• International Journal of Aeronautical and Space Sciences
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• v.18 no.4
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• pp.807-815
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• 2017

For liquid rocket engine(LRE)-based space launch vehicles, longitudinal instability, often referred to as the pogo phenomenon in the literature is predicted. In the building block of system-level task, accurate dynamic modeling of a fluid-filled tank is an essential. This paper attempts to apply the virtual mass method that accounts for the interaction of the vehicle structure and the enclosed liquid oxygen to LOX-filled tanks. The virtual mass method is applied in a modal analysis considering the hydroelastic effect of the launch vehicle tank. This method involves an analysis of the fluid in the tank in the form of mass matrix. To verify the accuracy of this method, the experimental modal data of a small hemispherical tank is used. Finally, the virtual mass method is applied to a 1/8-scale space shuttle external tank. In addition, the LOX tank bottom pressure in the external tank model is estimated. The LOX tank bottom pressure is the factor required for the coupling of the LOX tank with the propulsion system. The small hemispherical tank analysis provides relatively accurate results, and the 1/8-scale space shuttle external tank provides reasonable results. The LOX tank bottom pressure is also similar to that in the numerical results of a previous analysis.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.247-251
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• 2007

To extend the shelf-life of spinach after harvest, we investigated the effect of various packaging methods and storage temperature. In case of polypropylene film package, there was no weight loss, but in non-package, remarkably weight loss occurred as storage period extended and storage temperature risen. Content of vitamin C was decreased rapidly at early stage of storage, and decrease of vitamin C in low temperature storage was lower than that of room temperature storage, but its large difference according to packaging method was not observed. In hunter's value on spinach, b value in room temperature storage was higher than that of low temperature storage. In terms of freshness, shelf-life of spinach by low temperature storage $(1{\sim}3^{\circ}C)$ after PP film packaging lasted 34 days, and that by room temperature storage $(10{\sim}15^{\circ}C)$ after PP film packaging lasted 8 days, but that by room temperature storage after non-packaging lasted 3 days.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.351-356
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• 1994

The stability of carotenoid extracts from ascidian, Halocynthia roretzi, tunics during heating and solvent storage was examined. After 4 hours of heating at $100^{\circ}C,\;10\%$ of total carotenoids was decomposed. The stability of carotenoid extracts were determined in 4 organic solvents. Stability was checked for 1, 2, and 4 weeks at room temperature($15{\pm}2^{\circ}C$), $4^{\circ}C$, and $-20^{\circ}C$ by measuring absorbance. B7(alloxanthin) and B10(halocynthiaxanthin) were more stable than the other carotenoid components. The stability of carotenoid extracts from ascidian tunic was dependent on storage temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.344-350
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• 1994

Seasonal and regional variation of carotenoid contents in the muscles and tunic of the cultured ascidian(Halocynthia roretzi) was investigated. Carotenoid contents of tunic(47.87 mg/100g wet base) was much higher than that of muscles(2.35mg/100g wet base). The carotenoid contents was increased from April to August and then decreased in September. A total of 13 components were separated from the carotenoids extracted from ascidian tunic. The carotenoids of ascidian tunic accounted for followed by those of alloxanthin($31.3\%$), halocynthiaxanthin($15.5\%$), diatoxanthin($11.9\%$), diadinochrome($11.6\%$), mytilo-xanthin($10.8\%$), and astaxanthin($7.8\%$).

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.367-383
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• 1995

The relationship between floristic composition and soil environmental factors was investigated in the forest vegetation of Mt. Mohu.The forest vegetation unit of the Mt. Mohu could be divided into three communities, Quercus mongolica community, Pinus densiflora community and Quercus variabilis community. There were two subcommunities in Quercus mongolica community, which were Rhododendron schlippcubachii subcommunity and Stephanandra incisa subcommunity. The Quercus mongolica community was distributed at the altitude of 600~900 m, Pinus densiflora and Quercus variabilis communities were distributed on south-west slope at the altitudes of 430~520 m and 400~500 m, respectively.The DBH class of dominant species in each community showed that Quercus mongolica had 9 individuals/a at 11~15 cm class, Quercus variabilis 5.6 individuals/a at 11~15 cm class, and Pinus densiflora 8 individuals/a at 16~20 cm class. Quercus mongolica. Quercus variabilis and Pinus densiflora communities showed a bell-shape distribution.The contents of organic matter and soil water, and cation exchange capacity of the soil increased and the pH decreased in proportion to increased altitude. The soil environmental conditions of Quercus mongolica community were more favorable than those of Pinus densiflora and Quercus variabilis communities.The supposed successional sere of the forest vegetation of Mt. Mohu was as follows: Pinus densiflora community.Quercus variabilis community.Quercus mongolica community

• Journal of Korean Medicine Rehabilitation
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• v.30 no.3
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• pp.103-116
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• 2020

Objectives This study was designed to review the effect of herbal medicine on animal model with rheumatoid arthritis. Methods We reviewed studies published both in Korea and overseas, all published after 2008. We investigated 8 databases, 6 Korean databases and 2 of abroad. Searching was conducted through flowchart and 24 studies met our guideline. Datas were extrated and organized as animal model characteristics, experimental period, study design, herbal medicine used as intervention and rheumatoid arthritis indicator. Results 336 articles were primarily selected. After screening, 24 articles were left in the end. All 24 studies showed that the herbal medicine used in the animal experiment was effective on treating rheumatoid arthris, proven by macroscopic, histological, hematological and osteological indicators. Conclusions The result showed that herbal medicine is effective in treating rheumatoid arthritis through various pathways. However, study design and intervention were all different from each other and we could not specify the certain compound, material or substance of efficacy. Further study should be conducted to figure out the effectiveness of herbal medicine on rheumatoid arthritis.

