• Korean Chemical Engineering Research
• /
• v.45 no.2
• /
• pp.172-177
• /
• 2007

The hydrolysis reaction of sarin(GB), one of the nerve agents was studied in aqueous sodium hydroxide(NaOH) solutions to find the experimental conditions which can convert GB into the less toxic compounds. 10 wt% of GB was added into the aqueous NaOH(2.05 eq) in a small-scale jacket-attached reactor connected to a circulator. The reaction rate constants were measured at three temperatures(50, 70 and $90^{\circ}C$) and the reaction times required to degrade the material to > 99% were calculated at different temperatures. In this study, 10 wt% of GB was degraded to 99.99% in 1.2hr at $90^{\circ}C$ by the aqueous NaOH solution. The major hydrolysate of GB was isopropyl methylphosphonate.

• Journal of Environmental Health Sciences
• /
• v.23 no.2
• /
• pp.89-97
• /
• 1997

Most of urban streams in Korea have been changed channel forms and suffered from direct inflow of domestic sewage, etc. Therefore, maintenance of structure and function of those ecosystem are hard. The present study was carried out to examine the life survival maintenance ability of the stream by community analysis of aquatic animals in typical urban stream (Jungrang stream) in Seoul. The aquatic animals were composed of 31 species, 18 families, 8 orders, 5 classes in 4 phyla. Seasonal species number showed big fluctuation between 8 species in Winter and 24 species in Autumn. Major dominant species in Jungrang stream were Tubificidae sp.1, Chironomidae sp.1, Chironomidae sp.2 and Physa acuta, and above endurance species for water pollution occupied very high dominance indices. But, Cercion hieroglyphicum, Ischnura asiatica, Rantra chinensis, Herochares striatus, Agabus japonicus in benthic macroinvertebrates of a few individuals are appeared. Also, fry of Carassius auratus and Silurus asotus in fish are occurred. Therefore, we can be inferred on posibility of growth and spawning of above species in the stream. Jungrang stream has a small quantity of natural riffle areas, ponds and watergrass areas by channel form of water course. Aquatic animals in Jungrang stream has been suffered by reduction of self-purification reaction ability and have mass production of attached algae on the stream bed. For analysis of fluctuation of life survival maintenance ability in Jungrang stream, long-term survey is needed.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.9 s.114
• /
• pp.949-957
• /
• 2006

In this Paper, reduction of noise and vibration in ship cabins by using floating floor is studied. Two theoretical models are presented and predicted insertion losses of floating floor are compared to experimental results, where measurements have been done in mock-up built for simulating typical ship cabin structures. In ships, mineral wool is usually used as the impact absorbing materials. The first model (M-S-Plate Model) is that upper plate and mineral wool are assumed as a one-dimensional mass-spring system, which is in turn attached to the simply supported elastic floor. The second model (Wave-Plate Model) is that mineral wool is assumed as an elastic medium for wave propagation. The comparisons show that M-S-Plate model is in good agreement with experimental results when density of mineral wool is 140K, and fiber direction is horizontal. For higher density and vertical fiber direction, Wave-Plate model shows good agreements with measurements. It is found that including the elastic behavior of the floor is essential in improving accuracy of the prediction for low frequency ranges below $100{sim}200Hz$.

• Journal of Chest Surgery
• /
• v.41 no.4
• /
• pp.496-498
• /
• 2008

Cardiac papillary fibroelastomas are the second most common primary cardiac tumor. This tumor is usually benign and it involves the cardiac valve. However, most cardiac papillary fibroelastomas originate from a single site, and the incidence of cardiac papillary fibroelastomas originating from multiple sites is very rare (5%). A 55-year-old woman who presented with momentary dizziness and syncope was evaluated by performing echocardiography. Multiple tumors attached to the aortic valve were noted. The mass was removed freely without leaving any defect on the aortic valve leaflet. After the recovery period, the patient is currently being followed up at the outpatient department.

• Journal of Chest Surgery
• /
• v.39 no.11 s.268
• /
• pp.858-860
• /
• 2006

Papillary fibroelastoma is the second most common benign cardiac tumor, usually involving the cardiac valve. Papillary fibroelastoma attached at the right coronary cusp of the aortic valve was found in a 51-year-old woman, who was presented with chest pain and dyspnea. During the operation, the tumor mass was excised without causing damage on the aortic valve leaflet.

• Journal of the Korean Society of Physical Medicine
• /
• v.8 no.4
• /
• pp.525-532
• /
• 2013

