http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
상용 MC Nylon계 고분자 재료에서 초음파 특성의 온도 및 주파수 의존성
김명덕(Myung Deok Kim),김용태(Yong Tae Kim),이강일(Kang Il Lee) 한국비파괴검사학회 2012 한국비파괴검사학회지 Vol.32 No.5
본 연구에서는 상용화된 monomer-cast nylon (MC nylon)계 고분자 재료로 만든 6종류의 시편에 대하여 감쇠계수 및 위상속도와 같은 초음파 특성의 온도 및 주파수 의존성을 조사하였다. 시편의 초음파 특성은 수중에서 2 MHz부터 8 MHz까지의 광대역 주파수 범위에 대하여 펄스투과법을 이용하여 측정하였다. 수온은 10℃부터 60℃까지 10°C 간격으로 변화시켰다. 측정에 사용된 모든 시편에서 감쇠계수는 주파수가 증가함에 따라 증가하였으며, 주파수의 지수 의존성 n이 선형 (n=1) 에서 약간 벗어난 1.16부터 1.44이내의 값을 가졌다. 위상속도는 60℃에서 ivory 시편을 제외한 모든 경우에 대하여 주파수가 증가함에 따라 감소하는 음의 분산 특성을 나타냈다. 주파수에 의존하는 위상속도는 모든 시편에서 온도가 증가함에 따라 감소하는 특성을 나타내었다. In the present study, temperature and frequency dependences of ultrasonic properties such as attenuation coefficient and phase velocity was investigated for six kinds of commercial MC-Nylon polymer samples. The ultrasonic properties of the samples were measured by using a pulse transmission method in water over a broadband frequency range of 2 to 8 MHz. Water temperature was varied from 10 to 60℃ with the 10℃ interval. The attenuation coefficients of the samples increased with the frequency and the exponent n of frequency dependence ranged within 1.16 to 1.44, slightly deviating from the linear dependence (n=1). The phase velocities of the samples exhibited negative dispersion, i.e., decreasing velocity with increasing frequency, except for ivory sample at 60℃. The frequency-dependent phase velocities of the samples showed the decreasing tendency with increasing temperature.
사륜오토바이 사고 환자와 이륜오토바이 사고 환자에 대한 비교
김남호 ( Nam Ho Kim ),김명덕 ( Myung Deok Kim ),이태헌 ( Tae Hun Lee ),안무업 ( Moo Eob Ahn ),서정열 ( Jung Yeol Seo ),이재성 ( Jae Sung Lee ),김동원 ( Dong Won Kim ),이정열 ( Jung Ryul Lee ),박상헌 ( Sang Heon Park ),김유민 ( Yu 대한외상학회 2010 大韓外傷學會誌 Vol.23 No.2
Purpose: All-terrain vehicle (ATV)-related injuries have increased since the introduction of ATVs to Korea. The purpose of this study is to compare patients with ATV-related injuries (PATV) to patients with motorcycle (MC)-related injuries (PMC). Methods: We retrospectively analyzed the clinical records of PATV and PMC who visited an emergency center in 2008. The cases of PMC were 164, and those of PATV were 52. Results: While PMC are seen evenly in the first half year and the second half year, PATV are seen mainly the first half year (from March to June: 73%). For PMC the most frequent injury mechanism was collision with another vehicle, while for PATV, it was side overturn/roll over. The injury severity score (ISS), the revised trauma score (RTS), the trauma score and the injury severity score (TRISS) were 5.6±5.6, 7.7±0.7, 5.0±2.1 for PMC and 7.1±7.5, 7.7±1.1, 5.5±1.5 for PATV, respectively. The most common injury sites were the lower extremities for PMC and the face for PATV. The rates of admission, surgery and the length of hospital stay were similar between PMC and PATV. Conclusion: This study shows that the risk of ATV accidents is similar to that of MC accidents. We recommend that the same safety standards and regulations that are applied to MCs should be used for ATVs. Safe and enjoyable paths have to be sought for drivers of ATVs. (J Korean Soc Traumatol 2010;23:128-133)
정철 ( Cheol Jeong ),송재성 ( Jae-sung Song ),김명덕 ( Myung-deok Kim-jeon ),김경호 ( Kyoung-ho Kim ),이정구 ( Jung-goo Lee ),이성모 ( Sung-mo Lee ) 한국동물위생학회 2020 한국동물위생학회지 (KOJVS) Vol.43 No.1
Unlike previous studies that reported the infection rates of Dirofilaria immitis in companion dogs, D. immitis genes were tested directly on mosquitoes to see how many mosquitoes actually carry larvae. Mosquito samples were collected from six parks in Incheon from March to August 2018. A total of 18,589 mosquitoes was collected, classified by type and then made 575 sample pools based on 50 mosquitoes. The PCR method was used to detect Dirofilaria immitis genes of sample pools. Dirofilaria immitis genes were detected in 7 of the 575 pools, and these positive mosquito samples were collected in 4 out of the 6 parks. The types of detected mosquitoes were Aedes dorsalis and Ochlerotatus koreanus which have been identified to act as a vector for heart worm propagation in Incheon. Based on these results, it was concluded that D. immitis genes were found in mosquitoes in the neighborhood park.