• Journal of Korean Neurosurgical Society
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• v.50 no.1
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• pp.54-56
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• 2011

Ankylosing spondylitis (AS) is frequently associated with inflammatory lesions of the spine and continuous fatigue stress fractures; however, an association with an intraspinal synovial cyst has not been previously reported. A 55-year-old man with a five year history of AS who presented with back pain and a right radiculopathy was admitted to the hospital. Five years previously, he underwent a percutaneous vertebroplasty for an osteoporotic L1 compression fracture, and was diagnosed with AS at that time. Plain radiographs showed aggravated kyphosis and a stress fracture through the ossified posterior element, below the prior vertebroplasty. Magnetic resonance images revealed a right foraminal cystic lesion at the L2-L3 level with effacement of the nerve root. A 1.6 cm cystic lesion that appeared to arise from the L2-L3 facet joint without direct communication was excised from the L2-L3 foramen. Pathological examination confirmed synovial cyst. The patient's symptoms resolved immediately after surgery except for a mild dysesthesia of the right leg. We report herein a rare case of foraminal synovial cyst associated with AS accompanying posterior element fracture with a review of literature.

• Biomedical Science Letters
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• v.13 no.4
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• pp.355-360
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• 2007

In order to evaluate on the cytotoxicity of methyl mercury (MM) and antioxidant effect of phenolic compound, poncirin against MM-induced cytotoxicity, XTT assay was performed to determine the cell viability after human skin fibroblasts (Detroit 51) were grown in the media containing various concentrations of methylmercuric chloride (MMC). And also, the antioxidant effect of poncirin on the cytotoxicity induced by MMC was examined by cell viability and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity in these cultures. MMC decreased cell viability in dose-dependent manner in these cultures and the midcytotoxicity value was determined at concentration of 30 ${\mu}M$ MMC after human skin fibroblasts were treated with $10\sim50{\mu}M$ MMC for 72 hours, respectively. MMC was highly toxic on cultured human skin fibroblasts by toxic criteria. MMC-mediated cytotoxicity was related with oxidative stress by the diminution of toxic effect according to the treatment of vitamin E. In the antioxidant effect of poncirin, it showed vitamin E-like DPPH radical scavenging activity at 90 ${\mu}g/ml$ poncirin and also, remarkably increased cell viability compared with MMC-treated group. From these results, it is suggested that MMC-mediated cytoxicity was highly toxic and was related with oxidative stress in cultured human skin fibroblasts, and also phenolic compound such as poncirin showed the protection on MMC-induced cytotoxicity by antioxidant effect in these cultures.

• Journal of Korea Foundry Society
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• v.32 no.1
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• pp.32-37
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• 2012

In this study, microstructural evaluation was carried out on secondary hardening type ultrahigh strength steel, Fe-Co-Ni composition. This paper as a first part of whole research presented the microstructural behavior by cyclic heat treatment. The cyclic heat treatment method includes normalizing, stress relieving, solution treatment and aging. Especially, solution treatments performed triple times to get maximized solution hardening. Phase transformation and microstructure were observed by using optical microscope (OM), Electron back-scattered diffraction (EBSD) and X-ray stress analyzer. During the triple solution treatment, size of grain boundary was dramatically decreased by generating a packet from the martensite transformation of residual austenite in the inner part of grain, whereas the hardness increase was not significant.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.47-52
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• 2014

Background: This case study is to describe the manual therapy for the patient with posttraumatic stress (PTSD), sleep disturbance, and pain such as chronic low back pain (CLBP). Methods: The patient who participated in this study was a 60 year-old male PTSD patient with CLBP. His CLBP is not from any genetic or family history but a sequelae of torture that he had gone through about 30 years ago. Prior to the intervention, it was assessed that the PDS-K score was 16, PQSI-K was 12, SLR-90-R was low, VAS score was 10, and KODI socre was 25. The intervention was conducted through manual therapy (myofascial release, muscle energy technique, lumbar stabilization) twice a week for eight weeks in total. Results: After eight week-intervention, the PDS-K, SLR-90-R, VAS, and KODI score were improved whereas PQSI-K was not sufficiently fast improved. Conclusions: The manual therapy is substantially effective in dealing with PTSD and CLBP.

