• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.590-592
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• 2008

A spacer grid is one of the most important structural components in a LWR nuclear fuel assembly. The primary considerations are to provide a Zircaloy spacer grid with crush strength sufficient to resist design basis loads, without significantly increasing pressure drop across the reactor core. In this study, the dynamic crush strength analysis and test are carried out for the specimens of a spacer grid assembly.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.229-234
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• 2001

The aluminum extruded sections are used to the light construction of the high speed rail vehicle structures. However, the research works on the crashworthy design of aluminum extruded sections are not published sufficiently. In this paper, the collapse characteristics of aluminum extruded sections are investigated by crush test and simulation. The scale model studies are also performed to predict the impact energy absorption characteristics of full scale model through axial crush test and simulation.

• 오토저널
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• 제13권5호
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• pp.65-72
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• 1991

This paper presents the results of static crushing test that was conducted to characterize the energy absorption and collapse characteristics of composite box tubes. Fifteen specimens were fabricated with woven fabric prepreg using [0/90] glass/epoxy and were autoclave cured. Quasistatic compression test was performed on them. Collapse mode and energy absorption capacity vary significantly as a function of the thickness and length of a square side of composite box tube.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제32권4호
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• pp.308-316
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• 2006

Objectives Despite considerable advances in technique, experience and skill, the precise place of surgery in the treatment of facial nerve injury remains uncertain. We designed a facial nerve crush injury model in rats and evaluated the recovery of crushed nerve which is the most common injury type of facial nerve using adenovirus vector mediated in vivo gene transfer of Brain derived neurotrophic factor(BDNF). Materials and methods In 48 Sprague Dawley rats, we made a facial nerve crush injury model to main trunk before the furcation, and injected a $10^{11}$pfu adenoviral BDNF in experimental group(BDNF adenoviral injection group; ad-BDNF) and $3{\mu}l$ saline in control group(Saline injection group; saline). After a period of regeneration from 10 to 40 days, nerve regeneration was evaluated with functioinal test (vibrissae and ocular movement), electrophysiologic study(threshold, peak voltage, conduction velocity) and histomorphometric study of axon density. Results Vibrissae and ocular movement, threshold and conduction velocity improved as time elapse in both group, however axon density was increased significantly only in experimental group. Functional test in 10 days and 20 days showed no difference between experimental group and control group. Vibrissae movement, threshold, conduction velocity and axon density in 30 days revealed that the regeneration in quality of experimental group was significantly superior to that of control group. Conclusion In general, there is tendency for nerve regeneration in experimental group (BDNF-adenovirus injection group) during 40 days, functional recovery was detected successfully after facial nerve crush in 30 days postoperatively.

• Composites Research
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• 제22권4호
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• pp.1-12
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• 2009

본 논문에서는 복합재 원형튜브의 에너지 흡수 특성을 평가하기 위해 준정적 압괴실험을 시행하였다. 사용된 시편은 필라멘트 와인딩 공법으로 제작된 GFRP(유리섬유/에폭시수지) 원형 튜브이다. 복합재 튜브의 에너지 흡수 특성 분석을 위한 파라미터로서 튜브의 트리거메커니즘, t/D, 섬유배향각 등을 고려하여 그 특성을 비교하였다. 튜브의 형상 측면에서 튜브 직경이 커짐에 따라 delamination에 의한 국부좌굴 발생빈도가 증가하게 되어 불안정한 압괴모드가 발생하는데 이러한 현상은 섬유 배향각을 조정하여 안정적인 압괴모드를 도출할 수 있었다.

• 한방재활의학과학회지
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• 제19권1호
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• pp.39-55
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• 2009

Objectives : This study was designed to evaluate effects of electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture on pain and nerve regeneration after crush injury of sciatic nerve in rats. Methods : We divided the subjects into 5 groups : control group, acupuncture treated group, electroacupuncture treated group, Cervi Pantortichum Cornu pharmacopuncture treated group, electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture group. Hot plate test and degree of Substance P antibody in each group were observed at the 1st, 2nd, 3rd and 5th day. Sciatic function index and change of BDNF immunoreactivity had been estimated at the 7th, 14th, 21st day respectively. Atrophy of the gastrocnemius at the 21st day was observed. Results : All the experimental groups showed significant changes in hot plate test, degree of Substance P antibody, sciatic function index and change of BDNF immunoreactivity compared with control group. Especially, when electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture used together, results were more effective than other groups. Recovery of the gastrocnemius was also the same. Conclusions : It is suggested that electroacupuncture and Cervi Pantortichum Cornu pharmacopuncture may play a significant role on pain decrease and nerve regeneration after crush injury of sciatic nerve in rats and these two treatments could be more effective when used together.

