Nd-Fe-B permanent magnets have been used in a wide variety of applications because of their high magnetic flux density. So, demand for neodymium has been increasing in worldwide. In this study, an electrowinning process was performed in LiF-NdF3-Nd2O3 high temperature molten salts. However, a corrosion resistant material for use in the molten salt must be found for stable operation because of the harsh corrosion environment of the electrowinning process. Therefore, for this paper, boron nitride(BN), aluminum nitride(AlN), and silicon nitride(Si3N4) were selected as protective and structural materials in the high temperature electrolyte. To investigate the characteristics of BN, AlN, and Si3N4, in molten salts, materials were immersed in the molten salts for 24, 72, 120, and 192 hours. Also, surface condition and stability were investigated by SEM and EDS and corrosion products were calculated by HSC chemistry. As a result, among BN, AlN, and Si3N4, AlN was found to show the best protective material properties.
국산 재배삼 4년근의 뿌리, 장뇌삼 4년근과 8년근의 잎과 뿌리에 대한 물 및 80% 에탄올 추출물에 대한 구성사포닌 및 항산화 활성을 분석하였다. 재배삼 80% 에탄올 추출물에 대한 조사포닌 함량은 3.85% (d.b) 이었으며, 4년근 장뇌삼 뿌리와 잎의 조사포닌 함량은 각각 6.75 및 8.57% (d.b)이었으며, 8년근 장뇌삼은 각각 6.53 및 7.54% (d.b)이었다. 재배삼의 구성사포닌은 ginsenoside-Rh1의 함량이 6.07 mg/g으로 가장 높았고, 4년근 장뇌삼뿌리는 -Rb1이 11.63 mg/g, 잎은 -Re가 24.35 mg/g으로 가장 높았고 8년근 장뇌삼 뿌리는 -Rh1이 19.77 mg/g, 잎은 -Re가 20.43 mg/g으로 가장 높았다. 항 산화활성 (IC50값)은 삼의 종류 및 연근별로 1.84~21.88 mg/mL의 범위이었고 8년근 장뇌삼 잎 80% 에 탄올 추출물에서 가장 높았다. 총 항산화력은 5.56~20.67 mg AA eq/g의 범위를 나타내었으며, 8년근 장뇌삼 잎 증류수 추출물에서 가장 높은 값을 나타내었다.
With the recent rapid growth of RFID technologies, the Application of RFID systems into the medical or the military industries as well as into the distribution and logistics industry are now attempted continuously. The government and private sectors plan to carry out various small and large scale projects related to RFID systems. However, many companies attempting to apply RFID systems applications into their organizations are encountering many several difficulties because of the lack of installation experience and the absence of an useful guideline. This paper focuses on identification and classification of typical barriers to the successful application of RFID systems according to the five-step method of system application process. Moreover a "barrier map" is produced by conducting a survey and interviews by specialists. In addition, a practical guideline to overcome such barriers is presented and discussed.