• Composites Research
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• v.13 no.4
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• pp.75-82
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• 2000

A small diameter steel-ball impact experiment was performed to study the impact resistance of the surface of glass plates bonded with glass fabric/epoxy lamina. Five kinds of materials were used in this study: soda-lime glass plates, glass/epoxy lamina(one layer)-bonded and unbonded glass plates, glass/epoxy lamina(three layers)-bonded and unbonded glass plates. The range of impact velocity was 40 120m/s. The maximum stress and absorbed fracture energy were measured on the back surface of glass plates. With increasing impact velocity, various types of surface cracks such as ring, cone, radial and lateral cracks took place in the interior near the impacted site of glass plates. The cracks drastically decreased with glass/epoxy lamina coating. The surface fracture behavior could be evaluated using the maximum stress and the absorbed fracture energy.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.06a
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• pp.1-11
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• 2001

This Paper presents the result of a parametric study on the behavior of stiffened grid reinforced segmental wall resting on non-yielding foundation. The parametric study was conducted using the nonlinear finite element analysis. In the finite element analysis, the step by step construction of the wall such as backfill, block reinforcement, block/backfill and soil/reinforcement interfaces were carefully modeled. The mechanical behavior of stiffened grid reinforced segmental walls was then investigated based on the result of analysis with emphasis on the effect of reinforcement stiffness on the behavior of the wall. The results of analysis indicate that the horizontal wall displacement decrease; with increasing the reinforcement stiffness at a decreasing rate, and that the horizontal stress at the back of the reinforced soil block does not much vary with the reinforcement stiffness. It is also revealed that the calculated maximum vertical stress at the base of the reinforced soil block agrees well with that based on the Meyerhof distribution and that the reinforcement and the connection force are considerably smaller than what might be expected based on the current design assumptions. The implications of the findings from this study to current design approaches were discussed in detail.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.3
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• pp.115-124
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• 2003

In this study, the relationships between the displacement and stress of the tunnel using various analysis methods were compared with monitoring results carried out during construction and maintenance monitoring. The behavior of tunnel were measured in the subway tunnel passing comparative soft the weathering and analyzed both security and mechanical characteristics of the tunnel lining. With the results of simplified monitoring observed in top heading and bench excavation tunnel, it is confirmed that the crown settlement is larger than the surface settlement. it is interesting to note that the crown settlement and the crown shotcrete lining stress are widely used monitoring items for the back analysis. It is analyzed that the residual water pressure applied in the drainage type tunnel is reasonable.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.8 s.185
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• pp.154-162
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• 2006

By laying its drum horizontally, front-loaded washing machine mostly used in Europe that uses the head of the water to launder was appropriate for washing only small amount of laundry. However, the demands of customers are requiring front-loaded washing machine to handle big capacity laundry as well, and have faster rotation speed to increase drying ability. To meet such demands, more stress from bending and twisting are complexly loaded onto the shaft supporting the horizontal drum, causing problems in fracture strength and fatigue life. Shafting system is mainly divided into flange and shaft. Flange is located between the drum and shaft, transferring power from the shaft to drum, and acting as a supporter of the back of the drum. Shaft is connected from the flange to insert production, transferring power from the motor to drum, and mainly acting as stiffness against the horizontal weight of the shafting system. In this paper, strength analysis and experiment were executed on both the shaft and flange of front-loaded washing machine to suggest the design improvement of shafting system for big capacity, high-rotation drying. Also, verification of this evaluation was executed on fracture strength and fatigue life for studied shaft system.

• The Journal of Internal Korean Medicine
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• v.22 no.2
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• pp.207-213
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• 2001

Objectives : In order to study the clinical efficiency of Dohwatang, based on Oriental Medical References, using experimental animals, we studied ulcers, gastric juice secretion, free acidity, total acidity, and the action of transport rates in the intestine. Methods : We used rats administered with the above herbs. Results : Dohwa-tang showed remarkable inhibitory effects on peptic ulcers, gastric juice secretion, free acidity, and total acidity in pyloricligated rat. It also showed remarkable inhibitory effects on the transportability in the large intestine of rats. But Dohwa-tang didn't show any remarkable difference on stressed rats. Conclusions : Dohwatang works better for chronic pyloristenosis-peptic ulcer and for diarrhea than acute stress ulcer.

• Geomechanics and Engineering
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• v.13 no.5
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• pp.881-892
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• 2017

Design and management of concrete slabs in concrete-faced rock-fill dams are crucial issues for stability and overall dam safety since cracks in the concrete face induced by stress, shrinkage, and deterioration can cause severe leakage from the reservoir into the dam. Especially, the increase of dam height to a certain level to enhance the storage capacity and to improve hydraulic stability can lead to undesirable deformation behavior and stress distribution in the existing dam body and in the concrete slabs. In such conditions, simulation of a concrete slab with a numerical method should involve the use of an interface element because the behavior of the concrete slab does not follow the behavior of the dam body when the dam body settles due to the increase of dam height. However, the interfacial properties between the dam body and the concrete slab have yet to be clearly defined. In this study, construction sequence of a 125 m high CFRD in South Korea is simulated with commercial FDM software. The proper interfacial properties of the concrete slab are estimated based on a comparison to monitored vertical displacement history obtained from the concrete slab. Possibility of shear strength failure under the critical condition is investigated based on the simplified model. Results present the significance of the interfacial properties of the concrete slab.