PURPOSE: The aim of this study was to compare the effects of different loading swimming exercises on muscle recovery after sciatic nerve crush injury in rats. METHODS: For this study, thirty-one Sprague-Dawley male rats were randomly divided into five groups. There were the negative control group (NCG, n=5), the positive control group (PCG, n=7), the low intensity swimming exercise group (LISEG, n=7), the moderate intensity swimming exercise group (MISEG, n=7) and the high intensity swimming exercise group (HISEG, n=5). Each rat was weighed to determine the lead weight to be attached to the base of its tail. Subsequently, the PCG, the LISEG, the MISEG and the HISEG were underwent standard unilateral sciatic nerve crush. The LISEG (no load), the MISEG (lead weight equivalent to 2% average body mass) and the HISEG (lead weight equivalent to 4% average body mass) were received the 10 minute swimming exercise in a day for 10 days. The NCG and PCG were not received with any therapeutic intervention. The diameter of the calf muscle and the level of serum lactate dehydrogenase (LDH) were measured to detect the effects of the swimming exercise. RESULT: The maximum diameter of the calf muscles was significantly increased after seventh swimming exercise in the LISEG, the MISEG and the HISEG compared with the PCG (p<0.05). However, there was no statistically significant difference between the LISEG, the MISEG and the HISEG. Also, the level of the serum LDH was significantly decreased in the LISEG, the MISEG and the HISEG compared with the PCG (p<0.05). CONCLUSION: Taken together, these results suggest that swimming exercise could accelerate muscle recovery processes after crush injury, but the different intensity of the swimming exercise does not affect healing processes.

• The Korean Journal of Malacology
• /
• v.6 no.1
• /
• pp.1-10
• /
• 1990

The occurrence of the larvae, the size of the spats daily attached to the collectors, the difference of the spat size with temperature, and the darly growth of a mussel, Mytilus edulis, were investigated at the off Songpo, Chinhae Bay, the southern part of Korea during the period from March 1 to August 30 in 1986. The water timperature and specific gravity ranged from 7.0 $^{\circ}C$ to 27.4$^{\circ}C$ (mean 17,24$\pm$5.9$0^{\circ}C$), and from 1.0126 to 1.0126(mean, 1.0242$\pm$0.0023), respectively. D-shaped larvae had two peak occurrences in March 8, April 19, Umbo-shaped larvad three peaks in March 8, April 21 and June 17, and full grown larvae two peaks in May 13 and June 23, respectively. Therefore, it is assumed that the mussel had two mass spawning time in early March and mid April and two mass settling time in mid May and alte June. The maximum size of the planktonic mussel larvae ranged from 375-400${\mu}{\textrm}{m}$ and most larvae sizing below 300${\mu}{\textrm}{m}$ long settled in adquate substrate. Spats just after settlement had the range from 26.5 to 547.3${\mu}{\textrm}{m}$ with the minimum of 225.0 ${\mu}{\textrm}{m}$ in mean shell length. The spats settled in summer season, when the water temperature raised above $25^{\circ}C$, were smaller than those settled in spring season in mean shell length. The early growth of the mussel spat had been assumed considerably fast.

• The Journal of the Korean bone and joint tumor society
• /
• v.13 no.2
• /
• pp.195-200
• /
• 2007

Dedifferentiated parosteal osteosarcoma is an uncommon variant of osteosarcoma. Dedifferentiation is known to be associated with a greater metastatic potential and a more rapid lethal clinical course. Thus recognition of dedifferentiation is important to establish the treatment strategy. But there may be few significant clinical clues to distinguish between dedifferentiated parosteal osteosarcoma and conventional one. A 29-year-old woman presented with 2-year history of discomfort and swelling in her proximal thigh. Examination showed a large, hard, non-mobile mass. Radiographs revealed a large ossified mass attached to the proximal femur. Diagnosis of parosteal osteosarcoma was established by MRI and needle biopsy. But she had a history of abrupt severe thigh pain and increased swelling before surgery. Follow up MRI showed enlargement of mass with invasion to muscle around tumor. The patient underwent an en-bloc resection of tumor and reconstruction. Histological examination showed parosteal sarcoma with dedifferentiation. The patient expired due to local recurrence of tumor and distant lung metastasis 2 months after the surgery. In case with rapid growth of a lesion or unusual severe pain, one must have a high index of suspicion with regard to dedifferentiation.

• Journal of Chest Surgery
• /
• v.38 no.4 s.249
• /
• pp.316-318
• /
• 2005

Papillary fibroelastomas are benign, and they are the second most common primary cardiac tumors usually involving the cardiac valve. Papillary fibroelastoma attached to the free margin of right coronary cusp of the aortic vlave was found incidentally during the work-up of a 51-year-old woman, who was presented with palpitation and dyspnea. During the operation, the tumor mass was excised without leaving defect on the aortic valve leaflet.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.06a
• /
• pp.255-258
• /
• 2009

Leading developed countries have studied energy self-sufficient houses such as zero or low energy buildings to reduce energy consumption for buildings since the early 1990s. Moreover, some developed countries have actually constructed self-sufficient houses and operated them for demonstration, expanding use of such houses. Korea has also established Zero Energy Solar House(ZeSH) and studied energy independence. Therefore, this study analyzed research result regarding ZeSH, self-sufficient energy house hold of Korea, found out technologies used for heating energy independence, used building interpretation program(ESP_r) to evaluate performance of each factors and analyzed energy reduction quantitatively. Results from the research are as follows: Reduction rate of actual detached house's heating load was also analyzed quantitatively depending on application of each technology. When each factor was applied step-by-step, annual reduction rate of heating load depending on increase in insulation thickness reached 6.6~22.2 %. Annual reduction rate of heating load depending on increase insulation thickness, and change in window heating performance and area ratio reached 31.5 %. Annual reduction rate of heating load through high-sealing and high-insulation depending on change in leakage rate reached 40.0~88.9 %. Annual reduction of heating load, when Mass Wall and attached sun space was applied were applied reached 28.5~39.2 %, respectively.