develop theories and measurements related to stigma in patients with tuberculosis.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.2
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• pp.121-130
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• 2019

Glutamate toxicity-mediated mitochondrial dysfunction and neuronal cell death are involved in the pathogenesis of several neurodegenerative diseases as well as acute brain ischemia/stroke. In this study, we investigated the neuroprotective mechanism of dieckol (DEK), one of the phlorotannins isolated from the marine brown alga Ecklonia cava, against glutamate toxicity. Primary cortical neurons ($100{\mu}M$, 24 h) and HT22 neurons (5 mM, 12 h) were stimulated with glutamate to induce glutamate toxic condition. The results demonstrated that DEK treatment significantly increased cell viability in a dose-dependent manner ($1-50{\mu}M$) and recovered morphological deterioration in glutamate-stimulated neurons. In addition, DEK strongly attenuated intracellular reactive oxygen species (ROS) levels, mitochondrial overload of $Ca^{2+}$ and ROS, mitochondrial membrane potential (${\Delta}{\Psi}_m$) disruption, adenine triphosphate depletion. DEK showed free radical scavenging activity in the cell-free system. Furthermore, DEK enhanced protein expression of heme oxygenase-1 (HO-1), an important anti-oxidant enzyme, via the nuclear translocation of nuclear factor-like 2 (Nrf2). Taken together, we conclude that DEK exerts neuroprotective activities against glutamate toxicity through its direct free radical scavenging property and the Nrf-2/HO-1 pathway activation.