• The Journal of Korean Physical Therapy
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• v.22 no.3
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• pp.93-98
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• 2010

Purpose: To investigate temporal changes in IL-1${\beta}$ mRNA expression in spinal dorsal horn (DH) and dorsal root ganglion (DRG) in a rat lumbar disc herniation (LDH) model. Methods: Autologous nucleus pulposus, harvested from the tail disc between the second and third coccygeal vertebrae (Co2-3), was implanted next to the left L5 nerve root just proximal to the DRG after partial laminectomy. IL-1${\beta}$ mRNA expression was investigated in DRG and DH in our LDH model. Real-time PCR assays were done using a 7500 Real Time PCR system (Applied Biosystems, USA). Results: Expression of IL-1${\beta}$ in DRG and DH was observed for 30 days postoperatively. Expression of IL-1${\beta}$ mRNA in the ipsilateral DRG of the LDH group gradually increased from 5 to 30 days after surgery. The amount of IL-1${\beta}$ in the contralateral DRG peaked 10 days after surgery and then gradually decreased. However, there was no difference in IL-1${\beta}$ mRNA expression in spinal DH between the LDH group and the sham-operated group. Conclusion: Long-term expression of IL-1${\beta}$ in the LDH model may worsen the chronic pain state. Future studies on inhibition of IL-1${\beta}$ expression in the LDH model will be needed to develop selective treatment strategies for patients with LDH.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.904-908
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• 2008

As the various industrial production machinery has come into being by development of industrial technology, the productivity of the basic industrial production machinery has improved and the international competitiveness of the one of Korea has strengthened. However, at the same time, noise from various industrial production machinery disturbs the quiet environment. There are 35 kinds of the noise emission machinery defined in the noise and vibration control act according to the horse power and the number of machinery. These were classified in 1992 through investigation from 1990 to 1991, and the characteristic of the noise emission machinery may be different from the past one. So we need to investigate the characteristics of the noise emitted by machinery to control it rightly. Also we need to investigate the new noise emission machinery which has come into being recently. In this survey, we measured sound intensity of 32 noise emission machinery to calculate the sound power levels of those and investigated the characteristic of the sound power level of those according to the frequency. From the survey, we found that the forging machine, concrete pipe and pile making machine, sawing machine, etc. are the noisy machinery. And the automatic packing machine, sewing machine, centrifuge, etc. are the silent machinery. Also the generator, the concrete pipe and pile making machine, the printing machine, etc. emit the low frequency noise, and the molding machine, the stone cutter, the metal cutter, etc. emit the high frequency noise. Lastly, we intented to propose the proper guide line of classifying noise emission machinery.

• Journal of Yeungnam Medical Science
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• v.31 no.1
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• pp.33-37
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• 2014

Acinic cell carcinoma (ACC) is an uncommon malignant tumor of the salivary glands that is difficult to diagnose. It grows slowly and shows distant metastasis rarely. We experienced a case of recurrent ACC in the parotid gland with cardiac metastasis and hypertrophic osteoarthropathy. The 29-year-old man had been suffering from severe multiple bones and joints pain for 2 months. Ten years earlier, he underwent superficial parotidectomy due to a right subauricular mass. The mass was diagnosed with ACC. After surgery, the tumor recurred twice. Then the patient was diagnosed with cardiac metastasis via positron emission tomography-computed tomography and trans-thoracic echocardiography. He also had hypertrophic osteoarthropathy with multiple bone metastasis. He was given palliative radiotherapy and conservative treatment. ACC in the parotid gland with cardiac metastasis and hypertrophic osteoarthropathy has not yet been reported in literature. From this case, it is recommended to evaluate multiple distant metastasis in the ACC of the parotid gland when joint and bone pain are present.

• The Journal of Korean Physical Therapy
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• v.22 no.1
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• pp.67-73
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• 2010

Purpose: We tested whether repetitive transcranial magnetic stimulation (rTMS) improved recovery following spinal cord injury (SCI) in rats with transplantation of adipose tissue-derived stromal cells (ATSCs). Methods: Twenty Sprague-Dawley rats (200-250 g, female) were used. Moderate spinal cord injury was induced at the T9 level by a New York University (NYU) impactor. The rat ATSCs (approximately $5{\times}10^5$ cells) were injected into the perilesional area at 9 days after SCI. Starting four days after transplantation, rTMS (25 Hz, 0.1 Tesla, pulse width=$370{\mu}s$, on/off time=3 sec/3 sec) was applied daily for 7 weeks. Functional recovery was assessed using the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale as well as pain responses for thermal and cold stimuli. Results: Both groups showed similar, gradual improvement of locomotor function. rTMS stimulation decreased thermal and cold hyperalgesia after 7 weeks, but sham stimulation did not. Conclusion: rTMS after transplantation of ATSCs in an SCI model may reduce thermal hyperalgesia and cold allodynia, and may be an adjuvant therapeutic tool for pain control after stem cell therapy in SCI.