• 한국균학회지
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• 제24권4호통권79호
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• pp.322-328
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• 1996

왕호장근(Reynoutria sachalinensis)은 국내에서 자라는 마디풀과에 속하는 다년생 잡초로써 단위 면적당 Biomass가 매우 높으므로 버섯재배의 첨가 기질로써 이용가능성을 시험하였다. 대조구인 malt extract agar보다 왕호장근 1/4 희석 배지에서 느타리 균사 생장이 우수하였으며 1/8 희석 배지에서는 대조구보다 3배나 균사생장이 빨랐으며 균총의 밀도도 매우 높았다. 또한 느타리 균사가 왕호장근 한천배양기의 최적 산도 및 희석비율을 알아본 결과 pH 6.5, 희석비율 1/8이 느타리 균사생장에 가장 적합하였다. 왕호장근, 톱밥 및 미강를 각각 혼합하여 균사생장을 비교하여 본 결과 왕호장근을 넣은 배지에서 느타리 생강이 우수하게 나타났으며 1.5 내지 2배의 균사생장을 보였다. 왕호장근 한천배양기의 희석비율 l/4, 1/8와 pH 4.5, 6.5, 8.5에서 느타리 균사와 Trichoderma sp.의 대칭배양에서 산도 및 희석농도와 관계없이 느타리 균사생장이 월등하게 나타났으며 Trichoderma sp.의 균사생장을 억제하였다. 왕호장근, 톱밥, 미강을 혼합하여 종균 제조시 톱밥+왕호장근 10%+미강 10%의 배지에서 균사활착이 대조구보다는 4내지 5일 빨랐으며 2배 이상의 균사생장을 보였고 균사의 밀도도 가장 우수하였다.

• 한국군사과학기술학회지
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• 제23권3호
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• pp.229-236
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• 2020

A crush switch assembly(CSA) connected to an impact fuze provides electrical signal for detonation of the loaded main charge when an impact with the target is detected. Because the CSA experiences continuous changes in flight environment such as changes in velocity, vibration, and stresses, it is necessary to accurately predict the behavior of the fuze to maintain functionality during flight and to detonate when necessary. In this paper, random vibration analysis for flight environment and impact analysis on target hit are performed using FEA. Then, high speed impact tests are performed with the original and scaled down models to ensure operation validation of the manufactured products. The test results are then compared with M&S results to verify the capability of currently modeled CSA.

• 한방재활의학과학회지
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• 제18권4호
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• pp.25-37
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• 2008

Objectives : Ohyaksungi-san(Wuyaoshunqi-san) has been used for many years as a treatment for sciatica in oriental medicine. And electrical acupuncture also has been used as a treatment for sciatica in recent study. By the way, it is hard to find the study that apply two treatments in the same time. This study was designed to evaluate the effects of Ohyaksungi-san(Wuyaoshunqi-san) and electrical acupuncture on nerve regeneration after crush injury in rat sciatic nerve in the same time. Methods : This study was designed with 4 subgroups to evaluate the effects of Ohyaksungi-san(Wuyaoshunqi-san) and electrical acupuncture on nerve regeneration. As control groups, group I has not been treated during 3 weeks after crush injury in rat sciatic nerve. Group II has been treated Ohyaksungi-san(Wuyaoshunqi-san), Group III has been treated electrical acupuncture, and Group IV has been treated both during 3 weeks. This study has been estimated sciatic function index and change of GAP-43 immunoreactivity about sciatic nerve regeneration. Results : 1. The test for nerve regeneration had significantly good result of sciatic function index in the experimental groups as compared with control groups(p<.05). Especially, Group IV has the greatest result of sciatic function index. 2. GAP-43, the marker of nerve regeneration, more increased in the experimental groups as compared with control groups. Especially, Group IV has the greatest result of GAP-43. Conclusions : Ohyaksungi-san(Wuyaoshunqi-san) and electrical acupuncture have good effects on nerve regeneration after crush injury in rat sciatic nerve.

• 펄프종이기술
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• 제38권5호
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• pp.54-59
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• 2006

Paperboards used for linerboard of corrugated fiberboard box were coated with different concentrations of polylactic acid (PLA) solution and the effects of harsh environmental conditions such as high humidity and temperature (96% RH at $30^{\circ}C$ for up to 5 days), and freeze-thaw ($-20^{\circ}C$ for a day and then thaw at room temperature for 30 min) conditions on the ring crush (RC) strength of the boards were investigated. One to five percent PLA solutions were coated onto SC manila linerboard ($20{\times}27cm$) using a No. 20 wire bar coater and the ring crush strength was measured using a computer-controlled Advanced Universal Testing System in accordance with TAPPI Test Method T 822 om-93. The RC strength increased significantly when the concentration of coating solution increased and appreciable changes were found when the concentration increased from 0 to 2% (P<0.05). Similar pattern of results was found after 5-day storage at $30^{\circ}C$ and 96% RH. Although such highly humid condition increased moisture content in the samples up to 3.95 from 0.97 times, the RC strength decreased in the range from 29.9 to 48.5%. The freeze-thaw treatment increased the moisture content only up to 1.27% and the reduction in the RC strength ranged from 21.1 to 28.1 %. The results were promising: the samples coated with 5% PLA solution showed 29.9% reduction in the RC strength while that of control was 48.5% during highly humid condition stated above.